Characteristics of red cell concentrates subjected to a viricidal procedure and stored for 35 days

Abstract

Several approaches have been proposed to inactivate contaminating viruses in cellular blood products. Efforts to sterilise red cell concentrates have had limited success at the red cell and protein concentrations encountered in transfusion practice. We have studied the invitro properties of red cells exposed to a viricidal solution containing sodium chlorite and lactic acid, where the generation of chlorous acid acts as the sterilisation mechanism. Red cell concentrates (RCC's) were washed with one litre of normal saline containing 63 mG of lactic acid and 11.5 mG of sodium chlorite, concentrations previously shown to inactivate > 5 logs of Human Immunodeficiency Virus in 5 minutes. Total contact time of the sterilising solution with the red cells was 10 minutes, after which they were washed with one litre of normal saline followed by 500 mL of an additive solution (AAS - TUTA) formulated to preserve red cell metabolism. Red cell haemolysis, potassium leakage. Adenosine Tri-Phosphate (ATP), 2,3 DiPhosphoglycerate (2,3 DPG) and pH were measured over the 35 day storage period (Table).ATPuM/G HbFree HbmG/unitFree K+mmol/unitHCT%QC limit1.5<500<9.055±5RCC's2.3±0.3180±453.5±0.448±11 Mean+SD for 6 RCC's treated with sterilant, all results at Day 35. All parameters measured showed adequate maintenance over storage. Red cells which had been frozen in liquid nitrogen were similarly treated after thawing and deglycerolisation. No significant differences from control units were observed, with AAS - TUTA as a final suspending medium. While further invivo studies as well as more extensive viral inactivation data are required, these findings indicate that this method shows promise as a procedure to sterilise red cells.