Efficacy of autologous bone marrow mononuclear cell transplantation therapy in patients with refractory diabetic peripheral neuropathy

Background: Owing to the multifactorial nature of the pathogenesis of diabetic peripheral neuropathy (DPN), conventional drug therapies have not been effective. The application of stem cells transplantation may be useful for the treatment of DPN. This study was designed to assess the safety and therapeutic effects of autologous bone marrow mononuclear cells (BMMNCs) transplantation on the treatment of refractory DPN.Methods: One hundred and sixty-eight patients with refractory DPN were recruited and enrolled in the study. They received intramuscular injection of BMMNCs and followed at 1, 3, 6, 12, 18, 24, and 36 months after the transplantation. Clinical data, Toronto Clinical Scoring System (TCSS), and nerve conduction studies (NCSs) were compared before and after the transplantation.Results: The signs and symptoms of neuropathy were significantly improved after BMMNCs transplantation. The values of the TCSS scores at 1 month (9.68 ± 2.49 vs. 12.55 ± 2.19,P < 0.001) and 3 months (8.47 ± 2.39 vs. 12.55 ± 2.19,P < 0.001) after the treatment reduced significantly compared with the baseline value. This decrement remained persistent until the end of the study. The conduction velocity and action potential and sensory nerves were significantly improved after transplantation (3 and 12 months after the treatment vs. the baseline: motor nerve conduction velocity, 40.24 ± 2.80 and 41.00 ± 2.22 m/s vs. 38.21 ± 2.28 m/s,P < 0.001; sensory nerve conduction velocity, 36.96 ± 2.26 and 39.15 ± 2.61 m/s vs. 40.41 ± 2.22 m/s,P < 0.001; compound muscle action potential, 4.67 ± 1.05 and 5.50 ± 1.20 μV vs. 5.68 ± 1.08 μV,P < 0.001; sensory nerve action potential, 4.29 ± 0.99 and 5.14 ± 1.26 μV vs. 5.41 ± 1.14 μV,P < 0.001). No adverse event associated with the treatment was observed during the follow-up period.Conclusions: Autologous transplantation of BMMNCs may be an effective and promising therapeutic strategy for the treatment of refractory DPN.