Autoantibodies are immunoglobulins directed against self antigens. Most autoantibodies react with high-incidence red cell antigens. Recognition of these antibodies is important during serologic testing.
Autoantibodies may complicate routine testing by causing ABO and Rh typing problems.
AIHA is usually confirmed by a positive direct antiglobulin test (DAT) and demonstration of the autoantibody in the plasma or eluate.
AIHA is classified as either cold-reactive or warm-reactive. The table above lists different types of AIHA and the antibody classes involved. These will be discussed in detail on the following pages.
|Autoimmune Hemolytic Anemia||Antibody Type||Complement Association|
|Warm Autoimmune Hemolytic Anemia (WAIHA)||IgG autoantibodies||Sometimes|
|Cold Agglutinin Syndrome (CAS)||IgM autoantibodies||Yes|
|Mixed-Type (Serological features of both warm and cold autoantibodies)||Both IgM and IgG autoantibodies||Yes|
|Paroxysmal Cold Hemoglobinuria (PCH)||IgG biphasic hemolysin||Yes|