7. Have nuclei
Do not contain hemoglobin
Based on staining
Granular leukocytes
Neutrophils, eosinophils, basophils
Agranular leukocytes
Lymphocytes and monocytes
8.
9. The first evidence of an organism’s ability to fend off disease came from the
research of Russian zoologist, Elie Metchnikoff 1882
Metchnikoff’s theory of phagocytosis laid the foundation of one of the most
important aspects of innate immunity.
In late 1880s Paul Ehrlich first described neutrophils as polymorhponuclear
leukocytes new fixation techniques revealed lobulated nuclei and cytoplasmic
granules containing host-defense molecules.
10. Neutrophils are abundant in the circulation, present at a
concentration of 2x109 to 7x109 per litre and equal numbers are
marginated on vessel walls or sequestrated in closed capillaries.
The half-life in the blood is 6-7 hours and in the tissue it is
estimated to range from 1-4 days.
11. Neutrophils are so named because of their neutral staining with Wright stain. They
are also known as PMNs or polys or microphages.
They are round cells approximately 12-14 pm in diameter.
The multilobed nucleus contributes to the extreme elasticity of the cell, which is
important for the cell to make rapid transit from the blood through tight gaps in
the endothelium.
In 1904, Arneth introduced a method for classification of neutrophilic
granulocytes (six types) according to the number of nuclear lobes (40-50% being
with trilobed nucleus).
12. The blood and bone marrow form an abundant pool of cells and neutrophils
are recruited and called to the sites of infection and inflammation as and
when required on stimulation by a cytokine.
In the bone marrow, the myeloid precursor cells mature to segmented
neutrophils in about 9 days.
13. Four well-defined types of granules have been defined in
neutrophils, which are
azurophilic (Primary) granules
specific (Secondary) granules
(Tertiary) gelatinase granules
and secretory vesicles.
14. Matrix components:
Cellular
myeloperoxidase
Lysozyme
Heparin binding
protein
Defensins
Acid hydrolase
Glucorindase
Mannosidase
Matrix components:
Lysozyme
Alkaline phosphatase
Collagenase
Lactoferrin
LL 37
MMP 8
Matrix components:
Gelatinase
Cathepsin B and D
β-d- glucuronidase
α Manniosidase
Plasminogen activator
Membrane components :
CD 63
CD68
Membrane components :
CR 3
CR4
FML receptors
TNF r
Formyl peptide receptors
Membrane components:
Formyl peptide receptors
CD 11b
16. G‐CSF regulates mature neutrophil release from the bone marrow by interfering with the
CXCR4‐CXCL12 interaction.
Interleukin‐17 (IL‐17) granulopoiesis and neutrophil release by upregulation of G‐CSF.
IL‐17 builds on an interesting positive loop of neutrophil recruitment.
In chronic inflammation sites, neutrophils produce IL‐17 and can also attract
IL‐17‐producing CD4+ T lymphocytes (Th17 cells).
Neutrophils release CCL20 and CCL2 chemokines, which are ligands for CCR6 and
CCR2 chemokine receptors, respectively, on Th17 cells. This interaction maintains Th17
cells at inflammation sites. Therefore, Th17 cells secrete more IL‐17 and more
neutrophils are recruited
17.
18. The mature neutrophil is a highly specialized cell specifically equipped for the
destruction of microorganisms.
Adherence
Chemotaxis
Phagocytosis
Microbicidal activity
Oxidative Metabolism.
19.
20.
21. Adherence: When stimulated, the neutrophil interacts with, and sticks to,
substrate (endothelial cells) via specific molecules on the neutrophil and the
endothelial cell.
Chemotaxis — The granulocytes are attracted to the site of microbial insult in
response to specific chemotactic molecules such as complement proteins (C5a).
Phagocytosis — The neutrophil recognizes specific molecules on the bacterial
surface called opsonins (IgG, C3b) and engulfs the organisms via invagination of
the plasma membrane, which encloses the bacterium in a phagosome
22. In addition to the intracellular killing mechanisms, activated neutrophils possess
another powerful weapon in their armory-the neutrophil extracellular traps
(NETs)
This novel paradigm in innate immunity was discovered in 2004 by Brinkmann
et al. ETs are DNA-based net like fibers that mediate an antimicrobial function
outside the cell.
NET formation has been described as a novel cell death program. Steinberg and
Grinstein termed this novel cell death which is morphologically distinct from the
classical cell death program (apoptois and necrosis) as “NETosis”
23. Microbicidal activity- It is of 2 types
Intracellular killing and Extracellular killing
Intracellular killing:
The membrane of the phagosome fuses with those of cytoplasmic granules, resulting
in the discharge of granule contents into the phagosome, which is now termed a
phagolysosome.
The antimicrobial systems of the neutrophil include oxidative and non-oxidative
mechanisms that result in the death of the microorganism.
24. 1. Oxidative – by free radicals of O2
› i. MPO-dependent
› ii. MPO-independent
2. Oxidative – by lysosomal granules
3. Non-oxidative mechanisms
25. EXTRA CELLULAR Mechanisms:
Immune mechanisms
› Ab mediated lysis
› Cell mediated cytotoxicity
26. Extracellular killing:
The same enzymes and agents that are discharged into the phagosome may be
secreted into the extracellular microenvironment.
This may contribute to extracellular killing of bacteria, but has the disadvantage of
potential damage to adjacent cells and tissues as many of these enzymes are
histiolytic, such as collagenase, elastase, and the reactive oxygen species.
27.
28. Accumulation of plaque
in the dentogingival area
Recruitment of neutrophils
to the site via
transendothelial migration
and chemotaxis
Neutrophil:
The double
edged sword
Microbial
killing
mechanism of
neutrophils
Chronic
recruitment and
activation of
normal
neurophil
29.
30.
31. Leukocytes found in clinically healthy gingival sulci are predominantly neutrophils.
In healthy human gingival sulci, they are found to be 91.2% to 91.5% and
mononuclear cells are only 8.5 to 8.8%.
It is interesting to note that the main portal of entry of leukocytes into the oral
cavity is the gingival sulcus. The host reaction to gingival microorganisms is
characterized in part by an influx of polymorphonuclear neutrophils, considered to
be the first line of innate immunity.
32. Neutrophil recruitment requires adhesion to and transmigration through blood
vessel wall at the sites where the vascular endothelium is activated by pro-
inflammatory mediators.
Neutrophils will be stimulated to exit the gingival microvasculature, enter the
periodontal tissues and subsequently, migrate towards endogenous epithelial (IL-
8 and IL- 1beta) and serum-derived (plaque activated C5a) chemoattaractants and
then preferentially toward exogenous chemotactic signals (such as LPS and
fMLP) produced by plaque bacteria in the gingival crevice.
33. After emigration to the tissues, they never return to the bloodstream. They are
probably disposed of internally by cells of the reticuloendothelial system; however,
there are several routes of external neutrophil loss.
34.
35.
36. Periodontal pathogens have the capability to evade the host defense mechanisms.
The extracellular traps of neutrophils are an additional mechanism by which these
cells of innate immunity can fight back.
A study conducted by Vitkov et al., revealed an abundance of neutrophil
extracellular traps and some phagocytic neutrophils found on the gingival pocket
surface and in the purulent crevicular exudate. Trapping of crevicular bacteria
prevents their adhesion to and invasion of the gingival epithelium.
37.
38. Neutrophil priming was described by McPhail et al. in the early 1980s,
“the ability of a primary agonist, typically at substimulatory concentration, to
influence/enhance superoxide production triggered by a secondary stimulus.
A priming agent is a substance that by prior exposure enhances the response of a
neutrophil to an activating stimulus.
A 20-fold increase in the respiratory burst and release of superoxide anions in
response to a secretagogue agonist has been observed in a primed cell as opposed to
an unprimed cell
39. Two separate mechanisms have been proposed for priming.
Rapid priming occurs within minutes of being stimulated. The short duration of
response is as a result of transfer and release of preexisting intracellular granules
with preformed receptors to the plasma membrane.
Delayed priming takes more time as compared to rapid priming. Here, the
priming agent causes an activation of transcription factors which results in the
active synthesis of new protein molecules (including receptors and cytokines).
40.
41.
42. The tissue destruction found in periodontal disease results, for the most part, from
the actions of the immune system and related effector mechanisms.
Mediators produced as a part of the host response that contribute to tissue
destruction include proteinases, cytokines, and prostaglandins. Matrix
metalloproteinases (MMPs) are considered to be primary proteinases involved in
periodontal tissue destruction by degradation of extracellular matrix molecules.
MMPs are a family of proteolytic enzymes that degrade extracellular matrix
molecules, such as collagen, gelatin, and elastin. MMP-8 and MMP-1 are both
collagenases; MMP-8 is released by infiltrating neutrophils.
43. Conditions such as agranulocytosis, congenital or cyclic neutropenia, and leukemia
result in severe breakdown of oral tissues.
Tempel et al. have described the severe bone loss and gingivitis associated with the
Chediak-Higashi syndrome.
The "lazy leukocyte syndrome", a nonspecific series of case reports, is characterized by
stomatitis, gingivitis, and recurrent ulcerations.
Chronic granulomatous disease is associated with severe oral infection and rapidly
progressing periodontal disease.
44. There are conditions in which severe oral disease and neutrophilic defects have
been reported, such as in Papillon Lefevre Syndrome and Down's Syndrome,
LAD, Aggressive Periodontitis, Chronic Granulomatous Disease (CGD), and
Acquired Immune Deficiency Syndrome (AIDS).
45.
46.
47. It is a rare autosomal recessive disorder that primarily affects neutrophils.
Its genetic etiology manifests itself early in life in the form of partial oculocutaneous
albinism, photophobia, frequent pyogenic infections and lymphadenopathy.
Oral findings include severe gingivitis, ulcerations of the tongue and buccal mucosa,
and early onset periodontitis leading to premature loss of both deciduous and
permanent dentitions.
Dental pain, swollen gingiva with purulence, severe horizontal bone loss and
lymphadenopathy.
48. The syndrome was first described by Beguez-Cesar in 1943, but acquired its name 10
years later by Chediak in 1952 and Higashi in 1954.
The average lifespan for children with Chediak- Higashi syndrome is only 6 years.
The few individuals that do survive beyond the first decade often progress to a
lymphoma-like disease known as the accelerated phase.
This phase can include fever, jaundice, hepato-splenomegaly, and pancytopenia that
leads to an even greater susceptibility to infection.
49. One of the hallmarks of the Chediak- Higashi syndrome is the presence of large
intracellular azurophilic inclusions in the cytoplasm of neutrophils.
These large inclusions impair neutrophil migration, possibly by inhibiting cell
deformability, and render neutrophils unable to metabolize and digest microbes.
As a result, patients with Chediak- Higashi syndrome are prone to recurrent
infections in early childhood.
A mutation in the LYST(lysosome trafficking regulation) gene, the only known
Chediak-Higashi syndrome-causing gene.
Bone marrow transplantation appears to be the most effective treatment for
correcting these neutrophil abnormalities.
50. It is caused by congenital defects in the enzyme NADPH oxidase. The defect
prevents free oxygen radicals from being produced, and the neutrophil’s inability to kill
intracellular organisms predisposes patients to recurrent bacterial and fungal infections.
In about two thirds of the cases, chronic granulomatous disease occurs as an X-linked
recessive disease, while the remaining one third of cases are inherited in an autosomal
recessive fashion.
It usually presents in the first year of life with recurrent bacterial and fungal infections
including pneumonia, lymphadenitis, liver abscess, osteomyelitis, septicemia, and otitis
media.
51. The most common presenting feature is lymphadenitis, followed by skin abscesses
and pneumonia.
Treatment of chronic granulomatous disease centers on control of infections.
Interferon-g has been shown to partially restore oxidase activity in neutrophils and
monocytes of some patients with X-linked chronic granulomatous disease, and to
reduce infection rates.
Patients with chronic granulomatous disease had a significantly greater occurrence
of oral ulcerations and gingival inflammation.
52. It is a multisystem disorder inherited as an autosomal dominant trait that affects
the dentition, the skeleton, connective tissues, and immune system.
Classically, it has been characterized by a triad of symptoms including
› skin abscesses,
› pneumonia, and
› elevated serum immunoglobulin E levels.
Eosinophilia, candidiasis, arthritis, chronic eczematoid dermatitis and other
recurrent infections are also common.
Clinically, the appearance of the soft tissue lesions is rather unique.
53. Contributing to the high rate of recurrent infections in hyperimmunoglobulin E
patients is a defect in neutrophil chemotaxis. Three hypotheses exist for the
chemotactic defect in the neutrophils:
› A specific IgE against an infecting bacterium (S. aureus) causes the release of
histamine that may inhibit neutrophil chemotaxis.
› Bacterial antigens cause monocytes to secrete chemotaxis inhibiting mediators or
IgG.
› Mononuclear cells may create a specific factor which inhibits neutrophil
chemotaxis.
54. Treatment of HES is dependent upon antibiotics, local debridement, and surgical
incision and drainage of infections.
Oral findings in hyperimmunoglobulin E patients include ulcerations and gingivitis.
Failure to shed the primary dentition in this case, in contrast with the early loss of
primary teeth due to periodontitis seen in other disorders of host defenses, is
surprising.
55. It is defined as a low absolute neutrophil count for greater than 6 months.
The risk of infection due to neutropenia is typically inversely proportional to the
absolute neutrophil count. Specifically, the risk of stomatitis, gingivitis, and cellulitis
increases when the absolute neutrophil count <1000 cells/ml.
The frequency of more serious infections such as pneumonia, peri-rectal abscess, and
sepsis increases when the absolute neutrophil count <500/ml.
56. It is characterized by a prolonged noncyclic neutropenia as the sole abnormality, with
no underlying disease to which the neutropenia can be attributed.
It is usually not inherited; however, the familial form follows an autosomal dominant
mode of inheritance.(Glansslen 1941)
Most patients with chronic benign neutropenia will live a normal lifespan.
Individuals may suffer from increased incidences of recurrent oral ulcerations,
furuncles, upper respiratory infections, otitis media, cellulitis, lymphadenopathy,
pneumonia and sepsis as a result of the limited neutrophil response to infection.
57. Diagnosis of chronic benign neutropenia is made by a persistent absolute neutrophil
count <500/ml with a normal total white blood cell count due to elevated numbers of
lymphocytes and monocytes.
A possible causative agent for this condition is anti-neutrophil antibodies, typically
IgG, which have been found in 80–100% of patients tested.
Oral manifestations of chronic benign neutropenia include hyperplastic, edematous,
and fiery-red gingiva with areas of desquamation.
58. It is characterized by periodic recurring symptoms of fever, malaise, mucosal
ulcers, and possibly life-threatening infections related to the regular cyclical
fluctuations in the numbers of neutrophils.
The disease is transmitted via an autosomal dominant mode of inheritance.
It is caused by the periodic oscillations in both bone marrow production and release
of mature neutrophils, probably associated with the oscillation of other blood cells,
such as monocytes, eosinophils, lymphocytes, and platelets.
59. Oral conditions include recurrent gingivitis and aphthous lesions.
Analysis of the microbial flora found P. intermedia, Campylobacter rectus,
Capnocytophaga gingivalis, and Capnocytophaga sputigena.
Marked gingival inflammation, fever, oral ulcerations, otitis media, and upper
respiratory infections associated with cyclic neutropenia.
60. It is an inherited hematologic disorder manifesting in the first year of life and
characterized by severe bacterial infections.
The significant laboratory findings are an absolute neutrophil count of less than
2,000/ml and an arrest of neutrophil hematopoiesis at the promyelocyte/myelocyte
stage.
Treatment with antibiotics has more recently prolonged the lifespan of children
suffering from this disease.
Patients that survived infancy were affected by gingivitis, and most were noted to
have periodontitis with alveolar bone loss.
61. It is an uncommon complication of Rheumatoid arthritis, in which splenomegaly and
leukopenia are the major additional features.
Several mechanisms have been suggested to explain this phenomenon, including
› insufficient formation of neutrophils,
› reduced release of neutrophils from the bone marrow,
› shortened neutrophil life span, and
› excessive neutrophil margination.
The incidence of periodontitis is as at least as great in Felty’s syndrome patients as in
others with severe neutropenias and oral ulcerations and stomatitis.
62. It is an extremely rare disorder that manifests in both quantitative and qualitative
neutrophil defects.
It is characterized by recurrent infections due to both a deficiency in neutrophil
chemotaxis and a systemic neutropenia, while the phagocytic function of the
neutrophil remains intact.
Within the bone marrow, the quantity and morphology of the neutrophils are
normal.
Peripherally, however, there exists not only a severe neutropenia but also
functional defects of neutrophils with regard to chemotaxis and random migration.
63. Directional locomotion is thought to be dependent on microtubule assembly within
the neutrophil, while the random movement relies on actin/myosin-like
microfilaments associated with the cytoplasmic surface of the cell membrane.
The abnormal function of these microfilaments leads to a defect in cell
deformability, and this hinders the release of newly formed neutrophils from the
bone marrow.
Impaired random and directional motility leads to a diminished in vivo migration of
neutrophils into the tissue and to sites of inflammation.
64. High fever, cough, bilateral pneumonia, oral stomatitis and purulent skin abscesses.
Laboratory tests revealed a peripheral neutropenia, and impairment of both
neutrophil chemotaxis and random motility.
Painful stomatitis, gingivitis and recurrent ulcerations of the buccal mucosa and
tongue.
The prognosis for the dentition of patients with lazy leukocyte syndrome appears
poor.
65. It is a blood dyscrasia characterized by a decrease in or even the disappearance
of granular leukocytes (including neutrophils) in conjunction with peripheral
leukopenia.
Decreased production of granulocytes is usually due to bone marrow hypoplasia,
although drugs, chemicals, ionizing radiation, infection, vitamin deficiencies,
and bone marrow tumors can cause similar effects.
66. Patients often are febrile and may exhibit necrotizing, gangrenous lesions of
mucous membranes, to include oral, gastrointestinal, and vaginal membranes, but
without purulence.
Oral signs and symptoms include generalized, painful stomatitis, spontaneous
bleeding and necrotic tissue.
Radiographs generally reveal a progressive pattern of bone loss at an early age .
Depending on the cause and duration of the agranulocytosis, severe periodontitis
and tooth loss can be expected.
67. The name leukocyte adhesion deficiency was given to this condition by
Anderson & Springer in 1986.
The initial studies on leukocyte adhesion deficiency patients found a defect in
the neutrophil integrins CD11 and CD18.
Subsequent investigations into this disorder have identified two types of
leukocyte adhesion deficiencies, LAD-I and LAD-II. LAD-I is a disorder that
involves a deficiency in three membrane integrins.
68. CD18/C11a (LFA-1) binds to leukocytes and to endothelium via intercellular
adhesion molecules (ICAM).
CD18/CD11b (Mac-1) binds to ICAM and complement and facilitates
complement- mediated phagocytosis.
The deficiency of these integrins prevents the neutrophil from adhering to the
vessel wall at the site of an infection.
69. LAD-I is an inherited disorder that follows an autosomal recessive pattern
Patients presented with acute gingival inflammation of both primary and
permanent dentitions, as well as gingival proliferation, recession, tooth mobility,
and pathologic migration.
The primary teeth were lost by age 4 and either partial or total loss of the
permanent teeth occurred by age 13. Bone loss was evident by age 3, and reached
60% by age 8.
Histology of the gingival tissue showed a dense plasma cell infiltrate and the
marked absence of extravascular neutrophils.
70.
71. LAD-II was first described in 1992 by Etziomi et al. Only four cases have been
documented to this. Clinical and radiographic features:
› A) Acute inflammation including gingival proliferation, mobility, and pathological
migration of dentition.
› B) Characteristic fiery red marginal and papillary tissues and associated plaque and
calculus.
› C) Generalized severe bone loss of permanent dentition.
› D) Lateral cephalogram at age 14, post-extraction of remaining dentition, depicting
severe resorption of both maxilla and mandible
The neutrophil defect in LAD-II is of the sialyl-Lewis x glycoprotein (CD15s),
which allows neutrophils to attach to selectins (CD62E) on the endothelial
surface.
72. It is rare autosomal recessive disease described as a diffuse palmoplantar keratosis
associated with aggressive periodontitis of both primary and permanent dentitions.
Appears equally in males and females.
The two essential features of Papillon-Lefevre syndrome are
› Hyperkeratosis of the palms and soles (either diffuse or localized) and
› Generalized rapid destruction of the periodontal attachment apparatus resulting in
premature loss of both primary and permanent teeth.
73. Myeloperoxidase is a hemeprotein located in the azurophilic lysosomes of
neutrophils and monocytes.
The functional significance is its ability to oxidize chloride ions, which in the
presence of H2O2 leads to the production of the microbiocidal agent
hypochlorous acid (HOCl).
The myeloperoxidase– H2O2–Cl system represents the most efficient component
of the oxygen-dependent antimicrobial system of neutrophils, with effects against
a wide range of bacteria, fungi, and viruses.
74. Myeloperoxidase deficiency can be both congenital or acquired through
a number of conditions including
hematological neoplasms,
iron deficiency,
lead intoxication,
renal transplants,
severe infectious diseases, and
diabetes mellitus.
75. The pathological sequela of reduced neutrophil function in the oral cavity and the
mechanisms behind dysfunction have added to our understanding of infectious
diseases.
Numerous examples have been given, and the overriding conclusion must be that any
impairment of neutrophil function will lead to some degree of increased
susceptibility to infection.
Perhaps the tissue most sensitive to pathological changes in the oral cavity is the
periodontium.
76. In cases of severe neutrophil dysfunction, there is severe periodontal breakdown,
but also in cases of ‘'mild" neutrophil dysfunction, where there is no other
infection, such as in individuals with LJP, there is severe periodontal breakdown.
The molecular basis of neutrophil dysfunction is beginning to be understood in
individuals with LJP, LAD, CGD, and AIDS.
It is our hope that further research in this area will help to delineate the
pathogenesis of these and other oral diseases.
77. Guyton AC, Hall J E (1996): Resistance of the body to infection: Leukocytes,
granulocytes, the monocytes-macrophages system and inflammation, Chapter 33. In
Textbook Medical Physiology, 9th ed. WB Saunders Co., USA. Pages: 435-444.
Miyasaki KT (1996): Altered leukocyte function and periodontol disease, Chapter
10. In Clinical Periodontology, Caranza FA, Newman MG (Eds.), 8thed. WB
Saunders Co, USA. Pages: 132-149.
Charon JA et al (1985): Gingivitis and Oral ulceration in patients with neutrophil
dysfunction, J Oral Pathol, 14,150-155.
Shafers WG et al (1993): Chapter 14. In Textbook of pathology, 4`h ed. Pages: 719-
759.
Malcolm A (1994): Hematologic Diseases, Chapter 16. In Burket's Oral Medicine,
9'h ed. JB Lipincott Co, Philadelphia. Pages: 510-543
78. Genetic Susceptibility to Periodontal Disease, Carranza 12th edition
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