ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 0722

Estimating two-year risk of relapse in individuals with ANCA-associated vasculitis in a randomized controlled trial of plasma exchange and glucocorticoids

Mats Junek1, Quazi Ibrahim2, Peter Merkel3, Eswari Vilayur4, Ron Wald5, Todd Fairhead6, David Massicotte-Azarniouch6, Louis Girard7, Christian Pagnoux8, Nader Khalidi2, David Jayne9 and Michael Walsh2, 1St Joseph's Healthcare Hamilton, Hamilton, ON, Canada, 2McMaster University, Hamilton, ON, Canada, 3University of Pennsylvania, Philadelphia, PA, 4John Hunter Hospital, Newcastle, New South Wales, Australia, 5St Michael's Hospital, Toronto, ON, Canada, 6University of Ottawa, Ottawa, ON, Canada, 7University of Calgary, Calgary, AB, Canada, 8Mount Sinai Hospital, Toronto, ON, Canada, 9University of Cambridge, Cambridge, United Kingdom

Meeting: ACR Convergence 2025

Keywords: ,

Session Information

Date: Sunday, October 26, 2025

Title: (0711–0730) Vasculitis – ANCA-Associated Poster I

Session Type: Poster Session A

Session Time: 10:30AM-12:30PM

Background/Purpose: People with anti-neutrophil cytoplasm antibody (ANCA) associated vasculitis (AAV) vary in their risk of a relapse of disease. Estimating an individual’s risk may inform decision-making around their care.

Methods: We developed and internally validated a model to predict the risk a relapse of AAV using a cohort of patients from a randomized controlled trial with severe AAV defined as an eGFR < 50 mL/min/1.73m2 or diffuse alveolar haemorrhage. We estimated risk of relapse within two years of remission. Candidate variables to estimate risk of relapse were selected using Lasso regression in Cox proportional hazard time-to-event models. Non-parametric estimates of baseline survival at two years were used to obtain absolute estimates of risk of relapse. Frequency of variable inclusion in the model was assessed using the same procedure across 1000 bootstrap samples. We assessed model discrimination using concordance statistics, and calibration using the mean calibration slope.

Results: 649 participants met inclusion criteria of whom 100 relapsed within 2 years. The final model included participant sex, type of induction immunosuppression, ANCA serotype, non-hemorrhagic respiratory involvement, mucous membrane/eye involvement, and eGFR at remission (Table 1). Variables selected for inclusion in the final model were selected across 76% or more bootstraps. The optimism-corrected area under the receiver operator curve statistic was 0.71 (95% confidence interval [CI] 0.71-0.71). The mean calibration slope was 0.99 (95% CI 0.65-1.34). 18 (11.1%) of individuals at the lowest quartile of estimated risk of relapse experienced relapse and 58 (35.8%) of those at the highest quartile of estimated risk of relapse (Figure 1).

Conclusion: Our model accurately estimates the risk of relapse for individuals with AAV within two years after remission.

Supporting image 1Table 1: Cox proportional hazard regression model studying association between relapse within 2 years for individuals with ANCA-associated vasculitis. Overall model significance: Likelihood ratio chi-squared = 53.35, p-value < 0.001 for the final model and 69.78.

Supporting image 2Figure 1: Kaplan Meier curve of relapse-free survival based on quartile of predicted risk of relapse as well as the risk of relapse contained within each quartile

Disclosures: M. Junek: AbbVie/Abbott, 1, Roche, 5; Q. Ibrahim: None; P. Merkel: AbbVie, 2, 5, Alpine, 2, Amgen, 2, 5, ArGenx, 2, AstraZeneca, 2, 5, Boehringer-Ingelheim, 2, 5, Bristol-Myers Squibb (BMS), 2, 5, CSL Behring, 2, Eicos, 5, Electra, 5, GlaxoSmithKlein (GSK), 2, 5, iCell, 2, Interius, 2, Kinevant, 2, Kyverna, 2, 11, Lifordi, 11, Metagenomia, 2, Neutrolis, 2, 5, 11, Novartis, 2, NS Pharma, 2, Otsuka, 2, Q32, 2, 11, Quell, 2, Regeneron, 2, Sanofi, 2, Sparrow, 2, 11, Takeda, 2, 5, UpToDate, 9, Vistera, 2; E. Vilayur: None; R. Wald: None; T. Fairhead: None; D. Massicotte-Azarniouch: None; L. Girard: None; C. Pagnoux: AstraZeneca, 1, ChemoCentryx, 1, GlaxoSmithKlein(GSK), 1, 5, InflaRx GmbH, 1, otsuka, 1, 5, Pfizer, 1, 5, Roche, 1, 5; N. Khalidi: AbbVie/Abbott, 5, Bristol-Myers Squibb(BMS), 5, GlaxoSmithKlein(GSK), 6, Mallinckrodt, 6, NS Pharma, 5, Otsuka, 6, Roche, 2, Sanofi, 5; D. Jayne: Alentis, 2, 11, Amgen, 2, 6, AstraZeneca, 1, 2, 6, Aurinia, 1, 11, Boehringer-Ingelheim, 2, 6, Bristol-Myers Squibb(BMS), 2, 6, ChemoCentryx, 2, 6, Chinook, 1, Chugai, 2, 6, CSL Vifor, 2, 6, Fate, 2, GlaxoSmithKlein(GSK), 2, 6, GSK, 1, Hansa, 1, Novartis, 1, 2, 6, Otsuka, 2, Roche, 2, 6, Takeda, 1, 2, 6; M. Walsh: AstraZeneca, 2, Bayer, 2, GlaxoSmithKlein(GSK), 2, Novo Nordisc, 12, Support for event adjudication committees, Otsuka, 2, Visterra, 2.

To cite this abstract in AMA style:

Junek M, Ibrahim Q, Merkel P, Vilayur E, Wald R, Fairhead T, Massicotte-Azarniouch D, Girard L, Pagnoux C, Khalidi N, Jayne D, Walsh M. Estimating two-year risk of relapse in individuals with ANCA-associated vasculitis in a randomized controlled trial of plasma exchange and glucocorticoids [abstract]. Arthritis Rheumatol. 2025; 77 (suppl 9). https://acrabstracts.org/abstract/estimating-two-year-risk-of-relapse-in-individuals-with-anca-associated-vasculitis-in-a-randomized-controlled-trial-of-plasma-exchange-and-glucocorticoids/. Accessed .

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/estimating-two-year-risk-of-relapse-in-individuals-with-anca-associated-vasculitis-in-a-randomized-controlled-trial-of-plasma-exchange-and-glucocorticoids/