Lung functional decline in patients with Interstitial Pneumonia with Autoimmune Features (IPAF)

Abstract

Rationale: IPAF (interstitial pneumonia with autoimmune features) includes patients with interstitial lung disease (ILD) who have a clinical features of connective tissue disease not fulfilling criteria of systemic autoimmune disorder. Aim of this study was to evaluate real-world clinical characteristics and lung functional changes in IPAF patients.

Methods: We identified 44 (8,6%) IPAF patients out if 512 ILD-team discussed cases during the period of January 2017 and June 2019. Twenty patients (45%) had baseline lung function and CO diffusion with at least one additional functional evaluation at minimum interval of 6 months. Pulmonary symptoms, lung function and response to therapy were analyzed.

Results: IPAF patients (age 69.9±11.5 years, 25% men) had baseline lung function of FVC: 82.9 ± 18.9 %pred, FEV1: 84.4 ± 22.4 %pred, DLCO 71.4 ± 22.4 %pred. Main symptoms included exercise induced dyspnea (77%), cough (66%), 73% presented with basal crackles and 48% with joint pain. Most common HRCT pattern was pUIP (n=19; 43%). Majority of patients were on immunosuppressive therapy (n=20; 45%), while 14 (32%) received antifibrotic treatment. Lung functional decline was present in 14 patients (average 427 ml and 10 % over 1 year period), while stable lung function was observed in 6 patients mainly receiving antifibrotic treatment.

Conclusion: IPAF is associated with FVC decline in a high proportion of patients in real life setting. Patients on antifibrotic therapies show slower decline, while combination with different anti-inflammatory drugs need further investigation to determine safety and effectivity of optimal treatment.