Occult Hepatitis B Virus Infection In Anti-Hbc-Positive Pregnant Women

Background: The aim of this study was to explore the prevalence and characteristics of OBI in pregnant women positive for the hepatitis B core antibody (anti-HBc).Methods: The serum samples of 416 pregnant women positive for anti-HBc were collected from the Second Affiliated Hospital of Anhui Medical University and the clinical records were obtained. The qualitative and quantitative serological markers of HBV were detected. HBV DNA was tested using nested polymerase chain reaction (PCR), and the products of the PCR were sequenced.Results: HBV DNA was detected in 63 of 416 HBsAg-negative subjects with a median HBV DNA level of 50.6 (0, 411) IU/mL, and the prevalence of OBI in the anti-HBc-positive pregnant women were 15.14% (63/416, 95% CI: 11.7% - 18.58%). The positive HBV DNA test rate was significantly higher in the Rotor-Gene Q than in the Mx3000P. The sequencing results showed that HBV genotype B (97.28%) was the predominant type and I57F, I150T, C64R/P/Y, S61P, and T125M/A were the predominant amino acid (AA) mutation sites.Conclusions: Multiple types of mutants coexist with small amounts of wild-type HBV and interact to maintain low viral loads. These mutations may influence HBsAg detection by impairing the binding of antibodies to antigens.