Enteric-coated mycophenolate sodium for progressive systemic sclerosis-a prospective open-label study with CT histography for monitoring of pulmonary fibrosis

The purpose of this study was to assess the impact of enteric-coated mycophenolate sodium (EC-MPS) on skin and pulmonary manifestations of patients with progressive systemic sclerosis (Ssc). A prospective, open-label single-centre trial with EC-MPS 2 x 720mg/day over 12 months and a long-term follow-up of 50 months were conducted. Modified Rodnan skin score (mRSS) was used to assess the skin and pulmonary function tests to assess the pulmonary involvement. In order to quantify the extent of alveolitis/fibrosis via densitometry, the high attenuation value, median lung density and percentiles of lung tissue densities were obtained by high-resolution computed tomography. Eleven patients were included. Three patients had to stop medication before month 6 (2x side effects, 1x progression). For the remaining eight patients, the median mRSS was non-significantly reduced from 13.5 at baseline to 11 at month 12. According to the CT histography, median lung density and high attenuation values remained stable. However, the course of percentiles -200 to -300 and particularly -300 to -400 Hounsfield units slightly increased in seven of eight patients after 12 months, suggesting worsening of pulmonary involvement. Accordingly, median diffusing capacity for carbon monoxide showed a tendency to decline (75.1 % vs. 70.2) while forced vital capacity non-significantly improved (78.0 vs. 85.5 %) during the study. Four patients are still on EC-MPS without clinical signs of progression after 50 months follow-up. EC-MPS showed non-significant improvement of the skin. Pulmonary fibrosis remained stable with only a slight tendency towards progression which might be ascribed to the medication as well as the natural course of the disease. CT histography appears to be a sensitive method for the detection of progression of pulmonary fibrosis and therefore should be considered for further studies in Ssc.