In CNS, transient global or severe focal ischemia leads to devastating irreversible cellular losses and functional impairments of the nervous tissue. Stem/progenitor cells have been considered the salvage therapy. However, besides decision on the cells source, stage of their development and proliferation, the limited survival of any implanted exogenous cells in the host tissue is one of the major obstacles for effective neurotransplantation. In preclinical animal experiment this problem gets even more complicated by necessity to use xenogeneic systems for initial testing of any human transplants and persistant lack of adequately humanized animal models. Other still unresolved questions which must be addressed are the routes, dosage and timing of cells delivery. Thus, the final answer must be at first approximated experimentally in animal models, then finally proved by case reports followed by clinical trials performed according to EBM rules. Here I will review the preclinical data gathered in our laboratory which led us toward the first, MRI monitored, clinical experiment on autologous, cord blood -derived progenitors transplantation. The neurally committed cells, prelabelled by the high signal of iron oxide nanoparticles (SPIO) were infused into the frontal horn of the lateral ventricle of 16 month old child with severe global cerebral ischemic injury. The dynamics of cell engraftment was visualized in time by MR imaging. Gradually decreased signal was noted over 4 month without any adverse side-effects. The child was followed up for next 6 month and his neurological status slightly but significantly improved. This is the first case study based on neurally –induced stem cells from the patient’s frozen cord blood and considered feasible, well tolerated and safe procedure which could be monitored by MRI after intraventricular cell transplantation.
NeuroRepair Department, Mossakowski Medical Research Centre PAS, Warsaw, Poland