Influence of methylene blue photoinactivation treatment on coagulation factors from fresh frozen plasma, cryoprecipitates and cryosupernatants

Objective: To study the influence of virus photoinactivation with methylene blue (MB) on the coagulation factors of fresh frozen plasma (FFP) and the corresponding cryoprecipitates and cryosupernatants derived from it. Materi als and Methods: The photoinactivation procedure of the German Red Cross (S pringe) was applied using Biomat (Grifols, Spain). Twenty isogroup pools of three plasma units were made from 60 U of FFP. The pools were split into t hree bags. One of them was photoinactivated, and pre- and post-inactivation samples (MB-plasma) were obtained. The second bag was treated in the same way, followed by the preparation of MB-cryoprecipitate and MB-cryosupernata nt. The third bag was not photoinactivated, and was processed in the same w ay to obtain control cryoprecipitate and cryosupernatant. The prothrombin t ime and activated partial thromboplastin time were analysed, as well as fib rinogen, factors (F) II, V, VII, VIII, IX, XI and XIII, antithrombin III, v on Willebrand (vW) F:RCo, vWF:Ag and the multimeric structure of vWF. Resul ts: In plasma, the proteins most sensitive to photoinactivation were fibrin ogen, FV, FVIII, FIX and FXI (24, 32, 28, 23 and 27% loss, respectively). I n the MB cryoprecipitate, the losses were higher for FVIII (23%), moderate for fibrinogen, FXIII and vWF:RCo (18, 14 and 13%, respectively) and minima l (only 3%) for vWF:Ag. In MB-cryosupernatants, the losses were higher for FV (26%) and moderate for fibrinogen (16%), FIX (18%) and FXI (19%), as wel l as for FII and FXIII (15%). The multimeric structure of vWF was not modif ied in MB-plasma or in MB-cryoprecipitates. The supernatants (both MB treat ed as well as controls) showed an absence of multimers of very high and hig h molecular weight. Conclusions: The quantitative and qualitative conservat ion of coagulation factors achieved in MB-plasma-derived products suggest t hat they are useful for the global replacement of coagulation factors and f or deficiencies in FV and FXI. In countries lacking the economic resources to obtain virally inactivated concentrates, MB-cryoprecipitates could be us eful in von Willebrand's disease and fibrinogen and FXIII deficiencies. MB- cryosupernatants could be employed in thrombotic thrombocytopenic purpura, in the correction of total or partial deficiencies of prothrombin complex f actors and in specific deficiencies of FV and FXI. Copyright (C) 2000 S. Ka rger AG, Basel.