Evaluation of a renal risk score for Japanese patients with ANCA-associated glomerulonephritis in a multi-center cohort study

Abstract

BackgroundIn patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis, prediction of renal survival should guide the choice of therapy, but a prediction of the histological classification has inconsistencies.ObjectivesTo evaluate the usefulness of renal risk score (RRS) for Japanese patients with ANCA-associated glomerulonephritis (AAGN) and compare the prediction for end-stage renal disease (ESRD) between RRS and the histological classification.MethodsWe retrospectively analyzed 96 patients with AAGN who underwent a renal biopsy. Renal survival was categorized by RRS, and the histological classification was assessed separately. We compared the predictive values for RRS and the histological classification.ResultsThe median observational period was 37.5 (interquartile range [IQR] 21.5–77.0) months. The median RRS point at the time of renal biopsy was 2 (IQR 0–7.8), and the patients were categorized into low- (n = 29), medium- (n = 43), and high-risk groups (n = 24) using RRS. As expected, the renal prognosis was the worst in the “high-risk” group and the best in the “low-risk” group. In the histological classification, the survival deteriorated progressively from “focal” (best) to “mixed,” “crescentic,” and “sclerotic” (worst) classes, different from the order in the original proposal for this system. Multivariable Cox regression analysis revealed that RRS was independently associated with ESRD. The difference in prediction for renal survival between RRS and the histological classification was not significant using area under receiver-operating-characteristic curves.ConclusionWe evaluated the usefulness of RRS in Japanese patients with AAGN and found it a stable predictor of renal survival in such patients.

Development of a Kidney Prognostic Score in a Japanese Cohort of Patients With Antineutrophil Cytoplasmic Autoantibody Vasculitis

“… 15 Despite differences in patient characteristics, such as race and types of ANCA, the ARRS has been validated to better reflect renal prognosis compared with the glomerular classification proposed by Berden et al. 24 , 31 …”

“… 28 Regarding renal pathology, 3 nephrologists knowledgeable in the discipline reassessed and discussed glomerular, tubular, interstitial, and vascular lesions at the same time. 24 , 29 , 30 , 31 Regarding renal pathological findings, we referred to the report by Berden et al. and The Oxford classification of IgA nephropathy.…”

“… 8 and the ARRS, and have demonstrated the correlation between glomerular classification and renal prognosis. 21 , 22 , 23 , 24 However, these studies had a small sample size, and no large cohort studies have been reported to date. Moreover, no studies have comprehensively analyzed important renal pathological findings, such as glomerular, interstitial, tubular, and vascular lesions.…”

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

“…There are some differences between our and other studies. Patients with renal-limited vasculitis, which accounts for around 20% of our cases, were not included in other studies [ 39 , 40 , 47 , 49 ]. In the cohort of An et al ., in comparison with our cohort, more patients were MPO-ANCA positive (88% vs 50.6% respectively), younger (57.5 vs 63.8 years), and with more recent and shorter period of enrollment (from 1997 to 2018 vs 1990 to 2022).…”