Bowman Capsule Rupture and Its Clinical Significance in Patients with Anti-Glomerular Basement Membrane Disease

Background: Anti-glomerular basement membrane (GBM) disease represents the most severe form of crescentic glomerulonephritis. Previous studies demonstrated that Bowman’s capsule rupture (BCR) contributed to the progression of crescentic glomerulonephritis. However, its role in anti-GBM disease remains unclear. The aim of this study was to investigate the landscape of BCR and its association in patients with anti-GBM disease. Methods: A total of 72 patients diagnosed with biopsy-proven anti-GBM disease with complete clinicopathologic and outcome data were retrospectively enrolled. Results: Extensive BCR was occurred in 70 patients (97.2%) with an average of 52.79% on biopsies. The severity of BCR showed strong association with worsen kidney function (incidence of oligoanuria, eGFR decline, and serum creatinine elevation; P < 0.001), and levels of anti-GBM antibody (P = 0.013). Histologically, the severity of BCR was positively correlated with crescents formation (P = 0.001) and increased cellular-fibrous crescents specifically (P = 0.047). Kaplan–Meier analysis revealed significantly divergent outcome in kidney survival (P = 0.006) and kidney recovery (P = 0.016) when patients divided into different groups according to the severity of BCR. The incorporation of BCR into two proposed prediction models-risk stratification tool and renal risk score-could improve their prognostic performance. Conclusion: BCR serves as both a defining histopathological feature and a critical determinant of kidney injury progression. As a simple, standalone parameter, it demonstrates robust predictive value for kidney outcomes in patients with anti-GBM disease.