Quantitative HBsAg and HBV DNA levels: correlation in pregnant women with hepatitis B virus infection in Southern Viet Nam

Serum HBV DNA levels reflect the ability of hepatitis B virus (HBV) to spread and replicate. In pregnant women, when HBV DNA levels are more than 200,000 IU/mL, they are advised to use antiviral therapy to prevent mother-to-child transmission (MTCT). However, the HBV DNA test is expensive and not available in all health facilities. Quantitative HBsAg (qHBsAg) assay is cheaper and may replace the HBV DNA test. Objective. To determine the correlation between qHBsAg and HBV DNA levels in pregnant women. Patients and methods. Pregnant women with HBV were recruited in three hospitals from October 2019 to November 2020. A total of 665 women were examined. Among them, 417 women in the quantification range of HBV DNA test were selected for analysis. The mean age was 29.30 years (range: 18–43). The blood samples were taken for the qHBsAg assay and viral load test. The qHBsAg test was quantified by electrochemiluminescence, and the viral load test was measured by a real-time polymerase chain reaction (RT-PCR). Results. There was a strong correlation between qHBsAg and HBV DNA levels (r = 0.64, p < 0.001; n = 417). The correlation was strong in the HBeAg-positive group (r = 0.79, p < 0.001; n = 112), and there was no correlation in the HBeAg-negative group (r = 0.06, p = 0.41; n = 177). This correlation was stronger in the group of young women (18–35 years old) than in the group of older women (36–43 years old). Conclusion. In pregnant women with HBV infection, qHBsAg and viral load levels had a positive correlation, especially in the HBeAg-positive and the young women groups. The qHBsAg assay may replace the HBV DNA test when deciding on antiviral treatment in facilities with limited conditions to prevent MTCT. Key words: hepatitis B virus, quantitative HBsAg, HBV DNA test, pregnant women, mother-to-child transmission