Clinicopathological characteristics, risk factors and renal outcome in IgA nephropathy with crescents

The aim of the study was to investigate the clinicopathological characteristics, risk factors and renal outcome in IgA nephropathy (IgAN) patients with crescents. Four hundred and fifty-eight biopsy-proven primary IgAN patients included between January 2010 and October 2021 for a retrospective analysis were divided into three groups according to crescent score of the updated Oxford classification: C0 group (n = 255), C1 group (n = 187) and C2 group (n = 16). The clinicopathological features and renal outcomes were recorded. In univariate and multivariate models, the association between crescents and renal outcome and C2-associated clinical factors were analyzed. Patients with a higher proportion of crescents presented worse clinical characteristics with regard to kidney function, proteinuria, hematuria, hemoglobin, uric acid, cholesterol, and serum albumin, while global glomerulosclerosis, segmental adhesion, tuft necrosis, segmental glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis (T1/2), and lymphocyte and monocyte infiltration were more severe. By multivariate logistic regression analysis, eGFR (OR 0.981, 95% CI 0.964–0.999, P = 0.039), proteinuria (OR 1.655, 95% CI 1.180–2.321, P = 0.004), and hematuria (OR 4.752, 95% CI 1.426–15.835, P = 0.011) were significantly associated with C2. C2 was significantly associated with poorer renal survival even in patients receiving immunosuppressive therapy. Nevertheless, only eGFR at baseline, rather than crescents, was an independent predictor for renal survival in multivariate Cox analyses. IgAN patients with crescents presented more severe clinical and pathological features. Renal function, proteinuria and hematuria contributed to identifying patients with crescents. Crescents were associated with poorer renal survival, even in patients receiving immunosuppressive therapy, but it was not an independent predictor.