Concurrent antiglomerular basement membrane disease and immune complex glomerulonephritis

Antiglomerular basement membrane (GBM) disease is characteristically described with linear deposition of IgG along GBM. However, the concurrent glomerular immune complex deposition was not rare and might be contributed to the development of anti-GBM disease. In the current series, glomerular immune complexes were identified in 10 of 47 patients who presented with renal-biopsy-proven anti-GBM disease. Six of the 10 patients complicated with a well-documented glomerulonephritis, including two patients with membranous nephropathy, one patient with IgA nephropathy, one patient with membranoproliferative glomerulonephritis, one patient with Schonlein-Henoch nephritis, and one patient with hepatitis B virus associated membranous nephritis. The other four patients had immune complexes with IgG or IgM predominance deposited in glomerular mesangium without a well-documented glomerulonephritis. Clinical and pathological data of patients with immune complex deposition (n = 10) were compared with those of patients with anti-GBM disease alone (n = 37). There was no significant difference in age, gender, clinical and pathological manifestations, and renal outcome between the two groups. In general, the association of glomerular immune complexes did not lead to a benign prognosis. Plasma exchange and extensive immunosuppressive therapy should be carried out as soon as possible. The immune complexes deposited in glomeruli might participate in the initiation of anti-GBM disease.