Crescents and Global Glomerulosclerosis in Chinese IgA Nephropathy Patients: A Five-Year Follow-Up

Background/aims: This study aims to evaluate the clinical significance of crescent and global glomerulosclerosis formation on renal outcome in patients with IgA nephropathy (IgAN).

Methods: Biopsy-proven primary IgAN patients from West China Hospital of Sichuan University were studied retrospectively between 2008 and 2015. Clinicopathological features and treatment modalities were recorded. The patients were divided into several groups on the basis of cellular and/or fibrocellular crescents scores and global glomerulosclerosis scores. Crescent (C) was scored according to the updated Oxford classification (C0/C1/C2). Global glomerulosclerosis (G) was scored according to the frequency of global glomerulosclerosis: G0 (≤25% of glomeruli), G1 (26-50% of glomeruli), and G2 (> 50% of glomeruli). The primary endpoint was defined as a 50% reduction in renal function or end stage renal disease. Patients were followed up for at least 12 months, or shorter if they reached study endpoints. 1328 patients with IgAN were recruited. Mean follow-up time was 46.1±23.6 months. The percentage of patients with C1 and C2 was 19.3% and 5.9% respectively. Higher crescent scores was associated with lower estimated glomerular filtration rates (eGFR), decreased serum albumin levels, increased amounts of urine protein, higher serum creatinine, as well as greater proportions of M1 and E1. The percentage of patients with G0, G1 and G2 was 70.5%, 20.7% and 8.8%, respectively. Elevated glomerulosclerosis scores were associated with lower eGFR levels, increased amounts of urine protein, higher levels of serum creatinine, higher incidences of arterial hypertension, as well as greater proportions of M1. There was a significantly higher proportion of T1/2 in patients with G2. In a multivariate model, crescent and global glomerulosclerosis were identified as independent predictors of decreased renal survival.

Conclusion: Global glomerulosclerosis and crescents, as detected in renal biopsies, are strong predictors of long-term renal outcome of IgAN.