A potentially improved approach to methylene blue virus inactivation of plasma: the Maco Pharma Maco-Tronic system

Plasma was subjected to methylene blue (MB) photochemical virus inactivatio n using the Maco Pharma Maco-Tronic system which allows three units to be i lluminated together, thus reducing processing time. The plasma bag system u sed incorporates an integral membrane plasma filter and a dry MB pill which dissolves in the plasma to give a 1-muM concentration. There is computer-c ontrolled processing and datalogging. In an assessment of 10 pools of Group A plasma, the losses of coagulation f actors, following MB/light treatment, were 23% fibrinogen, 10% FV, 26% FVII I, 11% FIX and 13% FXI. Group O, Group B and Group AB plasmas were not test ed. Von Willebrand factor (vWf)multimers showed no substantial change when trea ted with-MB, and no losses were seen for antithrombin III (ATIII), protein C and vWf:Ag. Measurements of C3a, C5a, prothrombin fragment 1+2 and FXIIa indicated that there was no activation as a result of filtration.