The Added Value of Crescents on Oxford Classification Score in Risk Stratification of End-stage Kidney Disease in Patients with IgA Nephropathy.

ABSTRACT

INTRODUCTION: Crescents (C) have been recently added to the Oxford classification of IgA nephropathy (IgAN) consisting of mesangial hypercellularity (M), endocapillary hypercellularity (E), segmental sclerosis (S) and tubular atrophy/ interstitial fibrosis (T) (MEST). The aim of the study was to assess the added impact of crescents, on development of end-stage kidney disease (ESKD) in IgAN patients Methods. On-hundred fifteen IgAN patients (76% male, mean age 37 ± 13 years, mean serum creatinine 4.0 ± 4.3 mg/dL, mean proteinuria 3.4 ± 2.5 g/d) were followed for 43 ± 29 months. MEST score was defined according to Oxford classification (M0/M1, E0/ E1, S0/S1). To increase the power, T was defined as T0 ≤ 25% and T1 > 25%. Crescents were defined as C0, "absence" and C1 "at least one" crescent. In sensitivity analysis, the risk of ESKD was estimated at different cut-off levels of at least 10, 20, and 30% crescents. RESULTS: Forty patients (35%) developed ESKD. Among those 14% with at least one crescent, 21 patients (46%) developed ESKD. In 11 patients with C ≥ 30%, 66% and among 57 patients with T1, 60% and in 27 patients with T1 + C1 74% developed ESKD. In adjusted model, only C ≥ 30% (HR = 3.15, 95% CI 1.15 to 11.00; P = 0.027) and the presence of T1+ C1 (HR = 7.18, 95% CI 1.90 to 27.10, P = 0.004) were associated with increased risk of ESKD. The median kidney survival was 78.0 months (95% CI 70.5 to 85.6 months), in patients with T0 + C0 and 32.3 months (95% CI 19.3 to 45.3 months) in patients with T1 + C1. CONCLUSION: In this study T ≥ 25%, and the presence of crescents ≥ 30%, were independently associated with increased risk of ESKD. This risk was strongly increased in the combined presence of at least one crescent and T1 ≥ 25%, that predicted a high ESKD rate.  DOI 10.52547/ijkd.6685.