Type II: Antibody Dependent Cytotoxic Hypersensitivity 

• Type II hypersensitivity is an allergic reaction due to the interaction of antibodies and cell associated antigens. 

 • When antibodies bind to the antigens located on the surface o cells, the cells become cytotoxic. Hence the name cytotoxic reaction

 In type II hypersensitivity IgG type antibodies are involved. 

 Eg. Agglutination and lysis of blood cells due to mismatched blood group,. transfusion. Erythroblastosis foatalis, Autoimmune hemolytic anemia, etc. 

 • Based upon the type of antigen involved in the reaction, cytotox hypersensitivity is classified into two types, namely: 

Isoimmune reactions 

Transfusion reactions Erythroblastosis foatalis Transplant rejection reactions.

 Autoimmune reactions are:

 Autoimmune hemolytic anemia

 Autoimmune thrombocytopaenic purpusa 

Autoimmune thyroiditisA

utoimmune glomerulonephritis. Mysthenia gravis.

• In cytotoxic reaction the cell damage occurs in anyone of the fol lowing methods: 

• Phagocytosis 
• Lysis. 
•  Killing.