Objective: To investigate the clinical and pathological characteristics of anti-glomerular basement membrane (GBM) antibody associated diseases with different clinical patterns.
Methods: The clinical and pathological data of 41 patients with anti-GBM antibody associated diseases, screened in our institute in recent six years, were retrospectively analyzed.
Results: 22 of the 41 patients presented as Goodpasture syndrome, 2 of them having normal renal function. 32 of the 41 patients had anti-GBM antibody positive only (single positive). 31 of the 32 single positive patients were male with an average age of (26.8 +/- 9.7) years. The remaining 9 patients were both anti-GBM antibody and antineutrophil cytoplasmic antibody (ANCA) positive (double positive); 7 of the 9 were female with an average age of (44.5 +/- 19.6) years. There was significant difference in gender and age between the single and double positive groups (P < 0.05). 30 of the 32 patients with renal biopsy had crescentic glomerulonephritis and the remaining two with normal renal function had mild mesangial proliferative glomerulonephritis only. 24 of the 30 (80%) crescentic glomerulonephritis patients had all glomeruli affected by crescents with severe glomerular capillary loop and Bowman's capsule damage. With immunofluorescence examination, 16 of the 23 cases had typical IgG and C(3) linear deposition along glomerular capillary walls, but the remaining 7 had fine granular IgG and/or C(3) deposition. In a few cases, granular deposition was found even in mesangium. There was no correlation between the immunofluorescence patterns and the severity of glomerular damage (P > 0.05). All patients had anemia, hematuria and proteinuria, 7 of the 41 cases presented as nephrotic syndrome. After intensive immunosuppressive therapy, only four patients, including the two patients with normal renal functions, achieved remission, the remaining patients either were in renal replacement therapy or died.
Conclusions: Anti-GBM antibody associated diseases are not rare in China. Single positive patients are mainly young male, while double positive patients are mainly middle-aged female. Most of the patients with anti-GBM antibody associated diseases have crescentic glomerulonephritis (rapidly progressive glomerulonephritis, RPGN) with a bad prognosis. However, not all the patients have typical linear deposition of IgG and C(3) along glomerular capillary walls. Only a few non-oliguric patients with normal renal function or mild renal damage may achieve remission.