Treatment of Severe Adult Traumatic Brain Injury Using Bone Marrow Mononuclear Cells

BACKGROUND: Numerous pre-clinical studies using bone marrow derived cells for the treatment of traumatic brain injury and stroke have demonstrated efficacy in terms of blood-brain barrier preservation, neurogenesis, and other functional outcomes. Phase 1 clinical trials using bone marrow mononuclear cells infused intravenously in children with severe TBI demonstrated safety and potentially a CNS structural preservation treatment effect. This study sought to confirm the safety, logistic feasibility, and potential treatment effect size of structural preservation/inflammatory biomarker mitigation in adults to guide Phase 2 clinical trial design. METHODS: Adults (aged 18-55) with severe traumatic brain injury (GCS 5-8) and without signs of serious other injury or irreversible brain injury (see Table 1) were evaluated for entry into the trial. A dose escalation format was performed in 25 patients: 5 controls, followed 5 patients in each dosing cohort (6,9,12 X10(6) cells/kg body weight), then 5 more controls. Bone marrow harvest, cell processing to isolate the mononuclear fraction, and re-infusion occurred within 48 hours after injury. Patients were monitored for harvest/infusion related hemodynamic changes, infusional toxicity, and adverse events. Outcome measures included MRI based measurements of supratentorial and corpus callosal volumes as well as DTI based measurements of fractional anisotropy and mean diffusivity of the corpus callosum and the corticospinal tract at the level of the brainstem at 1 month and 6 months post-injury. Functional and neurocognitive outcomes were measured and correlated with imaging data. Inflammatory cytokine arrays were measured in the plasma pre-treatment, post-treatment, and at 1 and 6 month follow-up. RESULTS: There were no serious adverse events related to harvest/infusion. There was a mild pulmonary toxicity of the highest dose that was not clinically significant. Despite the treatment group having greater injury severity, there was structural preservation of critical regions of interest that correlated with functional outcomes. Key inflammatory cytokines were down-regulated after BMMNC infusion. CONCLUSIONS: Treatment of severe, adult traumatic brain injury using an intravenously delivered autologous bone marrow mononuclear cell infusion is safe and logistically feasible. There appears to be a treatment signal as evidenced by CNS structural preservation, consistent with previous pediatric trial data. Inflammatory biomarkers are down-regulated after cell infusion. A Phase 2, prospective, randomized trial excluding the highest dose is warranted and can be powered based upon structural outcome variables. This article is protected by copyright. All rights reserved.© 2016 AlphaMed Press. Language: en