Autologous stem cell transplantation for early type 1 diabetes mellitus.

Type 1 diabetes mellitus (T1DM) is the result of the autoimmune response against pancreatic insulin producing beta cells. This autoimmune response begins months or even years before the first presentation of signs and symptoms of hyperglycemia and at the time of clinical diagnosis near 30% of beta-cell mass still remains. In daily clinical practice, the main therapeutic option for T1DM is multiple subcutaneous insulin injections that are shown to promote tight glucose control and reduce much of diabetic chronic complications, especially microvascular complications. Another important aspect related to long-term complications of diabetes is that patients with initially larger beta-cell mass suffer less microvascular complications and less hypoglycemic events than those patients with small beta-cell mass. In face of this, beta-cell preservation is another important target in the management of type 1 diabetes and its related complications. For many years, various immunomodulatory regimens were tested aiming at blocking autoimmunity against beta-cell mass and at promoting beta-cell preservation, mainly in secondary prevention trials. In this review, we summarize some of the most important studies involving beta-cell preservation by immunomodulation and discuss our preliminary data on autologous nonmyeloablative hematopoietic stem cell transplantation in newly-diagnosed T1DM.