This study will determine if transfusion of platelets containing HLA antibodies (certain antibodies to white blood cells) are more likely to cause transfusion reactions than transfusion of platelets that do not contain HLA antibodies.

People 18 years of age or older who donate platelets at the NIH Clinical Center may be eligible for this study.

An extra tube of blood (about one teaspoon) is obtained from participating donors at the time of their donation at the NIH Platelet Center. The blood plasma in the extra tube is tested for HLA antibodies and antibodies to certain white blood cells called granulocytes. The research sample is assigned a code number for identification and sent to the HLA Laboratory in the Department of Transfusion Medicine.

Leukocyte antibodies can cause febrile transfusion reactions, pulmonary reactions to granulocyte transfusions, and transfusion related acute lung injury (TRALI). Despite the fact that the role of leukocyte antibodies in these reactions was first described almost 50 years ago, and that TRALI is now the leading cause of transfusion related fatalities, much remains uncertain concerning the role of HLA antibodies in these reactions. The primary purpose of this study is to retrospectively and prospectively determine if the incidence and nature of transfusion reactions differs in Clinical Center (CC) patients that were transfused with platelet components from donors with HLA antibodies and those without HLA antibodies. In addition, this study will prospectively determine the incidence of HLA antibodies in the NIH Department of Transfusion Medicine (DTM) platelet donor population. In this natural history study a 10-mL blood sample will be drawn from 600 platelet donors at the time that they are in the DTM donating platelets and it will be tested for HLA antibodies in the DTM. The blood sample for HLA antibody testing will be collected with other samples collected as part of the regular platelet donation process. Reactions in platelet transfusion recipients will be assessed by reviewing CC and DTM patient records.

• INCLUSION CRITERIA:

  1. Both male and female donors
  2. Any ethnic group
  3. 18 years of age or older
  4. Must meet the criteria for donating platelets in the DTM

EXCLUSION CRITERIA:

1. Donors are not eligible to donate platelets in the DTM