Autologous Bone Marrow Stem Cells in Spinal Cord Injury; Our Experience in Clinical Studies, Animal Studies, Obstacles faced and steps for future

BACKGROUND: Following traumatic vertebral injuries and resultant spinal cord injury, most patients are doomed to a life either of quadriplegia or paraplegia. Current treatment option is limited to the stabilization of the vertebral fracture along with medications to prevent secondary damage leading to further deterioration and wishful waiting for recovery. In most instances recovery is insignificant. Safety of intrathecal injection of autologous bone marrow stem cells is proven but its efficacy varies between patients (1). Intralesional application has been reported to be more efficacious than intrathecal application (2, 3, 4). We have analyzed our experience in human patients followed up for 3 year period and have found several grey areas in spinal cord injury(5) one of them is to explore the differences between Intrathecal and intralesional application of stem cells with and without scaffolds in the latter technique. Towards achieving this goal we started a pilot study in animals where instead of post-vertebral fixation intrathecal injection, we have performed intralesional application of autologous BMSC along with scaffolds (6). These scaffolds not only help retain the transplanted cells at the site of injury but also allow more neural precursors to grow compared to application without scaffolds (7). This study analyses the data retrospectively to plan further prospective studies with a view to improvise the results. MATERIALS AND METHODS: Study 1 : 100 to 120 ml of Bone marrow was tapped from the right posterior iliac crest under local anesthesia from human spinal injury victims (n=108; 76 males, 32 females) about 3 weeks to 18 months after surgical fixation of the vertebrae. The Level of injury was varied- Cervical (13 patients.) Upper Thorax- T1-T7 (35 patients) Lower thorax T8-T12 (46 patients) Lumbar (2 patients.) Age Group Range: 8 yrs to 55 yrs. The bone marrow mononuclear cells were processed under cGMP SOP’s Class 10000 clean room and class 100 Biosafety hood as reported earlier (1) and were injected intrathecally into the subarachnoid space of the patients below L2 level after endotoxin tests and confirming CD34 status using flow cytometry. Study 2: 20-30ml of Bone marrow was tapped from the right posterior iliac crest under local anesthesia of canine spinal injury victims immediately after the injury and the bone marrow processed as reported earlier (6) were injected intralesionally embedded in thermoreversible hydrogel scaffolds at the site of the injury after endotoxin tests and CD34 analysis using flow cytometry. Both the animals had an