ANCA-associated vasculitis in idiopathic pulmonary fibrosis

Abstract

Rationale: Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor prognosis. Patients with IPF represent a heterogeneous population with several described clinical phenotypes. More recently, the development of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis in IPF patients, with an incidence higher than that in the general population, has drawn attention.Patient concerns: A 64-year-old woman previously diagnosed with IPF presented to the emergency department with hemoptysis and hypoxemic respiratory failure.Diagnoses: High-resolution chest computed tomography revealed bilateral ground-glass opacities associated with areas of consolidation superimposed on the patient's fibrotic background pattern. Diffuse alveolar hemorrhage was confirmed by the presence of hemorrhagic bronchoalveolar lavage fluid. Hematological and biochemical investigations revealed an inflammatory syndrome, moderate anemia, and rapidly progressive glomerulonephritis. Serological analysis revealed perinuclear antineutrophil cytoplasmic antibody positivity and high levels of antimyeloperoxidase antibodies antibodies. The patient underwent kidney biopsy, which revealed necrotizing glomerulonephritis. Clinical and laboratory findings were diagnostic of microscopic polyangiitis with lung and renal involvement.Interventions: Cyclophosphamide in combination with methylprednisolone was administered as remission induction therapy. The maintenance therapy consisted of mycophenolate mofetil and prednisone.Outcomes: The patient achieved clinical, radiological, and serological remission within six weeks of treatment.Lessons: The association between IPF and ANCA-associated vasculitis may represent a distinct clinical phenotype. Autoimmune testing for ANCAs should be considered part of the diagnostic work-up and follow-up of patients with IPF because of the clinical and therapeutic implications of developing vasculitis in an already vulnerable patient.

Presentation and progression of MPO-ANCA interstitial lung disease

“…Clinical features compatible with MPA diagnosis develop in up to 25% MPO-ANCA-positive patients whose ILD was initially classified as idiopathic pulmonary fibrosis (IPF) [ [17] , [18] , [19] , [20] ]. However, there is still debate over whether ANCA should be investigated systematically or on a case-by-case basis in the evaluation of patients with suspected IPF [ [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] ]. The spectrum of ANCA-associated ILD, particularly MPO-ANCA ILD, and the extent of immune dysregulation thus remain subjects that require further elucidation.…”

Clinical and Prognostic Significance of p-ANCA Positivity in Idiopathic Pulmonary Fibrosis: A Retrospective Observational Study

“…Among systemic vasculitides, Microscopic Polyangiitis (MPA) is strongly associated with Perinuclear Anti Neutrophil Cytoplasmic Antibody (p-ANCA) positivity, and it is the vasculitis most frequently associated with interstitial lung disease (ILD), although patients with ILD and ANCA positivity without manifestations of systemic vasculitis have also been reported [4]. In addition, ANCA-positive conversion has been described in patients with an initial diagnosis of idiopathic pulmonary fibrosis (IPF) [5], with manifestations of systemic vasculitis in some patients [6]. The onset of ILD may precede or be concomitant with the development of a complete vasculitis syndrome in most individuals.…”