Selection of Unrelated Compatible Platelet Donors by Lymphocyte HL-A Matching

Abstract

Thrombocytopenic patients who are refractory to transfusions of platelets obtained from random donors will respond to platelets from HL-A-identical siblings. The efficacy of using HL-A lymphocyte typing to select unrelated compatible platelet donors, however, has not been well documented. In this study, three patients who were not responding to random donor platelets were transfused with platelets obtained from selected unrelated persons matched for HL-A. The median response in circulating platelets (increment times body-surface area per unit) measured at 20 hours was 11.2, 9.1 and 17.0 (X 10³) as compared to 0, 0 and 2.2 (X 10³), respectively, to nonmatched platelets. These observations indicate that alloimmunization in multi-transfused patients is primarily due to HL-A antigens and that lymphocyte HL-A typing can be used to select unrelated compatible platelet donors for refractory patients.