Clinicopathological features and predictors of anti-GBM disease combined with membranous nephropathy.

Abstract

Background: Anti-glomerular basement membrane (anti-GBM) disease is a rare and life-threatening form of small vessel vasculitis that primarily affects the kidneys and lungs. In rare cases, it occurs with membranous nephropathy (MN). This study aimed to investigate the clinical manifestations, pathological features, prognosis and predictors of anti-GBM disease with MN.

Methods: We enrolled 24 patients with combined anti-GBM disease and MN, and 69 patients with classic anti-GBM disease (without MN). We compared the clinical and pathological differences, as well as the prognoses between the two groups and attempted to identify predictors of anti-GBM disease combined with MN.

Results: A greater proportion of patients with combined disease were male, had a history of smoking, and had nephrotic syndrome (NS). Compared with patients with classic anti-GBM disease, those with anti-GBM disease with MN presented improved renal function, higher hemoglobin and serum C3 levels, and significantly improved renal outcomes (P < .05). In 16 out of 24 double-positive patients, a lower proportion of glomerular crescents and a higher rate of immunoglobulin G4 positivity were observed compared with only 20 of the 69 patients with classic anti-GBM disease confirmed by renal biopsy (P < .05). Furthermore, smoking status, hemoglobin levels and low-density lipoprotein levels were identified as factors associated with the development of anti-GBM combined with MN, potentially serving as predictors.

Conclusions: This study provides insights into the distinct clinical and pathological characteristics of anti-GBM disease with MN. The identification of predictors may contribute to the early recognition and management of these patients.