COOMBS Direct Test. Also Known As, DAT, Direct Anti-human Globulin Test.
To help diagnose the cause of hemolytic anemia as caused by autoimmune disease or induced by drugs; to investigate a transfusion reaction; to diagnose hemolytic disease of the newborn. The direct antiglobulin test (DAT) is used primarily to help determine if the cause of hemolytic anemia, a condition in which red blood cells (RBCs) are being destroyed more quickly than they can be replaced, is due to antibodies attached to RBCs. This may occur in autoimmune-related hemolytic anemias, which are caused by a person producing antibodies against their own RBC antigens (autoantibodies). Examples of this include autoimmune disorders such as systemic lupus erythematosus, malignant diseases such as lymphoma and chronic lymphocytic leukemia, and infections such as mycoplasma pneumonia and mononucleosis. It can also occur in some people with the use of certain medications, such as penicillin.
A DAT may be used to help diagnose hemolytic disease of the newborn (HDN) due to an incompatibility between the blood types of a mother and baby. When a baby is born, the mother may be exposed to the foreign antigens on the baby’s RBCs and may produce antibodies directed against the baby’s RBC antigens. This may occur when an Rh-positive baby is born to an Rh-negative mother. Formerly, antibodies to the Rh antigen were the most common cause of hemolytic disease of the newborn, but this condition is now rare due to preventive treatments given to the mother during and after each pregnancy. The most common cause of hemolytic disease of the newborn nowadays is an ABO incompatibility between a Group O mother and her baby. This type of fetal-maternal incompatibility is generally mild.
|Related Tests||RBC Antibody Screen; Blood Typing; Red Blood Cell Antibody Identification|