PREDICTION OF INTERSTITIAL LUNG DISEASE PROGRESSION IN SYSTEMIC SCLEROSIS PATIENTS: A COHORT STUDY ANALYSIS

Introduction. Systemic sclerosis (scleroderma) is an autoimmune disease that often causes inflammatory fibrosing lesions of the pulmonary interstitial tissue, referred to as interstitial lung disease. It is associated with a significant reduction in survival and is the leading immediate cause of the systemic scleroderma patients’ death. Progression rate of interstitial lung disease varies greatly. Since the specific immunosuppressive and antifibrotic treatment is only justified in case of progressive lesions, predicting the interstitial lung disease progression is of great practical importance. Aim: To develop approaches to predicting the progression of interstitial lung disease in systemic scleroderma patients. Materials and Methods. Our analysis included the data of patients observed in the Registry of Myositis, Systemic Scleroderma and Mixed Diseases (REMISSiZ). Inclusion criteria: Age 18+ years, the proven case of systemic scleroderma, eligibility for ACR/EULAR (2013), and the repeated high-resolution computed tomography of lungs with an interval of at least 1 year. All patients underwent 6-minute walking tests. Results and Discussion. The study included 44 patients (43 women) aged 62.9 ± 11.5 years in average. The average follow-up duration was 530 ± 231 days. Radiological progression was associated with younger age, p=0.03, severity of Raynaud’s phenomenon, p=0.032, shorter disease duration, p=0.038, and shorter distance covered in the 6-minute walk test, p=0.05. The progression of functional impairment, determined by the dynamics of the distance covered in the 6-minute walk test, was associated with a decrease in blood oxygen saturation at rest (p=0.003), the severity of breath shortness according to the Borg scale (p=0.006), the initial distance of the 6-minute walk test (p <0.001), the presence of topoisomerase I antibodies (anti-Scl-70, p=0.034), and complaints of breath shortness (p=0.043) and dysphagia (p=0.034). As a result of reverse stepwise selection of variables, three independent significant predictors were selected from the above indicators: Dysphagia, anti-Scl-70, and the initial walking distance in the 6-minute walk test. Based on these indicators, a regression formula is presented for predicting the progression of functional impairment in systemic scleroderma patients. Conclusions. X-ray-detected progression of interstitial lung disease in systemic sclerosis patients is associated with younger age and Raynaud’s phenomenon severity. To predict the decline in the systemic sclerosis patients’ functionality, it is advisable to consider the presence of dysphagia and topoisomerase I antibodies (anti-Scl-70).