Unrecognized causes of platelet transfusion failure in the presence of anti-HL-A antibodies.

When in a patient who is receiving random donor platelet infusions there is an inadequate rise in platelet count and anti-human HL-A antibodies are noted in the serum, it is natural to assume that platelet destruction results from an immunologic cause. Nonimmunologic causes of such failure do occur, however. Two of the most common are disseminated intravascular coagulation and splenomegaly.