Systemic Immune-Inflammation Index and Prognostic Nutritional Index as Predictors of Renal Survival in Crescentic Glomerulonephritis

Purpose: Crescentic glomerulonephritis (GN) is a rapidly progressive kidney disease associated with a high risk of end-stage renal disease (ESRD). This study aimed to assess whether systemic inflammation and nutritional status, as measured by the systemic immune-inflammation index (SII) and prognostic nutritional index (PNI) at diagnosis, can predict one-year renal survival in patients with crescentic GN. Methods: This retrospective study included 82 adult patients with biopsy-proven Type 1 or Type 3 crescentic GN. Baseline SII and PNI were calculated from pre-treatment blood samples. Clinical, laboratory, and histopathological data were collected. Patients were followed for 12 months and classified into two groups based on the development of ESRD. Results: The cohort (63.4% male) had a mean age of 53.65 ± 15.87 years; 26 patients (31.7%) progressed to ESRD. Multivariate analysis identified elevated SII [OR: 1.79; 95% CI: 1.22-18.81; p = 0.03], low PNI [OR: 0.92, 95% CI: 0.96-0.99; p = 0.03], hypoalbuminemia [OR: 0.36, 95% CI: 0.15-0.84; p = 0.02], reduced estimated glomerular filtration rate [OR: 0.93, 95% CI: 0.88-0.98; p = 0.009], anemia [OR: 0.37; 95% CI: 0.22-0.63; p < 0.001], higher crescent ratio [OR: 1.05, 95% CI: 1.02-1.09; p = 0.02], and plasmapheresis requirement [OR: 0.074, 95% CI: 0.016-0.349; p = 0.001] as independent predictors of ESRD. Receiver operating characteristic analysis determined cutoff values of 176.38 for SII (area under the curve [AUC]: 0.679, p = 0.01) and 31.88 for PNI (AUC: 0.650, p = 0.03). Glomerulosclerosis ratio and interstitial fibrosis/tubular atrophy were not independently associated with ESRD (p = 0.13 and p = 0.14, respectively). Conclusion: SII and PNI are independent but moderate predictors of one-year renal survival in crescentic GN. Incorporating these readily available biomarkers with histological evaluation may enhance risk stratification and help guide early, aggressive immunosuppressive therapy.