Clinical features of hepatitis B patients at immune-tolerance phase with basal core promoter and/or precore mutations.

Little data exist on basal core promoter/precore (BCP/PC) mutations in chronic hepatitis B (CHB) patients at the immune-tolerance (IT) phase. We studied consecutive treatment-naïve, CHBe-antigen (HBeAg)-positive patients who had undergone liver biopsy and genotyping. Those in the IT phase or immune-clearance (IC) phase were enrolled for comparison of the frequency of BCP/PC mutations and their clinical presentations. Subgroup analyses for the IT group were also performed between patients with and without mutations, and IC patients between fibrosis stages ≤2 vs fibrosis >2. Among 301 patients enrolled, 88/301 (29.24%) and 213/301 (70.76%) were at the IT and IC phase, respectively. The frequency of BCP/PC mutations in IT phase was significantly lower than those in IC phase (15.91% vs 64.79%, P < .001). The BCP mutation only was significantly more frequent than the PC mutation in both groups and also in all IC subgroups. IT patients with BCP/PC mutations had significantly higher quantitative anti-HBc levels compared with those of patients with wild-type virus (P < .05). They also had significantly lower mean levels of alanine transaminase, aspartate transaminase, total bilirubin and qAnti-HBc compared with those of IC patients (all P < .05). Additionally, they were significantly younger in mean age, had higher platelet count, higher levels of HBV DNA and surface antigen, as well as higher frequency of genotype B than those of IC patients with fibrosis >2 (all P < .05). BCP/PC mutations were found in IT patients with CHB. They had distinct clinical characteristics when compared with patients with wild-type or at IC phase. Further studies are needed to understand their natural history and treatment outcomes.

Hepatitis B virus particles preferably induce Kupffer cells to produce TGF-ß1 over pro-inflammatory cytokines.

BACKGROUND: Kupffer cells and related cytokines are thought to play a critical role in liver fibrosis; however, the role played by Kupffer cells in hepatitis B virus-related fibrogenesis is unknown. METHODS: Primary rat Kupffer cells were cultured with different titres of hepatitis B virus particles and the concentrations of transforming growth factor (TGF)-ß1, interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF)-α in the culture supernatant were measured every 24h for 7 days. The mRNA and protein levels of these cytokines in Kupffer cells were also analysed using quantitative real-time polymerase chain reaction and western blotting, respectively. RESULTS: Kupffer cells maintained normal morphology and function throughout the 7-day exposure to hepatitis B virus. The concentration of TGF-ß1 secreted by hepatitis B virus-stimulated Kupffer cells (6 log IU/ml hepatitis B virus) increased 5.38- and 7.75-fold by Days 3 and 7, respectively (p<0.01). Western blotting showed that TGF-ß1 expression in Kupffer cells exposed to high titres of hepatitis B virus increased 1.80- and 2.42-fold by Days 3 and 7, respectively (p<0.01). In contrast, Kupffer cell expression and secretion of pro-inflammatory cytokines (IL-6, IL-1 and TNF-α) was unchanged throughout the experiment. CONCLUSION: Hepatitis B virus preferentially stimulates Kupffer cells to produce the pro-fibrogenic/anti-inflammatory cytokine TGF-ß1 rather than the pro-inflammatory cytokines IL-6, IL-1 and TNF-α. This may partly explain why overt liver fibrosis still presents in cases of chronic hepatitis B virus infection with minimal (or no) necro-inflammation.