A rapidly progressive glomerulonephritis unmasking the etiology of “a presumed” idiopathic pulmonary fibrosis: About a case report and a review of the literature

Asmaa Mourachid; Abdelhadi Cheggali; Kawtar Idrissi Kaitouni; Selma Siham El Khayat; Ghislaine Medkouri; Mohamed Zamd; Naoufal Mtioui; Mohamed Benghanem

doi:10.5455/CRSM.20250511064052

Abstract
Introduction: Idiopathic pulmonary fibrosis (IPF) represents a fibrosing interstitial pneumonia of unknown cause. ANCA vasculitis, in particular microscopic polyangiitis (MPA), is noticed to be associated with interstitial lung disease and morbid pulmonary fibrosis.

Case presentation: We report to share our experience with a 71-year-old woman diagnosed six months earlier with idiopathic pulmonary fibrosis. She presented to the emergency department with hemoptysis, and the biological assessment revealed severe renal failure. A renal biopsy was realized, and the diagnosis of ANCA-associated vasculitis, specifically microscopic polyangiitis, was retained.

Description: This case study emphasizes the importance of considering ANCA-associated vasculitis in patients with pulmonary fibrosis, particularly when systemic symptoms or renal involvement arise. The primary goal of our case is to present the clinical, histological, and radiological signs of pulmonary fibrosis in association with ANCA vasculitis. We aim to increase awareness of this underappreciated association and highlight its occurrence in order to prevent morbidity, mortality, and especially renal impairment resulting from late diagnosis.

Key words: ANCA vasculitis, microscopic polyangiitis, renal failure, pulmonary fibrosis.