Bronchiectasis as the Sentinel Manifestation of ANCA ‐Associated Vasculitis: A Case Report and Literature Review

ABSTRACT Bronchiectasis in ANCA‐associated vasculitis (AAV) is usually attributed to structural damage from established disease. We report a 74‐year‐old woman with 7 years of culture‐negative bronchiectasis, incompletely responsive to corticosteroids, in whom AAV was diagnosed after she developed palpable purpura, haemoptysis, hematuria and acute kidney injury. MPO‐ANCA was markedly elevated (250.2 U/mL; reference 2 at 15 months) and near‐complete resolution of the pulmonary consolidations. This case describes an airway‐first AAV phenotype. She met none of the trigger features that current guidelines use to prompt autoimmune screening, identifying a diagnostic blind spot in progressive culture‐negative bronchiectasis without systemic features.