Prevalence and clinical impact of sarcopenia in liver transplant recipients:A meta-analysis

BACKGROUND The prevalence of sarcopenia in patients undergoing liver transplantation(LT)remains to be determined partly because of different diagnostic criteria.Sarcopenia has recently been recognized as a new prognostic factor for predicting outcomes in LT candidates.AIM To estimate the prevalence of sarcopenia and evaluate its clinical effect on LT candidates.METHODS This systematic search was conducted in PubMed,Web of Science,Embase,and Cochrane Library for original English-language articles that investigated the prevalence and influence of sarcopenia in patients undergoing LT from database inception to November 30,2022.Cohort studies of the definition of sarcopenia that estimate sarcopenia prevalence and evaluate its effect on clinical outcomes and the risk of mortality were included.RESULTS Twenty-five studies involving 7760 patients undergoing LT were included.The pooled prevalence of sarcopenia in patients undergoing LT was 40.7%[95%confidence intervals(95%CI):32.1-49.6].The 1-,3-,and 5-year cumulative probab-ilities of post-LT survival in patients with preoperative sarcopenia were all lower than those without sarcopenia(P<0.05).Sarcopenia was associated with an increased risk of post-LT mortality in patients undergoing LT(adjusted hazard ratio:1.58;95%CI:1.21-2.07).Patients with preoperative sarcopenia had a longer intensive care unit stay,a high risk ratio of sepsis,and serious post-LT complications than those without sarcopenia.CONCLUSION Sarcopenia is prevalent in a substantial proportion of patients undergoing LT and is strongly and independently associated with higher a risk of mortality risk.

Current understanding of mesenchymal stem cells in liver diseases

Liver diseases caused by various factors have become a significant threat to publichealth worldwide. Liver transplantation has been considered as the only effectivetreatment for end-stage liver diseases;however, it is limited by the shortage ofdonor organs, postoperative complications, long-term immunosuppression, andhigh cost of treatment. Thus, it is not available for all patients. Recently,mesenchymal stem cells (MSCs) transplantation has been extensively explored forrepairing hepatic injury in various liver diseases. MSCs are multipotent adultprogenitor cells originated from the embryonic mesoderm, and can be found inmesenchymal tissues including the bone marrow, umbilical cord blood, adiposetissue, liver, lung, and others. Although the precise mechanisms of MSC transplantationremain mysterious, MSCs have been demonstrated to be able toprevent the progression of liver injury and improve liver function. MSCs can selfrenewby dividing, migrating to injury sites and differentiating into multiple celltypes including hepatocytes. Additionally, MSCs have immune-modulatoryproperties and release paracrine soluble factors. Indeed, the safety and effectivenessof MSC therapy for liver diseases have been demonstrated in animals.However, pre-clinical and clinical trials are largely required to confirm its safetyand efficacy before large scale clinical application. In this review, we will explorethe molecular mechanisms underlying therapeutic effects of MSCs on liverdiseases. We also summarize clinical advances in MSC-based therapies.