Multimers of von Willebrand antigen in therapeutic factor VIII concentrates.
By crossed immunoelectrophoresis (XIEP), the pattern of von Willebrand factor antigen (vWF:Ag) was investigated in six commercially available factor VIII (F VIII) concentrates and in normal human plasma. At least 5 subpopulations of vWF:Ag were recognized by XIEP in the therapeutic F VIII concentrates and in normal plasma. F VIII preparations high in ristocetin cofactor activity (vWF:RICof) and low in the ratio of vWF:Ag to vWF:RiCof were found to be similar in the multimeric structure of vWF:Ag to normal plasma. However, F VIII concentrates low in activity of vWF:RiCof and high in the ratio of vWF:Ag to vWF:RiCof were found to be deficient in the slowly migrating, high molecular weight multimers of vWF:Ag present in normal plasma.
D000941:Antigens / Q000032:analysis*; D001793:Blood Preservation; D055598:Chemical Phenomena; D002621:Chemistry; D002850:Chromatography, Gel; D005169:Factor VIII / Q000627:therapeutic use*; D005612:Freeze Drying; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D011487:Protein Conformation; D012310:Ristocetin / Q000494:pharmacology; D014841:von Willebrand Factor / Q000032:analysis
D000941:Antigens; C029417:Von Willebrand antigen; D014841:von Willebrand Factor; D012310:Ristocetin; D005169:Factor VIII