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Abstract: SA-PO973

ANCA Renal Risk Score (ARRS) 2023: The Updated and Revised ARRS

Session Information

Category: Glomerular Diseases

  • 1402 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Bate, Sebastian G., Manchester University NHS Foundation Trust, Manchester, United Kingdom
  • Tan, Pek Ghe, Imperial College London, London, London, United Kingdom
  • Scott, Jennifer, The University of Dublin Trinity College, Dublin, Ireland
  • Chapman, Gavin, The University of Edinburgh Division of Health Sciences, Edinburgh, Edinburgh, United Kingdom
  • Brown, Nina, Northern Care Alliance NHS Foundation Trust Salford Care Organisation, Salford, United Kingdom
  • Floyd, Lauren, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom
  • Ilyas, Duha, Manchester University NHS Foundation Trust, Manchester, United Kingdom
  • Martin-Nares, Eduardo, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran Departamento Endocrinologia y Metabolismo de Lipidos, Ciudad de Mexico, Ciudad de México, Mexico
  • Lees, Jennifer S., Queen Elizabeth University Hospital, Glasgow, United Kingdom
  • Stevens, Kate I., Queen Elizabeth University Hospital, Glasgow, United Kingdom
  • Brilland, Benoit, CHU d’Angers, Angers, France
  • Augusto, Jean francois, CHU d’Angers, Angers, France
  • Aydin, Mehmet Fethullah, Bursa Uludag Universitesi, Bursa, Bursa, Turkey
  • Hinojosa-Azaola, Andrea, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran Departamento Endocrinologia y Metabolismo de Lipidos, Ciudad de Mexico, Ciudad de México, Mexico
  • Dhaygude, Ajay Prabhakar, Lancashire Teaching Hospitals NHS Foundation Trust, Preston, United Kingdom
  • Wiech, Thorsten, Universitatsklinikum Hamburg-Eppendorf, Hamburg, Hamburg, Germany
  • Bajema, Ingeborg M., Universiteit Groningen Afdeling Gezondheidswetenschappen, Groningen, Groningen, Netherlands
  • Jayne, David R.W., Addenbrooke's Hospital, Cambridge, United Kingdom
  • Jennette, J. Charles, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States
  • Pusey, Charles D., Imperial College London, London, London, United Kingdom
  • Dhaun, Neeraj, The University of Edinburgh Division of Health Sciences, Edinburgh, Edinburgh, United Kingdom
  • Little, Mark Alan, The University of Dublin Trinity College, Dublin, Ireland
  • Tesar, Vladimir, Univerzita Karlova Prirodovedecka fakulta, Praha, Czechia
  • Geetha, Duvuru, Johns Hopkins University, Baltimore, Maryland, United States
  • Brix, Silke R., Manchester University NHS Foundation Trust, Manchester, United Kingdom

Group or Team Name

  • ARRS Working Group.
Background

Reliable prediction tools are needed to improve prognostication and personalisation of treatment in anti-neutrophil cytoplasmic antibody (ANCA) glomerulonephritides (GN). We aimed to update the ANCA Renal Risk Score (ARRS) prediction model.

Methods

We collated a retrospective multicentre international longitudinal cohort from referral centres and registries across the globe to revise the ARRS in a validation and recalibration study. The primary endpoint was end stage kidney disease (ESKD) and patients were censored at last follow-up. Cox proportional hazards models were used to reweight risk factors and develop a modified scoring system. Kaplan-Meier estimates, Harrell’s C statistics and calibration plots were used to assess model performance.

Results

Of a total of 1591 patients, 1439 were included in the final analyses (959 in the development cohort, 52% male, median age 64 years). The ARRS demonstrated a discrimination of C=0.800, comparable to the original cohort. Updating the model found an additional useful cut-off for kidney function (K), and serum creatinine replaced glomerular filtration rate which provided higher reliability (K0: <250 μmol/l = 0 points, K1: 250-450 μmol/l = 4 points, K2: >450 μmol/l = 11 points). The risk points for the percentage of normal glomeruli (N) and interstitial fibrosis and tubular atrophy (T) were reweighted (N0: >25% = 0 points, N1: 10-25% = 4, N2: < 10% = 7, T0: none, mild or < 25% = 0 points, T1: ≥ mild-moderate or ≥ 25% = 3 points). We created four risk groups based on the sum of points: low (0 – 4 points), moderate (5 – 11), high (12 – 18) and an additional very high-risk (21). The model discrimination was C=0.831 and a supplemental continuous model was developed to supply a patient-specific annual risk. Three-year kidney survival was 96%, 79%, 54%, and 19%. The ARRS23 performed similarly well in the validation cohort with excellent calibration.

Conclusion

We demonstrated the out-of-sample validity of the ARRS and present the modified and improved score to optimise prognostication and risk stratification for clinical practice and trials.

Funding

  • Government Support – Non-U.S.