Interstitial lung disease in patients with anti-neutrophil cytoplasm antibody-associated vasculitis: an update on pathogenesis and treatment

Abstract

Purpose of review Interstitial lung disease (ILD) is now recognized as a common complication of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV), especially myeloperoxidase (MPO)-ANCA-positive AAV and microscopic polyangiitis (MPA). This review focuses on current concepts pertaining to the pathogenesis, clinical assessment, and management of AAV-ILD. Recent findings ILD is typically identified before or at the onset of systemic AAV, and usual interstitial pneumonia (UIP) is the most common CT pattern. MPO-ANCA production, neutrophil extracellular traps formation, reactive oxidative species production, complement activation, environmental exposures, and genetic background might play a role in the pathogenesis of AAV-ILD. Recent research has identified promising biomarkers as potential diagnostic and prognostic tools in AAV-ILD. The optimal treatment for AAV-ILD is not well defined but might rely on a combination of immunosuppression and antifibrotics, especially in patients with progressive lung fibrosis. Despite the effectiveness of current therapies for AAV, the outcome of patients with AAV-ILD remains poor. Summary ANCA screening should be considered in patients with newly diagnosed ILD. Management of AAV-ILD should be overviewed by a collaborative team comprising vasculitis experts and respirologists. Graphical abstract http://links.lww.com/COPM/A33

Significance of clinical‐immunological patterns and diagnostic yield of biopsies in microscopic polyangiitis and granulomatosis with polyangiitis

“…However, peripheral nerve involvement, which was previously found without differences between both AAV [11,13,15], occurred more frequent in our MPA patients. As in previous AAV cohorts [3,4], ILD occurred more often in our patients with MPA and MPO-ANCA than in those with GPA and PR3-ANCA. In this sense, the presence of ILD, mainly UIP pattern, has been previously recognized as a poor prognostic factor associated with increased mortality [4].…”

“…As in previous AAV cohorts [3,4], ILD occurred more often in our patients with MPA and MPO-ANCA than in those with GPA and PR3-ANCA. In this sense, the presence of ILD, mainly UIP pattern, has been previously recognized as a poor prognostic factor associated with increased mortality [4].…”

“…Regarding MPA and GPA, several manifestations contribute to differentiate them, such as granulomatous inflammation involving ear, nose, and throat (ENT) territories, lower airways, and orbital structures, which are prominent features of GPA but absent in MPA [1,2]. In addition, interstitial lung disease (ILD) has recently emerged as a relevant manifestation of AAV, mainly MPA, which may occur concomitantly or years before an overt systemic vasculitis [3][4][5][6]. For this reason, ILD has been included as part of the key items of the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for MPA [7].…”

Presentation and progression of MPO-ANCA interstitial lung disease

“…Avacopan might hold promise if MPO-ANCA ILD is complement-mediated. Empirical management approach to patients with MPO-ANCA ILD has been proposed [ 8 , 77 , 78 ] and there are no guidelines, apart from patients with overt MPA [ 79 ].

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Pneumothorax as a complication of respiratory failure – two case reports and literature review

“…ANCA antibody-associated vasculitis may account for the development of interstitial lung disease (ILD). The risk is higher when vasculitis is accompanied by MPO-ANCA positivity or microscopic vasculitis is present [30][31][32][33]. There are 2 categories of patients with ILD and ANCA antibodies: patients with overt systemic vasculitis (AAV-ILD), or patients without clinical features of systemic vasculitis (ANCA-ILD) [30].…”