Ｓｊｏｅｇｒｅｎ症候群における血中第ＶＩＩＩ因子／ｖｏｎ Ｗｉｌｌｅｂｒａｎｄ因子複合体の意義

Abstract

The plasma level of factor VIII procoagulant protein/von Willebrand factor complex (FVIII/vWF) was evaluated in 18 patients with Sjogren's syndrome (SjS 5, SjS+RA 4, SjS+SLE 3, SjS+MCTD 3, SjS+PN 1, SjS+TA 2) .Factor VIII procoagulant activity (VIII : C), measured by the one-stage assay using commercially available human VIII : C-deficient plasma as the substrate, was relatively increased in the patients (121.5±40.7%), but not significant compared with normal subjects. On the other hand, von Willebrand factor antigen (vWF : Ag) assayed by the electroim-munodiffusion according to the method by Laurell was remarkably increased (287.5±1614%) . Ristocetin cofactor activity (RCof) measured by the aggregometer method using a RIPA-test kit® was also increased (176.6±52.9%) . The vWF : Ag/RCof ratio was significantly high (1.61±0.60) . The vWF multimeric analysis by the electrophoresis on 1.5% agarose gels with discontinuous buffer system performed on these 18 patients, revealed that 12 cases had normal multimeric patterns, 3 had supranormal multimers, and 3 had lost high molecular weight multimers.These findings suggest that plasma-vWF in patients with SjS is increased, while there is a variety of vWF multimeric structures, and also that there are some cases whose patterns of plasma-vWF multimers are normal inspite of their high vWF : Ag/RCof ratios.