Platelet Transfusions: Shortened Survival of HL‐A‐Identical Platelets aud Failure of in vitro Detection of Anti‐Platelet Antibodies after Multiple Transfusions

In a case of congenital thrombasthenia the survival of transfused platelets was found to be extremely shortened. Although no isoimmune‐antibodies could be detected by available immunologic techniques, such antibodies must be postulated as being responsible for the elimination of the donor platelets, since survival of the patient's own platelets is normal. The antibodies do not seem to be directed against an antigen of the HL‐A type since the survival time of the thrombocytes from an HL‐A‐identical sibling is equally shortened.