Characteristics and disease course of untreated patients with interstitial lung disease associated with systemic sclerosis in a real-life two-centre cohort
Moritz Scheidegger, Marouane Boubaya, Alexandru Garaiman, Imon Barua, Mike Oliver Becker, H. J. Bjørkekjær, Cosimo Bruni, Rucsandra Dobrota, Håvard Fretheim, Suzana Jordan, Øyvind Midtvedt, Carina Mihai, Anna‐Maria Hoffmann‐Vold, Oliver Distler, Muriel Elhaï
Abstract
BACKGROUND: Interstitial lung disease (ILD) is the leading cause of death in systemic sclerosis (SSc). According to expert statements, not all SSc-ILD patients require pharmacological therapy. OBJECTIVES: To describe disease characteristics and disease course in untreated SSc-ILD patients in two well characterised SSc-ILD cohorts. METHODS: Patients were classified as treated if they had received a potential ILD-modifying drug. ILD progression in untreated patients was defined as (1) decline in forced vital capacity (FVC) from baseline of ≥10% or (2) decline in FVC of 5%-9% associated with a decline in diffusing capacity for carbon monoxide (DLCO)≥15% over 12±3 months or (3) start of any ILD-modifying treatment or (4) increase in the ILD extent during follow-up. Multivariable logistic regression was performed to identify factors associated with non-prescription of ILD-modifying treatment at baseline. Prognostic factors for progression in untreated patients were tested by multivariate Cox regression. RESULTS: Of 386 SSc-ILD included patients, 287 (74%) were untreated at baseline. Anticentromere antibodies (OR: 6.75 (2.16-21.14), p=0.001), limited extent of ILD (OR: 2.39 (1.19-4.82), p=0.015), longer disease duration (OR: 1.04 (1.00-1.08), p=0.038) and a higher DLCO (OR: 1.02 (1.01-1.04), p=0.005) were independently associated with no ILD-modifying treatment at baseline. Among 234 untreated patients, the 3 year cumulative incidence of progression was 39.9% (32.9-46.2). Diffuse cutaneous SSc and extensive lung fibrosis independently predicted ILD progression in untreated patients. CONCLUSION: As about 40% of untreated patients show ILD progression after 3 years and effective and safe therapies for SSc-ILD are available, our results support a change in clinical practice in selecting patients for treatment.