Coombs', Direct (DAT)

Detect in vivo coating of IgG and/or complement components on RBCs.

The presence of potent cold autoagglutinins may interfere with test interpretation. Testing performed using clotted blood specimens may yield false-positive results with anticomplement.

Positive direct antiglobulin tests are associated with a variety of conditions which include hemolytic transfusion reaction, autoimmune hemolytic anemia, hemolytic disease of the fetus/newborn, and may be secondary to certain pathological conditions or drug therapy. Note: The presence of a positive direct antiglobulin test does not necessarily correlate with a pathological condition.

Fung MK, Grossman JB, Hillyer CD, Westoff CM, eds. AABB Technical Manual. 18th ed. Bethesda, Md: American Association of Blood Banks;2014.