Platelet function in variable platelet split products intended for neonatal transfusion

Abstract

Only a few systematic studies have examined the effect of variable produced small platelet (PLT) aliquots on PLT function before transfusion to neonates. Although neonatal transfusion could be critical, no standardization of production or systematic quality controls have been introduced so far. PLT split products were prepared in three different ways (30- or 60-mL bag, syringe aliquot) at different times from the parent unit (Days 1-4) and stored for 2 or 4 hours. The measures of PLT function include pH, lactate, P-selectin expression, and cytokines (beta-thromboglobulin [beta-TG], PLT-derived growth factor AB [PDGF-AB]). Additionally, syringe passage (0.5 mL/min) was assessed. High product variability of PLT content was found (40% deviation of PLT content from programmed target, 13%-19% PLT loss by product distribution), which resulted in PLT concentrations of split units between 0.94 x 10(9) and 1.66 x 10(9) PLTs per mL. Different gas transfer rates (pCO2) of PLT containers caused different pH values of the product (Trima 7.47 +/- 0.09 vs. COM.TEC 7.33 +/- 0.08; p < 0.0001), but acceptable results of PLT metabolism were found in all split units (minimum pH, 7.09; maximum lactate content, 13.1 mmol/L). P-selectin expression on PLTs increased by factor of 2 in the parent units stored for 4 days (16.9 +/- 8.6% 32.2 +/- 13.4%; p = 0.02). After Day 3, beta-TG and PDGF-AB increased by twofold. PLTs stored during passage for 100 minutes in syringes dropped pO(2) by 50 percent and caused 15 percent higher lactate levels. High variability of PLT content in split units requires at least additional PLT counts before transfusion in critical preterm or neonatal infants.