Evolution, trends, outcomes, and economics of hematopoietic stem cell transplantation in severe autoimmune diseases.

Hematopoietic stem cell transplantation (HSCT) has evolved for >20 years as a specific treatment of patients with autoimmune disease (AD). Using European Society for Blood and Marrow Transplantation registry data, we summarized trends and identified factors influencing activity and outcomes in patients with AD undergoing first autologous HSCT (n = 1951; median age, 37 years [3-76]) and allogeneic HSCT (n = 105; median age, 12 years [<1-62]) in 247 centers in 40 countries from 1994 to 2015. Predominant countries of activity were Italy, Germany, Sweden, the United Kingdom, The Netherlands, Spain, France, and Australia. National activity correlated with the Human Development Index (P = .006). For autologous HSCT, outcomes varied significantly between diseases. There was chronological improvement in progression-free survival (PFS, P < 10-5), relapse/progression (P < 10-5), and nonrelapse mortality (P = .01). Health care expenditure was associated with improved outcomes in systemic sclerosis and multiple sclerosis (MS). On multivariate analysis selecting adults for MS, systemic sclerosis, and Crohn disease, better PFS was associated with experience (≥23 transplants for AD, P = .001), learning (time from first HSCT for AD ≥6 years, P = .01), and Joint Accreditation Committee of the International Society for Cellular Therapy and European Society for Blood and Marrow Transplantation accreditation status (P = .02). Despite improved survival over time (P = .02), allogeneic HSCT use remained low and largely restricted to pediatric practice. Autologous HSCT has evolved into a treatment modality to be considered alongside other modern therapies in severe AD. Center experience, accreditation, interspecialty networking, and national socioeconomic factors are relevant for health service delivery of HSCT in AD.