Methods of pathogen inactivation in whole blood and red blood cells: current state of knowledge

Abstract

Although pathogen reduction technology was implemented for platelet concentrates and plasma, the risk of pathogen transmission has not been completely eliminated as no inactivation procedures were implemented for red blood cells and whole blood. Research was therefore focused on developing methods for effective pathogen inactivation in red blood cell components. Attempts were made to apply either chemical compounds (porphyrins and Sylsense compounds) or photosensitizers such as methylene blue (Theraflex MB Plasma System) and amotosalen hydrochloride (Intercept System) already in use for pathogen inactivation in plasma. None proved effective for pathogen inactivation in red blood cells. Approval was recently given to pathogen inactivation methods based on S-303 compound (for red blood cells) and with riboflavin (for whole blood). Clinical trials are ongoing. Pilot studies have shown that during storage of packed red blood cells subjected to pathogen inactivation with S-303 demonstrated slight loss of red blood cells, decrease in hemoglobin concentration, significantly lower lactate concentration, and lower pH. Pathogen inactivated whole blood stored at room temperature for up to seven days showed slight hemolysis (within the normal range). This paper presents several pilot clinical trials with pathogen inactivated red blood cells or whole blood. It focuses primarily on the recovery of red blood cells in the recipient's organism and on hemoglobin concentration.