AAV Relapse Risk — SCE Rheumatology MCQ

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ModerateVasculitisAAV Relapse RiskSCE Rheumatology

A 58-year-old man with ANCA-associated vasculitis has achieved remission after cyclophosphamide-based induction and is starting remission-maintenance treatment. Which baseline characteristic is most consistently associated with a higher risk of future relapse?

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Correct answer: E — PR3-ANCA rather than MPO-ANCA

PR3-ANCA specificity is associated with a substantially higher relapse risk than MPO-ANCA specificity in ANCA-associated vasculitis. This association persists beyond the conventional clinical labels of GPA and MPA and is supported by large cohort data and a systematic review of patients receiving cyclophosphamide induction. ANCA specificity is therefore relevant when assessing relapse risk and planning maintenance treatment. Age, sex, ethnicity and body mass index may influence disease presentation, comorbidity or treatment toxicity, but none is as consistently established as PR3-ANCA positivity as a predictor of relapse. Serial changes in ANCA may provide additional prognostic information, but an ANCA rise alone should not be equated with clinical relapse.

Reference: He P et al. Prevalence and risk factors of relapse in patients with ANCA-associated vasculitis receiving cyclophosphamide induction: a systematic review and meta-analysis of large observational studies. 2021. https://pubmed.ncbi.nlm.nih.gov/33677596/