Comparative Evaluation of Five Prognostic Scoring Systems in Pauci-Immune Necrotizing and Crescentic...

Pauci-immune necrotizing and crescentic glomerulonephritis (PiNCGN) is a leading cause of rapidly progressive kidney failure. Several prognostic tools - Berden classification, Mayo Clinic Chronicity Score (MCCS), Percentage of ANCA Crescents Score (PACS), ANCA Renal Risk Score (ARRS), and the improved ANCA Kidney Risk Score (AKRiS) - have been developed to predict renal outcomes, but data on their performance in anti-neutrophil cytoplasmic antibody (ANCA)-negative patients remain scarce. This study evaluated the prognostic value of these scoring systems in a PiNCGN cohort.

We retrospectively analyzed 100 patients with biopsy-proven PiNCGN. Demographic, laboratory, and histopathological data were collected, and patients were categorized according to all five risk scores. Outcomes included all-cause mortality and end-stage kidney disease (ESKD), defined as initiation of dialysis or kidney transplantation. The Kaplan-Meier survival and log-rank tests were applied to assess prognostic discrimination.

Of 100 patients, 86 were ANCA-positive and 14 ANCA-negative. Median age was 58.5 years; 41% were male. Induction therapy consisted of glucocorticoids with cyclophosphamide or rituximab, followed by azathioprine, mycophenolate, or rituximab for maintenance. Over a median follow-up of 12 months, 52 patients died and 21 progressed to ESKD. In ANCA-positive patients, ARRS and AKRiS best predicted ESKD. In ANCA-negative patients, AKRiS additionally predicted both mortality and ESKD. Other scores demonstrated limited utility.

ARRS and AKRiS provided the most consistent prognostic stratification in PiNCGN, with AKRiS uniquely retaining value in ANCA-negative patients. These findings highlight the potential clinical utility of composite scoring systems across the spectrum of PiNCGN, although prospective multicenter validation remains warranted.