Frequently Asked Questions (FAQs)
The Direct Coombs Test (DCT) is used to detect IgG antibodies or complement components on the RBC surface membrane. It is useful in diagnosing autoimmune hemolysis hemolytic diseases of the newborn drug-induced hemolysis and hemolytic transfusion reactions. A positive DCT indicates the presence of red cell autoantibodies, alloantibodies following transfusions or of coating of red cells with excess immunoglobulins. It requires additional workup to elucidate the etiology of the immunoglobulins by performing tests for antibody specificity. A negative DCT does not rule out hemolysis. For instance, DCT is negative in some cases of drug-induced hemolytic anemias, hemoglobinopathies, hereditary spherocytosis and other hereditary hemolytic anemias.