Objective: Cell-based technologies are considered to be a new approach for the treatment of cerebral palsy (CP). Given the potent anti-inflammatory activity and high regenerative potential of M2 macrophages, these cells may be a promising source for cell transplantation. To evaluate the safety and efficacy of autologous M2 macrophages, we performed an open-label, Phase I/ II, non-controlled clinical trial in children with severe CP. Patients and methods: Fifty-seven children with severe CP, including 33 boys and 24 girls, with a median age of 4 years were enrolled in the study. The patients were treated with intrathecal administration of autologous M2 macrophages. The primary outcome measure was safety, and the secondary outcome measure was functional improvement in neurologic scales, including the 66-item Gross Motor Function Measure test, Peabody Developmental Motor Scale-Fine Motor test, Ashworth scale, Medical Resarch Council scale, and an easy-to-understand unified questionnaire for evaluation of cognitive functions in our modification. Results: Intrathecal introduction of M2 cells in a median dose of 11.2×10 6 did not induce any serious adverse events either related with cell injection or during 5 years of follow-up. After 3 months, the Gross Motor Function Measure score increased from 19±4.5 to 77±7.8, the Peabody Developmental Motor Scale-Fine Motor test score improved from 0.9±0.23 to 4.4±0.51, and the Ashworth score decreased from 3.5±0.11 to 2.5±0.16. The assessment of cognitive functions revealed an increase from 1.22±0.24 to 3.98±0.95, and a reduction of seizure syndrome was registered. In addition, M2 injection was accompanied by an increased production of brainderived neurotrophic factor (p U =0.015). Conclusion: The data obtained suggest that cell therapy based on M2 macrophages is safe, does not induce any severe cell-related reactions or long-term side effects and comorbidities, and is accompanied by significant neurologic improvements in severe CP patients.
