Posttransfusion purpura: Therapeutic failure of Pl^Al‐negative platelet transfusion

Abstract

The effect of platelet type-specific transfusion in posttranfusion purpura is reported. Seven days after receiving 4 units of whole blood during total hip replacement a 69-year-old woman developed fulminant thrombocytopenic purpura. Her undiluted serum inhibited the clot retraction of PlAl-positive but not PlAl-negative blood. Anti-PlAl titer of her serum, determined by 51Cr platelet lysis technique, was 1:64. The serum had no lytic activity against platelet-rich plasma from two PlAl-negative donors. No anti-HLA antibody was detectable in the serum by lymphocytotoxicity technique, and serum obtained prior to transfusions had no platelet lytic activity. Four units of PlAl-negative platelet concentrate were administered, the first instance in which this treatment has been used. No rise in platelet count ensued, and the patient succumbed to purpura. Exchange transfusion or plasmapheresis remain the treatments of choice.

Elution of Anti-Zwa (-P1^A1) from Autologous Platelets after Normalization of Platelet Count in Post-Transfusion Purpura

“…In support of this hypothesis, material containing platelet membrane glycoproteins lib/ Ilia, known to carry the Zw and Bak antigens can be detected in normal human plasma and serum [28,29]: simi lar observations have been made by two other groups [27,30]. It has also been shown that during the acute phase of the illness, transfused Zwa-negative donor platelets are rap idly destroyed [31]. However, further experimental investi gations have to be done to confirm this hypothesis.…”

Posttransfusion Purpura Associated with an Anti-Bakb

“…However, since most cases are due to anti-Zwa and the Zwa antigen frequency is 97.5% in the Caucasoid population, one must assume that most ran dom platelet transfusions are incompatible. Lack of effi cacy has also been reported for Zwa-negative platelets in isolated cases [19], A similar situation was observed in patient Gn. The patient did not at all respond to platelet transfusions, neither to random nor to sibling prepara tions.…”

Posttransfusional Immunologic Thrombocytopenia

“…Once this has developed after a transfusion, it is question able if transfusions with PlAl-negative blood are useful, since the PlAl-negative donor platelets may also be destroyed. Gerstner et al [6] found that their patient continued to bleed, with fatal result, when they tried to treat PTTP by transfusion of PlAl-negative platelets, but the number of transfused pla telets may have been too small: it is well known that platelets from at least 4-6 units of blood are necessary to achieve a clinical effect in ordinary cases of acute hemorrhag ic thrombocytopenia. It may be helpful in the future to store frozen PlAl-negative pla telets from several donors to treat severe cases of PTTP.…”