AKRiS may be a useful prognostic tool for renal outcomes in Japanese patients with ANCA-associated glomerulonephritis, potentially providing better predictive accuracy compared to the ARRS.
Key Findings
Results
Both the ARRS and AKRiS demonstrated progressively worse renal survival with increasing risk categories in Japanese patients with AAGN.
109 patients with biopsy-proven AAGN were analyzed from 13 institutions in Nagasaki Prefecture between January 1995 and December 2019
Mean patient age was 69 years; 50% male
Both ARRS and AKRiS risk group separations were statistically significant (both p < 0.001) by log-rank test
Median observation period was 863 days (interquartile range 254.5–2034)
Results
AKRiS demonstrated higher discriminative accuracy than ARRS for predicting end-stage kidney disease in the ROC analysis.
Area under the curve (AUC) was 0.82 for AKRiS compared to 0.76 for ARRS
Both scores were assessed using Kaplan-Meier analysis, log-rank test, and receiver operating characteristic (ROC) curve analysis
The AKRiS is a revised version of the ARRS, first reported in 2024
Results
The study cohort was predominantly MPO-ANCA positive, consistent with the known epidemiology of ANCA-associated vasculitis in Japanese populations.
Myeloperoxidase-ANCA (MPO-ANCA) positivity was observed in 90.8% of patients
The cohort consisted of 109 patients with biopsy-proven AAGN
This high proportion of MPO-ANCA positivity is characteristic of Asian patient populations with AAGN
Results
Using the AKRiS classification, the majority of patients fell into the low- and medium-risk categories.
47 patients were classified as low-risk
39 patients were classified as medium-risk
15 patients were classified as high-risk
8 patients were classified as very high-risk
Background
The AKRiS had not previously been evaluated in Japanese patients prior to this validation study.
The ANCA Renal Risk Score (ARRS) was originally proposed in 2018 as a prognostic tool for renal outcomes in AAGN
The revised ANCA Kidney Risk Score (AKRiS) was reported in 2024
This retrospective multicenter study represents the first validation of AKRiS in a Japanese cohort
What This Means
This research examined whether a scoring tool called the ANCA Kidney Risk Score (AKRiS) could accurately predict which patients with a kidney disease called ANCA-associated glomerulonephritis (AAGN) would go on to develop kidney failure. The study looked back at records from 109 Japanese patients treated across 13 hospitals in Nagasaki Prefecture over a roughly 25-year period. Patients were assigned to low, medium, high, or very high risk groups based on their scores, and the researchers then checked how well those groupings predicted who actually developed end-stage kidney disease.
The results showed that both the older ARRS scoring tool and the newer AKRiS successfully separated patients into groups with meaningfully different rates of kidney survival — higher risk scores corresponded to worse outcomes. However, AKRiS performed somewhat better, with an area under the curve (a standard measure of predictive accuracy) of 0.82 compared to 0.76 for the older ARRS score. Notably, over 90% of patients in this Japanese cohort had a specific antibody type (MPO-ANCA), which is more common in Asian populations than in Western ones.
This research suggests that AKRiS may be a reliable tool for predicting kidney outcomes specifically in Japanese patients with AAGN, a population that had not previously been studied with this newer scoring system. Better risk prediction tools could help doctors tailor treatment intensity and monitoring to individual patients based on their likelihood of progressing to kidney failure.
Yamashita A, Kitamura M, Muta K, Iwata M, Otsuka E, Torigoe K, et al.. (2026). Validation study of the antineutrophil cytoplasmic antibody (ANCA) kidney risk score in Japanese patients with ANCA-associated glomerulonephritis.. Renal failure. https://doi.org/10.1080/0886022X.2026.2678630