[Fulminant alveolar hemorrhage: evolution of giant cell arteritis to ANCA-positive vasculitis?]. / Hémorragie intra-alvéolaire fulminante : transformation d'une maladie de Horton en vascularite ANCA-positive?

INTRODUCTION: Giant cell arteritis (GCA) is a granulomatous vasculitis of the large and medium size vessels with a remarkable sensitivity to corticosteroids, although it may be dependent to therapy. In rare cases, a vasculitis of the medium or small-size vessels may mimic, be associated to, or follow GCA. We report a case of GCA dependent to corticosteroids that was followed five years after diagnosis by an alveolar hemorrhage leading to the diagnosis of a possible Wegener's granulomatosis. EXEGESIS: A 70-year-old man had a diagnosis of GCA fulfilling the ACR criteria in 1999. Temporal artery biopsy revealed a typical histological pattern. The initial response to corticosteroids was excellent, but the patient became dependent to corticosteroids, so he was given methotrexate from 2002. Severe alveolar haemorrhage occurred in December 2004, leading to the diagnosis of possible ANCA positive, anti-proteinase 3 positive Wegener's granulomatosis. CONCLUSION: ANCA-positive vasculitis may complicate the course of GCA. This evolution should be rapidly recognized, because its treatment differs to that of GCA.