Autoimmune hemolytic anemia (AIHA) is a condition characterized by the destruction of red blood cells (RBCs) by the body's own immune system. AIHA can be divided into two categories: warm antibody AIHA (WAIHA) and cold antibody AIHA (CAIHA). The types are differentiated by the temperature at which the antibodies that cause the destruction of the RBCs are most active.
Warm Antibody AIHA
WAIHA is the most common type of AIHA. In WAIHA, the antibodies (IgG or IgM) that cause RBC destruction are most active at body temperature (37°C). The antibodies attach to the red blood cells and cause their destruction, leading to a decrease in the number of circulating red blood cells. This type of AIHA is usually caused by a combination of environmental and genetic factors, and is more likely to affect older adults. Treatment usually involves corticosteroids or other immunosuppressive drugs.
Cold Antibody AIHA
CAIHA is a rare type of AIHA. In CAIHA, the antibodies (IgM) that cause RBC destruction are most active at temperatures below normal body temperature (33°C). This type of AIHA is usually caused by an underlying infection, and is more likely to affect younger adults. Treatment usually involves the use of intravenous immunoglobulin and/or plasmapheresis.
The main difference between warm and cold antibody AIHA is the temperature at which the antibodies are most active. WAIHA is the most common type of AIHA and is usually caused by a combination of environmental and genetic factors. CAIHA is a rare type of AIHA and is usually caused by an underlying infection. Treatment for both types of AIHA usually involves the use of corticosteroids or other immunosuppressive drugs.
