Bowman’s capsule rupture and the Oxford MEST-C score in adult patients with Immunoglobulin a vasculitis nephritis: a single center experience

OBJECTIVE: Bowman’s capsule rupture (BCR) is a glomerular pathological change, but it is still not well recognized in immunoglobulin A vasculitis nephritis (IgAV-N). The Oxford MEST-C score is a classification for IgA nephropathy; however, its clinical correlation and prognostic value in adult patients with IgAV-N are unclear. METHODS: A retrospective study of 145 adult patients with IgAV-N diagnosed by renal biopsy was conducted. Clinical manifestations, pathological changes and the prognosis of IgAV-N patients were compared depending on the presence or absence of BCR, International Study of Kidney Disease in Children (ISKDC) classification and MEST-C score. The primary endpoint events were end-stage renal disease, renal replacement therapy and all-cause death. RESULTS: In total, 51 of 145 (35.17%) patients with IgAV-N presented with BCR. Patients with BCR had more proteinuria, lower serum albumin, and more crescents. Compared with IgAV-N patients with crescents only, 51/100 patients with crescents combined with BCR had a higher proportion of crescents in all glomeruli (15.79% vs. 9.09%; p = 0.003). Patients with higher ISKDC grades had more severe clinical presentation, but it did not reflect the prognosis. However, the MEST-C score not only reflected clinical manifestations but also predicted prognosis (p < 0.05). BCR contributed to the effectiveness of the MEST-C score in predicting the prognosis of IgAV-N (C-index: 0.845 to 0.855). CONCLUSIONS: BCR is associated with clinical manifestations and pathological changes in patients with IgAV-N. The ISKDC classification and MEST-C score are related to the patient’s condition, but only the MEST-C score is correlated with the prognosis of patients with IgAV-N, while BCR can improve its predictive ability.