The primary clinical efficacy end point was the modified Rodnan skin score (mRSS).24 A 25% sustained improvement in the mRSS at any point in the follow-up was considered clinically important and a successful outcome.25 Secondary outcome measures included the Health Assessment Questionnaire-Disability Index (HAQ-DI) and physician global assessment (PGA) determined by a visual analogue scale on a scale from 0 to 100. Values for the percentage predicted lung volumes were referenced from NHANES/Hanikson et al26 and for diffusing capacity of the lungs for carbon monoxide (DLCO) from Knudson et al.27 The disease duration was defined as the time from the first non-Raynaud's symptom related to scleroderma to study entry.