Functional outcome of bone marrow stem cells (CD45(+)/CD34(-)) after cell therapy in chronic spinal cord injury in Wistar rats

Therapy with diverse cell types has been proposed to regenerate spinal cord injuries seeking to minimize the consequences for the lives of chronic patients. The types considered are: mononuclear and mesenchymal adult stem cells, embryonic stem cells, and Schwann cells. Ninety male Wistar rats that underwent spinal cord contusion injury (NYU Impactor) were followed with the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale for 14 days. Animals with scores < or = 16 were randomly divided into 2 groups: control (vehicle) versus cell therapy group. The mononuclear fraction (CD45(+)/CD34(-)) obtained by puncture-aspiration of the bone marrow was isolated by a density gradient (d = 1.077). The parenchymal cell infusion was performed using a syringe (100 U/1 mL) with a 30G1/2 needle. The animals were followed for 10 days before euthanasia. Statistical analyses comparing groups were performed by the Mann-Whitney test and group comparisons by the Wilcoxon test. Among 90 injured rats, 65 (72.2%) survived, including 44 whose scores were < or = 16. Eleven animals finished the study in the control group (64.7%) and 17 in the therapy group (80.9%). The statistical analyses did not demonstrate significance (P > .05) for either test. Mononuclear adult stem cell therapy was not demonstrated to be functionally effective for chronic spinal cord injury.