Abstract

To understand clinical features and immunity of chronic HBV-infected patients with high or low level HBsAg, the differences of serum two-component-determined circulating immune complexes (TCIC) and peripheral blood lymphocyte subsets between these patients were analyzed. 126 patients with chronic hepatitis B virus infection were divided into two groups including 44 with low-level HBsAg and 82 with high-level HBsAg, and three phases including non-active phase, immune active phase and immune tolerant phase by level of HBsAg and natural history of chronic hepatitis B virus infection. Antibody capture-ELISA method and flow cytometry were used to assay serum TCIC and peripheral blood lymphocyte subsets in 44 patients with low-level HBsAg (Group A), 82 patients with high-level HBsAg (Group B) and 22 healthy volunteers (Group C), respectively, and the results were analyzed and compared. Among these 44 patients in Group A, 40 patients (90.9%) were stable in non-active phase and the positive rate of HBsAg/IgG-CIC was the highest, accounting for 15.9% (7/44), while the positive rate of HBsAg/C3-CIC was the highest in Group B, accounting for 46.3% (38/82). The positive rates of serum TCIC, A value and non-active CD3⁺CD8⁺ percentages in Group A were all lower than those in Group B with corresponding phases (P<0.01-0.05), however, the percentages of CD4⁺/CD8⁺were higher than those in the corresponding phases of Group B(P<0.01). Patients with low-level HBsAg were correlated to low capability of TCIC synthesis and elimination and there was a low dose-induced immunotolerance phenomenon.

Key words: Immune complex, chronic HBV infection, HBsAg, lymphocyte subsets, immunotolerance.