Evaluation of Safety and Efficacy of Repeated Mesenchymal Stem Cell Transplantation in Patients with Amyotrophic Lateral Sclerosis (ALS) by Investigating Patient’s Specific microRNAs as Novel Biomarkers: A Clinical Trial Study

Background: Since there is currently no cure for amyotrophic lateral sclerosis (ALS), it is essential to search for diagnostic biomarkers and novel treatments to reduce the severity of this disease. One of these treatment approaches is stem cell transplantation Objective: This study aims to evaluate the safety and efficacy of repeated transplantation of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) in patients with ALS by analyzing clinical and molecular data. Methods: This one-arm, single-center, open-label without a control group, prospective clinical trial, twenty-one confirmed ALS patients entered the study based on defined inclusion and exclusion criteria and underwent repeated stem cell transplantation (3 times BM-MSCs transplantation (1×10^6, MSC/Kg BW per injection) concurrently intrathecally (IT) and intravenously (IV), with one-month interval). Clinical assessment using ALS functional rating scale-revised (ALSFRS) and forced vital capacity (FVC) values and also molecular investigation by evaluating specific microRNAs expression (mir206, 133a-3p, 338-3p) in patient's serum and Cerebra spinal fluid (CSF) samples were done three times during the 3-month follow-up period. Result: No serious adverse effects were reported during the study. Besides, significant improvement in FVC when compared the baseline with the end of the research and the p-value was (0.036), and stability in ALSFRS was observed, and the p-value was (p=0.16) following stem cell transplantation in patients; also, the mentioned microRNA expression was non-significant (p > 0.05) as reported as well. Conclusion: Our results demonstrated that repeated transplantation of BM-MSCs was a safe procedure in ALS patients, leading to delay in disease progression and improvement in clinical symptoms. Future studies are needed to confirm these results.