POSTTRANSFUSION PURPURA-LIKE SYNDROME-ASSOCIATED WITH CD36 (NAK(A)) ISOIMMUNIZATION

Background: CD36 deficiency, which could lead to CD36 isoimmunization, has been reported in the Japanese population. CD36 isoantibody has been involved in platelet transfusion refractoriness. Case Report: A 50-year-old woman originally from Corsica developed severe acute thrombocytopenia after massive transfusion. She was found to be CD36 deficient, and platelet immunoassays revealed a CD36 (Nak(a)) platelet isoantibody. Although the involvement of another mechanism could not be entirely ruled out, the thrombocytopenia was attributed to posttransfusion purpura-like syndrome. The antibody was also involved in platelet transfusion refractoriness. CD36 deficiency was present in two members of the patient's family as well. Flow cytometry studies demonstrated the absence of CD36 expression on the surface of blood monocytes and cultured erythroblasts and megakaryocytes from one of the two CD36-deficient family members studied, but, in the absence of previous immunization, these CD36-deficient patients were not isoimmunized. In contrast, CD36 deficiency was not found in a population of 808 healthy blood donors in the Paris, France, area. Conclusion: CD36 isoantibody might be involved in some cases of posttransfusion purpura and platelet transfusion refractoriness. These findings also confirm the extremely low frequency of CD36 deficiency among whites.