[Posttransfusion thrombocytopenic purpura. 1st case described in Spain].

Following a total blood transfusion, a 65 year old woman suffered severe thrombocytopenia characterized by purpura and haemorrhage. An immunological study revealed the existence of IgG and IgM type antibodies in the serum attached to the patient's platelets and to the eluate obtained from these. The specificity of the antibody was Zwa. The patient's platelets are Zwa-negative. Even in the remission phase of the thrombocytopenia it was still possible to obtain antibodies in the platelets of the eluate. Questions raised by this factor are discussed and, despite the difficulties posed, an attempt is made to find a coherent immunological explanation based on the results of the serological study.