CHARACTERIZATION OF INTERSTITIAL LUNG DISEASE IN THE PRESENCE OF ANTINEUTROPHIL CYTOPLASMIC ANTIBODIES
Authors: Khai-Tuan Andrew Bui et al.
ANCA-related interstitial lung disease (ILD) has recently been described. The significance and evolution of this association remains unclear. in this retrospective study 265 patients with available ANCA results and at least two clinic visits were included with a mean follow-up duration of 69.3 (± 10.6) months. 26 (9.8%) showed ANCA positivity (proteinase 3 and/or myeloperoxidase). The most frequent final clinical diagnosis in the ANCA-negative group was idiopathic pulmonary fibrosis, whereas connective tissue disease-associated ILD was more prevalent in the ANCA-positive group. The most common patterns were usual interstitial pneumonia, nonspecific interstitial pneumonia and organizing pneumonia. A total of 17 (65.4%) patients with positive ANCA had a clinical diagnosis of ANCA-associated vasculitis (AAV) at some point during the follow-up period. In 5 (29.4%) patients, AAV developed following ILD diagnosis. Despite similar disease evolution of ANCA-positive ILD and ANCA-negative ILD, patients with ILD and positive ANCA received more glucocorticoids, immunosuppressive therapy and had more hospitalizations of all cause.
It is important to recognize that ILD may precede the development of AAV. The described high prevalence of ANCA-positivity in ILD argues for a rather liberal search for MPO/PR3 antibodies in ILD.