Effect of prophylactic antiviral intervention on T cell immunity in hepatitis B virus-infected pregnant women.

BACKGROUND: Antiviral intervention in hepatitis B virus (HBV)-infected pregnant women can effectively reduce mother-to-child transmission. However, the immunological characteristics of pregnant women with chronic HBV infection and the effects of antiviral intervention during pregnancy on maternal immune response remain unknown. We aimed to investigate these effects by comparing mothers who received antiviral intervention during pregnancy with those who did not. METHODS: Pregnant women positive for hepatitis B surface antigen and hepatitis B e-antigen (HBsAg+ HBeAg+) were enrolled at delivery, including 34 received prophylactic antiviral intervention during pregnancy (AVI mothers) and 15 did not (NAVI mothers). T lymphocyte phenotypes and functions were analysed using flow cytometry. RESULTS: At delivery, maternal regulatory T cell (Treg) frequency in AVI mothers was significantly higher than that in NAVI mothers (P < 0.002), and CD4+ T cells in AVI mothers displayed a decreased ability to secrete IFN-γ (P = 0.005) and IL-21 (P = 0.043), but an increased ability to secrete IL-10 and IL-4 (P = 0.040 and P = 0.036), which represented a higher Treg frequency, enhanced Th2 response and suppressed Th1 response. Treg frequency among AVI mothers was correlated negatively with serum HBsAg and HBeAg levels. After delivery, the ability of CD4+ T cells or CD8+ T cells to secrete IFN-γ or IL-10 was similar and no significant difference in Treg frequency was found between the two groups. CONCLUSIONS: Prophylactic antiviral intervention during pregnancy has an effect on T cell immunity in pregnant women, which was characterised by increased maternal Treg frequency, enhanced Th2 response and suppressed Th1 response at delivery.

Characterization of T cell immunity in chronic hepatitis B virus-infected mothers with postpartum alanine transaminase flare.

BACKGROUND: Postpartum alanine transaminase (ALT) flares occur frequently in chronic hepatitis B virus (HBV)-infected mothers with antepartum antiviral therapy (AVT). We aimed to characterize the T cell immunity in HBV-infected mothers experiencing postpartum ALT flares. METHODS: Twenty HBV-infected pregnant women who received AVT at 26-28 weeks of gestation were enrolled and followed up until 15-18 weeks postpartum. Among the 20 HBV-infected pregnant women, 6 experienced postpartum ALT flare (AF mothers), while 14 did not (NAF mothers). T lymphocyte phenotypes and functions were analyzed using flow cytometry. RESULTS: Compared to NAF mothers, the quantitative HBsAg levels in AF mothers decreased significantly at 6-8 or 15-18 weeks postpartum. Significant differences in HBeAg levels between these groups were only found at delivery. Regulatory T cell (Treg) numbers in AF mothers were lower than those of NAF mothers before AVT; however, there were no significant differences in Treg numbers at other follow-up points. Expression of other T cell phenotypes were similar between the two groups. T cells in AF mothers produced more pro-inflammatory cytokines (IFN-γ, IL-21, TNF-α, IL-2) or less anti-inflammatory cytokine (IL-10) than those in NAF mothers before, during, or after antiviral treatment. The ratio of IFN-γ to IL-10 producing by CD4+ T cells or CD8+ T cells was higher in AF mothers than that in NAF mothers during pregnancy or after delivery. CONCLUSIONS: The characteristics of T cell immunity was distinct between mothers with postpartum ALT flare and those without ALT flare from pregnancy to postpartum, which indicated that T cell immunity might get involved in postpartum ALT flare.