3. Immunity ?
• The ability of an organism to resist a
particular infection or toxin by the action
of specific antibodies or sensitized white
blood cells.
10. LYMPHOCYTES
• Lymphocytes are the specialized cells that react in a
specific manner to antigens and elicit and propagate
immune responses.
• B cells, T cells, Natural killer cells.
• B cells- Antibody synthesis.
• T cells- 1. Cytotoxic T cells- Kill infected cells
2. Helper T cells- modulate immune response to
antigen
13. Immune Response
• Primary Response
• The primary immune response is the resultant response when
the immune system is exposed to an antigen for the first time
• Lag period present
• IgM mediated
• Secondary response
• The secondary immune response results if the immune
system is challenged with antigen after sensitization
• No lag period
• IgG mediated
14. Hypersensitivity Reaction
• When the immune mechanism results in injury to the
own body- its called hypersensitivity reaction.
• 4 types of hypersensitivity reaction
17. Type 3
• Immune complex reaction
• IgG
• Complement and phagocytes
• Eg- Serum sickness, SLE
18. Type 4
• Cell Mediated Hypersensitivity
• T cells
• Macrophages
• Contact dermatitis.
19. Clinical implications
1. Immunology of tonsils
2. Immunology of allergic rhinitis
3. Immunology of allergic fungal sinusitis
4. Immunology of autoimmune ear disease
5. Immunology of autoimmune thyroid diseases
6. Rheumatological disease.
7. Immunotherapy
20. Are tonsils important ?
• Heinrich Wilhelm Gottfried von Waldeyer-
Hartz
Described in 1884 about Waldeyers ring.
The tonsils are lymphoepithelial structures
that provide a protective immunological ring
at the openings of both digestive and
respiratory tracts
21. Immunology of Tonsils
• Tonsils are secondary lymphoid organs
• It generates antigen sensitized B cells
• Histologically tonsils are just like any other lymphoid
organ – with all active and differentiation stages of B
cells
22. What is the function of crypts ?
• Tonsils differ from other lymphoid organs in that it lacks
the afferent lymphatics
• Epithelial surface area of tonsils- 45cm2
• Crypts increase the surface area
295cm2.
23. How does antigen
sensitization occur ?
• Tonsils receive the antigen through their crypts
• At the base of these crypts are specialized transport
channels called M pores.
• Near these crypts are the langerhan like giant
cells(APC)
• These APC will match with MHC II T cells- which will
further activate the B cells and produce antibodies.
24. • Tonsils also produce IgA
• IgA acts as a mucosal antiseptic paint.
• This IgA combines with antigens , toxins either reduce
their absorption or render them harmless
• Tonsils also contain- Natural killer cells and provide
innate immunity
25. • Recurrent throat infection with Clinical no tonsils
enlargement in a paediatric age group ???
• BRUTONS disease, or any other dysglobulinaemia
26. Why does tonsils get inflamed ??
• During the activation of these immune cells there is
local release of inflammatory cytokines.
• PHYSIOLOGICAL INFLAMMATION
• This inflammations need not be always infective in
nature.
• LATE IMMUNE RESPONSE.
27. Does Tonsillectomy cause any
change in Immunity ??
• DONOVAN Et.Al study showed that activated B cells
population declined and the level of IgA secreted were
lower than normal levels of other immunoglobulins in
the same patient pre and post tonsillectomy
28. Allergic fungal sinusitis
• Caused by aspergillus and other fungi.
• The patients suffering from this has been found to have
immediate type of hypersensitivity to skin prick. And
raised IgE specific to Aspergillus.
• Hypothesised to be Type 1 or 3 hypersensitivity reaction
• Invasive forms of fungal sinusitis is noted in patient
with conditions that lead to reduced number of
immunoglobulins.
29. Allergic Rhinitis
• Incidence : 10-15%
• Type one hypersensitivity reaction.
• Degranulation of IgE-sensitized basophils and
mast cells, leading to mediator release.
• Histamine results in immediate reactions-
nasal obstruction, itching, sneezing-
Controlled with Antihistamines
• Delayed reactions due to T cells mediated
response is controlled with steroid
administrations.
30.
31. • Chronic allergen exposure tends to cause obstruction,
possibly via a continuing inflammatory response, with
less itch and sneeze and with posterior catarrh rather
than anterior rhinorrhoea
32. Autoimmune inner ear
disorders
• Old concept- inner ear is protected from systemic
immunoglobulin cause it is protected by the blood-
labrynthine barrier.
• Endolymphatic sac is the centre of immunological
activity of inner ear.
39. Hashimotos Thyroiditis.
• Autoimmune
• CTLA 4 (cytotoxic T lymphocyte Antigen 4)
• HLA DR5
• Assoc. with other autoimmune diseases like type 1 DM,
vitiligo, Pernicious anemia.
• Autoantibodies are present against- Thyroid peroxidase,
thyroglobulin and TSH receptors.
• Hypothesised to be Type IV reaction
41. Disease Autoimmune Disease
RA Rheumatoid factor, ACPA
SLE dsDNA, Sm, Ro (SS-A), La
(SS B), PCNA,
Vasculitis PR3, MPO
42. Relapsing polychondritis.
• HLA DR4 associated
• Predominantly affects the cartilage- Probably immune
response to collagen type 2.
•
43. • Laryngo-tracheal involvement: initial stages may
present with hoarseness of voice, tenderness of the
trachea. Later on may present with breathing difficulty
due to laryngotracheomalacia.
• Associated with Cardiac valvular pathology, Necrotizing
glomerulonephritis, joint deformity.
44. Behcets Disease
• Behçet's syndrome is a multisystem disorder presenting
with recurrent oral and genital ulcerations as well as
ocular involvement
• The etiology and pathogenesis of this syndrome remain
obscure
• Circulating autoantibodies against enolase of
endothelial cells, selenium binding protein and anti-
Saccharomyces cerevisiae antibodies
45. • The ulcers are usually painful, are shallow or deep with
a central yellowish necrotic base, appear singly or in
crops, and are located anywhere in the oral cavity.
• The ulcers persist for 1–2 weeks and subside without
leaving scars
46.
47. Sjogren’s syndrome
• Sjögren's syndrome is a chronic, slowly progressive autoimmune
disease characterized by lymphocytic infiltration of the exocrine
glands resulting in xerostomia and dry eyes.
• Enlargement of major salivary glands
• Xerostomia
• Dysphagia
• Lymphadenopathy
• Primary or secondary
• Non-organ-specific antigens (rheumatoid factors) and extractable
nuclear and cytoplasmic antigens (Ro/SS-A, La/SS-B).
48. Granulomatosis with Polyangiitis
(Wegener's)
• Granulomatous vasculitis of the upper and lower
respiratory tracts together with
glomerulonephritis.
• Paranasal sinus pain, purulent or bloody nasal
discharge, with or without nasal mucosal
ulceration.
• Nasal septal perforation, saddle nose deformity.
• Serous otitis media.
• Subglottic tracheal stenosis resulting from active
disease
49. • demonstration of necrotizing granulomatous vasculitis
on tissue biopsy
• antiproteinase-3 ANCA
50.
51. Immunotherapy
• It is the only treatment that can lead to a life-long
tolerance.
• Increases serum IgG1, IgG4 and Local IgA
• Specifically acts on T cells – Th1 activation is favoured
over Th2 cells.- DEVELOPS TOLERANCE
• IL10
52.
53. Indications of immunotherapy
• The primary indication is that of symptoms not
adequately controlled by avoidance measures and
pharmacotherapy.
• CI: Beta blockers, pregnancy, acute asthma.
54. • Started with low dose once a week
• Then dosage increased to reach the maintenance level- frequency
lowered once maintenance is attained
• 2 to 5 years
• At a time 6-10 allergens can be used.
• Lessening of symptoms may begin as soon as 12 weeks
• Patients who do not achieve symptomatic improvement after 1
year of immunotherapy should have it discontinued
55. Immunotherapy in head and
neck malignancy
• Used alone or in adjuvant with other modalities of
treatment.
• How they act ?
• Mark the cancer cells so that the immune system can
identify them as harmful
• Boost the immune mechanism to make it more effective
in the killing of cancer cells
56. Type of immunotherapy for
HNC
• Check point inhibitors: which disrupt the signals that
allow the cancer cells hiding from the immune system
• Cytokines: that promote and direct the immune
mechanism in a particular manner to kill the cancer
cells
• Vaccine which are used to activate the immune
mechanism as well to prevent certain cancers.
57. Immunotherapy in other areas
of ENT
• RIBOMUYL immunotherapy- a combination of antigen
derived from 3 most common bacteria affecting
paediatric age group. (Klebsiella pneumoniae,
Streptococcus pyogenes, haemophilus Influenzae)
• Dosage: 1 tablet/ sachet morning empty stomach for 4
consecutive days per week for 3 consecutive weeks.
• 1 tablet/ sachet morning empty stomach for 4
consecutive days in a month for 5 months.
58. Reference
• Scott brown 7th edition
• Ballengers 17th ed
• Harrison- textbook of internal medicine 17th ed
• Immunology in ENT- springers publication
