Chia-Ming Chu

Hepatitis B virus infection

Since the introduction of the hepatitis B vaccine and other preventive measures, the worldwide prevalence of hepatitis B infection has fallen. However, chronic infection remains a challenging global health problem, with more than 350 million people chronically infected and at risk of hepatic decompensation, cirrhosis, and hepatocellular carcinoma. An improved understanding of hepatitis B virology, immunology, and the natural course of chronic infection, has identified hepatitis B virus replication as the key driver of immune-mediated liver injury and disease progression. The approval of potent oral antiviral agents has revolutionised hepatitis B treatment since 1998. Conventional and pegylated interferon alfa and nucleoside and nucleotide analogues are widely authorised treatments, and monotherapy with these drugs greatly suppresses virus replication, reduces hepatitis activity, and halts disease progression. However, hepatitis B virus is rarely eliminated, and drug resistance is a major drawback during long term therapy. The development of new drugs and strategies is needed to improve treatment outcomes.

HBsAg seroclearance in asymptomatic carriers of high endemic areas: Appreciably high rates during a long‐term follow‐up

Spontaneous hepatitis B surface antigen (HBsAg) seroclearance in chronic HBV infection has long been suggested as a rare event in high endemic areas. The prevalence of HBsAg in the general population of Taiwan, however, decreased remarkably from 15%‐20% before age 40 to 5%‐10% after age 60 or 70. This study aimed to reexamine the rates of HBsAg seroclearance by a long‐term follow‐up of 1965 hepatitis B e antibody–positive asymptomatic adult carriers. Of these, 1076 (55%) were males, the mean (± SD) age was 35.6 ± 9.2 years and the mean follow‐up was 10.8 ± 5.4 years. Hepatitis relapsed in 314 patients, 0.5 to 18 (mean ± SD = 5.8 ± 4.4) years after the entry. The probability of hepatitis relapse correlated positively with male sex (P < 0.0001) and age at entry (P < 0.0001). Serum HBsAg cleared in 245 patients at the mean age of 47.8 ± 9.6 years. The cumulative probabilities of HBsAg seroclearance were 8.1% after 10 years, but increased disproportionally to 24.9% and 44.7%, respectively, after 20 and 25 years. In multivariate analysis, the probability of HBsAg seroclearance correlated positively with age at entry (P < 0.0001) and sustained remission of hepatitis (P < 0.0001) and marginally significantly with male sex (P = 0.053). Conclusion: Cumulative rate of HBsAg seroclearance in asymptomatic adult carriers from high endemic areas was approximately 40% after 25 years of follow‐up. The low HBsAg seroclearance rates in previous studies might be due to the relative short period of follow‐up. (HEPATOLOGY 2007;45:1187–1192.)

Age-specific prognosis following spontaneous hepatitis B e antigen seroconversion in chronic hepatitis B.

Hepatitis B e antigen (HBeAg) seroconversion in chronic hepatitis B virus infection confers a favorable prognosis, but untoward outcomes may develop in some patients. The impact of the age of HBeAg seroconversion on prognosis is not clearly known. HBeAg‐positive patients with biopsy‐proven chronic hepatitis B were followed up long‐term. Follow‐up studies included liver biochemistry, alpha‐fetoprotein, and ultrasonography every 3 to 6 months or more frequently if clinically indicated. Of the patients who underwent spontaneous HBeAg seroconversion, the incidences of HBeAg‐negative hepatitis, cirrhosis, hepatocellular carcinoma (HCC), and hepatitis B surface antigen seroclearance were compared between patient groups with different ages at the time of HBeAg seroconversion using Kaplan–Meier survival analysis and Poisson regression model. Spontaneous HBeAg seroconversion was documented in 508 patients. Of the 483 patients who had no evidence of cirrhosis or HCC at the time of HBeAg seroconversion, HBeAg seroconversion occurred before age 30 in 218 patients (group A), between age 31 and 40 in 199 patients (group B), and after age 40 in 66 patients (group C). The 15‐year cumulative incidences of HBeAg‐negative hepatitis, cirrhosis, and HCC increased with increasing age of HBeAg seroconversion, the lowest being in group A (31.2%, 3.7%, and 2.1%, respectively) and highest being in group C (66.7% [P < 0.0001], 42.9% [P <0.0001], and 7.7% [P = 0.29], respectively). The hazard ratio of HBeAg‐negative hepatitis, cirrhosis, and HCC was 2.95, 17.6, and 5.22, respectively, in group C compared with group A. Conclusion: Patients with HBeAg seroconversion before age 30 have excellent prognosis, whereas patients with delayed HBeAg seroconversion after age 40 have significantly higher incidences of HBeAg‐negative hepatitis, cirrhosis, and HCC. (HEPATOLOGY 2010.)

Fulminant hepatic failure in acute hepatitis C: increased risk in chronic carriers of hepatitis B virus

BACKGROUND/AIMS The role of hepatitis C virus (HCV) in fulminant hepatitis remains controversial. This study was conducted to investigate the risk of fulminant hepatitis C in relation to HCV genotypes and concurrent infection of other viruses. PATIENTS 109 HCV RNA positive patients from 334 consecutive cases hospitalised to a medical centre in northern Taiwan for overt acute viral hepatitis were prospectively evaluated. METHODS HCV RNA was detected by a combined reverse transcription-polymerase chain reaction assay. HCV genotypes were analysed using a genotype specific probe based assay in the 5’ untranslated region. RESULTS 39 patients tested positive for hepatitis B surface antigen but negative for IgM antibody to hepatitis B core antigen, indicating concurrent chronic hepatitis B virus (HBV) infection. Twelve patients were hepatitis G virus (HGV) RNA positive. Genotyping of HCV disclosed 1b in 93, 1b mixed with 2a/2c or 1b mixed with 2b in 11, and not classified in five. Serum titres of HCV RNA were <105 copies/ml in 77, 105–107 copies/ml in 25, and >107copies/ml in seven. Eleven patients (10.1%) had fulminant hepatitis as a complication. Development of fulminant hepatitis did not correlate with age and gender of the patients, concurrent HGV infection, HCV genotypes, or serum titre of HCV RNA. However, the incidence (95% confidence interval) of fulminant hepatitis in patients with underlying chronic HBV infection was 23.1% (9.9 to 36.3%), which is significantly higher than in those without (2.9% (−1.0 to 6.8%)). In 39 patients with concurrent chronic HBV infection, the clinical and virological characteristics showed no significant difference between those with fulminant hepatitis and those without. CONCLUSIONS Acute hepatitis C in patients with concurrent chronic HBV infection is associated with a substantial risk of fulminant hepatitis.

Incidence and risk factors of progression to cirrhosis in inactive carriers of hepatitis B virus.

OBJECTIVES:Most hepatitis B virus (HBV) carriers are incidentally identified as inactive carriers (positive hepatitis B e antibody 87ith normal alanine aminotransferase (ALT) levels), but their long-time outcome and risk of cirrhosis are incompletely understood.METHODS:A total of 1,965 inactive carriers (mean age: 35.6 years; males: 1,076) were studied. Cirrhosis was diagnosed using a high-resolution real-time ultrasound.RESULTS:During an 11.5-year mean follow-up, 314 carriers developed reactivation of hepatitis B (ALT was more than twice the upper limit of normal and positive HBV DNA was found using hybridization assays). The risk of reactivation of hepatitis B correlated significantly with advanced age at study entry (P<0.0001) and male sex (P<0.0001). A total of 57 patients developed cirrhosis, with the cumulative incidence being 15% after 25 years. The risk of cirrhosis correlated significantly with advanced age at entry (P=0.004) and reactivation of hepatitis B (P<0.0001). Of the 1,651 carriers without reactivation of hepatitis B, 10 developed cirrhosis, and advanced age at entry was the only significant factor (P=0.03). Of the 314 patients with reactivation of hepatitis B, cirrhosis developed in 47 of them, with the cumulative incidence being 8, 16, 27, and 46% at 5, 10, 15, and 20 years, respectively, after the onset of reactivation. Male sex (P=0.037) and advanced age at reactivation (P=0.006) were the two independent risk factors.CONCLUSIONS:The so-called inactive carrier state cannot be generally viewed as an innocent long-lasting condition of good prognosis; regular follow-up is necessary.

Identification and characterization of a prevalent hepatitis B virus X protein mutant in Taiwanese patients with hepatocellular carcinoma

The aim of this study was to investigate whether there was a particular hepatitis B virus (HBV) X protein (HBx) mutant associated with Taiwanese patients with hepatocellular carcinoma (HCC). Initially, the entire coding region of HBx gene from the serum samples of 14 Taiwanese patients were sequenced. A novel mutant, HBx-A31, was preferentially found in patients with HCC. Sera from 67 patients with HCC and 100 patients with chronic hepatitis B were thus subjected for codon 31 analysis using a dual amplification created restriction site method. HBx-A31 was detected more frequently in patients with HCC (52% versus 12%; P<0.001) and in patients with liver cirrhosis (44% versus 6%; P<0.001). Site directed mutagenesis experiment revealed that HBx-A31 was less effective in transactivating HBV enhancer I-X promoter complex, less efficient in supporting HBV replication, and less potent in enhancing TNF-α induced increment of CPP32/caspase 3 activities in HepG2 cells. In conclusion, a prevalent HBx mutant was identified in Taiwanese patients with hepatocellular carcinoma. Development of this mutant might represent a strategy of the virus to escape immune surveillance and thus contribute to the process of multiple-step hepatocarcinogenesis.

Altered expression patterns of lipid metabolism genes in an animal model of HCV core-related, nonobese, modest hepatic steatosis

BackgroundBecause the gene expression patterns of nonobese hepatic steatosis in affected patients remain unclear, we sought to explore these patterns using an animal model of nonobese hepatic steatosis.MethodsWe developed mice that conditionally express the hepatitis C virus (HCV) core protein regulated by the tetracycline transactivator (tTA). Microarray analyses and reverse-transcription polymerase chain reaction were performed using liver samples of both the double transgenic mice (DTM), which express both the HCV core and tTA, and single transgenic mice (STM), which express tTA alone, at 2 months of age. Functional categories of genes with altered expression were classified using gene ontology programs. Serum glucose, lipid levels, and systemic blood pressure were also measured.ResultsApproximately 20–30% of hepatocytes from the DTM were steatotic. No significant differences were observed in the serum glucose, lipid content, or blood pressure levels between the DTM and STM. Gene expression analyses revealed Sterol-regulatory element-binding protein (SREBP) pathway activation and dysregulation of the following genes involved in lipid metabolism: 3-hydroxy-3-methylglutaryl-coenzyme A synthase 1, Apolipoprotein AII, Apolipoprotein CI, acyl-CoA thioesterase I, and fatty acid binding protein 1; in mitochondrial function: solute carrier family 25 member 25 and cytochrome c oxidase subunit II; in immune reaction: complement component 3, lymphocyte antigen 6 complex, locus A, lymphocyte antigen 6 complex, locus C, lymphocyte antigen 6 complex, locus D, and lymphocyte antigen 6 complex, locus E.ConclusionSome genes of lipid metabolism, mitochondrial function, and immune reaction and the SREBP pathway are involved in HCV core-related, nonobese, modest hepatic steatosis.

Comparison of long-term effects of lymphoblastoid interferon alpha and recombinant interferon alpha-2a therapy in patients with chronic hepatitis B.

Summary.  To compare the long‐term effect of natural lymphoblastoid interferon‐alpha (IFN‐αnl) and recombinant IFN‐α2a therapy in patients with chronic hepatitis B, 210 patients in two trials were followed‐up for 1.1–15.5 years following the end of therapy. They included 34 patients who received placebo (control), 67 treated with IFN‐αnl (36 after prednisolone priming) and 109 treated with IFN‐α2a (56 after prednisolone priming). The cumulative sustained response was higher in patients who had been treated with IFN‐αnl after prednisolone priming than was exhibited using IFN‐αnl alone, IFN‐α2a alone or the placebo (P < 0.05), or IFN‐α2a following prednisolone priming (P = 0.052) at the end of 11 years. Hepatocellular carcinoma (HCC) was detected in 1.5% of the IFN‐αnl group, 3.7% of the IFN‐α2a group and 14.7% of the control group (control vs IFN‐αnl or IFN‐α2a, P < 0.05). The cumulative HCC development was higher in the control group than in the IFN‐αnl group (P < 0.002) and the IFN‐α2a group (P = 0.06). The cumulative survival rate was lower in the control group than in the IFN‐αnl group (P < 0.01) and the IFN‐α2a group (P = 0.02). Multivariate analysis revealed that IFN‐αnl therapy and female gender are significant predictors of sustained response; preexisting cirrhosis, age at entry and IFN therapy are significant factors in both HCC development and survival. In conclusion, IFN‐αnl treatment may have a better long‐term effect on hepatitis B virus (HBV) clearance than IFN‐α2a and placebo, and IFN therapy may provide better long‐term beneficial effects than placebo in terms of HBV clearance, reduction of HCC and prolonged survival.

Amino acid substitutions in codons 9–11 of hepatitis C virus core protein lead to the synthesis of a short core protein product

Background : Previous in vitro experiments have indicated that if the ninth codon of the hepatitis C virus (HCV) core gene is mutated from arginine to lysine, a short 16‐kDa (P16) instead of a 21‐kDa (P21) core protein will be produced. In this study, we aimed to investigate whether similar mutations existed in patients with chronic HCV infection and whether such mutations led to the expression of P16.

Serial HBV DNA levels in patients with persistently normal transaminase over 10 years following spontaneous HBeAg seroconversion

Summary.  Earlier studies addressing the hepatitis B virus (HBV) DNA cut‐off level for inactive chronic HBV infection largely involved patients with normal alanine aminotransferase (ALT) for only 1–2 years and based on a single time HBV DNA assay. This study was conducted to address this issue using serial HBV DNA assays in patients with persistently normal ALT (PNALT) over 10 years following spontaneous hepatitis B e antigen (HBeAg) seroconversion. Serial serum specimens (mean 9 samples per patient) of 62 patients with PNALT and no disease progression over 10 years (median 18.1 years) after spontaneous HBeAg seroconversion were assayed for HBV DNA. Excluding assays within 1 year after HBeAg seroconversion, 21% and 82.3% of the patients with PNALT had HBV DNA levels persistently lower than 4 log10 and 5 log10 copies/mL, respectively, and only 8% had a level ≥5 log10 copies/mL in at least two assays. Of the 27 patients with PNALT defined by ALT <30 U/L for male and <19 U/L for female, only 33% had serum HBV DNA level persistently <4 log10 copies/mL. There was no significant difference in the serial HBV DNA changes among patients with different gender, HBV genotype or age at HBeAg seroconversion. Liver biopsy in nine patients invariably showed minimal necroinflammation and one showed Ishak fibrosis score 4. These results suggest that 5 log10 copies/mL (20 000 IU/mL) is a more appropriate cut‐off HBV DNA level for inactive chronic HBV infection in the setting of PNALT.