Abstract
BACKGROUND: The prognostic value and response to immunosuppressive therapy (IST) of patients with crescents in the different backgrounds of pathological presentations in immunoglobulin A nephropathy (IgAN) is unclear. METHODS: A total of 1262 IgAN patients were enrolled. Crescents (C, 0/1/2), fibrinoid necrosis (FN, 0/1) and endocapillary hypercellularity (E, 0/1) were integrated into different degrees of glomerular activity (0-4 points): mild (0), moderate (1-2) and severe (≥3). The effect of IST on patients with different glomerular activity scores and chronic tubular and interstitial lesions (T, 0/1/2) were analysed using Cox regression analysis. The kidney outcome was defined as an estimated glomerular filtration rate decrease ≥30% or end-stage kidney disease. RESULTS: C2 was an independent risk factor for kidney outcomes {overall cohort: hazard ratio [HR] 1.85 [95% confidence interval (CI) 1.03-3.31], P = .040; T0 patients: HR 6.52 [95% CI 2.92-14.54], P < .001; reference to C0} in those without IST, while the HR decreased to 0.83 (95% CI 0.54-1.27; P = .396) in the overall cohort and 2.39 (95% CI 1.00-5.67; P = .049) in T0 patients with IST. For patients with severe glomerular activity, IST decreased the risk of kidney outcomes by 70% in the overall cohort [HR 0.30 (95% CI 0.12-0.74), P = .009; reference to those without IST] and 86% in T0 patients [HR 0.14 (95% CI 0.04-0.54), P = 0.005; reference to those without IST]. CONCLUSIONS: IST could reduce the risk for kidney outcomes in IgAN patients with C2 and T0 lesions together, as well as in those with crescents and at least one other active lesion, including FN and E1 lesions.