Pathogenesis of flares in liver inflammation in hepatitis B virus-infected women during and after pregnancy

Abstract

Abstract Women with chronic hepatitis B (CHB) are at risk of increased liver inflammation during pregnancy. To investigate the pathogenesis of these hepatic flares we studied immune responses and gut microbiota in 19 women with CHB (12 without and 7 with antiviral (NUC) treatment) and 3 uninfected controls in each trimester and at two and six months postpartum. Increased serum alanine aminotransferase (ALT) activity as a liver inflammation marker was defined as a value greater than the upper limit of normal and twice the baseline value. While increased plasma levels of soluble CD163, inflammatory cytokines and chemokines generally occurred during episodes of liver inflammation, increases of IL-22 and IFN-γ levels during pregnancy preceded a postpartum ALT increase. In contrast, levels of IL-27, a cytokine produced by the trophoblast, increased also in women with normal ALT levels. The fecal microbiota of HBV-infected patients with and without NUC treatment had lower α-diversity (inverse Simpson index) than those of uninfected controls. 16srRNA amplicon analysis and PCA showed patient-specific clustering of microbiota. To identify factors predictive of a postpartum ALT increase, we compared 16srRNA DNA data from patients with a postpartum ALT increase to those with normal postpartum ALT levels (four patients per group). Combining all time points, the gut microbiota of those with postpartum ALT increase differed significantly from those with normal ALT activities (UMAP, PERMANOVA p<0.003). In conclusion, the composition of the fecal microbiota was patient-rather than time point-specific and differed between patients with and without postpartum ALT increase. Supported by NIH Bench-to-Bedside Award (B.R. and D.T.Y.L.)