Queensland Renal Biopsy Registry Sub Study: Multi-centre prospective observational cohort study investigating association between anti-neutrophil cytoplasmic antibodies (ANCA) results and relapse of ANCA associated vasculitis

ANCA-associated vasculitis is an autoimmune condition where the immune system mistakenly attacks small blood vessels throughout the body — particularly in the kidneys and lungs. It can go into remission, but relapses are common and can cause serious organ damage. Blood tests measuring ANCA (anti-neutrophil cytoplasmic antibodies) levels are already used to help diagnose this condition, but it's unclear whether a rise in ANCA levels reliably predicts an upcoming relapse. This study will regularly monitor ANCA levels in patients with vasculitis over time to determine whether a two- to four-fold rise in ANCA levels consistently precedes a clinical flare by up to 6 months. If this proves true, doctors could use ANCA monitoring to intervene earlier and potentially prevent organ damage from relapses. You may be eligible if you have been diagnosed with ANCA-associated vasculitis based on laboratory, imaging, or biopsy results, and are already enrolled in the Queensland Renal Biopsy Registry. Those who test ANCA-negative would not be eligible.