The value of the current histological scores and classifications of ANCA glomerulonephritis in predicting long-term outcome.

Abstract

Three different histological scores-histopathologic classification (Berden), Renal Risk Score (RRS) and the Mayo Clinic Chronicity Score (MCCS)-for anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (ANCA-GN) were compared to evaluate their association with patient and kidney prognosis of ANCA-GN. Patients aged >18years with at least 1year of follow-up and biopsy-proven ANCA-GN entered this retrospective study. Renal biopsies were classified according to Berden's classification, RRS and MCCS. The first endpoint was end-stage kidney disease (ESKD), defined as chronic dialysis or estimated glomerular filtration rate <15mL/min/1.73 m2. The second endpoint was ESKD or death. Of 152 patients 84 were males, with median age of 63.8years and followed for 46.9 (interquartile range 12.8-119) months, 59 (38.8%) reached the first endpoint and 20 died. The Kaplan-Meier curves showed that Berden and RRS were associated with first (Berden: P=.004, RRS: P<.001) and second (Berden: P=.001, RRS: P<.001) endpoint, MCCS with the first endpoint only when minimal+mild vs moderate+severe groups were compared (P=.017), and with the second endpoint (P<.001). Among the clinical/histological presentation features, arterial hypertension [odds ratio (OR)=2.75, confidence interval (95% CI) 1.50-5.06; P=.0011], serum creatinine (OR=1.17, 95% CI 1.09-1.25; P<.0001), and the percentage of normal glomeruli (OR=0.97, 95% CI 0.96-0.99; P=.009) were the independent predictors of ESKD at multivariate analysis. When the three scores were included in multivariate analysis, RRS (OR=2.21, 95% CI 1.15-4.24; P=.017) and MCCS (OR=2.03, 95% CI 1.04-3.95; P=.037) remained predictive of ESKD, but Berden (OR=1.17, 95% CI 0.62-2.22; P=.691) did not. RRS and MCCS scores were independent predictors of kidney survival together with high serum creatinine and arterial hypertension at diagnosis, while Berden classification was not.