The association of anti-glomerular basement membrane (GBM) antibody-mediated
glomerulonephritis and glomerular
immune complexes is common and probably arises from a number of mechanisms. In the series, glomerular
immune complexes were identified in 6 of 17 patients who initially presented with
anti-GBM disease. In four cases, glomerular
immune complexes were noted in renal biopsies obtained at clinical presentation; in the other two, they were first demonstrated seven and 28 months after presentation, when circulating
anti-GBM antibody levels were undetectable. Circulating
immune complexes were detected in only two of six patients, either 28 months before or 17 months after the demonstration of the glomerular membranous lesion. The association of glomerular
immune complexes and
anti-GBM disease may be coincidental with immunologically-unrelated
immune complexes localizing in the GBM for physico-chemical reasons; or the presence of glomerular-bound
anti-GBM antibodies may predispose to the deposition of molecules with particular affinity for these
antibodies. One patient with glomerular
immune complexes used
heroin, which may be associated with
immune complex formation and the development of
glomerulonephritis; and one patient was subsequently thought to have
systemic lupus erythematosus (SLE). An antecedent
infection was found in two of the four patients who had glomerular complexes at presentation, but in only three of 13 with uncomplicated
anti-GBM disease. Three of 6 patients with superimposed glomerular complexes had a history of exposure to organic
solvents before the onset of disease, while none in the group with
anti-GBM disease alone had.