[Two brothers with reflux nephropathy].

This paper reports two brothers with reflux nephropathy. Patients who were 10-year-old and 12-year-old were referred to our hospital due to proteinuria and deterioration of renal function. Diagnosis of reflux nephropathy was made on drip infusion pyelography (DIP), voiding cystogram (VCG), and renal biopsy findings. The following findings were observed in renal tissues; focal and segmental sclerosis by light microscopy, IgM deposition by immunofluorescent microscopy, and glomerular basement membrane alterations and detachment of podocytes by electron microscopy. The HLA typing and analysis showed that both brothers and their mother possessed HLA-A9, which is reported to be closely associated with progression of primary reflux nephropathy to end-stage renal disease.

Identification of Goodpasture antigens in human alveolar basement membrane.

Goodpasture (GP) antigens, protein components reactive with human autoantibodies against glomerular basement membrane (GBM), were identified in human alveolar basement membrane (ABM) using an enzyme-linked immunoassay (ELISA), Western blotting and immunoprecipitation. All six anti-GBM antisera studied, three obtained from patients with glomerulonephritis and pulmonary haemorrhages (i.e. GP syndrome), and three from patients with glomerulonephritis alone, distinctively reacted with collagenase-digested (CD) ABM. Very cationic 22-28 kD and 40-48 kD components were detected by blot analysis combined with two-dimensional gel electrophoresis. These proteins showed some similarities to GP antigens in human GBM with respect to the monomer-dimer composition and charge distribution. Inhibition ELISA revealed that the binding of anti-GBM antisera to CDGBM decreased when they were pre-incubated with CDABM, suggesting that the anti-GBM antisera recognized the same epitope(s) on the GBM and ABM. Heterogeneity of the GP antigens in human ABM was demonstrated by blotting; monomeric antigens were absent or at low levels in the CDABM of three out of 10 normal individuals. In immunoprecipitation, anti-GBM antisera from patients with and without pulmonary haemorrhage showed different reactivities with CDABM. The former antisera precipitated both monomeric and dimeric components, but the latter did not. The observations of variation in monomer-dimer composition of ABM, and the different binding of anti-GBM antisera to it may explain why only some patients with anti-GBM nephritis have lung involvement.