Role of Stem Cell Transplantation in the Treatment of Ulcerative Colitis

Introduction and Aim of the Work
- 1 -
Introduction
Inflammatory bowel disease (IBD) represents
a group of idiopathic chronic inflammatory intestinal
conditions. The two main disease categories are
Crohn's disease (CD) and ulcerative colitis (UC),
with both overlapping and distinct clinical and
pathological features (Charles, et al., 2009).
Ulcerative colitis is a chronic disease leading to
inflammation of the colon and in more severe degrees even
causing painful ulcers in the colon which can bleed, cause
mucous production and infection. Symptoms can recur or
be minimal for months and years. Common symptoms
include bloody diarrhea, abdominal pain and weight loss
which may be mild to severe and affect individual's quality
of life (Lakatos PL, et al., 2007).
In a meta-analysis performed by Mayo Clinic,
incidence of ulcerative colitis was reported as 2 to 14 per
thousand person-years (Mahid, et al., 2006).
The disease pathogenesis is still incompletely
understood. The genetic and environmental factors
such as altered luminal bacteria and enhanced the
intestinal permeability play a role in the dysregulation
of intestinal immunity, leading to the gastrointestinal injury
(Ricart E, et al., 2010).

- 2 -
Standard medical therapy is directed against the
inflammatory and immune processes that are known to play
an important role in the disease process. Medical therapy is
of variable success in ameliorating cardinal symptoms of
the disease (diarrhea, abdominal pain), in treating extra
intestinal manifestations, and in preventing complications
Currently, therapy is most often implemented in
a stepwise fashion, progressing through amino salicylates
[sulfasalazine, mesalazine (mesalamine)], corticosteroids,
immunosuppressive medications including tioguanine
(thioguanine) compounds (mercaptopurine, azathioprine),
methotrexate, and ciclosporin, and finally anti-TNF drugs.
This common approach is predicated on the addition of
more potent medications to agents that are believed
to be safer but that may also be less effective
Primary and secondary failure to respond to
approved therapies and, in some cases, inability to provide
a surgical solution to a particular patient due to extension
and or location of lesions represents unmet needs in the
treatment of IBD (Ricart E, et al., 2010).
A novel and exciting approach could be offered
through the current development in the field of
stem cell biology (Masson, et al, 2004).
Consequently, bone marrow stem cells have been
sought of as a promising new approach capable of
addressing mostly unmet medical needs (Weissman, 2000).

- 3 -
The considerable excitement surrounding the stem
cell field is based on the unique biological properties of
these cells and their capacity to self-renew and regenerate
tissue and organ systems, a flurry of studies reported bone
marrow derived stroma to brain, bone marrow to
liver, skin to brain, brain to heart and other such
stem cells differentiation (Morrison, 2000).
Two streams of research, experimental and clinical,
are the origin of the increasing utilization of stem cell
therapies for severe immune-mediated diseases (IMIDs)
including IBD. The considerable excitement surrounding
the stem cell field was initially based on the unique
biological properties of these cells; later, the
immunomodulatory ability of stem cell therapy has become
also apparent (Ricart E, et al., 2010).

- 4 -
Aim of the Work
To investigate the role of autologous bone marrow
stem cells intravenous injection in treatment for cases of
ulcerative colitis disease.

 Ulcerative Colitis Chapter 1
- 5 -
Ulcerative Colitis
Inflammatory bowel disease:
Inflammatory bowel disease (IBD) commonly refers
to ulcerative colitis (UC) and Crohn's disease (CD), which
are chronic inflammatory diseases of the GI tract of
unknown etiology (Hyams, 2002).
Ulcerative colitis is characterized by diffuse mucosal
inflammation limited to the colon. It is classified according
to the maximal extent of inflammation observed at
colonoscopy, while Crohn's disease is characterized by
patchy, trans mural inflammation, which may affect any
part of the gastrointestinal tract, it may be defined by: age
of onset, location, or behavior (Silverberg, et al., 2005).
In particular, the definitions of ulcerative colitis
and Crohn's disease acknowledge the revised
Montreal classification which attempts to more
accurately characterize the clinical patterns of IBD
(Satsangi, et al., 2006).
Unclassified (IBDU) is the term best suited for the
minority of cases where a definitive distinction between
UC, CD, or other cause of colitis cannot be made after
considering clinical, radiological, endoscopic and
pathological criteria, because they have some features of
both conditions. Indeterminate colitis (IC) is a term
reserved for pathologists to describe overlapping features in
IBDU (Satsangi, et al., 2006).

- 6 -
Ulcerative colitis:
Ulcerative colitis is a lifelong disease arising from an
interaction between genetic and environmental factors,
observed predominantly in the developed countries of the
world. The precise etiology is unknown and therefore
medical therapy to cure the disease is not yet available
(Dignass, et al., 2012).
It is a chronic inflammatory condition causing
continuous mucosal inflammation of the colon without
granulomas on biopsy, affecting the rectum and a variable
extent of the colon in continuity, which is characterized by
a relapsing & remitting course (Silverberg, et al., 2005).
Clinical disease activity is grouped into remission,
mild, moderate and severe. This refers to biological
activity and not to treatment responsiveness
(Rice-Oxley and Truelove, 1950).
The term severe colitis (or „acute severe colitis‟) is
preferred to „fulminant‟ colitis, because the term
„fulminant‟ is ill-defined. Severe colitis as defined
according to Truelove and Witt's' criteria is easy to apply in
outpatients, mandates hospital admission for intensive
treatment and defines an outcome (only 70% respond to
intensive therapy) (Dignass, et al., 2012).
Response is defined as clinical and endoscopic
improvement, depending on the activity index used.
In general, this means a decrease in the activity index
of >30%, plus a decrease in the rectal bleeding and
endoscopy sub scores, but there are many permutations
(D'Haens, et al., 2007).

- 7 -
The term relapse is used to define a flare of
symptoms in a patient with established UC who is in
clinical remission, either spontaneously or after medical
treatment. It is considered when a combination of rectal
bleeding with an increase in stool frequency and abnormal
mucosa at sigmoidoscopy are present. It may be infrequent
(≤1/year), frequent (≥2 relapses/year), or continuous
(persistent symptoms of active UC without a period of
remission) (D'Haens G et al., 2007).
The term „chronic active disease‟ has been used in
the past to define a patient who is dependent on, refractory
to, or intolerant of steroids, or who has disease activity
despite immunomodulators. Since this term is ambiguous it
is best avoided. Instead, arbitrary, but more precise
definitions are preferred, including steroid-refractory or
steroid-dependence (Van Assche, et al., 2010).
Steroid-refractory colitis if patients have active
disease despite prednisolone up to 0.75 mg/kg/day over a
period of 4 weeks. Steroid-dependent colitis patients who
are either unable to reduce steroids below the equivalent of
prednisolone 10 mg/day within 3 months of starting
steroids, without recurrent active disease, or who have
a relapse within 3 months of stopping steroids
(Van Assche, et al., 2010).
Immunomodulator-refractory colitis patients who
have active disease or relapse in spite of thiopurines at an
appropriate dose for at least 3 months (i.e. azathioprine 2–
2.5 mg/kg/day or mercaptopurine 1– 1.5 mg/kg/day in the
absence of leucopenia) (Dignass, et al., 2012).

- 8 -
Classifications:
A. Classification according to disease extent
The preferred classification is an endoscopic
classification as outlined in the Montréal classification
into ulcerative proctitis (limited to the rectum), left-sided
colitis (up to the splenic flexure) and extensive colitis, and
by maximal extent upon follow up (Dignass, et al., 2012).
There are several reasons why patients with UC
should be classified according to disease extent. The extent
of inflammation will influence the patient's management
and the choice of delivery system for a given therapy. For
instance, topical therapy in the form of suppositories (for
proctitis) or enemas (for left-sided colitis) is often the first
line choice, but oral therapy often combined with
topical therapy is appropriate for extensive colitis.
Also, it influences start and frequency of surveillance
Table (1): The Montreal classification of UC (Silverberg, et al., 2005).
E1 Proctitis
Involvement limited to the rectum (i.e.
proximal extent of inflammation is distal to
recto-sigmoid junction)
E2 Left-sided
Involvement limited to the proportion of the
colon distal to the splenic flexure
(analogous to „distal‟ colitis)
E3 Extensive
Involvement extends proximal to the
splenic flexure, including pan colitis

- 9 -
B. Classification according to disease severity
Classification of UC based on disease severity is
useful for clinical practice and dictates the patient's
management. Many disease activity indices or criteria have
been proposed, but none have been adequately validated.
Although modifications of the original Truelove and Witts'
criteria are used in daily practice, the modified Mayo score
is used more frequently in current clinical trials.
For clinical practice a combination of clinical
features, laboratory findings, imaging modalities and
endoscopic parameters including histopathology will
all assist physicians in their patients' management
A distinction should be made between disease
activity at a point in time (remission, mild, moderate,
severe) and the response of disease to treatment. Moderate
colitis has become necessary to distinguish from mildly
active disease, because the efficacy of some treatments may
differ. The simplest clinical measure to distinguish
moderate from mildly active colitis is the presence of
mucosal friability (bleeding on light contact with the rectal
mucosa at sigmoidoscopy) (D'Haens, et al., 2007).
There is no fully validated definition of remission.
The best way of defining remission is a combination of
clinical parameters (i.e. stool frequency ≤ 3/day with no
bleeding) and a normal mucosa at endoscopy. Absence of
an acute inflammatory infiltrate at histology is helpful

- 10 -
Table (2): Disease severity index of UC (Truelove and Witts, 1995).
Mild Moderate Severe
Bloody stools/day < 4 4 - 6 ≥ 6
Pulse < 90 bpm ≤ 90 bpm > 90 bpm
Temperature < 37.5 °C ≤ 37.8 °C > 37.8 °C
Hemoglobin > 11.5 g/dL ≥ 10.5 g/dL < 10.5 g/dL
ESR < 20 mm/h ≤ 30 mm/h > 30 mm/h
CRP Normal ≤ 30 mg/L > 30 mg/L
Table (3): Mayo activity scoring index (D'Haens, et al., 2007).
0 1 2 3
Stool
frequency
Normal
1-2/day
> normal
3-4/day
> normal
5/day
> normal
Rectal
bleeding
None Streaks Obvious
Mostly
blood
Endoscopic
finding
Normal
Mild
friability
Moderate
friability
Spontaneous
bleeding
Global
assessment
Normal Mild Moderate Severe
The Mayo score ranges from
0 to 12, with higher scores
indicating more severe disease.
 0 to 1: Remission
 2 to 5: Mild disease
 6 to 9: Moderate disease
 10 to 12: Severe disease
Table (4): Endoscopic scores for UC (Dignass, et al., 2012).
Baron Score (Baron JH, et al., 1964)
0
Normal: matt mucosa, ramifying vascular pattern clearly
visible, no spontaneous bleeding, no bleeding to light touch
1 Abnormal, but non-hemorrhagic: appearances between 0 and 2
2
Moderately hemorrhagic: bleeding to light touch,
but no spontaneous bleeding seen on initial inspection
3
Severely hemorrhagic: spontaneous bleeding seen ahead of
instrument at initial inspection and bleeds to light touch
Schroeder Score (Schroeder KW, et al., 1987)
0 Normal or inactive disease
1 Mild (erythema, decreased vascular pattern, mild friability)
2 Moderate (marked erythema, absent vascular pattern, friability, erosions)
3 Severe (spontaneous bleeding, ulceration)
Feagan Score (Feagan BG, et al., 2005)
0 Normal, smooth, glistening mucosa, with vascular pattern visible; not friable
1 Granular mucosa; vascular pattern not visible; not friable; hyperemia
2 As 1, with a friable mucosa, but not spontaneously bleeding
3 As 2, but mucosa spontaneously bleeding

- 11 -
Pathophysiology:
Increasing evidence suggests that there is a defect in
the function of the intestinal immune system.
As a consequence, there is a breakdown of the defense
barrier of the gut, which, in turn, results in exposure of the
mucosa to microorganisms or their products. The result is
a chronic inflammatory process mediated by T-cells.
Hence, therapy should be directed at improving the
intestinal immune system. It has been postulated that
genetic factors may predispose certain individuals to
developing a "leaky gut" (William Tremaine, et al., 2008).
In ulcerative colitis, inflammation always begins in
the rectum, extends proximally a certain distance, and then
abruptly stops. A clear demarcation exists between
involved and uninvolved mucosa and no "skip areas" are
present. It primarily involves the mucosa and submucosa,
with formation of crypt abscesses and mucosal ulceration.
The mucosa typically appears granular and friable. The
small intestine is never involved, except when the distal
terminal ileum is inflamed in a superficial manner, referred
to as backwash ileitis (William Tremaine, et al., 2008).
In severe cases, pseudo polyps form, consisting of
areas of hyperplastic growth with swollen mucosa
surrounded by inflamed mucosa with shallow ulcers.
Necrosis can extend below the lamina propria to involve
the submucosa and the circular and longitudinal muscles,
although this is unusual. As the disease becomes chronic,
the colon becomes a rigid foreshortened tube that
lacks its usual haustral markings, leading to the
lead pipe appearance observed on barium enema
(William Tremaine, et al., 2008).

- 12 -
Etiology:
The etiology of IBD is unknown. Environmental,
infectious, genetic, autoimmune, and host factors have
been suspected. Interactions among these factors may be
more important (Buhner, et al., 2006).
A. Genetic Factors
IBD is seen two to four times greater in the Jewish
population as compared with other ethnic groups.
Ashkenazi Jews have the greatest risk within the Jewish
population. Other epidemiologic studies have shown higher
rates in whites, lower rates in African Americans, and the
lowest rates in Asians (Ahmad, et al., 2001).
The prevalence of IBD is also increased in relatives
of those who have CD and UC. For patients who have UC,
the occurrence of IBD in their offspring was 6.26%; for
patients who have CD, the occurrence was 9.2%
(Orholm, et al., 1999).
Epidemiologic studies demonstrate familial
similitude for disease type, extent and extra-intestinal
manifestations for siblings with UC, but the concordance
rates are smaller than for CD. All studies that included the
evaluation of concordance rates between monozygotic and
dizygotic twins indicate that the genetic contribution to
disease susceptibility is smaller for UC than for CD
(Halfvarson, et al., 2003).
The region of the major histocompatibility complex
(MHC) locus on chromosome 6p that contains the genes
encoding the HLA Class I and II histocompatibility
molecules has been implicated in susceptibility to UC by
both association and linkage studies; however, the linkage

- 13 -
studies do not discriminate between risk for UC and CD.
Specifically, UC has been most consistently associated with
HLA Class II alleles (Satsangi, et al. 2003).
For example, in some populations the HLA-
DRB1*1502 allele (representing HLA-DR2) is positively
associated with UC and the HLA-DR4 and DR6 alleles
negatively associated; the differences in association among
populations may be accounted for by racial and ethnic
variability. The infrequent HLA-DRB1*0103 allele is
associated with extensive and severe UC and often
associated with the requisite for colectomy. Although there
is conflicting data in differing populations, other potential
genetic associations for UC include the interleukin-1 family
of genes on chromosome 2q13. Another potential
'functional candidate gene' is the multidrug resistance gene
(MDR1) that is located in an area of linkage on
chromosome 7 (Pallone; Silverberg; Ahmad, et al. 2003).
In addition, there is a strong likelihood that genetics
also impact on the incidence of extra-intestinal
complications of UC. In particular, the association between
HLA-B27 and the development of ankylosing spondylitis
and sacroiliitis in patients with UC has been reproduced
and approaches 100%. Peripheral arthropathies (type I and
II) accompanying UC are also associated with HLA
polymorphisms that associate with erythema nodosum and
uveitis (Orchard, et al. 2002).
Of note, the association of UC with primary
sclerosing cholangitis is also related to the presence of
several HLA Class II alleles and is modified (prevented)
by the environmental factor of cigarette smoking
(Mitchell, et al. 2002).

- 14 -
B. Environmental Factors
 Cigarette smoking:
There are several environmental clues to
susceptibility and development of UC (Krishnan and
Korzenik, 2002).
The long-standing finding that cigarette smoking
protects against the development of ulcerative colitis has
withstood the test of time. Indeed, case series continue to
demonstrate a protective effect of smoking on both the
development and course of UC (Abraham, et al., 2003).
Although smokers are less likely to develop UC, however,
ex-smokers are more likely to develop extensive or severe
colitis. Others believe that ex-smokers account for the
preponderance of the second age peak for UC in
patients > 40 years (Halme, et al., 2002).
The protective effect of smoking also extends to
the extra-intestinal manifestations and the post-surgical
complications of UC. For example, smoking protects
against the development of PSC, smoking, or non-smoking,
accounts for the differing incidence of PSC associated
with UC (Mitchell, et al., 2002).
 Appendectomy:
Another consistent epidemiologic clue to the
pathogenesis of UC is the observation that appendectomy,
particularly at a younger age, both reduces the likelihood of
developing and the severity of disease. It seems to be an
additive protective factor to cigarette smoking against the
development of UC. In contrast to UC, prior appendectomy
does not seem to be protective against development of PSC
(Feeney et al.; Cosnes, et al.; Mitchell, et al., 2002).

- 15 -
 Bacteria:
One ubiquitous factor in animal models of colitis and
in human disease is the relationship with bacteria. In
experimental models of IBD, colitis does not develop in
animals that are raised in germ-free environments
(Sartor, 2004).
Commensal bacteria, not pathogens, are sufficient to
induce colitis, but this is determined by both host and
bacterial specificities. Also, different phenotypic patterns of
colitis are seen with specific bacterial species. Commensal
bacteria can induce a protective effect that can be
transmitted by bacteria-responsive regulatory CD4+ T-cells
(Cong, et al. 2002).
Although it has not been possible to identify bacterial
strains that are specific to UC, there are increased numbers
of mucosa-associated (adherent) Bacteroides species and
Enterobacteriaceae species in patients with inflamed
segments (Swidsinski, et al. 2002).
Whether early exposure to common environmental
microbes is protective against UC as it is with other
autoimmune disorders, in line with the so-called hygiene
hypothesis, remains to be determined (Weiss, 2002).
Alternatively, functional activity of microbial strains
may also lead to 'DYSBIOSIS' and affect the metabolic
activity of colonocytes or enterocytes, leading to the
development of UC. The potential inductive or protective
role of bacteria has also led to considerable interest in
prebiotic or probiotic therapies for UC and its
complications (Sartor, 2004).

- 16 -
C. Immunologic Factors
From an immunologic perspective, UC has less of a
Th1 response pattern than CD (Pallone, et al. 2003).
In IBD there are chronic inflammatory changes in the
GIT. These are mediated by different immunologic factors
for each disease, although they are both a consequence of
T-cell activation (Pallone and Monteleone, 1998).
The cytokine expression is different comparing
ulcerative colitis and Crohn's disease. In ulcerative colitis,
the inflammation is thought to be regulated by Th2-cells,
which mediate B cells and antibody responses; however
this has not been proven. It has been shown that there is
increased expression of IL-5, which is a Th2 cytokine,
but IL-4, another Th2 cytokine, is not increased
(Fuss, et al., 1996).
The Th2 contribution may be helping the antibody
response, because in UC, there is an increase in IgG plasma
cells presumably mediated by T-cells (Macdonald, 2000).
Recent evidence indicates that, in contrast to the Th1
cytokines that are associated with the pathogenesis of
Crohn's disease (interferon-γ, TNF-α and IL-12),
animal models of ulcerative colitis may be associated
with increased natural killer cell activity and IL-13
(Heller, et al. 2002).
In addition, attention is being directed at the down
regulatory role of transforming growth factor-ß in colitis
and the possibility that defective signaling of transforming
growth factor-ß may account for inadequate tissue repair
(Pallone, et al. 2003).

- 17 -
Diagnosis:
A gold standard for the diagnosis of UC is not
available. The diagnosis is made on the basis of clinical
suspicion supported by appropriate macroscopic findings
on colonoscopy, typical histological findings on biopsy
and negative stool examinations for infectious agents
There is some evidence to suggest that patients with
UC stratified by age have different outcomes. Patients
diagnosed before the age of 16 had a more aggressive
initial course, while older age at diagnosis was found
to be associated with a lower risk of colectomy
(Barreiro-de-Acosta, et al., 2010).
There is also some evidence that UC diagnosed in
the very young has a different etiology and prognosis. This
is taken into consideration by the pediatric modification to
the Montréal classification (Levine, et al., 2011).
It is a disease that used to carry a high mortality and
major morbidity. With modern medical and surgical
management, the disease now has a slight excess of
mortality in the first 2 years after diagnosis, but little
subsequent difference from the normal population. The
clinical course is marked by exacerbation and remission.
About 50% of patients have a relapse in any year. An
appreciable minority has frequently relapsing or chronic,
continuous disease and overall, 20-30% of patients with
pancolitis come to colectomy. After the first year
approximately 90% of patients are fully capable of work
(defined by < 1 month off work/year), although significant
employment problems remain an issue for a minority
(Langholz, et al., 1994).

- 18 -
 Clinical picture
The onset may be gradual or sudden. The course is
variable, with periods of exacerbation, improvement, and
remission that may occur with or without specific medical
therapy (William Tremaine, 2008).
Symptoms of UC are dependent upon extent and
severity of disease. The cardinal symptom of ulcerative
colitis is bloody diarrhea. Diarrhea may vary from 1 to 20
or more loose or liquid stools a day, usually worse in the
morning and immediately after meals, and patients with
moderate or severe symptoms often have nocturnal stools.
Constipation with rectal bleeding is a presenting symptom
in about 25% of patients with disease limited to the rectum.
Abdominal pain is usually cramping, which is worse after
meals or bowel movements. Anorexia, weight loss, and
nausea in the absence of bowel obstruction are common
with severe and extensive disease but uncommon with mild
to moderate disease or disease limited to the left colon. In
children, urgency, incontinence, and upper gastrointestinal
tract symptoms are more frequent and growth failure is
common. It is associated with an equivalent increased risk
of colonic carcinoma (Friedman, et al., 2008).
A full medical history should include detailed
questioning about the onset of symptoms, particularly the
stool frequency and consistency, recurrent episodes of
rectal bleeding or bloody diarrhea, urgency, tenesmus,
abdominal pain, incontinence, nocturnal diarrhea, weight
loss, features of extra-intestinal manifestations, and
systemic symptoms of malaise, anorexia, or fever are
features of a severe attack (Dignass, et al., 2012).

- 19 -
History should include recent travel, food
intolerances, contact with enteric infectious illnesses,
medication (antibiotics and NSAIDs drugs), smoking habit,
sexual practice, vaccination, family history of IBD,
Colorectal cancer, and previous appendictomy should be
explored (Dignass, et al., 2012).
However, severe colitis is still a potentially
life-threatening illness. Immediate admission to
hospital is warranted for all patients fulfilling
Truelove and Witts' criteria for severe colitis to
prevent delayed decision making which may lead
to increased perioperative morbidity and mortality
In mildly active ulcerative colitis, physical
examination findings are often normal or there
may be abdominal tenderness, particularly with
palpation over the sigmoid colon. Patients with
more severe disease may have pallor, dehydration,
tachycardia, fever, diminished bowel sounds,
and diffuse abdominal tenderness with rebound.
Tenderness with rebound is ominous and suggests toxic
dilatation or perforation (Sands, 2004).
Also, it should include general well-being, pulse rate,
body temperature, blood pressure, measurement
body weight and height, calculation of BMI, abdominal
examination for distention and tenderness, palpable
masses, perianal inspection, digital rectal examination,
oral inspection, check for anemia, fluid depletion,
and check for eye, skin and/or joint involvement
(Sands, 2004).

- 20 -
Ulcerative colitis is associated with a wide variety of
systemic complications which classically called extra-
intestinal manifestations, immune-mediated phenomena
that affect the joints, eye, skin, or hepatobiliary tract, but
they can be defined more broadly to include complications
in other organ systems and complications that arise as a
direct pathophysiologic consequence of extensive bowel
inflammation or resection. It occurs in up to 36% of
patients (Edward, 2008).
Arthritis affecting the axial skeleton can be classified
into the more common, frequently asymptomatic,
sacroiliitis and the less common, more progressive,
ankylosing spondylitis. Symptomatic sacroiliitis manifests
as low back pain and stiffness, typically worse in the
morning and with rest while spondylitis resulting in
progressive stiffness and lordosis of the spine. The
symptoms usually accompany exacerbations but may
appear before the disease and don't necessarily follow its
course (Johns Hopkins, 2013).
About 19% of patients with UC experience
dermatological changes. The two most common
dermatologic manifestations are pyoderma gangrenosum
and erythema nodosum. Other dermatological sequelae
include dermatitis, erythematous rash, psoriasis, carcinoma,
urticaria, pityriasis, lupus erythematosus, vitiligo and
ecchymosis (Edward, 2008).
Ocular complications occur in 1-13% of patients
with IBD. The most common forms are anterior uveitis
(also known as iritis) and scleritis. An inflammatory
retinopathy or keratitis (corneal inflammation) may occur
less frequently. Symptoms include headache, photophobia
and blurred vision (Johns Hopkins, 2013).

- 21 -
The most important hepatobiliary condition
associated with IBD is primary sclerosing cholangitis. This
idiopathic chronic cholestatic liver disease is characterized
by inflammation and fibrosis of the biliary tree.
Autoimmune hepatitis is associated rarely with IBD, but
when it is, it usually is associated with ulcerative colitis.
Some patients may have features of both autoimmune
hepatitis and primary sclerosing cholangitis (the so-called
overlap syndrome) (Edward, 2008).
In most situations, extra-intestinal manifestations
respond to standard medical therapy. On rare occasions,
a total proctocolectomy may be necessary to control
severe extra intestinal manifestations of this disease
(Edward, 2008).
Fig.(1): Extra-colonic manifestations of UC (Johns Hopkins, 2013)

- 22 -
 Endoscopy
Flexible proctosigmoidoscopy or colonoscopy with
multiple biopsies (at least two biopsies from five sites
including the distal ileum and rectum) is the first line
procedure for diagnosing colitis. It allows classification of
disease based on endoscopic extent, severity of mucosal
disease and histological features. Active disease
confirmed sigmoidoscopy as a first line procedure
No endoscopic feature is specific for UC. The most
useful endoscopic features of UC are considered to be
continuous and confluent colonic involvement with clear
demarcation of inflammation and rectal involvement.
Endoscopic severity of UC may be best reflected by the
presence of mucosal friability, spontaneous bleeding and
deep ulcerations (Dignass, et al., 2012).
There are mucosal changes including loss of
the normal vascular markings, mucosal granularity,
mucosal friability, mucous exudate, and focal ulceration
(William Tremaine, 2008).
Fig.(2): Endoscopic image of ulcerative colitis (Samir, 2004)

- 23 -
With colonoscopy, the extent of disease can be
determined and the terminal ileum can be examined for
evidence of backwash ileitis in UC or ileal involvement in
CD. Patients with left-sided UC may have inflammatory
changes around the appendix, called a cecal patch,
as a manifestation of the disease; this finding should
not be confused with segmental colitis due to CD
In acute severe colitis, full colonoscopy is rarely
needed and may be contraindicated, because of the risk of
perforation or hemorrhage. Patients should have abdominal
radiography. Also, phosphate enema is considered safe,
except with colonic dilatation (Terheggen, et al., 2008).
Endoscopic findings are predictive of outcome at for
patients with UC in remission. Endoscopic reassessment is
appropriate at a relapse, or for steroid-dependent or -
refractory UC or when considering colectomy. Patients
with UC (extending proximal to the rectum), the risk of
malignancy is increased above that for the general
population after 8-10 years of disease. So, periodic
colonoscopy with biopsies for surveillance for dysplasia is
indicated after 8-10 years of disease. The risk for patients
with less extensive UC (with involvement of the colon
distal to the splenic flexure) also is increased, but the
magnitude of the risk is not defined. There doesn't appear
to be an increased risk of the rectal cancer for ulcerative
proctitis without colitis above the rectum. Patients with
left-sided UC of 8-10 years‟ duration, or longer, should
undergo periodic surveillance biopsies. The optimal
interval between surveillance examinations has not been
defined, and the examinations usually are performed
at 1-2 year intervals (William Tremaine, 2008).

- 24 -
Table (5): UC Endoscopic Index of Severity (UCEIS) (Travis, et al., 2012)
Vascularpattern
Normal (0)
Normal vascular pattern with
arborisation of capillaries clearly
defined, or with blurring or patchy
loss of capillary margins
Patchy
obliteration
(1) Patchy obliteration of vascular pattern
Obliterated (2) Complete obliteration of vascular pattern
Bleeding
None (0) No visible blood
Mucosal (1)
Some spots or streaks of coagulated blood on
the surface of the mucosa ahead of the scope,
which can be washed away
Mild (2) Some free liquid blood in the lumen
Moderate
or severe
(3)
Frank blood in the lumen ahead of
endoscope or visible oozing from mucosa
after washing intra-luminal blood, or visible
oozing from a hemorrhagic mucosa
Erosions&Ulcers
None (0)
Normal mucosa, no visible erosions or
ulcers
Erosions (1)
Tiny (≤5 mm) defects in the mucosa, of a
white or yellow color with a flat edge
Superficial
ulcer
(2)
Larger (N5 mm) defects in the mucosa,
which are discrete fibrin-covered
ulcers when compared to erosions,
but remain superficial
Deep ulcer (3)
Deeper excavated defects in the mucosa,
with a slightly raised edge
Fig. (3): Histology of
normal colon and UC
(Johns Hopkins, 2013)

- 25 -
 Histology
Histopathological examination of biopsy specimens
should be carried out according to the BSG guideline, „A
Structured Approach to Colorectal Biopsy Assessment‟
(Jenkins, et al., 1997).
For a reliable diagnosis of ulcerative colitis multiple
biopsies from five sites around the colon (including the
rectum) and the ileum should be obtained. Multiple implies
a minimum of two samples. Repeat biopsies after an
interval may help to solve differential diagnostic problems
and establish a definitive diagnosis especially in adults, by
showing additional features (Dignass, et al., 2012).
There should be an attempt to define the type of IBD,
to mention other coexistent diagnoses or complications and
to mention the absence or presence of any dysplasia and its
grade. Medical and surgical therapy may modify the
histological appearances of IBD and these should be taken
into account when assessing IBD biopsy pathology
(Hyde, et al., 2002).
Also, mucosal biopsy specimens from involved areas
of the gastrointestinal tract are useful for excluding self-
limited colitis and other infections and non-infectious
colitis due to ischemia, collagenous and lymphocytic
colitis, drug effect, radiation injury, and solitary rectal ulcer
syndrome. Non-caseating granulomas are a feature of CD
and can be helpful for distinguishing it from UC
A hallmark of active UC is the presence of a
polymorphonuclear cell infiltration into the epithelial crypts
(cryptitis) and lamina propria (Beckmann, et al., 2007).

- 26 -
 Radiologic Features
Imaging can be helpful in diagnosis, assessment of
disease extent and severity and for investigation of
suspected complications. Each modality has its own
advantages and drawbacks and the tests are often
complimentary (Hall and Brenner, 2008).
Barium fluoroscopy (Double contrast barium
enema) allows for exquisite detail of the colonic mucosa,
and also allows bowel proximal to strictures to be assessed.
It is however contraindicated if acute severe colitis is
present due to the risk of perforation. Mucosal
inflammation lends a granular appearance to the surface of
the bowel. Mucosal ulcers are undermined (button-shaped
ulcers). When most of the mucosa has been lost, islands of
mucosa remain giving it a pseudo-polyp appearance. In
chronic cases the bowel becomes featureless with loss of
normal haustral markings, luminal narrowing and bowel
shortening (lead pipe sign). Small islands of residual
mucosa can grow into thin worm like structures (so-called
filiform polyps) (Roggeveen, et al., 2005).
A. Pseudo-polyp-------- B. Target sign ------- C. Loss of haustration
Fig.(4): Radiological features in UC (Gore, et al., 1996)

- 27 -
Computed Tomography (CT) will reflect the same
changes that are seen with a barium enema, with the
additional advantage of being able to directly visualize the
colonic wall, the terminal ileum and identify extra-colonic
complications, such as perforations or abscess formation. It
is important to note however that CT is insensitive to early
mucosal disease (Gore, et al., 1996).
A cross section of the inflamed and thickened bowel
is having a target appearance, due concentric rings of
varying attenuation, also known as mural stratification. In
chronic cases, submucosal fat deposition is seen
particularly in the rectum (fat halo sign). Strictures are also
common, and are not all malignant. Colorectal carcinoma is
often sessile. Focal loss of mural stratification or
excessive mural thickness (1.5 cm) should prompt
endoscopic evaluation (Gore, et al., 1996).
The current status of Magnetic Resonance Imaging
(MRI) in UC is that of a promising, noninvasive technique
for imaging extent of more severe disease. The most
striking abnormalities in UC are wall thickening and
increased enhancement. The median wall thickness in UC
ranges from 4.7-9.8 mm. In general, the more is severe the
inflammation, the thicker the colonic wall. A colonic wall
thickness <3 mm is usually considered as normal, 3-4 mm
as a "gray zone," and >4 mm as pathological. Enhancement
of the mucosa with no or less enhancement of
the submucosa is producing a low SI strip the
so-called submucosal stripe. Other features are the loss
of haustral markings, backwash ileitis shows
mild enhancement and no wall thickening and
there is increased SI of the pericolonic fat noted
(Gore, et al., 1996).

- 28 -
Plain film is nonspecific but may show evidence of
mural thickening. Ultrasound cannot comprehensively
assess the gut when used in isolation. Doppler are useful in
the assessing the degree of disease activity. It has
reasonable sensitivity for documenting presence of
complicating abscess, particularly in thinner patients and is
a useful first line test in this context (Dietrich, 2009).
Virtual colonography is an evolving technology.
The limited data currently available do not demonstrate a
diagnostic value for assessing the disease extent in patients
with suspected or proven UC (Dignass, et al., 2012).
Recent studies assess the assessment of the severity
of ulcerative colitis using endorectal ultrasonography
(ERUS) corresponds with clinical severity of the disease.
ERUS is a valuable, relatively cost-effective diagnostic tool
of high overall accuracy, which may be helpful in clinical
evaluation and monitoring of ulcerative colitis
A variety of nuclear medical techniques can be used
in the assessment of IBD, but they have no role in primary
diagnosis. Technetium-99m labelling of WBCs remain a
widely acceptable scintigraphic method for the evaluation
of disease extension and severity. Positron emission
tomography alone or with CT using fluorine-18
fluorodeoxy glucose is a promising method of measuring
inflammation in IBD. These techniques considered when
colonoscopy is not completed successfully or other imaging
modalities are negative (Stathaki, et al., 2009).

- 29 -
 Laboratory Findings :
Laboratory studies are of value in assisting with the
management of IBD but are of minimal help in establishing
the diagnosis. Laboratory values may be used as surrogate
markers for inflammation, nutritional status and to look for
deficiencies of necessary vitamins and minerals. Serologic
studies have been proposed to help diagnose IBD and to
differentiate CD from UC (Kefalides and Hanaeur, 2002).
With new-onset IBD or at relapse, infection should
be ruled out with stool studies, including cultures for
bacterial pathogens and examinations for ova and parasites
and Clostridium difficile toxin. Any patient hospitalized
with a flare of colitis should, at a minimum, have a C
difficile toxin assay performed because, commonly,
pseudomembranous colitis is super-imposed on UC
(Kefalides and Hanaeur, 2002).
Also, there is an exudation of inflammatory cells into
the colonic lumen that can be identified as the presence of
fecal leukocytes (William Tremaine, 2008).
Acute phase reactants, including the ESR, CRP,
and transferrin, usually correlate with disease activity but
may be normal in mildly active disease. Hypokalemia, and
metabolic acidosis can occur with severe disease because of
their wasting with diarrhea (William Tremaine, 2008).
Blood tests can also be used to help determine
nutritional status. The most commonly used marker is
serum albumin and prealbumin. Hypoalbuminemia may
reflect malnutrition; it can also develop because of the
protein-losing enteropathy that can occur with active IBD
(Kefalides and Hanaeur, 2002).

- 30 -
Complete blood cell count (CBC) can be useful
indicators of disease activity and iron or vitamin
deficiency. An elevated WBC count is common in patients
with active inflammatory disease or due to a complicating
abscess but it does not necessarily indicate infection.
Anemia is common and may be an anemia of chronic
disease, presumably due to cytokine effects on the bone
marrow or an iron deficiency anemia due to blood loss that
is confirmed by serum iron studies or as a result of
malabsorption of vitamin B12 or folate especially with CD
(Kefalides PT and Hanaeur SB, 2002)
Cytomegalovirus (CMV) should be considered in
severe or refractory colitis, as reactivation is common in
patients with IBD on immunosuppression. Additional tests
may need for patients who have travelled abroad
Several new fecal tests have become available that
assist, initially, with the diagnosis of IBD in general, but
not specifically UC. Perhaps in the future they will
contribute to measurements of disease activity. For
example, elevated concentrations of calprotectin,
a neutrophil granulocyte-derived Ca++
binding protein,
have been evaluated as both a diagnostic assay to
identify inflammatory diarrhea and as measurement of
inflammatory activity (Beckmann, et al., 2007)
Similarly, the concentration of lactoferrin, another
neutrophil granulocyte-derived protein, can be quantified,
most recently by using a polyclonal antibody-based enzyme
linked immunoassay that can discriminate between active
IBD and IBS. It can quantify disease activity but has yet to
be incorporated into clinical trials as a disease-activity
endpoint (Summerton, et al., 2002; Kane, et al., 2003).

- 31 -
The peri-nuclear antineutrophil cytoplasmic
antibody (pANCA) is positive in about 2/3 of patients with
UC and about 1/3 of patients with CD while the
anti-Saccharomyces cerevisiae antibody (ASCA) is
positive in about 2/3 of patients with CD and about 1/3 of
patients with UC. These tests used together to help
distinguish UC from CD. However, the positive predictive
value of the two tests together is 63.6% for UC and 80%
for CD; thus, distinguishing the two diseases with these
tests is less than ideal (William Tremaine, 2008).
There are several potential roles for serologic
markers in UC. The most desirable would be as a
pathognomonic marker of disease specificity or prognosis,
the second as a screening tool to discriminate IBD
from other digestive disorders, and the third to assist in
the understanding of disease mechanisms or
immune interactions (Dubinsky, et al., 2002).
In adult populations the ability to diagnose UC by
flexible sigmoidoscopy or colonoscopy is less of an issue
and offers immediate confirmation and access to histology.
So, serologic markers have, thus far, not been necessary to
screen or exclude UC compared with conventional
investigations. The potential for serologic studies to
discriminate between UC & CD, particularly for patients
with 'indeterminate colitis' has been evaluated by
(Joossens, et al., 2002).
They found that the presence of pANCA does not
help to discriminate between UC and CD in patients with
IC. By contrast, the presence of anti-Saccharomyces
cerevisiae antibodies is more helpful, but their sensitivity in
indeterminate colitis is so low that a positive or negative
predictive value will be low (Vasiliauskas, 2003).

- 32 -
Nutritional aspects in UC
The inflammation of the GIT with the associated
symptoms of pain, nausea, and diarrhea is leading to
reduced food intake and uptake leading to malnutrition.
The prevalence of nutritional deficiencies and malnutrition
is higher in patients with CD than in patients with UC
(Lochs, et al., 2006).
The etiology of malnutrition is multifactorial.
Medication, increased exudative losses of protein or small
bowel bacterial overgrowth is additional causes of
malabsorption (Han, et al., 1999).
Anemia and iron deficiencies are more prevalent in
patients with UC. In patients with severe diarrhea,
low levels of potassium, magnesium, calcium and
phosphate can be encountered. The levels of fat
soluble vitamins correlate with the severity of steatorhea
(Remy Meier, 2008).
Table (6): Nutritional deficiencies in IBD (Remy Meier, 2008).

- 33 -
The diagnosis of malnutrition is done by using
several anthropometric and biochemical parameters as
weight, height, skinfold thickness, body composition
analysis, and serum albumin. It is also important to record
the food intake in the last 1-2 weeks. Patients often
consume an unbalanced diet which may lead to nutritional
deficiencies (Vagianos, et al., 2007).
Resting energy expenditure varies depending on
inflammatory activity. The Energy requirements have been
calculated with the Harris-Benedict equation. However,
physical activity, inflammatory activity, malabsorption and
the degree of obesity should be taken into account. The
more obese the less energy/kg is required and vice versa.
Consequently requirements may be calculated on the basis
of ideal BW (or adjusted BW) and may amount to 25-30
Cal/kg ideal BW/24h (Lochs, et al., 2006).
Protein requirements in patients with IBD are
generally increased. Inflammation induces a catabolic
response with endogenous proteolysis and ensuing negative
nitrogen balance. To limit nitrogen losses in patients with
active IBD, 1.5 g/kg BW protein per day should be
provided. It is recommended to increase protein intake to
2g protein/kg BW/24 h in infectious or severely
malnourished patients (Han, et al., 1999).
The nutritional support required during an acute
exacerbation differs from the nutritional regimen during
remission. The aims of nutritional support in IBD are to
treat or to prevent nutritional deficits, to reduce disease
activity, to improve growth and development in children
and adolescents, to reduce the need for surgery or
aggressive medical treatment, and to maintain remission
(Remy Meier, 2008).

- 34 -
There are no specific data available for ulcerative
colitis to improve or to maintain nutritional status with oral
supplements. Specific nutritional support is more beneficial
in Crohn's disease than in ulcerative colitis. Enteral
nutrition is the preferred route for nutritional repletion
because of the potential trophic effects on the intestinal
mucosa, the preservation of gastrointestinal function, the
beneficial effects on the intestinal flora and mucosal barrier
integrity (Harries, et al., 1983).
In addition, complication rates and costs have been
reported to be lower than with parenteral nutrition. For a
long time, it was suggested that bowel rest with TPN may
reduce intestinal inflammation and decrease disease activity
in patients with IBD. Parenteral nutrition is of limited
benefit in ulcerative colitis. Sometimes parenteral nutrition
is instituted to decrease a debilitating defecation frequency,
when patients are hospitalized with acute toxic colitis
(Remy Meier, 2008).
Enteral tube feeding has shown to be ineffective in
patients with active UC. The remission rates are not higher
than the rate of spontaneous remission when patients
consume normal food. A comparison of TPN with EN in
acute UC showed similar effects on nutritional status,
disease activity and complications, but neither TPN
nor EN had a positive effect on inflammatory activity
(González-Huix, et al., 1993).
Pre- and probiotics have been shown to be beneficial
in gastrointestinal diseases. Prebiotics are soluble poli- or
oligo-saccharides and serve in the intestine as substrates for
fermentation (Johannsson, et al., 1997).

- 35 -
Probiotics are non-pathogenic bacteria which are
able to exert positive health benefits in the gastrointestinal
tract. They are able to adhere to the intestinal mucosa and
can stimulate the secretion of serum IgA and mucus
production. They may reduce the levels of pro-
inflammatory cytokines and increase levels of anti-
inflammatory cytokines. Also, they can produce defenses
and heat shock proteins (Johannsson, et al., 1997).
Pre- and probiotics can interact with the commensal
bacteria and may therefore influence the intestinal
ecosystem. This effect is eminent in the colon, where
anaerobic bacteria can ferment non-absorbable dietary
carbohydrates. Through fermentation, the intestinal pH
decreases, which is stimulates the growth of non-
pathogenic bacteria and liberate short chain fatty acids.
Butyrate is the main energy source for the colonic epithelial
cells. This prevents the expression of specific genes
encoding cytokines intensifying inflammatory response.
Also, it increases apoptosis of inflammatory cells. So far,
the use of pre-and probiotics was found to be more
beneficial in UC than in CD. The use of a fermentable
Plantago ovate (dietary fibre) supplementation
achieved similar relapse rates in UC as Mesalazine
(Buda, et al., 2003; Gionchetti, et al., 2000).
Most patients with IBD in remission have a normal
nutritional status. There are no specific diets recommended
if the patients are in remission and can eat normally. A
normal "healthy" diet rich in fruits, vegetables and fish can
be recommended. In patients with ileum resection or
sulfasalazine treatment, vitamin B12 levels have to be
monitored. Ca++
and vitamin D status should be controlled
in patients treated with steroids (Belluzzi, et al., 1996).

- 36 -
Traditional pharmacological treatment of UC:
Therapy for IBD is a rapidly evolving field, with
many new biological agents under investigation that are
likely to change therapeutic strategies radically in the next
decade (Mowat, et al., 2011). Details of the principal drugs
can only be summarized in this document.
 Amino salicylates
5-Aminosalicylic acid (5-ASA) or mesalazine
(„mesalamine‟ in the USA) can be delivered in millimolar
concentrations to the gut lumen by a variety of oral tablets,
sachets or suspensions using pH-dependent release
mechanism, multi-matrix delivery systems, or conjugation
via a diazo bond to a variety of carrier molecules with
release of 5-ASA after splitting by bacterial enzymes in
the large intestine. They can also be used as topical agents
in the form of liquid or foam enemas, or suppositories
(Sandborn and Hanauer, 2003).
They act on epithelial cells by a variety of
mechanisms to moderate the release of lipid mediators,
inflammatory cells, cytokines and reactive oxygen species
(Sutherland and Macdonald, 2006).
The choice of 5-ASA is debated, but is influenced by
tolerability (mesalazine is tolerated by 80% of those
unable to tolerate sulfasalazine), dose schedule (single or
twice daily dosing with better compliance), route of
delivery, availability and cost are relevant factors in
choice (Dignass, et al., 2009).

- 37 -
For UC, greater clinical improvement is associated
with doses of ≥ 2.0 g/day are more effective than < 2.0
g/day. Clinical improvement characteristically occurs at
twice the remission rate (Bergman and Parke, 2006).
There is now robust evidence to suggest that single
daily dosing is as effective as multiple dosing, and may
even be superior. Maintenance with all 5-ASA drugs may
reduce the risk of colorectal cancer by up to 75%
(Eaden, et al., 2000).
Side effects of 5-Aminosalicylic acid occur in
10-45% of patients, depending on the dose. Headache,
nausea, epigastric pain, diarrhea, thrombocytopenia,
rash and oligospermia in men are most common. Serious
idiosyncratic reactions (including Stevense Johnson
syndrome, pancreatitis, agranulocytosis, or alveolitis)
are rare (Van Staa, et al., 2004).
Also, they associated with nephrotoxicity (including
interstitial nephritis and nephrotic syndrome), which
appears both to be idiosyncratic and, in part, dose related
(Muller, et al., 2005).
For patients on maintenance 5-ASA, many clinicians
believe that creatinine and full blood count should be
monitored every 3–6 months and it should be stopped if
renal function deteriorates (Muller, et al., 2005).

- 38 -
 Corticosteroids
Corticosteroids are used in the form of oral
prednisolone, prednisone, budesonide, or intravenous
hydrocortisone and methylprednisolone. Topical
suppositories, foam or liquid enemas also used. Many
strategies attempt to maximize topical effects
while limiting the systemic side effects of steroids
(Seow, et al., 2009).
Corticosteroids are potent anti-inflammatory agents
for moderate to severe relapses of UC. They have no role in
maintenance therapy (Manguso and Balzano, 2007).
They act through inhibition of several inflammatory
pathways: suppressing interleukin transcription,
suppression of arachidonic acid metabolism and stimulation
of apoptosis of lymphocytes within the lamina propria of
the gut (Benchimol, et al., 2008).
A combination of oral and rectal steroids is better
than either alone. Adverse events are significantly more
frequent at a dose of 60 mg/day compared to 40 mg/day,
without added benefit, so 40 mg/day appears optimal for
outpatient management of acute UC (Lee, et al., 1996).
Budesonide (colonic release preparation) is a poorly
absorbed corticosteroid with limited bioavailability and
extensive first-pass metabolism that has therapeutic benefit
with reduced systemic toxicity in ileo-caecal CD, or UC.
Beclometasone dipropionate has been studied in oral and
enema forms in UC, and is no better than 5-ASA also, it
appears as effective as prednisolone for mild - moderate
left-sided and extensive colitis (Campieri, et al., 2003).

- 39 -
Regimens of steroid therapy are various. There is no
evidence to support any particular regimen. The commonly
used regimen is done by a starting dose of 40 mg
prednisolone per day, reducing by 5 mg/d at weekly
intervals. A standard weaning strategy helps identify
patients who relapse rapidly or do not respond and
need adjunctive therapy. Shorter courses (< 3 weeks)
are associated with early relapse and doses of
prednisolone ≤ 15 mg day are ineffective for active disease
(Kane, et al., 2002).
Steroid resistance or unresponsiveness should
lead to escalation of treatment, or consideration of
surgery. Medical therapies include an immunosuppressive
appropriate to the acuteness and type of the disease
(Kane, et al., 2002).
Side effects of corticosteroids due to supra-
physiological doses include cosmetic (acne, moon face,
edema), sleep and mood disturbance, dyspepsia or glucose
intolerance (Subramanian, et al., 2008). Prolonged use
(usually >12 weeks, but sometimes less) include cataracts,
osteoporosis, osteonecrosis of the femoral head, myopathy
and susceptibility to infection (Newby, et al., 2005).
Efficacy should be balanced against side effects, but
decisive treatment of active disease in conjunction with a
strategy for complete withdrawal of steroids is often
appreciated by a patient suffering miserable symptoms
during withdrawal acute adrenal insufficiency and
corticosteroid withdrawal syndrome may occur
(Lichtenstein, et al., 2006). Guidelines recommend
monitoring for eye, bone and other side effects particularly
in patients on steroids for more than 3 months
(Abreu, et al., 2006).

- 40 -
 Thiopurines
Azathioprine (AZA) or mercaptopurine (MP) is
widely used in UC and CD as adjunctive and sparing
therapy. Purine antimetabolites inhibit ribonucleotide
synthesis, but mechanism of immunomodulation is by
inducing T-cell apoptosis by modulating cell (Rac1)
signaling (Tiede, et al., 2003).
AZA is non-enzymatically metabolized to MP,
which involves loss of a nitro-imidazole side chain; this is
thought to explain some of the side effects seen with AZA
and which may be less of a problem with MP. MP is
subsequently metabolized to 6-thioguanine nucleotides (6-
TGN). 6-TGN has been used for treatment of IBD with
caution because of potential hepatotoxicity
(McGovern, et al., 2002; Bowen and Selby, 2000).
AZA is more effective than mesalazine at induction
of clinical and endoscopic remission in steroid dependent
ulcerative colitis and should be first-choice therapy in this
situation providing other causes of persistent symptoms
such as CMV or cancer have been excluded. Thiopurines
are effective maintenance therapy for patients with UC who
has failed or who cannot tolerate mesalazine and for
patients who require repeated courses of steroids. The
evidence for using thiopurines in UC is weaker than in CD
(Ardizzone, et al., 2006; Timmer, et al., 2007).
Tailoring or optimization can occur prior to or during
treatment. The appropriate maintenance dose of AZA is 2-
2.5 mg/kg/day and of MP is 0.75-1.5 mg/kg/day. The
„maximum‟ dose will differ between individuals and
effectively means that level at which leucopenia develops
(Gilissen, et al., 2005).

- 41 -
Adverse events occur in up to 20%. The commonest
are allergic reactions (fever, arthralgia, rash) that
characteristically occur after 2-3 weeks and cease
rapidly when the drug is withdrawn. Hepatotoxicity and
pancreatitis are uncommon (Gisbert and Gomollon, 2008).
Bone marrow toxicity has been reported to occur up
to 11 years after starting AZA and blood monitoring should
continue throughout thiopurine therapy. Manufacturers
recommend monitoring thiopurine therapy weekly by full
blood counts (FBCs) for the first 8 weeks of therapy
followed by blood tests at least every 3 months
(Colombel, et al., 2000).
Although a significant proportion of patients
experience adverse effects with thiopurines when the drug
is tolerated for 3 weeks, long-term benefit can be expected
(Macdonald, et al., 2009). In absolute terms, the risk
remains very small (<1% risk after 10 years of thiopurine
use) and the benefits of AZA outweigh any risks
(Lewis, et al., 2000).
In IBD, large population-based studies have shown
no increased risk. Whereas a second suggested a fourfold
increased risk of lymphoma in patients with IBD treated
with AZA/MP compared with background population
(Kandiel, et al., 2005).
There is an increased risk of non-melanoma skin
cancer in patients treated with thiopurines. Patients should
be advised to avoid excessive sun exposure and use a high-
strength sun block (Fraser, et al., 2002).

- 42 -
 Methotrexate
Polyglutamated metabolites of methotrexate (MTX)
inhibit dihydrofolate reductase, but this cytotoxic effect
does not explain its anti-inflammatory effect. Inhibition of
cytokine and eicosanoid synthesis probably plays a role. It
is positioned as a second-line immunosuppressive agent in
patients resistant or intolerant of AZA, although it is
currently unclear whether thiopurines are any more
efficacious than MTX for induction or maintenance of
remission in IBD (Oren, et al., 1996).
A low dose (12.5 mg once weekly) was not shown to
be efficacious at inducing or maintaining remission. Using
larger weekly doses show higher response or remission
rates resistant or intolerant of AZA or MP. Parenteral
administration (either subcutaneous or intramuscular) may
be more effective that oral therapy and is recommended.
Monitoring therapy by measurement of FBC and liver
function tests are advisable before and within 4 weeks of
starting therapy, then monthly (Ei-Matary; Wahed, et al.,
2009; Nathan, et al., 2008).
Side effects are reported by 27- 49% of patients.
Early toxicity from MTX is primarily gastrointestinal
(nausea, vomiting, diarrhea and stomatitis). Co-prescription
of folic acid 5 mg (once a week, taken 3 days after MTX)
limits side effects. Long-term concerns are hepatotoxicity,
pneumonitis and opportunistic infections (Fraser, 2003).
MTX is teratogenic and should not be used if
conception considered. It may persist in tissues for long
periods; therefore conception should be avoided for 3-6
months after withdrawal. Breastfeeding isn't recommended
(Mahadevan and Kane, 2006)

- 43 -
 Calcineurin inhibitors
Ciclosporin (CsA) is an inhibitor of calcineurin,
which prevents clonal expansion of T cell subsets
(Shibolet, et al., 2005). It is rapidly effective as a salvage
therapy for patients with refractory UC, who would
otherwise face colectomy, but its use is controversial
because of the narrow therapeutic index of it (including
mortality rates of 3–4%), toxicity and long-term failure
rate. The drug should rarely be continued for more than 3-6
months and its main role is a bridge to thiopurine therapy
(Lichtiger, et al., 1994).
Measurement of blood pressure, FBC, renal
function and CsA concentration (aim for 100-200 ng/ml)
are advisable at 0, 1 and 2 weeks, then monthly. Blood
cholesterol and Mg++
should be checked before starting due
to risk of seizures (McDonald, et al., 2005).
Minor side effects occur in 31-51%, including
tremor, paraesthesiae, malaise, headache, abnormal liver
function, gingival hyperplasia and hirsutism. Major
complications are reported in 17%, including renal
impairment, pneumonia, infections and neurotoxicity (Van
Assche, et al., 2003). Toxicity can be reduced by using
lower doses (2 mg/kg/day IV), by oral micro emulsion
CsA, or by mono-therapy without corticosteroids
(D’Haens, et al., 2001).
Tacrolimus is another calcineurin inhibitor often
preferred in the transplant setting to CsA. Data from trials
show that it is effective in treatment of steroid refractory
thiopurine naïve UC. A dose is of 0.025 mg/kg twice a day
should achieve trough levels of 10-15 ng/ml (Ogata;
Herrlinger, et al., 2006).

- 44 -
 Anti-TNF therapies
There are presently two biological agents licensed
for the treatment of IBD in UK; both are monoclonal
antibodies against TNF α (anti-TNF) (Mowat, et al., 2011).
Infliximab (IFX) is a chimeric anti-TNF antibody,
consisting of 75% human IgG and 25% murine component
that actively binds membrane-bound and soluble TNFα.
IFX is given by IV infusion only (Mowat, et al., 2011).
Adalimumab (ADA) is a humanized anti-TNF
antibody, given by sub-cutaneous injection only. At the
present time both agents are licensed for the treatment of
Crohn's disease that has failed to respond to standard
immunosuppression (Mowat, et al., 2011).
Three intravenous infusions of IFX at 0, 2 and 6
weeks were effective in inducing clinical remission;
inducing endoscopic remission and clinical response at 8
weeks. The efficacy of infliximab for treating patients with
moderate to severe UC refractory to corticosteroids and
immunomodulators concluded that it was effective for
inducing clinical remission, clinical response, promoting
mucosal healing, and reducing the need for colectomy in
the short term (Lawson, et al., 2006).
Most recently, the anti-TNF antibody golimumab
has been shown to induce clinical remission and mucosal
healing. Treatment at weeks 0 and 2 (400/200 mg, 200/100
mg) significantly induced clinical remission and mucosal
healing at week 6 suggesting that several anti-TNF
antibodies favor mucosal healing in ulcerative colitis
(Sandborn, et al., 2012).

- 45 -
Treatment with anti-TNF therapy is relatively safe if
used for appropriate indications. It should be balanced with
the potential curative option of surgery in UC. Due to the
nature of their effects on TNF, all anti-TNF therapies share
a similar profile of adverse events, including increased risk
of infections from intracellular pathogens, most notably,
TB, other opportunistic infections, autoimmunity,
infusion reactions, and other more rare side-effects
(Mowat, et al., 2011).
Pre-treatment screening for exposure to TB is
important via a history, chest x-ray and tuberculin skin test
if applicable in patients who are about to begin anti-TNF
therapy (Theis and Rhodes, 2008).
The combination of IFX and a thiopurine analogue
or corticosteroids is probably justified to decrease
immunogenicity, which is the source of infusion reactions
and loss of response (Tekkis, et al., 2010).
There is insufficient evidence at present to
recommend the use of interferon γ release assays. Re-
activation of chronic hepatitis B has been reported in
patients treated with IFX. There are no data to suggest it
has any effect on course of chronic hepatitis C.
Pre-treatment screening for exposure to hepatitis B is
important; vaccination should be considered in the non-
immune high-risk patient (Esteve, et al., 2004).
Antibodies formation to infliximab (ATI) can
trigger both acute infusion reactions and delayed serum-
sickness-like reactions. Minor acute reactions usually
respond to slowing the infusion rate or treatment with
antihistamines, paracetamol and sometimes corticosteroids.
Episodic therapy and consequent „drug holiday‟ is

- 46 -
associated with increased formation of ATIs, and should be
avoided. ATI formation is associated with increased
incidence of infusion reactions and loss of response (Baert,
et al., 2003). Although ADA is a fully humanized antibody,
it is also associated with the formation of antibodies to
adalimumab (ATA) which have been shown to reduce
efficacy in rheumatoid arthritis and CD (West, et al., 2008).
Prolonged medical therapy for a potentially
pre-malignant condition with anti-TNF therapy creates its
own anxieties. The Mayo Clinic practice and Edinburgh
series confirmed the relatively rare occurrence of
malignancy including basal & squamous cell cancers
(Lees, et al., 2009).
Anti-TNF therapy was associated with an increased
risk of NHL when compared to the general population, but
the risk remained small (6.1 per 10000 patient-years). Anti-
TNF therapy also led to an increased rate of NHL
compared to those treated with immunosuppressants
alone, although this did not reach significance
(Kandiel, et al., 2005).
Reports of optic neuritis, seizure, and new onset or
exacerbation of central nervous system demyelinating
disorders, including multiple sclerosis, have been reported
with the use of all anti-TNFs. Also, Anti-TNF agents are
contraindicated for patients with class III-IV congestive
heart failure due to evidence of increased risks of death
from several clinical trials (Mowat, et al., 2011).

- 47 -
UC Management Guidelines
 Active ulcerative colitis
When deciding the appropriate treatment strategy for
active ulcerative colitis one should consider the activity,
distribution and pattern of disease. The disease pattern
includes relapse frequency, course of disease, response
to previous medications, side-effect profile of
medication and extra-intestinal manifestations. The age
at onset and disease duration may also be important factors
(Silverberg, et al.,2005).
It is most important to distinguish patients with
severe ulcerative colitis necessitating hospital admission
from those with mild or moderately active disease
who can generally be managed as outpatients
(Schroeder, et al., 1987).
Patients should be encouraged to participate actively
in therapeutic decisions which should be tailored to the
individual (Munkholm, et al., 2010).
The choice of therapeutic strategy should be
influenced by the balance between drug potency and
side-effect profile; previous response to treatment
(especially when considering treatment of a relapse,
treatment of steroid-dependent or refractory disease, or
immunomodulator refractory disease); and the presence of
extra intestinal manifestations which may require
systemic therapy (Su, et al., 2007).

- 48 -
 Treatment according to site of disease and disease activity
 PROCTITIS
Choice of topical formulation should be determined
by the proximal extent of the inflammation (suppositories
for disease to the recto-sigmoid junction, foam or liquid
enemas for more proximal disease) along with patient
preference, such as ease of insertion or retention of enemas
(Safdi, et al., 1997).
A mesalazine 1 g suppository once daily is the
preferred initial treatment for mild or moderately active
proctitis. There is no dose response for topical therapy
above a dose of 1 g daily. Mesalazine foam enemas are an
alternative. Suppositories may deliver drug more
effectively to the rectum and are better tolerated than
enemas. Topical mesalazine is more effective than topical
steroids; consequently topical steroids should be reserved
as second line therapy for patients who are intolerant of
topical mesalazine (Dignass, et al., 2012).
Combining topical with oral mesalazine or topical
steroid is more effective than either alone and should be
considered for escalation of treatment. Oral mesalazine
alone is less effective. Patients who fail to improve on
oral/topical mesalazine and topical corticosteroids should
be treated with the addition of oral prednisolone.
Refractory proctitis may require treatment with
immunosuppressants or biologics (Dignass, et al., 2012).
Fig. (5): Extent of bowel
involvement in UC
(Johns Hopkins, 2013)

- 49 -
 LEFT SIDED COLITIS
Left-sided colitis of mild-moderate severity should
initially be treated with an amino-salicylate enema 1
g/day combined with oral mesalazine >2 g/day. Foam
enemas are not inferior to liquid enemas for inducing
remission. Also, low volume enemas are not inferior to
high volume enemas and may be better tolerated. Topical
therapy with steroids or 5ASA alone as well as mono-
therapy with oral 5ASA is less effective than oral plus
topical 5ASA therapy. Topical mesalazine is more effective
than topical steroid (Dignass, et al., 2012).
Systemic corticosteroids are appropriate if a patient's
symptoms deteriorate, rectal bleeding persists beyond 10-
14 days, or sustained relief from all symptoms has not been
achieved after 40 days of appropriate mesalazine therapy
 EXTENSIVE COLITIS
Extensive UC of mild-moderate severity should
initially be treated with oral 5ASA >2 g/day, which should
be combined with topical mesalazine to increase remission
rates if tolerated. Systemic corticosteroids are appropriate if
symptoms of active colitis do not respond to mesalazine by
oral prednisolone combined with steroid enemas. An
appropriate regimen for active disease is prednisolone 40
mg/day for 1 week, reducing by 5 mg/day/week resulting in
an 8 week course, and many different regimes are used

- 50 -
 SEVERE UC OF ANY EXTENT
Acute severe UC is a potentially life-threatening
condition. In 1933, 75% patients died within the first year
after acute presentation with UC and in 1950 a mortality of
22% was reported amongst cases in the first year after
diagnosis. The response rate to appropriately dosed
intravenous steroids has not changed over the last 30 years
(Turner, et al., 2007).
Patients with bloody diarrhea ≥6/day and any signs
of systemic toxicity (tachycardia >90 bpm, fever >37.8 °C,
Hb <10.5 g/dL, or an ESR >30 mm/h) have severe colitis
and should be admitted to hospital for intensive treatment.
All patients admitted with severe colitis require appropriate
investigations to confirm the diagnosis and exclude enteric
infection (Van Assche, et al., 2011).
Corticosteroids are generally given intravenously
using methyl-prednisolone 60 mg/24 h or hydrocortisone
100 mg four times daily. Higher doses are no more
effective, but lower doses are less effective. Bolus injection
is as effective as continuous infusion. Treatment should be
given for a defined period as extending therapy
beyond 7 to 10 days carries no additional benefit
(Rosenberg, et al., 1990).
Consideration of mono-therapy with CsA or IFX if
there is no improvement by day 3, there is subsequent
deterioration or when steroids are best avoided, but for
patients already on immunosuppressive therapy, colectomy
is the first option. Other measures that may considered as
subcutaneous prophylactic low molecular weight heparin,
IV fluid, electrolyte replacement and blood transfusion

- 51 -
Table (7): Algorithm for treatment of active UC (Carter et al., 2004).
 Refractory UC
Treatment decisions are depending on the pattern of
relapse, timing of relapse (disease remains active in spite of
treatment or relapse occurs when it tapered 'drug
dependent'), concurrent therapy, previous response to
therapy, adherence to maintenance therapy and patient
opinion (adverse effects, speed of response, convenience)
(Sandborn, et al., 2009).
Opinion is divided whether to use the same induction
treatment as before to achieve remission or to use more
potent therapy. Also, maintenance therapy should also be
optimized. Patients who have an early (<3 months) relapse
require further induction therapy, but should also
commence AZA or MP to reduce the risk of a subsequent
relapse. (Dignass, et al., 2012).

- 52 -
 ‘Steroid-dependent’, active ulcerative colitis
Thiopurines is the first choice of therapy for patients
who flare when steroids are withdrawn. Patients with active
disease despite steroid therapy require appropriate
induction therapy, including consideration of anti-TNF
therapy. Azathioprine is significantly more effective than
mesalazine at achieving clinical and endoscopic
remission in the treatment of steroid-dependent UC
(Ardizzone, et al., 2006).
 Oral steroid-refractory ulcerative colitis
For active UC that is refractory to steroids, other
causes of persistent symptoms should be considered. If
active steroid-refractory UC is confirmed, alternative
therapy to induce steroid-free remission is required. Anti-
TNF therapy has clear evidence of benefit in this patient
group (Dignass, et al., 2012).
Adalimumab is now licensed for treatment of
severely active UC in Europe. Moderately active disease
outpatients have the surgical options or admission for IV
steroid therapy (Dignass, et al., 2012).
It should be noted that none of the treatments
discussed above have achieved steroid-free remission at
any time point in the majority of patients. The sequence (or
hierarchy) of therapy has to depend on the individual
circumstances and acceptability to the patient
(Ogata, et al., 2006).

- 53 -
 Intravenous-steroid refractory UC of any extent
The response to intravenous steroids is best assessed
objectively around the third day. Treatment options
including colectomy should be discussed with patients with
severely active UC not responding to IV steroids. Second
line therapy with ciclosporin, infliximab or tacrolimus may
be appropriate. If there is no improvement within 4-7 days
of salvage therapy, colectomy is recommended. The timing
of colectomy for severe colitis remains one of the most
difficult decisions that a gastroenterologist has to make.
Delaying will increase the morbidity and mortality
associated with subsequent surgery (Dignass, et al., 2012;
Randall, et al., 2010).
 Immunomodulator-refractory ulcerative colitis
Patients should be treated with anti TNF therapy or
tacrolimus although colectomy should also be considered.
Continued medical therapy that does not achieve a
clear clinical benefit is not recommended. It is best
reassessed to confirm diagnosis and exclude complications
Infliximab at either dose used (5 mg/kg or 10 mg/kg)
achieved clinical remission in a significantly greater
proportion of patients. Using infliximab (three IV infusions
at 0, 2, and 6 weeks) was effective in inducing clinical
remission in patients with moderate to severe UC refractory
to corticosteroids and/or immunomodulators (Lawson, et
al., 2006).Adalimumab also induced clinical remission with
standard induction dose of 160 mg, followed by 80 mg
after 2 weeks. Maintenance doses are then scheduled at 40
mg every other week (Gies, et al., 2010).

- 54 -
 Refractory proctitis and distal colitis
They present common clinical dilemmas. It is clearly
important to consider and identify the etiology of the
refractory course. One obvious explanation is that the
disease is refractory to medication being prescribed.
However, alternative explanations include poor adherence
to prescribed therapy, delivery of an inadequate
concentration of drug to inflamed mucosa, unrecognized
complications (constipation or infection), and Inappropriate
diagnosis. Therefore, the initial step is to review current
symptoms and treatment to date, with a careful discussion
about adherence followed by reassessment of the diagnosis.
Next step is to ensure that conventional therapy has been
used appropriately. Attention in particular should be paid to
the formulation of topical therapy and whether it was used
in conjunction with an adequate dose of oral therapy.
Endoscopically documented patients have therapeutic
options include admission for IV steroid therapy.
Alternatively, there is open label evidence supporting the
use of salvage medical therapies (Dignass, et al., 2012;
Hebden, et al., 2000; Sandborn, et al., 1994).
An abdominal X-ray can be useful to diagnose
proximal constipation, since abnormal intestinal motility
induces proximal colonic stasis in patients with distal
colitis which may affect drug delivery. If there is visible
faecal loading, a laxative should be considered
(Järnerot, et al., 1985).
There is evidence from studies that appendicectomy
may improve outcome in patients with refractory proctitis.
The outcome of colectomy and pouch formation for distal
colitis is usually good (Brunel, et al., 1999).

- 55 -
 Maintenance of remission
The goal of maintenance therapy in UC is to
maintain steroid-free remission, clinically and
endoscopically defined. More than half of patients with
UC have a relapse in the year following a flare. The
endpoint is the absence of relapse after 6 or 12 months
(Edwards and Truelove, 1963).
Maintenance treatment is recommended for all
patients. Intermittent therapy is acceptable in a few patients
with disease of limited extent. Choice of maintenance
treatment in UC is determined by disease extent, disease
course (frequency of flares), failure of previous
maintenance treatment, severity of the most recent flare,
treatment used for inducing remission during the most
recent flare, safety of maintenance treatment, and cancer
prevention. Options for a stepwise escalation of
maintenance therapy include dose escalation of oral/rectal
amino salicylates, the addition of azathioprine/
mercaptopurine or Infliximab/anti TNF therapy. Short term
use of systemic or topical steroids may be required when a
rapid response is needed (Dignass, et al., 2012).
Oral 5-ASA containing compounds are the first line
maintenance treatment in patients responding to 5-ASA or
steroids (oral or rectal). Rectal 5-ASA is the first line
in maintenance in proctitis and an alternative in
left-sided colitis. A combination of oral and rectal 5-ASA
can be used as a second line maintenance treatment
The minimum effective dose of oral 5-ASA is 1.2 g
per day. For rectal treatment 3 g/week in divided doses is
sufficient to maintain remission (Dignass, et al., 2012).

- 56 -
The dose can be tailored individually according to
efficacy. In some cases higher doses ± topical 5-ASA is
useful. There is no robust evidence to support the choice of
any specific preparation for maintenance. Although
sulfasalazine is equally or slightly more effective, other 5-
ASA preparations are preferred for toxicity reasons
E. Coli Nissle is an effective alternative to 5-ASA
for maintenance. No evidence has yet been reported that
any other probiotic is effective for maintaining of UC
remission. Also, insufficient data were regarded to
recommend antibiotics for maintenance of remission in UC
Azathioprine/mercaptopurine is recommended for
patients with mild to moderate disease activity who have
experienced early or frequent relapse whilst taking 5-ASA
at optimal dose or who are intolerant to 5-ASA, patients
that are steroid-dependent and for patients responding to
ciclosporin (or tacrolimus) for induction of remission
In patients responding to anti-TNF agents, both
maintaining remission with AZA/ MP and continuing anti-
TNF therapy with or without thiopurines are appropriate. In
patients with severe colitis responding to IV steroids, IV
CsA or IFX, AZA / MP should be considered to maintain
remission. However, in patients responding to INX
continuing it is also appropriate. The prior failure of
thiopurines favors maintenance with anti-TNF therapy. Due
to limited evidence, no recommendation can be given for
the duration of treatment with AZA or IFX, although
prolonged use of these medications may be considered if
needed (Dignass, et al., 2012).

- 57 -
 Surgical options in UC
Up to 30% of patients will ultimately require
colectomy for ulcerative colitis. The decision to operate is
best taken by the gastroenterologist and colorectal surgeon
in conjunction with the patient (Hoie, et al., 2007).
Delay in appropriate surgery is associated with an
increased risk of surgical complication. A staged procedure
(colectomy first) is recommended in the acute case when
patients do not respond to medical therapy, or if a patient
has been taking 20 mg daily or more of prednisolone for
more than 6 weeks. If the appropriate laparoscopic skills
are available, a minimally invasive approach is feasible and
may convey some advantages (Dignass, et al., 2012).
The operation of choice in patients with acute severe
colitis failing to respond to intensive medical treatment is a
subtotal colectomy, end ileostomy and preservation of a
long rectal stump. Ileo-anal pouch is anther procedure that
involves panproctocolectomy with permanent end
ileostomy or ileoanal pull through procedure (IAPP)
(Brown, et al., 2008).
To aid decision-making many factors that predict the
need for colectomy in acute severe colitis can broadly be
divided into clinical markers such as stool frequency
(>12/day), pyrexia (>38◦
C) and steroid-dependent disease
course, biochemical markers include a high CRP, low
albumin, and pH and radiological/endoscopic criteria
include the presence of colonic dilatation (>5.5 cm), the
depth of colonic ulceration, or mucosal islands on a plain
abdominal radiograph (Roussomoustakaki, et al., 1997).

Stem Cells and Stem Cell Therapy for UC Chapter 2
- 58 -
Stem Cells and Stem Cell therapy for UC
Discovery of Stem Cells:
. Stem cells are how we all begin. They are
undifferentiated cells that go on to develop into any of
more than 200 types of cell an adult human body holds
(Becker AJ, et al., 1963).
The stem cell is the origin of life, as stated first by
the great pathologist Rudolph Virchow, “All cells come
from cells”, and “All the cells of the human body arise
from a preexisting stem cell, the fertilized egg”
(Sell, 2004).
Fig. (6): Stem cells (Bloomberg News, 2012)

- 59 -
Introduction to Stem Cells:
The zygote is the ultimate stem cell produced from
fertilization. It is totipotent with the ability to produce all
the cell types of the species including the trophoblast and
the embryonic membranes. The zygote undergoes a process
of cell divisions and cell migrations known as cleavage. It
begins when several successive cell divisions resulting in a
doubling of the cell number and a reduction in the cell size.
At the 32 - 64 cell stage each cell is called a blastomere
(Sell, 2004).
The blastomeres stick together to form a tight ball of
cells called a morula. Each of these cells retains
totipotential. The next stage is the blastocyst which
consists of a hollow ball of cells; trophoblast cells along
the periphery develop into the embryonic membranes and
placenta while the inner cell mass develops into the fetus.
Beyond the blastocyst stage, development is characterized
by cell migration in addition to cell division
(Kuehnle and Goodell, 2002).
The gastrula is composed of three germ layers: the
ectoderm, mesoderm and endoderm. As development
proceeds, there is a loss of potential and a gain of
specialization, a process called determination. The cells of
the germ layers are more specialized than the fertilized egg
or the blastomere. The germ layer SCs give rise to
progenitor cells (precursor cells) which can further divide
to produce the terminally differentiated cell. The ectoderm
(outer layer) gives rise to the future nervous system and the
epidermis. The mesoderm (middle layer) gives rise to the
connective tissue, muscles, bones and blood, and the
endoderm (inner layer) forms the gastrointestinal tract and
the respiratory system (Kuehnle and Goodell, 2002).

- 60 -
Fig. (7): Development of Preimplantation Blastocyst in Humans(Terese Winslow, 2001).
Early in embryogenesis, some cells migrate to the
primitive gonad or genital ridge. These are the precursors to
the gonad of the organism and are called germinal cells.
These cells are not derived from any of the three germ
layers but appear to be set aside earlier. In adults, ovum and
sperm are derived from these cells by special cell division
called meiosis (Sell, 2004).
Fig. (8):Pluripotent stems cells (Mike Jones, 2006).

- 61 -
Definitions and Characteristics of SCs:
Stem cells (SCs) are undifferentiated cells that have
the capability of both Self-regeneration (self-renewal) and
Potency (differentiation) into mature specialized cells
through replication (Ricart E, et al., 2010).
Self-regeneration is the ability of stem cells to
divide and produce more stem cells. During early
development, the cell division is symmetrical i.e. each cell
divides to give rise to daughter cells each with the same
potential. Later in development, the cell divides
asymmetrically with one of the daughter cells produced is
also a stem cell and the other is a more differentiated cell
(Piscaglia, et al., 2008).
Potency is the ability to differentiate or the potential
to develop into different cell types. A totipotent stem cell
(e.g. fertilized egg) can develop into all cell types including
the embryonic membranes. A pluripotent stem cell can
develop into cells from all three germinal layers. A
multipotent stem cells could produce only cells of a
closely related family of cells (e.g. hematopoietic SCs).
Other cells can be oligopotent, bipotent or unipotent
depending on their ability to develop into few, two or one
other cell type(s) (Sell, 2004).
There are differences in how progenitor cell division
is described. For instance, according to one source (Robey,
2000), when a SC divides at least one of the daughter cells
it produces is also a SC; when a progenitor cell undergoes
cell division it produces two specialized cells. A different
source (Sell, 2004), explains that a progenitor cell
undergoes asymmetrical cell division, while a SCs
undergoes symmetrical cell division.

- 62 -
The apparent inconsistency of these two versions
illustrates the diversity and complexity of progenitor cells
and their role in differentiation. This diversity is reflected
in the nomenclature as well; progenitor cells are also called
Transit-amplifying cells, Precursor cells, Progenitors,
Lineage stem cells, and Tissue - determined stem cells
Table (8):Stem cells during differentiation at each stage (Sell, 2004).
Table (9): Types of cell division (Lindblad, 2004)
Early in development
Late in development: type 1
Late in development: type 2

- 63 -
Types of SCs:
A. Embryonic Stem Cells:
Embryonic stem cells (ESCs) are defined by
its origin. They are generally isolated from the
inner cell masses (ICMs) of blastocysts, which consist
of pluripotent cell populations that are able to
generate primitive ectoderm during embryogenesis.
More specifically the primitive ectoderm gives rise
during the gastrulating process to the primary germ
layers, including ectoderm, mesoderm, and endoderm
(Yao, et al., 2006).
They possess the dual ability to undergo unlimited
self-renewal and to differentiate in all fetal and
adult stem cells and their more differentiated
progenitors. They are pluripotent cells, capable of
forming tissues from all three germ layers in vitro and vivo
(Swenson and Theise, 2010).
Therefore, they represent a useful source of stem
cells for investigating the molecular events that are
involved in normal embryogenesis and generating a large
number of specific progenitors for cellular therapies. It
could use in studies of congenital birth defects,
chromosomal abnormality effects and childhood tumors
development (Trounson; Karp et al., 2006).

- 64 -
Advantages & Disadvantages of Embryonic SCs:
Advantages: They are
 Flexible: They have the potential to make
anybody cell.
 Immortal: One cell line can potentially supply
endless amounts of cells with carefully defined
characteristics.
 Easily available: human embryos can be obtained
from fertility clinics in developed countries.
Disadvantages: They could be
 Difficult to control: ESCs may be tumorigenic
when transplanted in vivo. The method for
inducing the cell type needed to treat a particular
disease must be defined and optimized
(Fujikawa, et al., 2005).
 At odds with a patient's immune system: It is
possible that transplanted cells would differ in
their immune profile from that of the recipient
and so would be rejected. But this could be
avoided through genetic engineering them to
express MHC antigen of the recipient.
 Ethically controversial: as life begins at
conception, doing research on human embryos is
unethical.

- 65 -
B. Adult Stem Cells:
The term adult stem cells (ASCs) refers to any cell
which is found in a developed organism that has two
properties: the ability to divide and create another cell like
itself and also divide and create a cell more differentiated
than itself. Also known as somatic (from Greek "of the
body") stem cells and germ line (giving rise to gametes)
stem cells, they can be found in children, as well as adults
(Doyonnas and Blau, 2004).
ASCs allow specific tissues to regenerate throughout
life. They also have the ability for self-renewal and multi-
lineage differentiation. In fact, the list for
identifying ASCs and lineage specific progenitor cells is
growing. A great deal of ASCs research has
focused on clarifying their capacity to divide or
self-renew indefinitely and their differentiation potential
(Preston, et al., 2003).
Distinct stem cell types have been established in
specific niches in many adult mammalian tissues and
organs, such as brain, skin, eyes, heart, kidneys,
lungs, gastrointestinal tract, pancreas, liver, breast,
ovaries, prostate, and testis(Griffiths, et al., 2005;
Liu, et al., 2004).
The replenishment of epithelial cell lineages within
the gastrointestinal tract (GIT) is a frequent process,
occurring every 2-7 days under physiological conditions.
This process may contribute to the generation of
new cell progenitors, which repopulate the damaged tissues
during diverse pathological disorders, such as inflammation
and ulceration (Schier and Wright, 2005).

- 66 -
This process is regulated by multipotent SCs, which
give rise to all gastrointestinal epithelial cell lineages and
can regenerate whole intestinal crypts and gastric glands.
The SCs of the GIT are localized within the
niches in the intestinal crypts and gastric glands
(Brittan and Wright, 2002).
These SCs can give rise to all cell types within the
crypt, including absorptive, goblet, entero-endocrine and
Paneth cells. Similarly, the SCs in the large intestine or
colon, which are localized at the bottom of crypts, may also
give rise to the proliferative progenitors that differentiate
toward all lineages during epithelium regeneration
(Reya and Clever, 2005).
Fig. (9): Embryonic stem cells (Kuehnle and Goodell, 2002).

- 67 -
Advantages & Disadvantages of Adult SCs:
Advantages: They are
 Already somewhat specialized: the inducement
may be simpler.
 Immune hardy: Recipients who receive products
of their own SCs will not experience immune
rejection.
 Flexible: it may be used to form other tissue
types.
 Mixed degree of availability: Some ASCs are
easy to harvest and others, such as neural (brain)
stem cells, can be dangerous to the donor.
Disadvantages: They could be
 Minimal quantity: difficulty in obtaining it in
large quantities
 Finite: They don't live as long in a culture as
ESCs.
 Genetically unsuitable: The harvested SCs may
carry genetic mutations for disease or become
defective during experimentation (Kuehnle and
Goodell, 2002).

- 68 -
Progenitor cells:
Stem cells generate an intermediate cell type or types
before they achieve their fully differentiated state. The
intermediate cell is called precursor or progenitor cell.
Progenitor cells in fetal or adult tissues are partially
differentiated cells that divide and give rise to differentiated
cells. Such cells are usually regarded as “committed” to
differentiate along a particular cellular pathway
(Robey, 2000).
The concept of a progenitor cell is difficult to define.
Like SCs, progenitor cells have a capacity to differentiate
into a specific type of cells. However, in contrast to SCs,
they are already far more specific than SCs: they are
pushed to differentiate into their “target” cell. Despite the
difficulty of defining progenitors, the term is frequently
used in researches (Noctor, et al., 2007).
Most progenitors are described as unipotant or
multipotant. In this point of view, they may be compared to
ASCs, on the other hand, they are said to be in a farther
stage of cell differentiation. They are in the “center”
between stem cells and fully differentiated cell. The kind of
potency they have depends on the type of their “parent”
stem cell and also on their niche (Noctor, et al., 2007).
Progenitors exhibit slow growth and their main role
is to replace cells lost by normal attrition. Growth factors
and cytokines trigger the progenitors towards the damage
tissue. At the same time, they differentiate to the target cell
to recover the injured tissue (Noctor, et al., 2007).

- 69 -
Plasticity of SCs:
Recently, several examples have been reported
which demonstrate that these stem cells, under certain
conditions, can be induced to form other cell types. This
property is called plasticity. For example neural stem cells
(NSCs) can give rise to blood and skeletal muscle. Also
BM cells can give rise to muscle, liver cells, and astrocytes
(Kuehnle and Goodell, 2002)
Therefore, they are considered multipotent, since
they can produce mature cell types of one or more lineages.
What determines SC potency largely depends on intrinsic
properties of SCs provided by the niche, microenvironment
where SCs reside, (Baharvand, et al., 2007).
Plasticity is the ability of stem cells to expand their
potential beyond the tissue from which they are derived.
For example, Dental pulp stem cells develop into tissue of
the teeth but can also develop into neural tissue (Nosrat, et
al., 2004). There are at least 2 alternative pathways to be
kept in mind when discussing mechanisms of SC plasticity:
i- Tran's differentiation is the direct conversion of one
cell type to another completely different one(Shen, et
al., 2003), e.g. Tran's differentiation of pancreatic
cells into hepatic cells and vice versa (Priller, 2004).
ii- Cell fusion: ESCs can fuse in vitro with a very small
proportion of BM stem cells, the fusion product, seen
as a new cell type, expressed genes of both fusion
partners in various degrees. Here the chromosomes of
the fused cells mosaic, presenting as a
mixture of chromosomes of different origin
(Doyonnas and Blau, 2004).

- 70 -
Bone Marrow:
Bone marrow (BM) contains hematopoietic stem
cells (HSCs) and stromal stem cells (SSCs) that collaborate
in a reciprocal manner at all stages, leading to the
generation of different BM and bloodstream cell lineages
(Murphy, et al., 2005).Bone marrow contains at least two
kinds of stem cells, hematopoietic stem cells and stem cells
for non-hematopoietic tissues (Friedenstein, et al., 1974;
Chopp, et al., 2000).
Recently, multipotent adult progenitor cells
(MAPCs), was identified which differentiated in vitro into
cells of all three germ layers and contributed to most
somatic tissues when injected into an early murine
blastocyst (Jiang, et al., 2002). A phenotypically identical
cell was isolated from human BM (Reyes, et al., 2001). It is
unclear, however, whether such MAPCs decline with donor
age, a phenomenon that has been observed for the
hematopoietic (Geiger and Van Zant, 2002) and
the mesenchymal stem cell compartment from BM
(Mendes, et al., 2002).
Fig. (10): Hematopoietic & stromal SCs differentiation (Terese Winslow, 2001).

Role of Stem Cell Transplantation in the Treatment of Ulcerative Colitis

Role of Stem Cell Transplantation in the Treatment of Ulcerative Colitis

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Role of Stem Cell Transplantation in the Treatment of Ulcerative Colitis

Similar to Role of Stem Cell Transplantation in the Treatment of Ulcerative Colitis (20)

Recently uploaded

Recently uploaded (20)

Role of Stem Cell Transplantation in the Treatment of Ulcerative Colitis