1. Hedayati Asl A.
Pediatrics Hematologist & Oncologist
BMT
MAHAK Children’s Cancer Hospital

3. • Direct action of chemo-radiotherapy
–Nausea, vomiting, diarrhoea, alopecia, pain
–Mucositis
–Haemorrhagic cystitis
• Endothelial dysfunction by conditioning
–Veno-occlusive disease / Capillary leak synd.
Thrombotic microangiopathy / Idiopathic
pneumonia syndrome / Engraftment syndrome
• Drug toxicity (CsA/FK, G-CSF, Antibiotics,)
• Infections
• Immune complications (GvHD, graft failure)

4. An understanding of the pathogenesis of this
reaction has been obtained via the study of
animal models of GVHD.
The basic requirements for the development
of this disorder were recognized as early as
the 1960s.

5.  Activated Donor T cells damage host
epithelial cells after an inflammatory cascade
that begins after the preparative regimen
 GVHD is the major barrier to successful
HSCT

7. Graft-versus-host disease is a direct result of
one of the principal functions of the immune
system: the distinction of self from non-self.
In an attempt to treat patients with severe and
life-threatening illnesses, immune cells may be
transplanted from a non-identical donor to the
patient.
These donor (eg, graft) cells may recognize
patient (eg, host) cells as foreign, thereby
initiating a graft-versus-host reaction which may
lead to GVHD .

10.  Characteristics:
 The graft must contain immunologically
competent cells.
 The host must possess transplantation
antigens that are lacking in the graft, thereby
appearing foreign to the graft; host cells
subsequently stimulate donor cells via these
specific antigenic determinants.
 The host must be incapable of mounting a
reaction against the graft for a period of time
sufficient to allow graft cells to attack the host.

11.  Since GVHD is primarily a T cell mediated
disease, this discussion of the pathogenesis of
the disorder consists of an overview of the
more important properties and interactions of a
transplanted T cell which may lead to the
disease.
 It is important to realize that additional
hematopoietic cells, such as natural killer cells,
also underlie the development of GVHD.

12.  Prior to discussing those aspects of T cell
function relevant to the pathogenesis of GVHD,
it is helpful to first briefly review the major
Histocompatibility Complex (MHC) or HLA (for
Human Leukocyte Antigens) in humans since
these molecules underlie the recognition of
antigen by T cells.
 The MHC is highly polymorphic from individual
to individual, and segregates in families in a
Mendelian codominant fashion.

13.  The genes of the HLA locus encode two distinct
classes of cell surface molecules, classes I and II.
 Class I molecules are expressed on the surfaces
of virtually all nucleated cells at varying densities,
while class II molecules are more restricted to cells
of the immune system, primarily B lymphocytes
and monocytes.
 There are three different class I (HLA-A, -B, -C)
and class II (HLA-DQ, -DR, -DP) antigens. HLA-A,
-B and -DR antigens appear to be the most
important loci determining whether transplanted
cells initiate a graft versus host reaction

16. DONOR RECIPIENT
 • Related/unrelated
 • HLA mismatched
 • Sex mismatched
 • Alloimmunisation
 • Source of stem cells
 • Age
 • Conditioning
 regimen
 • Prevention of GVHD
Incidence 10 to 80% (median ~ 40%)

17. Risk factors for the development of acute GVHD include :
 Degree of HLA disparity
 Increasing age of host
 Donor and recipient gender disparity
 CMV status of donor and host
 Intensity of the transplant conditioning regimen
 Peripheral blood stem cell versus bone marrow
transplantation
 Acute GVHD prophylactic regimen used

18.  Counterpart of graft
versus tumour
effect
 Acute <100 days
 May be lethal
 Chronic >100 days
 May be disabling

20.  Clinically significant acute graft-versus-host
disease (GVHD) occurs in 9 to 50 percent of
patients who receive an allogeneic
hematopoietic cell transplant (HCT) from a
genotypically HLA-identical sibling, despite
intensive prophylaxis with immunosuppressive
agents, such as methotrexate, cyclosporine,
tacrolimus, corticosteroids, or antithymocyte
globulin.

21.  Acute GVHD is also common in matched
unrelated donors and in haploidentical related
donors.
 Development of moderate (grade II) or severe
(grade III or IV) acute GVHD after HCT is
associated with a significant decrease in
survival. Furthermore, once acute GVHD
occurs, it may not be treatable.

22.  The skin, liver, gastrointestinal tract, and the
hematopoietic system are the principal target
organs in patients with acute GVHD

23. Epithelial cells of
 SKIN: keratinocytes
 LIVER: biliary ducts
 DIGESTIVE TRACT: enterocytes
« satellite cell necrosis »
(infiltrating immune cell + apoptotic cell)

25. Skin lesions in a patient with severe acute graft-versus-
host disease (GVHD). There is swelling, generalized
erythroderma, and bullous formation.

26. Graft versus host disease (GVHD)

27.  Anorexia, nausea
 Green watery diarrhea
 Abdominal pain, bloody diarrhea
 Gastro-duodenal biopsies

29.  Investigators at the University of Minnesota
have described acute GVHD of the upper
gastrointestinal tract characterized by anorexia,
dyspepsia, food intolerance, nausea, and
vomiting.
 This syndrome was verified by positive upper
endoscopic biopsies of the esophagus and
stomach.

31.  Cholestatic hepatopathy…
(other causes of hepatopathy: toxicity,
infection, VOD…)
 Other symptoms
Fever, eosinophilia …..

32.  Hepatic involvement is manifested by abnormal
liver function tests, with the earliest and most
common finding being a rise in the serum
levels of conjugated bilirubin and alkaline
phosphatase.
 This reflects the pathology associated with
liver GVHD: damage to the bile canaliculi,
leading to cholestasis.

33.  However, a rise in the serum concentration of
bilirubin or alkaline phosphatase is nonspecific.
 In this setting, the most common confounding
disorders include:
 Hepatic veno-occlusive disease, which is a
relatively common toxicity associated with the use
of high dose therapy.
 Hepatic infections (primarily viral hepatitis).
 Effects from the preparatory regimen.
 Drug toxicity, including the drugs used for GVHD
prophylaxis (cyclosporine and/or methotrexate).

34.  Although less common, acute GVHD can affect the
hematopoietic system. Early studies reported that the principal
focus of the graft-versus-host reaction occurred in the lymphoid
organs of the host. Immune competence was therefore
affected, leading to frequent and possibly fatal infectious
complications.
 In murine models, acute GVHD can affect hematopoiesis,
leading to a reduction of precursor hematopoietic cells but not a
clear decrease in peripheral blood counts . In humans, the
effect of GVHD on the hematopoietic system is usually not
dramatic. Persistent thrombocytopenia is a frequent
manifestation and a profound drop in the serum concentration
of immunoglobulins (such as IgA) may be observed.

35.  The development of thrombotic
microangiopathy following HCT has been
shown to adversely affect the survival of
patients with acute GVHD.
 Acute GVHD may also result in decreased
responsiveness to active immunization. One
study, for example, found a less effective
immune response to polio vaccination in
patients with GVHD.

36.  With acute GVHD, the induction of
autoimmune disease occurring in association
with autoantibody production may require the
expression of particular class II haplotypes.
 In a murine model of GVHD, for example, the
onset of lupus-like nephritis in animals
producing pathogenic IgG antinuclear
antibodies was dependent upon the MHC
haplotype expressed by the recipients.

37.  There are isolated case reports of patients with
acute and/or chronic GVHD who develop
nephrotic syndrome due to membranous
nephropathy.
 Most patients have had stabilization in renal
function and significant reductions in protein
excretion after therapy with steroids and/or
cyclosporine.

42.  Acute GVHD has been traditionally (and
arbitrarily) defined as a syndrome occurring during
the first 100 days following HCT, with neutrophil
engraftment assumed as a condition for the
diagnosis.
 Early onset or hyperacute GVHD, which was
originally seen in allogeneic HCT recipients who
did not receive GVHD prophylaxis, has been
described as a clinical syndrome that can occur at
any time following allogeneic infusion, independent
of neutrophil engraftment, and has been
associated with the use of alternative HCT donors.

43.  The most severe form of hyperacute GVHD
was described after haploidentical HCT, and
consisted of fever, rash, and massive
noncardiogenic pulmonary edema, often with
renal failure and seizures

44.  Clinical evaluation
The diagnosis of acute GVHD can be readily
made on clinical grounds alone in the patient
who presents with a classic rash, abdominal
cramps with diarrhea, and a rising serum
bilirubin concentration within the first 100 days
following transplantation.

45.  Histologic confirmation may be helpful to
corroborate a clinical impression of possible
acute GVHD.
 The skin and gastrointestinal tract are relatively
easy to biopsy.

46.  As previously mentioned, percutaneous liver
biopsy poses a significant risk of major
bleeding since most patients are
thrombocytopenic at the time of GVHD.
 Percutaneous transjugular liver biopsy is a
safer alternative if it can be adequately
performed.

47.  Analysis of the pattern of plasma and urine
polypeptides using proteomics has shown promise
in enabling early diagnosis of acute GVHD .
 As an example, it has been proposed that a panel
of markers including Interleukin-2 receptor-alpha,
tumor necrosis factor receptor-1, Interleukin-8, and
hepatocyte growth factor can confirm the diagnosis
of acute GVHD at the onset of clinical symptoms
and provide prognostic information independent of
GVHD severity

49.  An early study in experimental animals and
human subjects with biopsy-proven intestinal
GVHD has suggested that imaging of the colon
via 18F-FDG PET scanning may be a sensitive
and specific technique for distinguishing
intestinal GVHD from other competing
diagnoses.

50.  The presence of GVHD remains the most important
post-transplant factor influencing outcome following
allogeneic HCT. For the period from 100 days to 3
years post-transplant, hazard ratios (HR) for
transplantation-related mortality (TRM) increased with
increasing grades of acute GVHD:
 Grade 0 acute GVHD — hazard ratio (HR) for TRM:
1.0
 Grade I — HR 1.5 (95% CI 1.2-2.0)
 Grade II — HR 2.5 (95% CI 2.0-3.1)
 Grade III — HR 5.8 (95% CI 4.4-7.5)
 Grade IV — HR 14.7 (95% CI 11-20)

51.  Conversely, increasing degrees of acute GVHD
reduced the risk of relapse:
 Grade 0 acute GVHD- hazard ratio (HR) for
relapse 1.0
 Grade I — HR 0.94 (95% CI 0.8-1.2)
 Grade II — HR 0.60 (95% CI 0.5-0.8)
 Grade III — HR 0.48 (95% CI 0.3-0.8)
 Grade IV — HR 0.14 (95% CI 0.02-0.99)

54.  Can GVHD be prevented? (without an
increase of relapse risk)
 What is the best 1st line therapy?
 Is it possible to predict the response to
therapy and to avoid evolution to higher
grades of aGVHD?
 What about 2nd line treatments?
 Can we improve immune reconstitution?

55.  Conditioning therapy activates host
tissues: reduced intensity conditioning
regimen??
 Donor T cell response: depletion or
inactivation of donor T cells +++
 Effector stage ? To block cytokines???
(mainly used in Tt rather than in prophylaxis)
Target: the 3 phases of aGVHD?

60.  Corticosteroids as first line treatment of
•Why?
 Broad inhibition of major mechanisms involved
in GvHD:
 T cell apoptosis
 Cytokine suppression
 Interfering with other cells like macrophages
•Dose?
 1 vs 2 mg/kg vs higher doses

61.  « High dose » steroids 2 mg/kg:
primary Tt for more than 25y
 Questions:
Higher dose?
Lower dose?
 1st line combination of steroid +
 other IS treatment?
1st line treatment

63. •Early response is essential
•Drugs and antibodies:
–Uniform response rates 30-50%,
high rate of
infectious complications
–Drugs:
•MMF; Pentostatin; Rapamycin
–Antibodies:
•ATG, Thymoglobulin, Campath, Etanercept

65. • Poor prognosis of steroid-refractory AGVHD
• Many IS agents are active…but predispose to
infections+++
• Lack of uniform criteria of response to
various therapies
• Initial control of AGVHD is critical

66. • Intensified infection prophylaxis ++++
(viral, bacterial and mycotic infections
are the most common causes of death
in patients with severe aGVHD)
• Nutritional support, replacement
therapy of enteral losses of fluids...
• Bone mineral retention and repair
• Pain control

67. Thank you
… … ..for your attention
… … ..for your patience
… … ..for your cooperation
within the SCT team… … ..for your
participation in clinical
trials
aiming to improve
GvHD diagnosis,
prophylaxis and
treatment