Which type of immune responses responsible for caseation necrosis in TB?-: (A) Cell-mediated immunity, (B) Antibody mediated reaction, (C) Allergic reaction, (D) Immune complexes
Answer is A. Type 4 or delayed hypersensitivity or T cell mediated reaction is an immune response without formation of antibodies but is instead a slow and prolonged response .examples:reaction against mycobacterium infection ,virally infected cell,malignant cells and organ transplantation.Harshmohan textbook of pathology 7th edition