Deposition of hepatitis B e antigen in membranous glomerulonephritis: identification by F(ab')2 fragments of monoclonal antibody.

The pathogenic ability of hepatitis B e antigen (HBeAg) to induce membranous glomerulonephritis was evaluated by the most specific method presently available. Monoclonal antibody was raised against HBeAg, and F(ab')2 fragments were obtained and labeled with fluorescence. By this reagent, 10 out of 16 patients with membranous glomerulonephritis with hepatitis B surface antigen in the serum revealed granular deposition of HBeAg along glomerular capillary walls. Among the cases with glomerular HBeAg deposits, nine had detectable HBeAg in the serum and one had antibody to HBeAg (anti-HBe). The specificity of HBeAg staining was ascertained by blocking and inhibition tests, and the fluoresceinated anti-HBe F(ab')2 reagent did not stain the glomerular immune deposits in the patients with membranous glomerulonephritis who did not carry hepatitis B virus (HBV). None of the studied patients showed deposition of hepatitis B surface or core antigens in the glomerulus. On the basis of these results, immune complexes involving HBeAg may induce membranous glomerulonephritis in persons who carry HBV.