Post-transfusion purpura is a life-threatening adverse reaction associated with a reduction in platelet counts below 10
x 109/L and bleeding. It usually occurs in women who, due to their pregnancies, have developed antibodies directed
against human platelet antigen (HPA), most often anti-HPA 1a. The case described by us concerned an 83-year-old woman
who received two units of red blood cells (RBC) due to severe secondary anemia. Seven days after the transfusion, she
developed skin symptoms of thrombocytopenic diathesis, gastrointestinal bleeding, and a reduced number of platelets
(3 x 109/L), and the patient’s serum (genotype HPA-1b/1b) was positive for anti-platelet antibodies with HPA-1a specificity
and directed against human leukocyte antigen (HLA) class I and class II antibodies, unresponsive to the lymphocytotoxic
test. Prompt diagnosis by our transfusion medicine consultant and the initiation of treatment with intravenous immunoglobulins
certainly shortened the duration of thrombocytopenia and bleeding, and possibly also saved the patient’s life.