Posttransfusion purpura. A survey of 13 cases.

Thirteen cases of posttransfusion purpura (PTP) which were diagnosed in Germany and Austria from 1977-1985 are described. All patients were women with a mean age of 58.6 years (range, 36-77 years). All but one had been pregnant and received blood transfusions 2 to 12 days prior to the onset of PTP. The thrombocytopenic purpura was always severe with a nadir of platelet counts below 10 X 10(9)/l and lasted between 3 and 60 days. All patients recovered from PTP. Optimal therapy consisted of administration of high-dose IgG. Twelve of the 13 patients had developed platelet-specific Zwa antibodies (eight of them together with HLA antibodies), in one Zwa positive individual only HLA antibodies were detectable. Five of six HLA-DR typed patients carried DR3 which is considered an immunogenetic risk factor in PTP. Clinical awareness of this rare, but serious iatrogenic transfusion complication is prerequisite for prompt diagnosis and improved therapy.