title: Post-transfusion purpura associated with alloimmunization against the platelet-specific antigen, Baka.
abstract: Post-transfusion purpura (PTP) with severe thrombocytopenia occurred eight days after transfusion in a 28-year-old woman and responded to treatment with prednisone and plasma exchange. In contrast to nearly all previously studied cases of PTP, the patient's platelets were PlA1-positive and anti-PlA1 antibody could not be detected in serum obtained during the thrombocytopenic episode. Her serum was found to contain an antibody specific for a recently described platelet-specific alloantigen, Baka, in addition to multiple HLA-specific antibodies. The patient's platelets, typed following recovery, were Baka-negative. These findings indicate that post-transfusion purpura can occur in association with alloimmunization to platelet-specific antigens other than PlA1. In performing the serologic studies, a close relationship and possible identity between Baka and another recently reported platelet antigen, Leka, was observed. A method for analyzing mixtures of cytotoxic platelet-reactive antibodies without separating the individual antibodies is described.
mesh_terms: D000328:Adult; D016824:Antigens, Human Platelet; D001787:Blood Group Incompatibility / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology*; D005260:Female; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D039661:Integrin beta3; D007518:Isoantibodies / Q000032:analysis*; D007519:Isoantigens / Q000276:immunology*; D017713:Platelet Transfusion; D011696:Purpura, Thrombocytopenic / Q000209:etiology* / Q000276:immunology; D013997:Time Factors; D065227:Transfusion Reaction
chemical_list: C044561:3a alloantigen, human; D016824:Antigens, Human Platelet; D006680:HLA Antigens; C061248:ITGB3 protein, human; D039661:Integrin beta3; D007518:Isoantibodies; D007519:Isoantigens