Mobilization Of Hematopoietic Stem Cells And Dynamic Changes Of Serum Cytokines In Patients With HBV-related Acute-on-chronic Liver Failure

Acute-on-chronic liver failure (ACLF) encompasses patients with previouslywell-compensated liver disease in whom an acute decompensation of liver functionoccurs because of a precipitating event. In China, HBV-infected ACLF cases accountfor more than80%of ACLF cases owing to a high incidence of chronic HBV infection.Previous studies have shown that massive hepatocytes necrosis/apoptosis and lack ofliver regeneration contribute to the progression of liver failure. Mesurement of livercirculating cell death marker could aid to predict disease progression. Recent studiesindicate that bone marrow (BM)-derived stem cells contribute to liver regeneration. Butlimited information is available on the dynamic and mechanisms of mobilization ofBM-derived hematopoietic stem cells (HSCs) after ACLF.Objective: Our present study was aimed at elucidating whether1.(a) ACLF leadedto a release of HSCs into the peripheral circulation;(b) serum levels of inflammatorycytokines involved in HSCs mobilization and/or liver repair were changed in ACLFpatients.2. Serum levels of cell death marker were changed and its significance in liverdisease progression.Methods:1.20patients with HBV-related ACLF,20patients undergoing chronichepatitis B (CHB), and10healthy controls were enrolled. The biochemical parameterswere routinely performed. The percentages of peripheral blood CD34~+cells weredetermined by two-color flow cytometry. The absolute number of positive cells per-microliter was calculated as percentage of positive cells×PBMCs count. The serumlevels of stem cell factor (SCF), hepatocyte growth factor (HGF) and granulocytecolony stimulating factor (G-CSF) were determined by enzyme-linked immune sorbentassays (ELISA).2.31patients with HBV-related ACLF, twenty patients undergoingchronic hepatitis B (CHB), and ten healthy controls were enrolled into anotherrespective study. Total cytokeratin-18(M65) and caspase-cleaved cytokeratin-18(M30)were dynamic monitored by ELISA.Results:1. A significant increase in percentage of circulating CD34~+cells wereobserved in ACLF patients (1.10±0.84%) in comparison with healthy controls(0.15±0.16%，p <0.05) and CHB patients (0.07±0.04%，p <0.05). The absolute numbers of CD34~+cells in peripheral blood of ACLF patients was1.20±0.87×10~6/L, but only0.28±0.36×10~6/L in healthy controls and0.15±0.16×10~6/L in CHB patients, respectively,indicating an absolute increase of CD34~+cells in ACLF patients (p <0.05). Nosignificant difference was observed between CHB patients and healthy controls. Inparallel with mobilization of BM-derived CD34~+HSCs, significant increases (p <0.05)of serum SCF, HGF, G-CSF were observed in ACLF patients (1002.89±235.48pg/ml,6428.95±1468.89pg/ml, and387.58±201.24pg/ml) in comparison with CHB patients(680.93±125.81pg/ml,675.50±313.87pg/ml, and35.83±36.44pg/ml) and healthycontrols (775.30±195.45pg/ml,710.36±226.25pg/ml, and17.37±8.99pg/ml). Meanwhile,the absolute numbers of CD34~+cells were positively correlated with the levels of HGF(r=0.50, p <0.05) and G-CSF (r=0.575, p <0.05) in ACLF patients.2. In ACLFpatients，the serum levels of M30（508.65±340.16U/L）and M65（768.75±290.02U/L）were significantly higher than those in CHB patients（212.27±91.33U/L，p<0.05；384.40±134.46U/L， p<0.05） and healthy controls （94.12±17.64U/L， p<0.05；121.99±29.25U/L，p<0.05）. No significant difference of M30and M65was observedbetween improved group and deteriorated group (572.38±349.45U/L vs436.14±285.59U/L，p=0.29；817.25±307.66U/L vs703.90±221.37U/L，p=0.31). Inimproved group of ACLF patients, a significant decrease of serum M30(220.33±81.74U/L) and M65（410.37±139.35U/L） was determined in recovery periodthan advanced period (572.38±358.53U/L, p <0.05；817.25±315.66U/L, p<0.05). Indeteriorated group of ACLF patients, the serum M30and M65keep no changes betweenadvanced period and persisting period (555.72±436.99U/L vs436.14±299.53U/L，p=0.46；883.28±551.11U/L vs703.90±232.17U/L，p=0.33).Conclusion:1. we demonstrated that the mobilization of CD34~+HSCs that wasparalleled with an elevation of multiple stress-induced cytokines in ACLF patients,suggesting that a role of BM-derived HSCs mobilization in liver repair and regeneration.The data underline the potential role of BM-derived HSCs for cell therapy of ACLFpatients.2. The serum levels of M30and M65are sensitive indicators for hepatocytesnecrosis and apoptosis. Dynamic monitor of M30and M65levels may provide potentialmarkers for disease progression of ACLF patients.