The effect of prestorage white cell reduction on the function and viability of stored platelet concentrates

The role of residual donor white cells (WBCs) in producing the storage lesion of platelets used for transfusion was studied. The effect of prestorage WBC reduction on in vitro and in vivo measurements of the quality of stored platelet concentrates (PCs) was examined by using a newly developed WBC-reduction filter capable of preparing PCs with a mean residual WBC concentration of less than 1 per microL. For in vitro studies, a triplet study design was used, in which WBC-reduced PCs were matched to standard PCs and to WBC-enriched PCs obtained from the same donor at the same phlebotomy. Twelve donors were studied. Prestorage WBC reduction resulted in a higher pH and pO2 and a lower pCO2 than in standard PCs. In accord with previous in vitro studies, a significant rise in plasma glycocalicin and lactate dehydrogenase was measured during storage, but the levels were not significantly different in WBC-reduced PCs and standard PCs. Platelet aggregation and ATP release in response to graded doses of thrombin was similar in WBC-reduced and standard PCs. In vivo recovery and survival studies were comparable in WBC-reduced and standard PCs. Although the residual donor WBC content of PCs has a significant impact on storage pH, pO2, and pCO2, prestorage WBC reduction does not affect platelet structure, function, or viability as assessed by in vitro or in vivo measurements.