Hematopoietic stem-cell transplantation in systemic sclerosis: an update

Purpose of review To provide an overview of recently published work on autologous hematopoietic stem-cell transplantation (HSCT) in patients with systemic sclerosis (SSc). Recent findings Superiority of HSCT vs. intravenous cyclophosphamide pulses was demonstrated in the randomized controlled American Scleroderma: Cyclophosphamide or Transplantation (SCOT) Trial (n = 75), supporting the results from earlier studies. In the SCOT Trial, total body irradiation was used instead of the nonmyeloablative regimens used in other trials, and considered well tolerated during a follow-up time of 4.5 years. Three small uncontrolled prospective cohorts (n = 4, 14 and 18) and one retrospective analyses (n = 18), using various nonmyeloablative regimens, also showed improvement in skin involvement and lung volumes post-HSCT. Transplant-related toxicity and mortality remain an essential issue in HSCT. High treatment-related mortality was reported in one prospective cohort (n = 18), using alemtuzumab as a conditioning agent. Furthermore, cardiac complications, either treatment or disease related, require special attention. In translational studies, trends are reported in number of regulatory T cells and diversity of T-cell receptor repertoire at baseline and post-HSCT correlating with treatment response. Summary There is increasing evidence that patients with rapidly progressive SSc may benefit from HSCT. However, optimal patient selection, pretransplantation workup and posttransplant management, still have to be established.