Background: The emerging role of Stem cell technology and transplantation has helped scientists to study its potential role in neural repair and regeneration. The fate of stem cells is determined by its niche, consisting of surrounding cells and the secreted trophic growth factors. This present study evaluates the safety, feasibility and efficacy of bone marrow derived mononuclear stem cells (BM-MNC) in chronic ischemic stroke by studying the release of serum vascular endothelial growth factor (VEGF) and brain derived neurotrophic growth factor (BDNF).
Methods: Twenty (n=20) stroke patients recruited with the inclusion criteria as: 3 months to 1.5 years of index event, power of hand muscles atleast 2; Brunnstrom stage: 2-5; conscious and comprehendible, were randomized to study and control groups receiving autologous mean 60-70 million BM-MNC and controls receiving neuromotor rehabilitation regime only for 8 weeks. Clinical assessment (FM, mBI, MRC, Ashworth) and serum VEGF & BDNF were done at baseline and 8 weeks (2 months).
Results: No patients exhibited any complication or adverse events during the whole procedure. There was no statistical significant clinical improvement between study and control groups (FM: 95%CI; 15.2 to 5.35, p=0.25; mBI : 95% CI;14.3 to 4.5, p=0.31). VEGF and BDNF were increased after stem cell infusion and exercise training in both the groups (VEGF: 442.1 pg/ml vs 400.3pg/ml; p=0.67; BDNF:95% CI∼15.09 to 4.09, p=0.57), without any statistical significant result.
Conclusion: Autologous mononuclear stem cell infusion is safe and tolerable by chronic ischemic stroke. The paracrine hypothesis extends the traditional concept of stem cell niche to study the influence of stem cell released growth factors (VEGF and BDNF) on the microenvironment.