Objective: To determine if autologous nonmyeloablative hematopoietic stem cell transplantation (AHSCT) was beneficial for type 1 diabetic adolescents with diabetic ketoacidosis (DKA) at diagnosis.
Research design and methods: We enrolled 28 patients with type 1 diabetes, aged 14-30 years, in a prospective AHSCT phase II clinical trial. HSCs were harvested from the peripheral blood after pretreatment consisting of a combination of cyclophosphamide and antithymocyte globulin. Changes in the exogenous insulin requirement were observed and serum levels of HbA(1c), C-peptide, and anti-glutamic acid decarboxylase antibody were measured before and after the AHSCT.
Results: After transplantation, complete remission (CR), defined as insulin independence, was observed in 15 of 28 patients (53.6%) over a mean period of 19.3 months during a follow-up ranging from 4 to 42 months. The non-DKA patients achieved a greater CR rate than the DKA patients (70.6% in non-DKA vs. 27.3% in DKA, P = 0.051). In the non-DKA group, the levels of fasting C-peptide, peak value during oral glucose tolerance test (C(max)), and area under C-peptide release curve during oral glucose tolerance test were enhanced significantly 1 month after transplantation and remained high during the 24-month follow-up (all P < 0.05). In the DKA group, significant elevation of fasting C-peptide levels and C(max) levels was observed only at 18 and 6 months, respectively. There was no mortality.
Conclusions: We have performed AHSCT in 28 patients with type 1 diabetes. The data show AHSCT to be an effective long-term treatment for insulin dependence that achieved a greater efficacy in patients without DKA at diagnosis.
Trial registration: ClinicalTrials.gov NCT00807651.