Bowman capsule rupture in children with myeloperoxidase-antineutrophil cytoplasmic antibody-associated glomerulonephritis predicts poor renal survival

Background Recent developments indicated that Bowman capsule rupture (BCR) is observed in antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (AAGN). We aimed to explore the relationship between BCR and clinical manifestations, pathological changes, and prognosis in children with myeloperoxidase (MPO)-AAGN. Methods A total of 56 children with MPO-AAGN were divided into BCR (+) and BCR (-) groups according to the status of Bowman’s capsule. Results After retrospective analysis of the data, 24 children (42.9%) were found to have BCR. The results showed that BCR positively correlated with intrarenal immune cell infiltrates, obsolescence and crescents in glomeruli, tubulointerstitial inflammation, tubulitis, and tubular atrophy negatively correlated with normal glomeruli and immunoglobulin G deposition in the kidney. The clinical features and kidney pathological changes were more severe in the BCR (+) group than BCR (-) group, and the renal survival rate was significantly poorer in the BCR (+) group than BCR (-) group (χ2 = 5.45, p = 0.02). Moreover, estimated glomerular filtration rate (≤15 mL/min/1.73 m2), BCR and ANCA renal risk score (ARRS) were independent risk factors for the development of end-stage kidney disease (ESKD) in children with MPO-AAGN. After combining BCR with the Berden classification and ARRS, our data suggested that the Berden classification + BCR and ARRS + BCR showed better predictive values for ESKD than those of the Berden classification and ARRS, respectively. Conclusion BCR is an important pathological lesion that correlates with severe clinical manifestations, pathological changes, and poor prognosis in children with MPO-AAGN. Keywords: Antineutrophil cytoplasmic antibodies, Bowman capsule, Glomerulonephritis, Myeloperoxidase