Matching of histocompatibility (HL-A) antigens for platelet transfusion.

The average in vivo platelet survival was measured by both per cent recoveries (%R) and half-lives (t 1/2) of 51Cr-labeled platelets in 69 transfusions given to 43 thrombacytopenic patients. The results demonstrated that (1) increase in the number of HL-A incompatibilities in the platelet donor was significantly associated with decreased %R and t 1/2 of the infused platelets; (2) survival of transfused platelets from HL-A-matched single donors was consistently superior to those pooled from several grossly mismatched donors; and (3) survival of platelets infused when patients had circulating lymphocytotoxic antibodies was consistently lower than when patients did not have such antibodies, regardless of whether it was the first, second, or third such infusion.