The primary goal of chronic hepatitis B (CHB) treatment is to reduce hepatitis B surface antigen (HBsAg). T helper 17 (Th17) and regulatory T (Treg) cells are essential for the development of CHB. However, how Th17 and Treg cells contribute to HBsAg loss is still unknown. Therefore, this study aimed to search for the predictive value of Th17 and Treg cells for HBsAg loss in CHB patients with low HBsAg quantification.

The primary goal of chronic hepatitis B (CHB) treatment is to reduce hepatitis B surface antigen (HBsAg). T helper 17 (Th17) and regulatory T (Treg) cells are essential for the development of CHB. However, how Th17 and Treg cells contribute to HBsAg loss is still unknown. Therefore, this study aimed to search for the predictive value of Th17 and Treg cells for HBsAg loss in CHB patients with low HBsAg quantification.

Combined with quantification of HBsAg, the proportions of Th17 cells and Treg cells at baseline can be used as good predictors of HBsAg loss in patients with low HBsAg quantification treated with NA and PEG-IFN.

The study included 99 hepatitis B e antigen (HBeAg)-negative CHB patients who had completed a year of nucleos(t)ide analogue (NA) monotherapy and had received both NA and pegylated interferon (PEG-IFN) treatment for less than 96 weeks (96 wk). In the cured group, 48 patients lost HBsAg within 48 wk, while 51 patients did not (uncured group). Blood samples and clinical data were collected for research.

During PEG-IFN and NA combination therapy, the proportion of Th17 cells in the cured group increased significantly, while the proportion of Treg cells in the uncured group increased. From 0 to 24 wk, the proportion of Th17 cells in the cured group was significantly higher than in the uncured group, while the opposite was true for Treg cells. Patients with alanine aminotransferase (ALT) ≥ 2.5 upper limit of normal (ULN) at 12 wk had a higher proportion of Th17 cells and a lower proportion of Treg cells than those with ALT <2.5 ULN at 12 wk. Additionally, the proportion of Th17 cells is inversely associated with the level of HBsAg, whereas the level of Treg cells is positively related to HBsAg quantification. The clinical cure index, including age, HBsAg quantification, and the proportions of Th17 and Treg cells, had a higher area under the curve (0.957) for predicting HBsAg loss when compared to the proportions of Th17 and Treg cells and HBsAg quantification alone. Conclusions: Combined with quantification of HBsAg, the proportions of Th17 cells and Treg cells at baseline can be used as good predictors of HBsAg loss in patients with low HBsAg quantification treated with NA and PEG-IFN.