Functional Characteristics of S-59 Photochemically Treated Platelet Concentrates Derived from Buffy Coats

Abstract

Background: A photochemical treatment (PCT) process for inactivation of infectious pathogens and leukocytes has been developed and evaluated using single-donor platelet concentrates. This study assessed the application of PCT to platelets prepared from pooled buffy coats. In this study, in vitro functional characteristics of PCT platelets were compared to control platelets prepared from pooled buffy coats using the approved platelet-additive solution T-Sol^®. Platelets in platelet PAS III additive solution without PCT were evaluated as well. PCT also included the use of a psoralen (S-59) reduction device (SRD). Materials and Methods: Four types of platelet concentrates were compared: (1) platelet concentrate in plasma/T-Sol; (2) platelet concentrate in plasma/PAS III; (3) platelet concentrate in plasma/PAS III, PCT, 9 h SRD and (4) platelet concentrate in plasma/PAS III, PCT, 16 h SRD. PCT occurred on the day after whole-blood collection. In vitro assay parameters included: pH, pO₂, pCO₂, HCO^–₃, platelet count, mean platelet volume, plasma glucose, plasma lactate, total ATP, expression of p-selectin, hypotonic shock response and electron microscopy. Results: The results indicate that PCT is compatible with platelet concentrates prepared from pooled buffy coats for up to 7 days of storage. Conclusion: The PCT process resulted in acceptable in vitro platelet functional characteristics and is currently in clinical trials to evaluate the haemostatic efficacy of PCT platelets in thrombocytopenic patients requiring multiple platelet transfusions.