FREE SMALL AND IGG-ASSOCIATED LARGE HEPATITIS-B E-ANTIGEN IN THE SERUM AND GLOMERULAR CAPILLARY WALLS OF 2 PATIENTS WITH MEMBRANOUS GLOMERULONEPHRITIS

Nephrotic syndrome developed in two children who carried hepatitis B virus. Both their serums contained hepatitis B surface antigen and hepatitis B e antigen (HBeAg). Two physicochemically and immunologically different categories of HBeAg activity were identified in their serums — i.e., small molecular (free) and large molecular (associated with IgG). Their kidney-biopsy specimens disclosed pathologic changes typical of membranous glomerulonephritis. By a fluorescent-antibody technic, HBeAg was found to be deposited in diffuse granular fashion, along glomerular capillary walls, together with IgG and β1C, but no deposition of hepatitis B surface antigen was detected. The presence of HBeAg in association with IgG both in the serum and in the kidneys of these patients suggests that HBeAg caused membranous glomerulonephritis by inducing the formation and deposition of immune complexes. (N Engl J Med 300:814–819, 1979) MEMBRANOUS glomerulonephritis typifies nephropathies mediated by immune complexes, because the granular deposition involving immunoglobulins and complement components is invariably detected along glomerular capillary walls.1 2 3 Some of the antigens in these immune deposits have been identified, such as DNA,4 streptococcal,5 malarial,6 syphilitic7 and renal tubular epithelial antigens.8,9 The etiologic antigen is not identified, however, in most patients with idiopathic membranous glomerulonephritis. Idiopathic membranous glomerulonephritis is a chronic disease often lasting for years. A continuous supply of antigen has to be provided in the circulation to react with humoral antibodies, form soluble immune complexes and to be deposited in the kidney for. © 1979, Massachusetts Medical Society. All rights reserved.