Serial 18F-FDG PET Demonstrates Benefit of Human Mesenchymal Stem Cells in Treatment of Intracerebral Hematoma: A Translational Study in a Primate Model

This study evaluated the efficacy of human mesenchymal stem cells (hMSCs) in the treatment of intracerebral hematoma (ICH) using a primate model and serial F-18-FDG PET scans. Methods: Twenty-four Macaca fascicularis monkeys (male, 4.2 +/- 0.2 kg) were enrolled. The ICH models were established using a stereo-guided injection of 1.5 mL of autologous arterial blood between the right cortex and basal ganglia. One week (early treatment group, n = 8) or 4 wk (late treatment group, n = 8) after an ICH was established, (1-5) x10(6) hMSCs were transplanted near the hematoma using a stereotactic method. Control monkeys received saline only, either 1 or 4 wk (n = 4 for each subgroup) after ICH establishment. The efficacy of treatment was evaluated by serial F-18-FDG PET scans (n = 19) and neurologic deficit scoring weekly or biweekly. Pathologic analysis was performed 8 wk after hMSC transplantation. Results: One week after hMSC injection, higher F-18-FDG accumulated at the ipsilateral basal ganglia in both early and late hMSC-treated groups, indicating an early response to the treatment. When recovery reached a plateau, F-18-FDG uptake in the adjacent cortex was significantly higher in the early treatment group (P < 0.05). The neurologic deficit scoring was significantly lower in the hMSC-treated groups, which also indicated better recovery. Pathologic analysis revealed higher vessel density surrounding the remains of hematoma in the hMSC-treated groups. Conclusion: This preliminary study indicates that transplantation of hMSCs may improve the recovery from ICH in a primate model, and early treatment may lead to better results.