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Comparison of the in vitro characteristics of von Willebrand factor in British and commercial factor VIII concentrates
Author(s) -
Lawrie A. S.,
Harrison P.,
Armstrong A. L.,
Wilbourn B. R.,
Dalton R. G.,
Savidge G. F.
Publication year - 1989
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1989.tb00227.x
Subject(s) - von willebrand factor , in vitro , chemistry , haemophilia a , coagulopathy , ristocetin , coagulation , von willebrand disease , platelet , antigen , medicine , haemophilia , microbiology and biotechnology , immunology , biochemistry , surgery , biology
Summary. Qualitative/quantitative analysis of von Willebrand factor antigen (vWf:Ag) in either heat or solvent/detergent treated factor VIII concentrates, used for haemophilia replacement therapy, was undertaken to assess their suitability for the treatment of vWD. For the first time immunoaffinity purified vWf:Ag (Monoclate by‐product) was also evaluated by in vitro assessment. Potencies of vWf: Ag varied considerably but were consistently higher (28.9–420.5 iu/ml) than factor VIII:C (one‐stage) activity (8.13–42.44 iu/ml). The functional activity of vWf was assessed by either Ristocetin Cofactor (vWf:RCo) or collagen binding methods (vWf:CBA) with typical vWf:RCo/vWf:Ag ratios ranging from 0.08 to 0.94. Multimeric analysis confirmed that in vitro biological activity was dependent on the presence of the high molecular weight forms of vWf: Ag. A significant correlation ( r =0.95) between vWf:RCo activity and collagen binding was observed in all of the concentrates with the exception of the immunopurified product. The data suggest that either NHS 8Y (mean vWfRCo/vWf:Ag=0.94), Haemate P (mean vWf:RCo/vWf:Ag=0.69) and high purity Octapharma V.I (vWf:RCo/vWf:Ag=0.82) which contain medium/high MW vWf:Ag multimers are likely to be most cost‐effective in the treatment of symptomatic severe vWD patients than other currently available concentrates.