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Transforming growth factor beta is increased in plasma of patients with hematologic malignancies after transfusion of platelet concentrates

BACKGROUND: Transforming growth factor beta 1 (TGF‐beta 1) acts as a potent inhibitor of bone marrow proliferation. High concentrations were found in human platelets, which release this cytokine during storage. STUDY DESIGN AND METHODS: TGF‐beta 1 levels during a storage period of 5 days were compared in the plasma of platelet concentrates prepared by apheresis or by the buffy coat method. In addition, TGF‐beta 1 plasma levels were monitored in patients with hematologic malignancies before and after transfusion. RESULTS: TGF‐beta 1 levels in the supernatant of platelet concentrates were found to be 55 times higher than those in the plasma of healthy volunteer donors. During storage, an additional increase was observed. Accordingly, the transfusion of platelet concentrates resulted in a significant increase of plasma TGF‐beta 1 levels in patients with hematologic malignancies (before transfusion: 2.2 +/− 0.5 ng/mL; after transfusion: 2.9 +/− 0.6 ng/mL), and these higher levels persisted for at least 4 hours. CONCLUSION: Because TGF‐ beta 1 reduces the clonogenic capacity of hematopoetic progenitor cells, a myelosuppressive effect of platelet transfusions is suggested.