Characterization of human anti-glomerular basement membrane antibodies eluted from glomerulonephritic kidneys

Abstract

A B S T R A C T Eluates from glomerulonephritic kidneys of nine patients with anti-glomerular basement membrane (anti-GBM)-mediated nephritis were studied to define their antigenic specificity and content of kidney-fixing antibodies. Five of these patients had Goodpasture's syndrome with pulmonary and renal involvement clinically; four patients did not. All had in vivo fixation of JgG in the characteristic linear pattern by direct immunofluorescence, and eluted JgG fixed to normal human kidney sections. Eluates from kidneys of patients with Goodpasture's syndrome fixed more frequently to homologous nonglomerular renal and extrarenal antigenic sites and to heterologous GBM than did non-Goodpasture eluates over a hundredfold range of antibody concentrations; both could be blocked by prior absorption with soluble GBM antigens. By radial immunodiffusion and precipitation tests the content of JgG in the eluates was measured to range from 2 to 20% of the total protein eluted. By paired label isotopic fixation studies with some of the eluates the per cent of IgG that was kidney fixing ranged from 0.6 to 23.4%. Although the in vivo fixation studies with radiolabeled eluates failed to indicate significant fixation to monkey lung, the observations define quantitative as well as qualitative differences between anti-GBM antibody populations mediating the Goodpasture syndrome compared to those causing glomerulonephritis without lung involvement. This is publication No. 355 from the

Glomerulonephritis mediated by antibody to glomerular basement membrane. Immunological, clinical, and histopathological characteristics.

“…IF tests were done on snap-frozen kidney cores obtained by percutaneous or operative biopsy, cut at 4-6-/Am thickness and fixed as described (4). Sections were stained for IgG, IgM, IgA, IgD, IgE, B1C, and fibrinogen, as described by Coons and Kaplan (3).…”

“…Sections were stained for IgG, IgM, IgA, IgD, IgE, B1C, and fibrinogen, as described by Coons and Kaplan (3). Controls were done as described (4).…”

Detection of Anti-Glomercular Basement Membrane Antibodies by a Radioimmunological Technique CLINICAL APPLICATION IN HUMAN NEPHROPATHIES

“…Several techniques have been used to study anti-GBM immunity in animals and in man. Immunofluorescence can be performed directly on glomerulonephritic kidneys or after transfer of circulating or eluted anti-GBM antibodies onto normal kidney slices (1)(2)(3)(4)(5). The existence of anti-GBM antibodies is then suggested by the presence of linear deposits along the GBM (1)(2)(3)(4)(5).…”

“…Immunofluorescence can be performed directly on glomerulonephritic kidneys or after transfer of circulating or eluted anti-GBM antibodies onto normal kidney slices (1)(2)(3)(4)(5). The existence of anti-GBM antibodies is then suggested by the presence of linear deposits along the GBM (1)(2)(3)(4)(5). Agar gel precipitation and passive hemagglutination tests have also been used in experimental (3) or in human (1,6) GN for the detection of circulating anti-GBM antibodies.…”

A Review of Methods Available for the Identification of Both Organ-Specific and Non-Organ-Specific Autoantibodies

“…53 False positive results are common using human and monkey kidney and occur in conditions such as SLE where there is polyclonal increased IgG. True linear staining due to anti-GBM antibody is difficult to distinguish from non-specific staining, so ELISA assays are the method of choice as the specific antigen can be used.…”