title: Posttransfusion purpura. Report of a case with anti-P1A1 masked by HLA antibodies.
abstract: A case of posttransfusion purpura is reported in which the laboratory determination of the specificity of the causative antibody was initially confused by the presence in the patient's serum of HLA-directed antibodies. The patient was a multiparous 65-year-old woman with a previous history of blood transfusion. She developed the typical clinical features of posttransfusion purpura 8 days following the transfusion of 6 units of packed red cells. The patient was P1A1 negative, and her serum reacted strongly in a radiolabeled monoclonal antibody assay with both P1A1-positive and -negative platelets. Radioimmunoprecipitation demonstrated that the patient's serum contained antibodies both of anti-P1A1 and anti-HLA specificity. Western blotting of normal platelets incubated with the patient's serum verified that the anti-P1A1 antibody was directed against platelet membrane glycoprotein III.
authors.forename: R A
authors.initials: RA
authors.lastname: Dunstan
authors.forename: W F
authors.initials: WF
authors.lastname: Rosse
mesh_terms: D000368:Aged; D000918:Antibody Specificity; D001792:Blood Platelets / Q000276:immunology*; D005260:Female; D006023:Glycoproteins / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007518:Isoantibodies / Q000032:analysis*; D008565:Membrane Proteins / Q000276:immunology; D010980:Platelet Membrane Glycoproteins; D011693:Purpura / Q000209:etiology* / Q000276:immunology; D065227:Transfusion Reaction
chemical_list: D006023:Glycoproteins; D006680:HLA Antigens; D007518:Isoantibodies; D008565:Membrane Proteins; D010980:Platelet Membrane Glycoproteins