ANSWER: (D) Type IVREF: Immunology by David K. Male, Jonathan Brostoff, Ivan Maurice Roitt, David B. Roth page 477-478.See APPENDIX-21 for "HYPERSESSITIVITY REACTIONS""There are three variants of type IV hypersensitivity reaction - contact, tuberculin, and granulomatous. Both contact and tuberculin types develops within 72 hours while granulomatous develops between 21 to 28 days"APPENDIX - 21Hypersessitivity ReactionsTYPE 1:Allergy/Atopy/' AnaphylaxisTrue AnaphylaxisFree Ag - fixed IgE (on mast cell)Wheal and Flare reaction Casoni s test, anaphylaxis, prusnitz kunster reaction, Theobald smith phenomenon, Schultz dale phenomenon, Atopic dermatitis, Pseudoanaphylaxis (Anaphylactoid reaction)Free Ag - direct degranulation of mast cell (not IgE mediated)Iodine-containing radio contrast (me), aspirin and muscle reiaxants, morphineTYPE 2:AntibodydependentcytotoxichypersensitivityFree Ab - fixed AgIgM IgG/ComplementmediatedAutoimmune hemolytic anemiaHemolytic disease of the newborn (erythroblastosis fetalis)Autoimmune thrombocytopenic purpuraGoodpasture's syndrome: Pemphigus vulgarisBullous pemphigoid; Acute rheumatic feverPernicious anemia: Myasthenia gravis; Graves' diseaseADCC- antibody- dependent cell-mediated cytotoxicityAcute & chronic transplant rejectionTYPE 3: Immune complexFree Ag+ Free Ab - Immune complexSerum sicknessArthus reactionSystemic lupus erythematosus (SLE)Immunoglobulin therapyHyperacute graft rejectionAcute necrotizing vasculitisPolyarteritis nodosa Post streptococcal glomerulonephritisShick s testTYPE 4: Delayedhypersensitivity,cell-mediated,antibody-independentAg -T cell mediated (CD4/CD8)Delayed: CD4mediated .contact & tuberculin types with in 72 hours, Granulomatous type; 21-28 days]Contact dermatitis; Mantoux (tuberculin) testLepromin testChronic transplant rejectionMultiple sclerosisPhlyctenular keratoconjunctivitisJones mote reaction (cutaneous basophilic hypersensitivity)Direct cell toxicity:CD8 mediatedPerforin dependent killingFas-FasL dependent killingAlso know: Graft rejection is type 4 hypersensitivity unless type is provided. (Most of the MCQ guides have quoted this falsely)HyperacuteType 3AcuteType 4 >2 (both if provided)Acute cellular rejection = type 4 (better prognosis) Acute vascular rejection = type 2ChronicType 2