Clinical Outcomes of the Transplantation of Stem Cells from Various Human Tissue Sources in the Management of Liver Cirrhosis: A Systematic Review and Meta-Analysis

Aims: A systematic review and meta-analysis were performed to explore the clinical outcome of the transplantation of stem cells from various human tissue sources in cirrhotic patients. Methods: The relevant papers were searched via PubMed, EMBASE, and Cochrane Library databases. Changes in liver function before and after stem cell therapy were evaluated (self-control data). Difference in liver function and incidence of procedure-related complications, hepatocellular carcinoma (HCC), and death between patients undergoing stem cell therapy and conventional treatment were evaluated (case-control data). Results: Of 786 papers initially identified, 31 were included. The sources of stem cell included bone marrow (n=26), umbilical cord (n=3), peripheral blood (n=1), and human fetal liver (n=1). No severe procedure-related complications were reported. According to the meta-analyses of self-control data, model for end-stage liver diseases (MELD) score was significantly reduced at the 3rd-4th and 6th months after stem cell therapy, but this reduction was not statistically significant at the 1st-2nd or 12th postoperative months. Child-Pugh score was also reduced after stem cell therapy, but the reduction was not statistically significant at all follow-up time points. According to the meta-analyses of case-control data, MELD and Child-Pugh scores were not significantly different between treatment and control groups at all follow-up time points. The incidence of HCC was not significantly different between treatment and control groups (odds ratio [OR] to=0.41, P=0.53). The mortality was not significantly different between the two groups (OR=0.48, P=0.20). Conclusion: Stem cell therapy could improve the liver function without any severe procedure-related complications. However, compared with conventional treatment, the benefit of stem cell therapy appeared to be not significant in improving the liver function and survival.