Prognostic factors for lung function in systemic sclerosis: prospective study of 105 cases

¹ Dept of Rheumatology A, Paris Descartes University, Cochin Hospital, AP-HP, 75014 Paris, France
² Dept of Pneumology, Paris Descartes University, Cochin Hospital, AP-HP, 75014 Paris, France
³ Dept of Respiratory Physiology, Paris Descartes University, Cochin Hospital, AP-HP, 75014 Paris, France
⁴ Dept of Gastro-Enterology, Paris Descartes University, Cochin Hospital, AP-HP, 75014 Paris, France
⁵ Dept of Radiology A. Paris Descartes University, Cochin Hospital, AP-HP, 75014 Paris, France

^* To whom correspondence should be addressed. E-mail: yannick.allanore{at}cch.aphp.fr.

	Abstract

To identify prognostic factors for SSc-ILD and to clarify the possible causative role of manometric esophageal involvement.

Consecutive SSc-patients underwent pulmonary function tests (PFT) and esophageal manometry. They were included in this study if PFT were repeated more than 12 months after baseline. The primary endpoint was a decrease 10% in forced vital capacity (FVC). The secondary endpoints were a decrease 15% in carbon monoxide diffusing capacity (DLCO) and a decrease 20% in FVC.

Of the 105 patients (45 diffuse SSc, median disease duration 2.0 years), 23 (23%) had a FVC below 80%, 60 (59%) had a DLCO below 80%, and 57 (54%) had severe esophageal hypomotility at baseline. Over 72±46 months, 29 patients (28%) displayed a decrease 10% in FVC, 39 of 98 patients (40%) displayed DLCO decline, and 19 patients (18%) displayed a decrease 20% in FVC. In multivariate analysis, diffuse SSc was a significant predictor for a decrease 10% in FVC (p=0.01). No other predictor of a decrease in pulmonary function was identified.

Only diffuse SSc was predictive of a decrease in pulmonary function in this early-SSc cohort. This does not support preliminary data suggestive of a causative role of oesophageal involvement.