Hematopoietic stem cell transplantation for systemic sclerosis: Brazilian experience.

Background: In the past 20 years, hematopoietic stem cell transplantation (HSCT) has been investigated as treatment for systemic sclerosis (SSc). The goal of HSCT is to eradicate the autoreactive immune system, which is replaced by a new immune repertoire with long-lasting regulation and tolerance to autoantigens. Here, we describe the clinical outcomes of severe and refractory SSc patients that underwent HSCT at a single Brazilian center.

Patients And Methods: This is a longitudinal and retrospective study, including 70 adult SSc patients, with an established diagnosis of SSc, and who underwent autologous HSCT from 2009 to 2016. The procedure included harvesting and cryopreservation of autologous hematopoietic progenitor cells, followed by administration of an immunoablative regimen and subsequent infusion of the previously collected cells. Patients were evaluated immediately before transplantation, at 6 months and then yearly until at least 5-years of post-transplantation follow-up. At each evaluation time point, patients underwent clinical examination, including modified Rodnan's skin score (mRSS) assessment, echocardiography, high-resolution computed tomography of the lungs and pulmonary function.

Results: Median (range) age was 35.9 (19-59), with 57 (81.4%) female and median (range) non-Raynaud's disease duration of 2 (1-7) years. Before transplantation, 96% of the patients had diffuse skin involvement, 84.2%, interstitial lung disease and 67%, positive anti-topoisomerase I antibodies. Skin involvement significantly improved, with a decline in mRSS at all post-transplantation time points until at least 5-years of follow-up. When patients with pre-HSCT interstitial lung disease were analyzed, there was an improvement in pulmonary function (forced vital capacity and diffusing capacity of lung for carbon monoxide) over the 5-year follow-up. Overall survival was 81% and progression-free survival was 70.5% at 8-years after HSCT. Three patients died due to transplant-related toxicity, 9 patients died over follow-up due to disease reactivation and one patient died due to thrombotic thrombocytopenic purpura.

Conclusions: Autologous hematopoietic progenitor cell transplantation improves skin and interstitial lung involvement. These results are in line with the international experience and support HSCT as a viable therapeutic alternative for patients with severe and progressive systemic sclerosis.