Short-Term Lung Function Changes and Predictors of Progressive Systemic Sclerosis-Related Interstitial Lung Disease

Background: Systemic sclerosis (SSc) involves multiple organ systems and has the highest mortality among connective tissue diseases. Interstitial lung disease is the most common cause of death among SSc patients and requires closer studies and follow-ups. This study aimed to identify lung function changes and predictors of progressive disease in systemic sclerosis-related interstitial lung disease (SSc-ILD). Methods: A retrospective study extracted SSc patients from an electronic database January 2002-July 2019. Eligible cases were SSc patients >age 15 diagnosed with SSc-ILD. Factors associated with progressive disease were analyzed by univariate and multivariate logistic regression analyses. Results: Seventy-eight SSc-ILD cases were enrolled. Sixty-five patients (83.3%) were female, with mean age of 44.7±14.4, and 50 (64.1%) were diffuse type SSc-ILD. Most SSc-ILD patients had crackles (75.6%) and dyspnea on exertion (71.8%), and 19.2% of the SSc-ILD patients had no abnormal respiratory symptoms but had abnormal chest radiographic findings. The most common diagnosis of SSc-ILD patients was non-specific interstitial pneumonia (43.6%). The lung function values of diffusing capacity of the lung for carbon monoxide (DLCO) and DLCO per unit alveolar volume declined in progressive SSc-ILD during a 12-month follow-up. Male and no previous aspirin treatment were the two significant predictive factors of progressive SSc-ILD with adjusted odds ratios of 5.72 and 4.99, respectively. Conclusion: This present study showed that short-term lung function had declined during the 12-month follow-up in progressive SSc-ILD. The predictive factors in progressive SSc-ILD were male sex and no previous aspirin treatment. Close follow-up of the pulmonary function tests is necessary for early detection of progressive disease.