Passenger lymphocyte thrombocytopenia due to human platelet antigen 3a antibodies: Case report and review of literature.

We report a case of severe acute thrombocytopenia occurring within days after a cadaveric liver transplant, received from a female patient with aplastic anemia who died of intracranial bleeding. The donor, who was homozygous for the ITGA2B*002 (HPA-3b) gene, had developed human platelet antigen (HPA)-3a antibodies, whereas the recipient was homozygous for the ITGA2B*001 (HPA-3a) gene. Thrombocytopenia responded to an infusion of immunoglobulin G. This is the first report of a passenger lymphocyte syndrome manifesting with thrombocytopenia due to anti-HPA-3a. We review the literature on thrombocytopenia in the setting of PLS and discuss the differential diagnosis.