Mobilization of multilineage-differentiating stress-enduring cells into the peripheral blood in liver surgery

PURPOSE: This study investigated whether liver damage severity relates to the mobilization of multilineage-differentiating stress-enduring (Muse) cells, which are endogenous reparative pluripotent stem cells, into the peripheral blood (PB) and whether the degree of mobilization relates to the recovery of liver volume following human liver surgery. METHODS: Forty-seven patients who underwent liver surgery were included in the present study. PB-Muse cells were counted before surgery, on postoperative days (PODs) 3 and on POD 7. Liver volume was measured using computed tomography before and after surgery. RESULTS: The PB-Muse cell count increased after surgery. The number of PB-Muse cells before surgery was higher, but without statistical significance in the group with neoplasms than in the healthy group that included liver donors (p = 0.065). Forty-seven patients who underwent liver surgery were divided into major hepatic resection (MHR; hepatectomy of three or more segments according to the Couinaud classification, n = 22) and minor hepatic resection (mhr; hepatectomy of two segments or less according to the Couinaud classification, n = 25) groups. PB-Muse cells increased at high rates among MHR patients (p = 0.033). Except for complication cases, PB-Muse cells increased at higher rates in the group with advanced liver volume recovery (p = 0.043). The predictive impact of the rate of increase in PB-Muse cells on the recovery of liver volume was demonstrated by multivariate analysis (OR 11.0, p = 0.014). CONCLUSIONS: PB-Muse cell mobilization correlated with the volume of liver resection, suggesting that the PB-Muse cell number reflects the degree of liver injury. Given that the degree of PB-Muse cell mobilization was related to liver volume recovery, PB-Muse cells were suggested to contribute to liver regeneration, although this mechanism remains unclear.