<P> Coombs tests are performed using RBCs or serum (direct or indirect, respectively) from venous whole blood samples which are taken from patients by venipuncture . The venous blood is taken to a laboratory (or blood bank), where trained scientific technical staff do the Coombs tests . The clinical significance of the result is assessed by the physician who requested the Coombs test, perhaps with assistance from a laboratory - based hematologist . </P> <P> The direct Coombs test (also known as the direct antiglobulin test or DAT) is used to detect if antibodies or complement system factors have bound to RBCs surface antigens in vivo . The DAT is not currently required for pre-transfusion testing but may be included by some laboratories . </P> <P> The direct Coombs test is used clinically when immune - mediated hemolytic anemia (antibody - mediated destruction of RBCs) is suspected . A positive Coombs test indicates that an immune mechanism is attacking the patient's own RBCs . This mechanism could be autoimmunity, alloimmunity or a drug - induced immune - mediated mechanism . </P> <Ul> <Li> Hemolytic disease of the newborn (also known as HDN or erythroblastosis fetalis) <Ul> <Li> Rh D hemolytic disease of the newborn (also known as Rh disease) </Li> <Li> ABO hemolytic disease of the newborn (the direct Coombs test may only be weakly positive) </Li> <Li> Anti-Kell hemolytic disease of the newborn </Li> <Li> Rh c hemolytic disease of the newborn </Li> <Li> Rh E hemolytic disease of the newborn </Li> <Li> Other blood group incompatibility (RhC, Rhe, Kidd, Duffy, MN, P and others) </Li> </Ul> </Li> <Li> Alloimmune hemolytic transfusion reactions </Li> </Ul>

What happens if indirect coombs test is positive