Significance of platelet-reactive antibody screening for patients facing frequent platelet transfusions

It is not clear whether platelet-reactive antibody screening is clinically significant for patients facing frequent platelet transfusions. On the basis of data from 96 patients who had been examined for platelet-reactive antibodies by the mixed passive hemagglutination method for a variety of reasons, we investigated the following three issues retrospectively: (1) the relationship between platelet-reactive antibodies and the occurrence of problems in platelet transfusions, such as refractoriness or nonhemolytic reactions; (2) the influence of a history of transfusion on the production of those antibodies; and (3) the effect of screening for those antibodies on the prompt administration of appropriate platelet components. More than half of the platelet transfusion-related problems were associated with platelet-reactive antibodies. For patients with a history of transfusion, the mean period before a clinical problem occurred with platelet transfusions was 9 days,compared with 66 days for those without such a history. Accordingly, during the period, patients with a history of transfusions received fewer units of platelets and had fewer donor exposures than did patients without such a history. On the other hand, most patients who had been screened in advance for those antibodies received appropriate platelet components without delay, whereas an average of 10 days was needed before those who had not been screened received compatible platelets. The patients who had not been screened were transfused with 68 units of random platelets on average during the period. When frequent platelet transfusions are anticipated, especially for patients with a history of transfusion, screening for platelet-reactive antibodies beforehand would be helpful for prompt administration of appropriate platelets, although problems, such as the cost of those platelets and the burden on donors, remain to be resolved.