Associations of peripheral CD4+ CD25+ CD127low/- regulatory T cells with viral load and liver pathology in hepatitis B virus carriers

Objective To investigate the associations of peripheral CD4+ CD25+ CD127low/- regulatory T cells (Treg) with HBV viral load and liver pathology in hepatitis B virus (HBV) carriers. Methods Forty six chronic HBV carriers admitted in the first hospital of Jiaxing during October 2012 and February 2014, and 23 healthy subjects (controls) were enrolled in the study. CD4+ CD25+ CD127low/- Treg in peripheral blood of the two groups were detected by flow cytometry. Ultrasound-guided liver biopsies were performed in chronic HBV carriers and HBV DNA load was determined by real-time PCR method. Independent samples t test was used for the comparison between groups, and Spearman rank correlation or Pearson linear correlation analyses were performed. Results The frequency of the peripheral CD4+ CD25+ CD127low/- Treg in 46 HBV carriers was (5.11±1.47)%, which was significantly higher than that in healthy controls [(3.46±1.23)%, t=4.629, P<0.01]. The HBV DNA load in HBV carriers was (6.21±1.98)lg copies/mL, which was positively correlated with the CD4+ CD25+ CD127low/- Treg level (r=0.405, P<0.01). Among 46 HBV carriers, 21 (45.65%) were of inflammation grade 2 or above, and 16 (34.78%) were of fibrosis stage 2 or above. Peripheral CD4+ CD25+ CD127low/- Treg level was negatively correlated with inflammation and fibrosis in HBV carriers (r=-0.343 and-0.452, P<0.05). Conclusion CD4+ CD25+ CD127low/- Treg may be associated with the chronicity of HBV infection and the degree of liver damage. Key words: Hepatitis B virus; T-lymphocytes, regulatory; Viral load; Liver pathology