ASSESSMENT OF PREDICTIVE FACTORS OF PROGRESSION OF INTERSTITIAL LUNG DISEASE IN SYSTEMIC SCLEROSIS

Background: Recent studies failed to clearly demonstrate that cyclophosphamide is effective in the treatment of interstitial lung disease (ILD) in systemic sclerosis (SSc). This could relate to the lack of identification of a subgroup of patients at high risk of progression. Moreover, some data have suggested that esophagus involvement could be implicated in ILD related to SSc. Objectives: To identify predictive factors of ILD in SSc taking into account esophageal involvement. Methods: Consecutive SSc patients were prospectively investigated. At baseline patients underwent usual clinical and biological assessments together with pulmonary functional tests and complete gastro-esophageal assessment including manometry and fibroscopy. All patients were re-assessed after at least one year of follow-up for pulmonary functional tests. Our primary endpoint was the loss of more than 10% of forced vital capacity (FVC); our secondary endpoint was the loss of more than 15% of carbon monoxide diffusing capacity (DLCO). Univariate and multivariate comparisons were performed. In a subgroup of 47 patients, the kappa coefficient was calculated to assess the concordance between FVC decline and CT-scan deterioration during the follow-up. Results: 105 patients (90 women, mean age: 53±12 years) were included with a mean follow-up of 72±46 months. The median SSc duration at baseline was 1.5 years (IQ 25-75: 0-5), 45 patients (43%) had diffuse cutaneous SSc and 30 (29%) anti-topoisomerase I antibodies. Esophageal manometric impairment at baseline according to Hurwitz criteria was as follows: normal peristalsis (stage 1: 36%), uncoordinated peristalsis with normal pressure wave amplitude (stage 2: 9%), uncoordinated peristalsis with low pressure wave amplitude (stage 3: 28%), and aperistalsis with decreased lower esophageal sphincter pressure (stage 4: 27%). At baseline, 23 patients (22%) had FVC below 80% and 60/102 patients (59%) had DLCO below 80%. At the end of the follow-up, 29 patients (28%) had declined FVC and 39/98 patients (40%) had declined DLCO. In univariate analysis, predictive factors of declined FVC were diffuse cutaneous SSc (p=0.001), anti-topoisomerase I antibodies (p=0.009) and baseline FVC below 70% (p=0.04), but only diffuse cutaneous subset remained significant in multivariate analysis (p=0.02). Predictors of declined DLCO in univariate analysis were Hurwitz stage ≥3 (p=0.009) and aperistalsis (p=0.02), but these parameters were not significant in multivariate analysis (p=0.15 and p=0.66 respectively). The kappa coefficient between FVC decline and CT-scan deterioration was 0.6, showing a good concordance between the functional and radiological outcomes. Conclusion: In this prospective study assessing the predictive factors of declined pulmonary functional tests with assessment of a potential role for esophageal involvement, only diffuse cutaneous subtype appeared to be predictive of declined FVC. This does not support the preliminary data suggesting the role of esophageal involvement in ILD, but suggests to focus on the diffuse cutaneous subgroup of SSc patients for the future therapeutical investigations for ILD. Disclosure of Interest: None declaredCitation: Annals of the Rheumatic Diseases, volume 68, supplement 3, year 2009, page 470Session: Scleroderma, myositis and related syndromes (Poster Presentations )