Autologous hematopoietic stem cell transplantation (HSCT) is a very effective treatment option for patients with severe systemic sclerosis (SSc). In addition to various case series two randomized controlled trials could prove its superiority over intense cyclophosphamide pulse therapy. Nevertheless, HSCT is associated with a treatment-related mortality of approximately 10 %; therefore, further studies should be carried out to reduce the toxicity of HSCT by adaptation of the therapy regimen and the option of HSCT should be made available earlier to patients with a high risk of mortality. The mechanism of action of HSCT is still poorly understood. While profibrotic cytokines or even autoantibodies hardly appear to be influenced by the treatment, alterations to regulatory T‑cells may play a role. Further improvement of transplantation regimens as well as a better understanding of the underlying pathogenetic principles and mechanisms of action should be the aim of further studies on HSCT.
Keywords: CD34 selection; Cyclophosphamide; Mortality; T cells; Toxicity.