To assessing the safety, feasibility, efficacy and optimal cell dose of human leukocyte antigen (HLA≥4∶6) matched umbilical cord blood mononuclear cells (UCBMC) in the therapy of chronic complete spinal cord injury (SCI), and the effect of combined use of methylprednisolone (MP) and lithium carbonate on cell transplantation.

Twenty patients with SCI admitted to Department of Neurosurgery of 920 Hospital of Joint Logistics Support Force from February 2011 to January 2014 were selected and divided into 5 groups (group A, B, C, D, E) according to the random number table method, with 4 subjects in each group. UCBMC was injected at 4 points (2 points in each side) at the upper and lower edge of the injured spinal nerve. Group A, group B and group C were injected with 4, 8 and 16 μL (100 000 UCBMC/μL, 6.4 million cells) to the upper and lower dorsal root of SCI, group D received 16 μL cell injection plus 30 mg/kg MP intravenous injection, group E received 16 μL cell injection plus MP and 6-week oral lithium carbonate (750 mg/d). The subjects underwent intensive walking training for 3-6 months. The primary outcome was American Spinal Injury Association (ASIA) scores. Secondary outcomes include walking index of spinal cord injury (WISCI) and spinal cord independence measure (SCIM).

Twenty subjects averaged 7 years after C3-T11 SCI. Before treatment, 16 subjects (80%) could not walk 10 m even with assistance, and 18 subjects (90%) need assistance for bladder or bowel care. At 41-87 weeks, ASIA motor scores did not change but WISCI and SCIM scores improved. Fifteen subjects (75%) could walk 10 m with assistance, 12 subjects (60%) did not need assistance for bladder care or bowel care, 5 subjects converted from complete to incomplete. Meanwhile none of subjects lost further neurological functions.

UCBMC and locomotor training improved WISCI and SCIM but not motor scores. We hypothesize that UCMBC transplants stimulate growth of axons that activate central pattern generators for locomotion, micturition, and defecation. Combined use of MP and lithium carbonate had no obvious effect on cell transplantation.