The clinical and immunological features of patients with combined anti-glomerular basement membrane disease and membranous nephropathy.

The association of anti-glomerular basement membrane (GBM) disease, also known as Goodpasture's disease, with membranous nephropathy (MN) has been well documented. However, little is known about the clinical and immunological features of patients with such a combination. This study was designed to investigate the clinical and immunological features of anti-GBM patients with MN and to provide insight into the pathogenesis of this rare entity. Eight patients with combined anti-GBM disease and MN were found to have significantly lower levels of serum creatinine, a significantly lower proportion of oliguria/anuria, and significantly better renal outcomes compared with 30 patients with classical anti-GBM disease. Antibody levels against the EB conformational epitope of anti-α3(IV)NC1 were significantly lower in these patients, as was their levels of anti-α3(IV)NC1 immunoglobulin G1 (IgG1) and IgG3. Serum antibodies against the M-type phospholipase A2 receptor were undetectable in anti-GBM patients with MN but presented in 13 of the 20 patients with primary MN. Thus, patients with combined anti-GBM disease and MN have distinct clinical features and a different immunological profile of MN.