Aim: To characterize the peripheral T-cell subpopulation profiles and their correlation with hepatitis B virus (HBV) replication in different clinical stages of chronic HBV infection.
Methods: A total of 422 patients with chronic HBV infection were enrolled in this study. The patients were divided into three stages: immune-tolerant stage, immune active stage, and immune-inactive carrier stage. Composition of peripheral T-cell subpopulations was determined by flow cytometry. HBV markers were detected by enzyme-linked immunosorbent assay. Serum HBV DNA load was assessed by quantitative real-time polymerase chain reaction.
Results: CD8(+) T-cells were significantly higher in patients at the immune-tolerant stage than in patients at the immune-active and -inactive carrier stages (36.87 +/- 7.58 vs 34.37 +/- 9.07, 36.87 +/- 7.58 vs 28.09 +/- 5.64, P < 0.001). The peripheral blood in patients at the immune-tolerant and immune active stages contained more CD8(+) T-cells than CD4(+) T-cells (36.87 +/- 7.58 vs 30.23 +/- 6.35, 34.37 +/- 9.07 vs 30.92 +/- 7.40, P < 0.01), whereas the peripheral blood in patients at the immune-inactive carrier stage and in normal controls contained less CD8(+) T-cells than CD4(+) T-cells (28.09 +/- 5.64 vs 36.85 +/- 6.06, 24.02 +/- 4.35 vs 38.94 +/- 3.39, P < 0.01). ANOVA linear trend test showed that CD8(+) T-cells were significantly increased in patients with a high viral load (39.41 +/- 7.36, 33.83 +/- 7.50, 31.81 +/- 5.95 and 26.89 +/- 5.71, P < 0.001), while CD4(+) T-cells were significantly increased in patients with a low HBV DNA load (37.45 +/- 6.14, 33.33 +/- 5.61, 31.58 +/- 6.99 and 27.56 +/- 5.49, P < 0.001). Multiple regression analysis displayed that log copies of HBV DNA still maintained its highly significant coefficients for T-cell subpopulations, and was the strongest predictors for variations in CD3(+), CD4(+) and CD8(+) cells and CD4(+)/CD8(+) ratio after adjustment for age at HBV-infection, maternal HBV-infection status, presence of hepatitis B e antigen and HBV mutation.
Conclusion: Differences in peripheral T-cell subpopulation profiles can be found in different clinical stages of chronic HBV infection. T-cell impairment is significantly associated with HBV load.