Impaired platelet function among platelet donors

Background: Platelet transfusions are effective for the prevention and trea tment of bleeding in patients with disorders of platelet number and/or func tion. In recent years plateletpheresis concentrates have outnumbered pooled platelet concentrates, albeit with significant differences between nations . Thus, the platelet quality of individual donors has become increasingly i mportant. The aim of this study was to gain an estimate for the prevalence of unpaired platelet function among platelet donors. Study design and metho ds: We determined the interdonor variability in platelet plug formation wit h a PFA-100 analyzer, the prevalence of impaired thromboxane formation, and effects of the density, in alpha2 integrin polymorphism and density, Resul ts: (i) Collagen-epinephrine induced closure time (CEPI-CT) showed a great inter-subject variability in platelet donors and was higher than in healthy controls (P = 0.008). One-fifth of donors had abnormal CEPI-CT values and 11% exceeded > 300 s (max measurable value). (ii) Decreased serum thromboxa ne B-2 levels were found in 9%. of all donors, compatible with surreptitiou s intake of cyclooxygenase inhibitors or with an aspirin-like, defect. CEPI -CT correlated inversely with TxB(2)-levels in donors and controls. (iii) T he density of the alpha,integrin correlated negatively with CEPI-CT and CAD P-CT values in controls, but was not responsible for the observed impaired platelet function in donors. (iv) Finally, the ABO blood group system modul ates closure times. Conclusion: In sum, a large number of platelet donors p resent with prolonged closure time,. Decreased thromboxane formation and fr equent platelet donation partly account for this observation.