RT Journal Article SR Electronic T1 Thoracic involvement and imaging patterns in IgG4-related disease JF European Respiratory Review JO EUROPEAN RESPIRATORY REVIEW FD European Respiratory Society SP 210078 DO 10.1183/16000617.0078-2021 VO 30 IS 162 A1 Muller, Romain A1 Habert, Paul A1 Ebbo, Mikael A1 Graveleau, Julie A1 Groh, Mathieu A1 Launay, David A1 Audia, Sylvain A1 Pugnet, Gregory A1 Cohen, Fleur A1 Perlat, Antoinette A1 Benyamine, Audrey A1 Bienvenu, Boris A1 Gaigne, Lea A1 Chanez, Pascal A1 Gaubert, Jean Yves A1 Schleinitz, Nicolas YR 2021 UL http://err.ersjournals.com/content/30/162/210078.abstract AB Objective Immunoglobulin G4-related disease (IgG4-RD) is a rare orphan disease. Lung, pleura, pericardium, mediastinum, aorta and lymph node involvement has been reported with variable frequency and mostly in Asian studies. The objective of this study was to describe thoracic involvement assessed by high-resolution thoracic computed tomography (CT) in Caucasian patients with IgG4-RD.Methods Thoracic CT scans before treatment were retrospectively collected through the French case registry of IgG4-RD and a single tertiary referral centre. CT scans were reviewed by two experts in thoracic imagery blinded from clinical data.Results 48 IgG4-RD patients with thoracic involvement were analysed. All had American College of Rheumatology/European League Against Rheumatism classification scores ≥20 and comprehensive diagnostic criteria for IgG4-RD. CT scan findings showed heterogeneous lesions. Seven patterns were observed: peribronchovascular involvement (56%), lymph node enlargement (31%), nodular disease (25%), interstitial disease (25%), ground-glass opacities (10%), pleural disease (8%) and retromediastinal fibrosis (4%). In 37% of cases two or more patterns were associated. Asthma was significantly associated with peribronchovascular involvement (p=0.04). Among eight patients evaluated by CT scan before and after treatments, only two patients with interstitial disease displayed no improvement.Conclusion Thoracic involvement of IgG4-RD is heterogeneous and likely underestimated. The main thoracic CT scan patterns are peribronchovascular thickening and thoracic lymph nodes.Thoracic and lung involvements of IgG4-RD are heterogeneous and under-evaluated. Peribronchovascular involvement and lymph node enlargement are most frequent patterns. Interstitial disease pattern seems to be associated with a lower rate of treatment response. https://bit.ly/3B54HiR