Secondary outcome measures are: number of serious adverse events, pain and disability parameters; healing, time to healing and reduction of new ischemic digital ulcers; modified Rodnan skin score; Scleroderma Health Assessment Questionnaire (S-HAQ) including visual analogue scales (VAS) for scleroderma-specific symptoms; Quality-of-life (SF-36, EuroQol (EQ-5D); Cochin hand function score. We will also evaluate changes in capillary morphology and architecture using capillaroscopy; biochemical parameters; markers for endothelial activation and injury, inflammation, oxidative stress, circulating cells including endothelial cells, hematopoietic and endothelial progenitor cells, cytokines and growth factors, immunological responses. Follow-up visits will be scheduled at 48 hours and 2, 4, 8, 12, 24 and 52 weeks post-treatment.