小児IgA腎症の糸球体内Cross-linked fibrinに関する研究 第一報 : 蛍光抗体法および免疫電顕法による観察

Abstract

To elucidate the relationship between pathogenesis of glomerular damage and intraglomerular deposits of fibrin/fibrinogen-related antigen (FRA) in children with IgA nephropathy, the localization of FRA was determined by an immunohistopathological method using an anti-fibrinogen antibody capable of detecting FRA, an anti-D-dimer antibody capable of detecting cross-linked fibrin and its derivatives, and by a method using the effect of monochloroacetic acid treatment on kidney sections. The distribution of FRA deposits was divided into four types, and the predictable components were as follows : Type Ⅰ, fibrinogen (Fg) and/or fibrinogen degradation products (FgDP) ; Type Ⅱ, cross-linked fibrin degradation products (XLFbDP) and Fg or FgDP ; Type Ⅲ, a mixture of cross-linked fibrin (XLFb) and Fg, FgDP or XLFbDP ; Type Ⅳ, XLFb predominantly. In patients with Type Ⅲ or Type Ⅳ, mesangial proliferation and/or IgA deposits were observed more intensively within the capillary wall and/or mesangial area than those with Type Ⅰ or Ⅱ, in agreement with the cross-linked fibrin deposits within capillary walls or mesangial area, and the degree of mesangial electron dense deposit (EDD), mesangial interposition or basement membrane thinning on electron microscope was apparently higher in these cases. These findings suggest that intraglomerular coagulation in children with IgA nephropathy may cause glomerular damage.