Prevalence and risk factors of interstitial lung disease in early systemic sclerosis and systemic sclerosis sine scleroderma: a cross-sectional study

Introduction: Introduction: Interstitial lung involvement (ILD) is one of the main complications in patients with systemic sclerosis (SSc), representing a significant cause of mortality. According to previous reports, ILD can appear in many patients from early stages (eSSc) to patients with established disease without skin involvement (ssSSc). Methods: Patients were included in the ssSSc group if they met the ACR/EULAR 2013 classification criteria and had a Rodnan skin score 0. In the eSSc group, if they did not meet the former criteria but fulfilled the VEDOSS criteria. Patients must have undergone a high-resolution chest CT scan within the last six months. Experts in this complication reviewed the images, and the percentage of patients with ILD in each group was determined. A univariate and multivariate analysis was performed to determine potential risk factors for ILD, including conventional risk factors and clinical findings in both groups. Odds Ratios and their 95% confidence intervals were estimated. Statistical significance was considered when p was less than 0.05. Results: Data from 353 patients with SSc: 65 (18.4%) with ssSSc, and 75 (21.2%) eSSc (VEDOSS patients) were included in the study. The proportion of patients with ILD was 38% in the ssSSc group and 20% in VEDOSS patients group (p=0.03). Regarding risk factors, anticentromere antibody positivity was found to have a protective effect (OR 0.17, 95% CI 0.03-0.44, p=0.001), and anti-SCL-70 antibody presence was identified as a risk factor for ILD (OR 35.8, 95% CI 2.6-492, p=0.007). No association was found with male gender, digital ulcers, puffy fingers, or capillaroscopic findings. Conclusions: ILD in patients with SSc can occur from early stages or without skin involvement. Thus, an active search for ILD is warranted, as it can be present in 1 out of 5 patients with these disease subsets.