Study of the distribution of hepatitis B immunoglobulin in pregnant mice using small-animal imaging technology

Background: The safety and necessity of hepatitis B immunoglobulin (HBIG) in preventing the mother-to-child transmission of hepatitis B virus (HBV) are still controversial because of its unclear mechanism of action and the inconsistent injection programs used during gestation. Objectives: This study aimed to show the dynamic transportation and distribution of HBIG in the maternal body and to provide evidence for its clinical efficacy in preventing mother-to-child HBV transmission. Study design: Pregnant mice were injected with Cy7-labeled mouse anti-human monoclonal hepatitis B surface antibodies through the tail vein. In vivo imaging technology was used to observe the dynamic transportation and distribution of HBIG in the pregnant mice. Results: HBIG fluorescence signals were higher in the uterus than in the liver, spleen, and kidneys. Fluorescence signals in the uterine region were obviously higher at the third trimester than at early and mid pregnancy. Conclusions: HBIG is gradually deposited in the mouse placenta during pregnancy, with the phenomenon being more significant in the third trimester.