A two-year follow-up study of co-transplantation with neural stem/precursor cells and mesenchymal stromal cells in ischemic stroke patients.

Stem cell therapy is an emerging therapeutic modality in the treatment of stroke. We assessed the safety and feasibility of the co-transplantation of neural stem/precursor cells (NSPCs) and mesenchymal stromal cells (MSCs) in patients with ischemic stroke. Eight patients were enrolled in this study. All patients had a hemisphere with infarct lesions located on one side of the territories of the cerebral middle or anterior arteries as revealed with cranial magnetic resonance imaging (MRI). The patients received one of the following two types of treatment: the first treatment involved 4 intravenous injections of MSCs at 0.5×106/kg body weight; the second treatment involved one intravenous injection of MSCs at 0.5×106/kg weight followed by three injections of MSCs at 5×106/patient and NSPCs at 6 x 106/patient through the cerebellomedullary cistern. The patients’ clinical statuses were evaluated with the National Institutes of Health Stroke Scale (NIHSS), the modified Rankin Scale (mRS), and the Barthel Index (BI). Six patients were given 4 cell transplantations. The most common side effect of stem cell transplantation in these 6 cases was low fever that usually lasted 2-4 days after each therapy. One patient exhibited minor dizziness. All side effects appeared within the first 2-24 hours of cell transplantation and they resolved without special treatment. There was no evidence of neurological deterioration or neurological infection. Most importantly, no tumorigenesis was found at a 2-year follow-up. The neurological functions, disability levels, and daily living abilities of the patients in this study were improved. While these observations support the use of the combination transplantation of NSPCs and MSCs as safe and feasible method of improving neurological function, further studies that include larger samples, longer follow-ups, and control groups are still needed. This manuscript is published as part of the International Association of Neurorestoratology (IANR) special issue of Cell Transplantation.