Abstract: SA-PO654
Validation of a New Renal Risk Score for Patients with ANCA-GN
Session Information
- Glomerular Diseases: ANCA, Anti-GBM, Kidney Biopsy
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Bostad, Lars Sigurd, Haukeland University Hospital, Bergen, Norway
- Bostad, Leif, Haukeland University Hospital, Bergen, Norway
- Fismen, Anne-Siri, Western Norway University of Applied Sciences, Bergen, Norway
- Knoop, Thomas, Haukeland University Hospital, Bergen, Norway
- Bjoerneklett, Rune, Haukeland University Hospital, Bergen, Norway
Background
A new predicting model, renal risk score in ANCA associated GN, was published by Brix et al. in Kidney International Dec. 2018. It is a general principle that prognostic models need external validation for determination of generalizability.
Methods
Patients with ANCA-GN and risk factors included in the prognostic model; GFR > (G0) vs ≤15 ml/min/1,73m2)(G1), IF ≤ (T0) vs >25%(T1), and percentage of normal glomeruli (N0 >25%/N1 10-25%/N2 <10%), were identified in the Norwegian Kidney Biopsy Registry. According to the model, risk score points were assigned: G1=3, N1=4, N2=6, T1=2. Further, risk stratification was performed according to the model as follows: Low risk = 0-point, intermediate risk = 2-7 point, high-risk 8-11. Observation period was from the date of biopsy to date of ESRD/death/3 years post biopsy. ESRD during follow-up were identified by record linkage with The Norwegian Renal Registry. Kaplan-Meier and the ROC statistics were used to evaluate the prognostic performance of the model.
Results
We identified 250 patients with ANCA-GN of whom 43 progressed to ESRD during follow up. At 3-years of follow up cumulative risk of ESRD was 3.3% in low-, 22.4% in intermediate- and 44.0% in the high-risk group, p<0.001. In the ROC analysis AUC was 0.77 when assessed as 3 risk groups and 0.78 when assessed according to number of risk points.
Conclusion
We demonstrate that the prognostic value of this new prediction model for patients with ANCA-GN is good with an AUC of nearly 0.8 in the ROC analysis. However, the use of percentage normal glomeruli instead of glomerular classification (focal/crescentic/mixed/sclerotic) needs confirmation in larger cohorts. Further, the choice of grading initial eGFR in only 2 groups > versus ≤15 ml/min/1.73 m2 can also be questioned. It is also slightly surprising that demographic risk factors like age and gender are not included.