Parkinson’s disease (PD) is a common neurodegenerative disease. Previous studies have demonstrated the effect of cell-based therapies, but their clinical efficacy and safety have not been evaluated. This review protocol aimed to systematically evaluate the effect of stem cell therapy in patients with PD and to develop an evidence base for guiding policy and practice.

PubMed, Embase, MedlinePlus, The Lancet and Brain were searched over the period January 2001 to October 2019. The keywords used for searching were "Parkinson’s disease" and "cell therapy" and "mesenchymal stem cells" and "embryonic stem cells" and "brain-derived neural stem cells" and "neural progenitor cells" . The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and a measurement tool, Assessment of Multiple Systematic Reviews (AMSTAR), to assess systematic reviews were used to assess the reporting quality and methodological quality. Data extracted included study details, participant details, intervention details and outcome.

Nine valid research papers were screened out by systematic analysis. These nine studies were carried out in different countries, with different populations and cell types. According to evaluation methods used, all of the transplantation therapies reported can improve the symptoms of PD patients.

Cell transplantation is a potential treatment option for PD. More studies with strict study design, larger sample sizes, and longer follow-up are needed in the future.