Factor VIII and IX assays for post-infusion monitoring in hemophilia patients: guidelines from the French BIMHO group (GFHT)

Authors : Jeanpierre, E., Pouplard, C., Lasne, D., Le, Cam Duchez, V, Eschwege, V., Flaujac, C., Galinat, H., Harzalla, I., Proulle, V., Smahi, M., Sobas, F., Stepina, N., Toulon, P., Voisin, S., Ternisien, C., and Nougier, C.

Publication: Eur.J Haematol.; April 2020

Affiliations: CHU Lille, Institut d’Hematologie Transfusion, Inserm U1011, Lille, France Service d’Hematologie Hemostase, Hopital Trousseau, CHU de Tours, Universite Francois Rabelais, EA, 7501, Tours, France (…)

Abstract: Replacement therapy with plasma-derived or recombinant FVIII and FIX (pdFVIII/pdFIX or rFVIII/rFIX) concentrates is the standard of treatment in patients with hemophilia A and B respectively. Measurement of factor VIII (FVIII:C) or factor IX (FIX:C) levels can be done by one-stage clotting assay (OSA) or chromogenic substrate assay (CSA). The French study group on the Biology of Hemorrhagic Diseases (a collaborative group of the GFHT and MHEMO network), presents a literature review and proposals for themonitoring of FVIII:C and FIX:C levels in treated Hemophilia A and B patients respectively. The use of CSA is recommended for the monitoring of patients treated with pdFVIII or rFVIII including extended half-life (EHL) rFVIII. Execpt for rFVIII-Fc, great caution is required when measuring FVIII:C levels by OSA in patients substituted by EHL-rFVIII. The OSA is recommended for the monitoring of patients treated with pdFIX or rFIX. Large discordances in the FIX:C levels measured for extended half-life rFIX (EHL-rFIX), depending on the method and reagents used, must lead to great attention when OSA is used for measuring FIX:C levels in patients substituted by EHL-rFIX. Data of most of recent studies, obtained with spiked plasmas, deserve to be confirmed in plasma samples of treated patients.