Filtered platelet concentrates from pooled buffy coats show comparable storage lesions when stored for 9 d at 20-24 °C or when supplemented with ThromboSol™ at 2-6 °C

The present study investigated the quality of platelet concentrates from pooled buffy coat (PCBC) along different production steps and during storage to characterize storage lesions reflected by platelet activation, changing metabolic and cell turnover status (pH, LDH activity). These criteria were compared in conventionally stored PCBCs (20-24 degrees C, n=8, Group I) to cold stored PCBCs (2-6 degrees C, n=8, Group II) when supplemented with ThromboSol(TM). Platelet activation was measured on days 1, 3, 7 and 9 by flow cytometry using fluorescein-isothiocyanate-labeled monoclonal antibodies (mAbs) against glycoprotein IIb/IIIa (CD41a, PAC-1 and LIBS-1), P-selectin (CD62P) or CD40 ligand receptor (CD40L) in combination with a phycoerythrin-labeled panspecific platelet marker against GPIb (CD42b). The platelet activation assessed with mAbs PAC-1, CD41a, LIBS-1 and CD40L showed an overall activation of 98 +/- 4% (mean value +/- 1 SD) at day 7 in both groups, except for CD62P, which was significantly lower in Group II. A storage-dependent greater platelet loss occurred in Group II compared to Group I, 42% vs. 19% (p < 0.05 on day 9). We could demonstrate that platelets stored in ThromboSol(TM) show about the same in-vitro activation as conventionally stored PCBCs, but their clinical usefulness needs to be investigated.