1. Hypersensitivity Reactions

2. Injurious, patologic immune reactions causing tissue injury and disease Excessive or aberrant immune response to: Foreign antigens (non-self) - non-infectious (environmental) - infectious Self (autologous) antigens failure of self-tolerance (autoimmunity, autoimmune diseases)

3. Types of Hypersensitivity Reactions Type I Type II Type III Type IV Antibody mediated T cell mediated

4. Type II and type III (comparison)

5. Type II hypersensitivity animation Type II (Antibody-mediated diseases) (Cytotoxic type)

6. Effector mechanisms

10. Graves disease

11. Myasthenia gravis

12. Antibody-mediated diseases

13. Type III (immune complex-mediated diseases) Type III hypersensitivity animation

14. Effector mechanisms

17. Immune complex diseases

18. Serum sickness

19. Therapy Reduction fo inflammation (corticosteroids) Plasmapheresis (reduction of circulating antibodies and immune comoplexes) Anti-CD20-antibodies (reduction of B cell number) Inhibition of auto-antibody production (CD40L antagonists)

20. Type IV (Delayed-Type Hypersensitivity - DTH) Type IV hypersensitivity animation

21. Effector mechanisms

22. T cell-mediated diseases

23. Clinical manifestation of contact dermatitis

24. Reduction of inlammtaion (corticosteroids and TNF antagonists) T cell response inhibition (cyclosporin) Antagonists of costimulation Therapy