The duration of hepatitis B surface antigen (HBsAg) exposure rather than the quantity of HBsAg was found to affect the level of anti-hepatitis B virus (HBV) immune response in patients with chronic HBV infection, according to the results of a study published in Gastroenterology.

An understanding of the duration of HBsAg exposure and its impact on anti-HBV host cellular immunity is lacking even though chronic HBV infection is typically acquired at birth with persistence of high quantities of HBV antigens. An international team of researchers therefore investigated the effects of these factors on lymphocyte and HBV-specific T-cell populations by collecting blood samples and clinical data from 243 patients with HBV infection (aged 3–75 years) in the United Kingdom and China. They found that although T and natural killer cell phenotypes and functions did not change with the level of serum HBsAg, the number of HBs-specific T cells correlated with serum levels of HBsAg (r=0.3367; P <.00001). In addition, a multivariate linear regression model identified patient age as the only factor significantly associated with the number of HBs-specific T cells (P =.000115). HBs-specific T cells comprised 28.26% of the total HBV-specific T cells in patients aged <30 years and 7.14% in patients aged >30 years.

The authors concluded, “In an analysis of immune cells from patients with chronic HBV infection, we found the duration of HBsAg exposure, rather than quantity of HBsAg, associates with the level of anti-HBV immune response.” They added, “Although the presence of HBs-specific T cells might not be required for clearance of HBV infection in all patients, strategies to restore anti-HBV immune responses should consider patients younger than 30 years.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


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Reference

Le Bert N, Gill US, Hong M, et al.  Effects of hepatitis B surface antigen on virus-specific and global T cells in patients with chronic HBV infection [published online April 14, 2020]. Gastroenterology. doi:10.1053/j.gastro.2020.04.019