ABSTRACT
The current desirable endpoint of treatment against chronic hepatitis B virus infection (cHBV) is to achieve a functional cure, which is defined as HBsAg loss (sAg-L) with or without anti-HBs seroconversion. However, the immunological features that are associated with functional cure have not been studied in detail. Here, a total of 172 cHBV patients including 31 sAg-L patients, and 24 healthy individuals were examined for their T cell phenotypic profile and HBV-specific T cell responses by flow cytometry. sAg-L patients showed distinct CD4 and CD8 T cell phenotype fingerprints compared to those of HBsAg-positive patients, as indicated by the upregulation of CD25, CD40L and CTLA-4 expression on CD4 T cells; HLA-DR, CD95 and PD-1 on both CD4 and CD8 T cells; as well as a potent HBcAg-specific CD8 T cell response. The changes in the T cell phenotype in sAg-L patients began during rapid HBsAg decrease upon treatment onset, were maintained after sAg-L. HLA-DR expression on T cells was positively correlated with the level of HBsAg reduction and the magnitude of the HBcAg-specific T cell responses in cHBV patients. Importantly, increased HLA-DR and CTLA-4 expression on CD4, as well as HLA-DR and TIM-3 expression on CD8 T cells were identified as predictive factors for HBsAg loss within 48 weeks of therapy in cHBV patients. The onset of HBsAg decrease and subsequent loss in cHBV patients on treatment is associated with significant alterations of both CD4 and CD8 T cell phenotypes. Characterization of the T cell phenotype in cHBV patients possessed greater predicative value for sAg-L.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Conflict of interest: The authors have declared that no conflict of interest exists.