Autologous bone marrow derived stem cell therapy in patients with type 2 diabetes mellitus - defining adequate administration methods

AIM: To carry out randomized trial for evaluating effects of autologous bone marrow derived stem cell therapy (ABMSCT) through different routes. METHODS: Bone marrow aspirate was taken from the iliac crest of patients. Bone marrow mononuclear cells were separated and purified using centrifugation. These cells were then infused in a total of 21 patients comprising three groups of 7 patients each. Cells were infused into the superior pancreaticoduodenal artery (Group I), splenic artery (Group II) and through the peripheral intravenous route (Group III). Another group of 7 patients acted as controls and a sham procedure was carried out on them (Group IV). The cells were labelled with the PET tracer F18-FDG to see their homing and in vivo distribution. Data for clinical outcome was expressed as mean ± SE. All other data was expressed as mean ± SD. Baseline and post treatment data was compared at the end of six months, using paired t-test. Cases and controls data were analyzed using independent t-test. A probability (P) value of < 0.05 was regarded as statistically significant. Measures of clinical outcome were taken as the change or improvement in the following parameters: (1) C-peptide assay; (2) HOMA-IR and HOMA-B; (3) reduction in Insulin dose; subjects who showed reduction of insulin requirement of more than 50% from baseline requirement were regarded as responders; and (4) reduction in HbA1c. RESULTS: All the patients, after being advised for healthy lifestyle changes, were evaluated at periodical intervals and at the end of 6 mo. The changes in body weight, body mass index, waist circumference and percentage of body fat in all groups were not significantly different at the end of this period. The results of intra-group comparison before and after ABMSCT at the end of six months duration was as follows: (1) the area under C-peptide response curve was increased at the end of 6 mo however the difference remained statistically non-significant (P values for fasting C-peptide were 0.973, 0.103, 0.263 and 0.287 respectively and the P values for stimulated C-peptide were 0.989, 0.395, 0.325 and 0.408 respectively for groups I to IV); (2) the Insulin sensitivity indices of HOMA IR and HOMA B also did not show any significant differences (P values for HOMA IR were 0.368, 0.223, 0.918 and 0.895 respectively and P values for HOMA B were 0.183, 0.664, 0.206 and 0.618 respectively for groups I to IV); (3) Group Ishowed a significant reduction in Insulin dose requirement (P < 0.01). Group II patients also achieved a significant reduction in Insulin dosages (P = 0.01). The Group I and Group II patients together constituted the targeted group wherein the feeding arteries to pancreas were used for infusing stem cells. Group III, which was the intravenous group, showed a non-significant reduction in Insulin dose requirement (P = 0.137). Group IV patients which comprised the control arm also showed a significant reduction in Insulin dosages at the end of six months (P < 0.05); and (4) there was a non-significant change in the Hb A1c levels at the end of 6 mo across all groups (P = 0.355, P = 0.351, P = 0.999 and P = 0.408 respectively for groups I to IV). CONCLUSION: Targeted route showed a significant reduction in Insulin requirement at the end of six months of study period whereas the intravenous group failed to show reduction.