What type of reaction occurs during a transfusion of incompatible blood group?

What type of reaction occurs during a transfusion of incompatible blood group?

• A. Type I hypersensitivity
• B. Type II cytotoxic reaction
• C. Type III hypersensitivity
• D. Type IV hypersensitivity

Answer: (B)

During a transfusion of incompatible blood group, a Type II cytotoxic reaction occurs. This reaction is primarily mediated by immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies that react with antigens present on the surface of red blood cells. When a person receives transfused blood that has antigens which their own immune system recognizes as foreign, these antibodies bind to the transfused red blood cells. The binding of antibodies activates the complement system, leading to cell lysis and the destruction of the incompatible red blood cells. This process can result in serious complications, such as hemolytic transfusion reactions, which is characterized by symptoms like fever, chills, and, in severe cases, shock or acute kidney injury due to hemolysis. Other hypersensitivity reactions differ in their mechanisms. For instance, Type I hypersensitivity involves an immediate allergic reaction, typically mediated by IgE antibodies (such as in anaphylaxis), while Type III hypersensitivity is due to immune complex deposition and involves inflammation caused by these complexes. Type IV hypersensitivity involves delayed-type reactions mediated by T cells, not antibody-mediated destruction. Thus, the Type II cytotoxic reaction is specifically relevant to the destruction of cells occurring during transfusion of incompatible

During a transfusion of incompatible blood group, a Type II cytotoxic reaction occurs. This reaction is primarily mediated by immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies that react with antigens present on the surface of red blood cells. When a person receives transfused blood that has antigens which their own immune system recognizes as foreign, these antibodies bind to the transfused red blood cells.

The binding of antibodies activates the complement system, leading to cell lysis and the destruction of the incompatible red blood cells. This process can result in serious complications, such as hemolytic transfusion reactions, which is characterized by symptoms like fever, chills, and, in severe cases, shock or acute kidney injury due to hemolysis.

Other hypersensitivity reactions differ in their mechanisms. For instance, Type I hypersensitivity involves an immediate allergic reaction, typically mediated by IgE antibodies (such as in anaphylaxis), while Type III hypersensitivity is due to immune complex deposition and involves inflammation caused by these complexes. Type IV hypersensitivity involves delayed-type reactions mediated by T cells, not antibody-mediated destruction. Thus, the Type II cytotoxic reaction is specifically relevant to the destruction of cells occurring during transfusion of incompatible