Prevalence and outcomes of pleuroparenchymal fibroelastosis in patients with non-tuberculous mycobacterial pulmonary disease: a French retrospective cohort study.

Background: Pleuroparenchymal fibroelastosis (PPFE) is a recently described interstitial lung disease associated with multiple diseases. Japanese studies found an association between PPFE and non-tuberculous mycobacterial pulmonary disease (NTM-PD), but no study has been conducted in Europe. We aimed to assess in France the prevalence of PPFE among patients with NTM-PD, and to look for risk factors of PPFE and mortality. Method: We conducted a retrospective cohort study in two French hospitals from January 1, 2020 to March 31, 2022. NTM-PD patients were included if they had at least one chest high-resolution computed tomography (HRCT) scan available, to identify the presence or the occurrence of radiological patterns of PPFE based on established criteria. Risk factors for PPFE and five-year mortality were assessed using univariate and multivariate analyses. Results: A total of 101 patients were included, PPFE was identified in 14 patients (13.9%) and was associated with a lower body mass index (BMI) at diagnosis [odds ratio (OR) 21.4, 95% confidence interval (CI): 3.5-415.3 for BMI <18 kg/m² with PPFE, P<0.001] in multivariate exploratory analysis. Seventy patients had a minimum of two chest HRCT scans spaced by at least 3 years. Among them, 10 had PPFE: 8 at NTM-PD diagnosis, and 1 PPFE developing from pleural caps 9 years later. Five-year mortality could be studied for 71 patients. PPFE was associated with 5-year mortality (OR 6.3, 95% CI: 1.3-29.9, P=0.02) in multivariate exploratory analysis. Conclusions: PPFE is frequently observed among patients with NTM-PD, and seems to be associated with a lower BMI and the 5-year mortality, supporting its systematic screening in this population.