Immune complex mediated reaction
Ans. is 'c' i.e., Type III reactions Type III hypersensitivity o Type III hypersensitivity reaction is antigen-antibody immune complex mediated that are deposited in postcapillary venules of various tissues with subsequent complement fixation. o Immune complexes produce tissue damage mainly be eliciting inflammation. Type III hypersensitivity may be of two types A. Systemic or generalized Immune complex disease (serum sickness) - It occurs in three phases :? Phase I --> Formation of antigen - antibody immune - complex in the blood. Phase II --> Traveling of immune complex through blood and deposition in various tissues. Phase III ---> Induction of inflammation by immune complex. Generally, common sites of deposition of immune complex incude - Skin Joints Lungs Kidney Blood vessels B. Localized immune complex disease (Ahus reaction) Ahus reaction is a localized area of tisue necrosis resulting from acute immune - complex vasculitis, usually elicited in the skin.
Type I
Type II
Type III
Type IV