LAUSR

Background Interstitial lung disease (ILD) is related to specific radiographic features in lung imaging and/or the presence of restrictive disorders in pulmonary function tests (PFTs). ILD is one of the leading causes of death in systemic sclerosis patients. Major risk factors of ILD associated with SSc (SSc-ILD) include male sex, diffuse type of cutaneous SSc and presence of anti-Scl-70 antibodies. Objectives Taking into account that anti-Scl-70 antibody is an unfavorable predictor of ILD, we have assessed the time course of FVC and DLco in anti-Scl-70-positive and anti-Scl-70-negative patients. Methods It was a longitudinal study involving 77 pts with SSc-ILD (mean age was 46,2±13,4; 69% have limited subset of the disease; 93% were female). The mean duration of follow up was 58,9±11,4 months. Pts. were investigated with HRCT twice (at first visit and at the end of the study) and according the CT-changes were divided into 3 groups: the 1st group (16 pts) with improvement; 2nd group (39 pts) without any changes and 3rd group (22 pts) with worsening of fibrosis. We evaluated the forced vital capacity (FVC), diffusing capacity of carbon monoxide (DLCO) in one year and in 5 years and anti-Scl-70 antibodies at the end of the study. Results In anti-Scl-70-negative patients the average FVC remained unchanged within a year (91.4 ± 17.4% и 91.6 ± 17%, respectively), however, within 5 years FVC significantly increased to 99.1 ± 20% (p < 0.001), while in anti-Scl-70-positive patients the average FVC was lower at the baseline and remained virtually unchanged both 1 year and 5 years later (85.4 ± 17.3%. 85.5 ± 17 и 86 ± 21%, respectively), as a result in 5 years’ time the average FVC in anti-Scl-70-negative patients was significantly higher than in anti-Scl-70-positive patients (p = 0.009). At the baseline average DLco were below normal and were similar in anti-Scl-70-positive and anti-Scl-70-negative patients: 60 ± 19% и 61.2 ± 14.3% respectively (p & gt;0,05). Within 1 year DLco significantly decreased in all patients, however anti-Scl-70-positive patients demonstrated more pronounced DLco decrease to 53.4 ± 17.2% (p & lt;0.0001), while in anti-Scl-70-negative patients it was less pronounced to 57.2 ± 12.8% (p<0.05), respectively. Within 5 years significant DLco decrease was found only in anti-Scl-70-positive patients: 53.9 ± 16.4% (p<0.001). The time courses of DLco in anti-Scl-70-positive and anti-Scl-70-negative patients by group are shown in Table 1. Significant DLco decrease over the 5-year period was observed in Group 2 and Group 3, and the lowest DLco (<50%) were observed in Group 3.Table 1 The time course of DLco in anti-Scl-70-positive and anti-Scl-70-negative patients by group over the 5 year observation period Observation period Group 1 Group 2 Group 3 With anti-Scl-70(n = 4) Without anti-Scl-70(n = 11) With anti-Scl-70(n = 19) Without anti-Scl-70(n = 17) With anti-Scl-70(n = 17) Without anti-Scl-70(n = 3) In 1 year(M ± δ) 78.5 ± 18 61.5 ± 18 62 ± 19 64.1 ± 11 52 ± 17 64 ± 1.8 In 5 years(M ± δ) 70 ± 12.5 57 ± 14 56 ± 14 61.5 ± 9 45 ± 16 52 ± 7 P > 0.05 > 0.05 < 0.05 > 0.05 < 0.05 > 0.05 Conclusion Therefore, the presence of anti-Scl-70 antibodies was associated with significantly lower pulmonary function parameters specifically in pts with progressive ILD. Disclosure of Interests None declared