The clinical impact of platelet refractoriness: correlation with bleeding and survival

Despite supportive care with platelet (PLT) transfusions, bleeding complications occur in a substantial number of patients with thrombocytopenia due to cytotoxic therapy. Moreover, refractoriness to PLT transfusions remains a frequently encountered problem. The clinical impact of PLT transfusion failure was investigated in 117 patients, part of a randomized PLT transfusion trial, which excluded patients with HLA and/or HPA alloantibodies.

Between October 2003 and April 2005, a multicenter randomized controlled trial, testing the clinical efficacy of PLTs stored in plasma compared to PLT additive solution (PAS II), was performed. Using multiple regression analysis of observational data of patients randomized in one of the participating centers, the occurrence of PLT transfusion refractoriness was analyzed for a relation with bleeding complications and patient survival.

PLT transfusion failure occurred at least once in 49.6 percent of the patients. Mild to moderate bleeding complications occurred in 19 percent of the patients. PLT transfusion failure was, independently from thrombocytopenia, positively associated with bleeding complications (odds ratio, 3.4; 95% confidence interval, 1.1-11). Moreover, patients experiencing one or more 24-hour PLT transfusion failures had, compared to patients always showing a sufficient 24-hour increment, a significantly reduced median survival of 491 days (interquartile range [IQR], 156-858 days) versus 825 days (IQR, 355-996 days), respectively. In a Cox regression model, the effect on survival was independent of therapy, diagnosis, and age.

Our results suggest that PLT transfusion failure might be a sensitive clinical marker for the occurrence of bleeding and impaired patient survival. PLT transfusion failure, bleeding complications, and decreased survival could be manifestations of a more severe degree of endothelial damage.