Interstitial lung disease in patients with systemic scleroderma: approaches to predicting lesion volume

Abstract

Aim. To determine the factors that contribute to the prediction of the volume of pulmonary lesion in patients with systemic scleroderma (SSc).Materials and methods. The analysis included patients with SSc observed in the Registry of Myositis, systemic sclerosis and mixed connective tissue disease (REMISSIS), who underwent high-resolution computed tomography (HRCT) of the lungs. For the immunological characteristic, all patients were tested for anti-topoisomerase (anti-Scl-70), and anti-centromeric (anti-CENP-B) antibodies, and anticentromere antibodies (anti-Pm-Scl).Results. The study included 79 patients with SSc. There was 94.9 % women. Average age – 64.4 ± 11.5 years. Signs of interstitial lung disease (ILD), according to HRCT were detected in 50 patients. The largest extent of lung injury was noted in patients with SSc sine scleroderma (32.7 ± 29.3 %), a smaller extent in patients with diffuse form SSc (16.9 ± 17.1 %) and the lowest in patients with limited SSc (8.5 ± 14.2 %). In addition to the type of disease, the extent of lung injury in patients with SSc-ILD was statistically significantly higher in patients with arthralgia, dyspnea and the presence of antibodies to topoisomerase I and combined autoantibodies. Also, a statistically significant feedback was established with all indicators of the test with a 6-minute walk and forced vital capacity and a direct relationship with indicators of pulmonary artery systolic pressure. When evaluating the correlation between the extent of lung injury and the degree of dyspnea according to Borg, it was found that in patients who assessed dyspnea less than 3 points, the extent of lung injury was less than 25 %. Due to the high degree of correlation, a regression formula was created for the dependence of the extent of lung injury on the distance in the test with a 6-minute walk: extent of lung injury = (52.7–0.1) × distance 6MWT. A multivariate model was also obtained for predicting the extent of lung injury in SSc, in which the patient’s immunotype, distance in the 6-minute walk test, saturation after the 6-minute walk test, and the presence of dyspnea became the most effective.

Keywords

• systemic sclerosis
• interstitial lung disease
• extent of lung injury
• 6-minute walk test
• autoantibodies
• cross-sectional observational study
• multivariate model
• high-resolution computed tomography of the lungs