This document discusses different types of hypersensitivity reactions and their mechanisms. It describes Type I reactions mediated by IgE antibodies on mast cells and basophils, Type II reactions involving antibody-mediated cell damage or lysis, and Type III reactions caused by antibody-antigen complexes depositing in tissues. Treatment involves removing allergic triggers, using mast cell stabilizers, corticosteroids, leukotriene inhibitors, and immunotherapy. Allergens that commonly cause reactions include house dust, mite feces, animal dander, pollens, and molds.

1. The Cell-Mediated Immunity.
Hypersensitivity: classification, the
Mechanisms of Development,
Prophylaxis and Treatment
Svitich Oxana Anatolievna

2. differentiation of T cells…

9. МНС

10. MHC (HLA)
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15. The Cell-Mediated Immunity

19. Hypersensitivity: classification, the
Mechanisms of Development

21. Type I hypersensitivity

22. • The IgE-antigen reaction occurring on the
surface of basophils and mast cells leads to
receptor cross-linking and degranulation
(histamine and serotonin), which collectively
cause of vasodilation, increased vascular
permeability ets.
• These reactions can affect a single tissue or
organ (as in asthma) or multiple ones (as in
generalised anaphilaxis).

24. Type II hypersensitivity
• Unlike Type I reactions, Type II hypersensitivity is caused by
direct antibody-mediated cell damage or lysis.
• (i) complement-dependent red blood cell lysis, for example as
a result of haemolytic transfusion reactions (HTR).
• (ii) antibody-dependent red blood cell degradation (Rh
incompatibility).
• (iii) antibody-dependent cell-mediated cytotoxicity (ADCC),
which occurs when cytotoxic antibodies become fixed on the
surface of cytotoxic T cells and subsequent antigen binding
induce perforin-dependent cell lysis of the cell bearing the
antigen.

25. Type III hypersensitivity
• Type III hypersensitivity reactions are caused by
antibody-antigen complexes. When significant quantities
of such immune complexes are formed, they can deposit
in tissues and lead to a tissue reaction which is initiated
by complement activation and leads to mast cell
degranulation and an inflammatory reactions caused by
the activation of these cells.

31. Treatment
• Removal or avoidance of allergic triggers
• Mast cell stabilizers
• Anti-inflammatory corticosteroids and
leukotriene inhibitors
• Immunotherapy (desensitization)

32. thank you for attention

34. • Методы лабораторной диагностики
аллергии : выявление уровня сывороточных
IgE, циркулирующих и фиксированных
(тканевых) иммунных комплексов,
провокационные и кожные пробы с
предполагаемыми аллергенами, выявление
сенсибилизированных клеток тестами in vitro
— реакция бласттрансформации лимфоцитов
(РБТЛ), цитотоксические тесты и др.

35. Allergens
• By definition, an allergen induces type I IgE-mediated or
type IV T-cell–mediated immune responses. Allergic
triggers are almost always low molecular weight proteins;
many of them can become attached to airborne particles.
• Allergens that most commonly cause acute and chronic
allergic reactions include
• House dust
• Mite feces
• Animal dander
• Pollens (tree, grass, weed)
• Molds