Question

3. Explain the rationale for extensive use of corticosteroids in the treatment of autoimmune diseases and in the prevention of graft rejection.

Answer 1

Autoimmune disease involve the developement of antibodies and cell mediated immunity against the self antigens . These antibodies and reactive CD4 T cells cause damage to the antigen containing tissue by releasing an arsenal of cytokines.

Whereas In graft rejection , The host body T cells respond to antigen of donor's graft . This on activation cause damage to the tissue .

Corticosteroids benefit these condition By inhibhiting Phospholipase A2 which is responsible for Arachidonic acid formation. After it is inhibhited , No arachidonic acid is converted to Mediators of inflammation like prostaglandins , thromboxanes.

Futher it induces apoptosis of lymphocytes. It inhibhits the formation of transcription factors like NF-kb.. which induce the formation of IL-1 and AP-1 , thereby preventing inflammation and lymphocyte activation.