Abstract

BACKGROUND:

Passive transfer of platelet (PLT) antibody by blood transfusion can lead to severe thrombocytopenia, bleeding, and an acute transfusion reaction.

CASE REPORT:

A 49-year-old male on warfarin developed thrombocytopenic bleeding within 2 hours of transfusion with a single unit of fresh-frozen plasma (FFP). The patient's PLT count on admission was 122 x 10(9) per L. Two hours after transfusion, PLT count has decreased to 5 x 10(9) per L. The patient's PLT antibody screen by solid-phase enzyme-linked immunosorbent assay was negative and his genotype was HPA-1a/1b. The donor's genotype was HPA-1b/1b and antibody screen revealed anti-HPA-1a. A lookback investigation identified another case of severe thrombocytopenia after FFP infusion 4 years previously. REVIEW OF LITERATURE: A literature review identified 19 cases of passive transfer of PLT antibody that resulted in thrombocytopenia. The PLT nadir of 7 x 10(9) per L was reached within 6 hours after transfusion with a median time to PLT recovery of 5 days. Transfusion was accompanied by an acute transfusion reaction in 30 percent of recipients. Approximately 75 percent of recipients developed thrombocytopenic bleeding. All cases involved a female donor with a history of pregnancy. High-plasma-volume components accounted for the majority of cases while anti-HPA-1a was the most frequently implicated antibody.

CONCLUSION:

Unexplained posttransfusion thrombocytopenia should be investigated to rule out passive transfer of PLT antibodies. Implicated donors should be deferred from subsequent donations. Switching to predominantly male plasma for transfusion may lead to reduction in cases of thrombocytopenia due to passive transfer of PLT antibody. Rational use of blood products may further reduce incidence of this complication.