Ribavirin enhances the action of interferon-α against hepatitis C virus by promoting the p53 activity through the ERK1/2 pathway.

BACKGROUND/AIMS: Ribavirin significantly enhances the antiviral response of interferon-α (IFN-α) against Hepatitis C virus (HCV), but the underlying mechanisms remain poorly understood. Recently, p53 has been identified as an important factor involving the suppression of HCV replication in hepatocytes. We, therefore, decided to investigate whether and how ribavirin inhibits the replication of HCV by promoting the activity of p53. METHODS: HepG2 and HCV replicons (JFH1/HepG2) were utilized to study the relationship between ribavirin and p53. The effect of ribavirin on cell cycles was analyzed by flow cytometry. The activation of p53 and the signaling pathways were determined using immunoblotting. By knocking down ERK1/ERK2 and p53 utilizing RNA interference strategy, we further assessed the role of ERK1/2 and p53 in the suppression of HCV replication by ribavirin in a HCV replicon system. RESULTS: Using HepG2 and HCV replicons, we demonstrated that ribavirin caused the cell cycle arrest at G1 phase and stabilized and activated p53, which was associated with the antiviral activity of ribavirin. Compared to either ribavirin or IFN-α alone, ribavirin plus IFN-α resulted in greater p53 activation and HCV suppression. We further identified ERK1/2 that linked ribavirin signals to p53 activation. More importantly, knockdown of ERK1/2 and p53 partially mitigated the inhibitory effects of ribavirin on the HCV replication, indicating that ERK1/2-p53 pathway was involved in the anti-HCV effects of ribavirin. CONCLUSION: Ribavirin stimulates ERK1/2 and subsequently promotes p53 activity which at least partly contributes to the enhanced antiviral response of IFN-α plus ribavirin against HCV.

Host genetic variants and hepatitis B virologic features in HBeAg-negative hepatitis B carriers with long-term biochemical remission.

PURPOSE: A significant portion of HBeAg-negative chronic hepatitis B patients have persistently normal serum alanine aminotransferase levels (PNALT). We thus investigated host genetic variants and virological features in HBeAg-negative hepatitis B carriers. METHODS: Baseline clinical and virological features of 133 HBeAg-negative hepatitis B carriers (77 with PNALT and 56 with chronic hepatitis activity) with follow-up for more than 5 years were investigated. Three single nucleotide polymorphisms (SNPs) located within or around human leukocyte antigen (HLA)-DPA1, HLA-DPB1, and interleukin (IL) 28B loci were genotyped. RESULTS: The genotype frequencies of these SNPs were comparable between hepatitis B carriers with PNALT and those with chronic hepatitis. Compared with hepatitis B carriers with PNALT, those with chronic hepatitis had significantly higher baseline serum HBV-DNA levels (4.96 vs. 4.04 log10 IU/ml, P = 0.001). Baseline serum HBV-DNA level > 2000 IU/ml (OR, 8.42; 95% CI, 2.74-25.90, P < 0.001) were the only independent factor associated with chronic hepatitis activity. Changes of serum HBV-DNA in 30 hepatitis B carriers with PNALT had showed a significant reduction of viral load from baseline to last visit (mean difference of paired HBV-DNA levels: -0.78 log10 IU/ml, 95% CI: -1.57 to -0.013, P = 0.047). In contrast, no significant reduction of viral load was found in 28 patients with chronic hepatitis. CONCLUSIONS: The results indicate that lower baseline serum HBV-DNA level and viral load reduction over time are associated with long-term biochemical remission in HBeAg-negative hepatitis B carriers.

Serum p53 gene polymorphisms and severity of hepatitis B or C-related chronic liver diseases in Taiwan.

BACKGROUND AND AIMS: Polymorphisms of p53 gene are known to play an important role in hepatocarcinogenesis. We aimed to investigate the impact of p53 polymorphisms on disease progression by evaluating their prevalence among chronic hepatitis B (CHB) or hepatitis C (CHC) patients with different stages of liver disease. METHODS: A total of 215 CHB, 108 CHC patients with different stages of liver disease and 49 healthy controls were consecutively enrolled. The codon 249 p53 mutations as well as codon 72 polymorphisms were assayed by molecular methods, and their prevalence among the enrolled subjects was evaluated. RESULTS: All patients and controls had codon 249 wild-type sequences. Among codon 72 sequences, Pro/Pro allele frequency of Hepatitis B-related HCC (31.4%), cirrhosis (26.9%), HBV carriers (26.3%), hepatitis C-related cirrhosis (39.1%), and CHC patients (24%) were higher than that of healthy controls (18.4%). After adjustment for sex and age, codon 72 mutant and mixed type were associated with a higher likelihood of asymptomatic carrier state than those with wild type in CHB patients [odd ratio (OR): 2.53, 95% confidence interval (CI) 1.06-6.03, P = 0.037]. However, the prevalence of codon 72 mutant and mixed type were comparable with wild type among CHC patients with HCC (OR 0.70, 95% CI 0.28-1.72, P = 0.433). CONCLUSIONS: Although serum 249(serine) p53 mutation is rarely found in Taiwanese patients, HBV carriers have a higher prevalence of codon 72 mutants than patients with much severe liver diseases or HCV infection, which implies that codon 72 mutants may affect at an earlier stage of HBV infection. Further studies are necessary to delineate the interactions of p53 mutations with HBV infection.

Transient elastography to assess hepatic fibrosis in hemodialysis chronic hepatitis C patients.

BACKGROUND AND OBJECTIVES: Although percutaneous liver biopsy (PLB) is the gold standard for staging hepatic fibrosis in hemodialysis patients with chronic hepatitis C (CHC) before renal transplantation or antiviral therapy, concerns exist about serious postbiopsy complications. Using transient elastography (TE, Fibroscan(®)) to predict the severity of hepatic fibrosis has not been prospectively evaluated in these patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A total of 284 hemodialysis patients with CHC were enrolled. TE and aspartate aminotransferase-to-platelet ratio index (APRI) were performed before PLB. The severity of hepatic fibrosis was staged by METAVIR scores ranging from F0 to F4. Receiver operating characteristic curves were used to assess the diagnostic accuracy of TE and APRI, taking PLB as the reference standard. RESULTS: The areas under curves of TE were higher than those of APRI in predicting patients with significant hepatic fibrosis (≥F2) (0.96 versus 0.84, P<0.001), those with advanced hepatic fibrosis (≥F3) (0.98 versus 0.93, P=0.04), and those with cirrhosis (F4) (0.99 versus 0.92, P=0.13). Choosing optimized liver stiffness measurements of 5.3, 8.3, and 9.2 kPa had high sensitivity (93-100%) and specificity (88-99%), and 87, 97, and 93% of the patients with a fibrosis stage of ≥F2, ≥F3, and F4 were correctly diagnosed without PLB, respectively. CONCLUSIONS: TE is superior to APRI in assessing the severity of hepatic fibrosis and can substantially decrease the need of staging PLB in hemodialysis patients with CHC.

Association of IL28B gene variations with mathematical modeling of viral kinetics in chronic hepatitis C patients with IFN plus ribavirin therapy.

Asian patients with chronic hepatitis C (CHC) are known to have better virological responses to pegylated (Peg) IFN-based therapy than Western patients. Although IL28B gene polymorphisms may contribute to this difference, whether favorable hepatitis C virus (HCV) kinetics during treatment plays a role remains unclear. We enrolled 145 consecutive Taiwanese patients with CHC receiving Peg-IFN α-2a plus ribavirin for the study. Blood samples were taken more frequently at defined intervals in the first 3 d. Peg-IFN was administered at week 1. It was then administered weekly in combination with daily ribavirin for 24 or 48 wk. A mathematical model fitted to the observed HCV kinetics was constructed, which could interpret the transient HCV titer elevation after Peg-IFN treatment. The results demonstrated a comparable viral clearance rate (c = 3.45 ± 3.73) (day(-1), mean ± SD) but lower daily viral production rate (P = 10(6)-10(12)) in our patients than those reported previously in Western patients. Of 110 patients with a sustained virological response (SVR), 47 (43%) had a transient elevation of viral titer within 12 h (proportion of 12 h/3 d: 44% in non-SVR vs. 70% in SVR; P = 0.029). Among 91 patients with available rs8099917 data, patients with the TT genotype had an early surge of viral titer after therapy and a higher SVR and viral clearance rate than those with the GT genotype. In conclusion, Taiwanese patients with CHC receiving Peg-IFN plus ribavirin therapy have a lower daily viral production rate than Western patients, and the rs8099917 TT genotype may contribute to the increased viral clearance rate and better virological responses in these patients.

Serum hepatitis B surface antigen concentration correlates with HBV DNA level in patients with chronic hepatitis B.

BACKGROUND: Serum HBV DNA level is crucial in the management of chronic hepatitis B (CHB); however, the assay is expensive and cannot be used widely. Therefore, we explored the possibility of hepatitis B surface antigen (HBsAg) quantification as a surrogate marker for HBV DNA level in CHB patients. METHODS: A total of 289 CHB patients were enrolled, 251 were evaluated at baseline and 75 of them were also evaluated during anti-HBV treatment. Another 38 on-treatment patients were used for validation. Serum HBsAg titre was quantified by an immunoassay and HBV DNA level by a PCR-based method. Baseline and on-treatment data were analysed. RESULTS: In parallel to log(10) HBV DNA, the log(10) HBsAg was high in both immune tolerance and immune clearance phases, and significantly decreased in the inactive carrier state and was again increased in the reactivation phase of the CHB infection. There was a positive correlation between log(10) HBsAg and log(10) HBV DNA, which was greater in patients with chronic hepatitis, hepatitis B e antigen-positivity, greater alanine aminotransferase or HBsAg levels at baseline and during pegylated interferon treatment. Log(10) HBsAg could predict log(10) HBV DNA independently. An HBsAg titre of >900 IU/ml at baseline or >1,500 IU/ml within the first year of treatment could predict an HBV DNA level of >20,000 IU/ml, especially in subgroups of chronic hepatitis with alanine aminotransferase levels >40 IU/l. The dynamics of HBsAg might also predict serial HBV DNA changes. In the validation group, 64% of patients with on-treatment HBV DNA levels >20,000 IU/ml could be correctly predicted. CONCLUSIONS: Serum HBsAg concentration might serve as a surrogate marker of HBV DNA level in CHB patients.

Increased incidence of gastroesophageal reflux disease in patients with chronic hepatitis B virus infection.

BACKGROUND: Although chronic liver disease is associated with gastroesophageal reflux disease (GERD), the impact of chronic hepatitis B virus (HBV) infection on this association remains unclear. We thus aimed to evaluate the relationship between chronic HBV infection and GERD. METHODS: In this prospective population-based study, 1,001 adult subjects who underwent an upper gastrointestinal endoscopic examination in a health check-up and completed a gastroesophageal reflux questionnaire were consecutively enrolled. Endoscopic findings were classified according to the Los Angeles classification. Hepatitis B surface antigen was used as a marker of HBV infection. Univariate and multivariate approaches were used to evaluate the effects of chronic HBV infection on GERD. RESULTS: Chronic HBV infection was associated with heartburn sensation [odds ratio (OR) 1.27, 95% confidence interval 1.01-1.61, P = 0.037], and erosive esophagitis (adjusted OR 1.75, 1.03-2.97, P = 0.037). Although male gender is a risk factor of erosive esophagitis, further analyses stratified by gender and aspartate aminotransferase to platelet ratio index (APRI) showed that chronic HBV infection was associated with erosive esophagitis in female subjects (adjusted OR 2.70, 1.14-6.39, P = 0.024) and those with APRI of more than 0.3 (adjusted OR 3.94, 1.73-8.96, P = 0.001). Moreover, higher serum aspartate aminotransferase (AST) and triglyceride (TG) levels were risk factors of erosive esophagitis in patients with chronic HBV infection. CONCLUSIONS: Our findings indicate a close association between chronic HBV infection and GERD, especially in female subjects and those with higher APRI levels. Moreover, HBV carriers with higher AST or TG levels have higher incidence of erosive esophagitis. The interactions between chronic HBV infection and GERD need further studies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12072-010-9184-4) contains supplementary material, which is available to authorized users.

Pegylated interferon alfa-2a monotherapy for hemodialysis patients with acute hepatitis C.

BACKGROUND: Hemodialysis patients are at risk of hepatitis C virus (HCV) infection. However, little is known about the efficacy and safety of pegylated interferon (IFN) therapy for hemodialysis patients with acute hepatitis C. METHODS: From 2005 through 2008, 35 hemodialysis patients with acute hepatitis C who did not have spontaneous clearance of HCV by 16 weeks were treated with pegylated IFN alfa-2a at a dosage of 135 microg weekly for 24 weeks. In contrast, 7 patients with clearance of HCV by 16 weeks were under observation only. Thirty-six hemodialysis patients from 2002-2005 who had acute hepatitis C but did not receive treatment served as historical controls. The primary efficacy and safety end points were sustained virologic response (undetectable HCV RNA levels at 24 weeks after therapy) by intention-to-treat analysis and treatment-related withdrawal. RESULTS: The rate of sustained virologic response in the treatment group was significantly higher than the rate of spontaneous HCV clearance in the control group (88.6% vs 16.7%; P < .001). Two patients (5.7%) prematurely terminated treatment at 8 and 10 weeks because of constitutional symptoms, and both did not have sustained virologic response. All but one patient had rapid virologic response (undetectable HCV RNA levels at 4 weeks of therapy), and all patients who received >12 weeks of therapy had early and end-of-treatment virologic responses. All patients who had clearance of HCV by 16 weeks had undetectable HCV RNA levels until the end of follow-up. CONCLUSIONS: Pegylated IFN alfa-2a monotherapy is safe and efficacious for hemodialysis patients with acute hepatitis C. It is suggested that patients without spontaneous clearance of HCV by week 16 should receive therapy.

A sustained virologic response is durable in patients with chronic hepatitis C treated with peginterferon alfa-2a and ribavirin.

BACKGROUND & AIMS: A sustained virologic response (SVR) to therapy for hepatitis C virus (HCV) infection is defined as the inability to detect HCV RNA 24 weeks after completion of treatment. Although small studies have reported that the SVR is durable and lasts for long periods, it has not been conclusively shown. METHODS: The durability of treatment responses was examined in patients originally enrolled in one of 9 randomized multicenter trials (n = 1343). The study included patients who received pegylated interferon (peginterferon) alfa-2a alone (n = 166) or in combination with ribavirin (n = 1077, including 79 patients with normal alanine aminotransferase levels and 100 patients who were coinfected with human immunodeficiency virus and HCV) and whose serum samples were negative for HCV RNA (<50 IU/mL) at their final assessment. Patients were assessed annually, from the date of last treatment, for a mean of 3.9 years (range, 0.8-7.1 years). RESULTS: Most patients (99.1%) who achieved an SVR had undetectable levels of HCV RNA in serum samples throughout the follow-up period. Serum samples from 0.9% of the patients contained HCV RNA a mean of 1.8 years (range, 1.1-2.9 years) after treatment ended. It is not clear if these patients were reinfected or experienced a relapse. CONCLUSIONS: In a large cohort of patients monitored for the durability of an SVR, the SVR was maintained for almost 4 years after treatment with peginterferon alfa-2a alone or in combination with ribavirin. In patients with chronic hepatitis C infection, the SVR is durable and these patients should be considered as cured.

Association of metabolic profiles with hepatic fibrosis in chronic hepatitis C patients with genotype 1 or 2 infection.

BACKGROUND AND AIMS: Metabolic profiles are associated with severity of liver histology in chronic hepatitis C (CHC) infection. However, the influence of hepatitis C virus (HCV) genotypes, especially genotype 1 and 2, on the association between metabolic profiles and hepatic fibrosis remains unknown. METHODS: We consecutively enrolled 528 CHC patients infected by HCV genotype 1 or 2, and used univariate and multivariate approaches to determine the influence of HCV genotype on the association of metabolic characteristics with severity of liver histology. RESULTS: In univariate analysis, diabetes mellitus, obesity, higher grades of hepatic steatosis, homeostasis model assessment-insulin resistance index and alanine aminotransferase level, but lower serum total cholesterol and low-density lipoprotein level, were associated with advanced hepatic fibrosis. Advanced hepatic fibrosis was associated with an adjusted odds ratio of 13.72 (95% confidence interval, 2.15-87.7) for serum fasting blood glucose, 1.07 (1.01 to 1.13) for body mass index (BMI), and 0.03 (0.00-0.32) for total cholesterol level. Older age, lower serum total cholesterol level and more necro-inflammatory activity were associated with advanced hepatic fibrosis in both genotype 1 and 2 patients (P < 0.05). Advanced hepatic fibrosis was associated with an adjusted odds ratio of 31.18 (2.31-421.4) for fasting blood glucose level in genotype 1 infection, whereas 1.16 (1.05-1.28) for BMI in genotype 2 infection. CONCLUSIONS: Age, serum total cholesterol, and hepatic necro-inflammation have important associations with severity of hepatic fibrosis in CHC patients. Moreover, these associations are different between HCV genotype: the effects of fasting blood glucose level and BMI are increased on genotype 1 and genotype 2 patients, respectively.

HBsAg profiles in patients receiving peginterferon alfa-2a plus ribavirin for the treatment of dual chronic infection with hepatitis B and C viruses.

BACKGROUND: With use of peginterferon alfa-2a and ribavirin combination therapy in patients with dual chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, 11.2% of patients achieved clearance of hepatitis B surface antigen (HBsAg) at 6 months after treatment; however, reactivation of HBV DNA was observed in 36.3%. We investigated the predictive potential of HBsAg quantification. METHODS: HBsAg quantification was performed in 120 e antigen-negative patients dually infected with HBV and hepatitis C virus and treated with peginterferon alfa-2a/ribavirin for 48 weeks (HCV genotype 1; n = 74) or 24 weeks (HCV genotype 2/3; n = 46). HBsAg was quantified at baseline, week 4, week 12, end of treatment, and 24 weeks after treatment. RESULTS: The baseline median serum HBsAg level was 120 IU/mL and decreased gradually during treatment. Low baseline HBsAg was significantly associated with HBsAg clearance (40% for HBsAg level 20 IU/mL vs 2.2% for HBsAg level >20 IU/mL; P < .05). A decrease in HBsAg level from baseline to week 12 of 50% was associated with a reduced likelihood of HBV DNA reactivation in patients with baseline undetectable serum HBV DNA (positive predictive value, 89.5%). CONCLUSIONS: HBsAg quantification appears to be a useful indicator of posttreatment outcome in patients dually infected with HBV and hepatitis C virus.

The ratio of aminotransferase to platelets is a useful index for predicting hepatic fibrosis in hemodialysis patients with chronic hepatitis C.

Percutaneous liver biopsy is the gold standard for staging hepatic fibrosis of hemodialysis patients with chronic hepatitis C before renal transplantation or antiviral therapy. Concerns exist, however, about serious post-biopsy complications. To evaluate a more simple approach using standard laboratory tests to predict hepatic fibrosis and its evolution, we studied 279 consecutive hemodialysis patients with chronic hepatitis C and a baseline biopsy. Among them, 175 receiving antiviral therapy underwent follow-up biopsy to evaluate the histological evolution of fibrosis. Multivariate analysis of routine laboratory tests at baseline showed the aspartate aminotransferase-to-platelet ratio index was an independent predictor of significant hepatic fibrosis. The areas under curves of this ratio to predict fibrosis stages F2-4 were 0.83 and 0.71 in the baseline and follow-up sets; and 0.75 and 0.80 respectively, for patients with sustained or non-sustained virological response groups in the follow-up sets. By a judicious setting of cut-off levels for the baseline and non-sustained groups, and the sustained virological response group, almost half and 60 percent of the baseline and follow-up sets could be correctly diagnosed without biopsy. Our study found the aminotransferase-to-platelet ratio index is accurate and reproducible for assessing hepatic fibrosis in hemodialysis patients with chronic hepatitis C. Applying this simple index could decrease the need of percutaneous liver biopsy in this clinical setting.

Differential effects of interferon and lamivudine on serum HBV RNA inhibition in patients with chronic hepatitis B.

BACKGROUND: Lamivudine and interferon have been widely used for the treatment of patients with chronic HBV infection. Serum HBV RNA is detected during lamivudine therapy as a consequence of interrupted reverse transcription and because RNA replicative intermediates are unaffected by the drug. In this study, we aimed to determine the detectability of serum HBV RNA during sequential combination therapy of interferon and lamivudine. METHODS: HBV DNA and RNA in serum samples were quantified by reverse transcription of HBV nucleic acid extract and real-time PCR. Samples were analysed every 2 weeks to 3 months from three groups of patients: 10 male patients treated with nucleoside analogue monotherapy for 44-48 weeks (5 with lamivudine and 5 with entecavir), 6 males on sequential interferon and lamivudine combination therapy, and 3 males on lamivudine monotherapy for 20-24 weeks. RESULTS: HBV RNA was not detectable in any patients before treatment, but became detectable in 15 during antiviral treatment. Among the three groups, pre-treatment HBV DNA (8.1 +/-2.4 versus 7.7 +/-1.4 versus 5.1 +/-0.3 log(10) copies/ml; P=0.06), treatment and follow-up durations (45.5 +/-2.0 versus 49.7 +/-5.6 versus 48.7 +/-6.4 weeks; P=0.32) were comparable. HBV RNA was detectable at the end of treatment or follow-up in all patients with monotherapy, but in none of those with sequential combination therapy (100% versus 0%; P<0.001). CONCLUSIONS: Compared with lamivudine therapy with detectable serum HBV RNA in patients with chronic HBV infection, interferon treatment might reduce HBV DNA replication through the inhibition of HBV RNA replicative intermediates, resulting in the loss of serum HBV RNA.

Hepatitis B virus genotype B has an earlier emergence of lamivudine resistance than genotype C.

BACKGROUND: Hepatitis B virus (HBV) genotype B and C seem not to affect the therapeutic response to lamivudine (3TC). Whether a given genotype has an earlier emergence of 3TC resistance remains unclear. We thus conducted this study to elucidate the association of HBV genotype with the emergence of 3TC-resistant strains in Taiwanese patients. METHODS: Forty chronic hepatitis B patients who developed resistance after 3TC therapy were retrospectively enrolled. HBV genotype, serum alanine aminotransferase (ALT) and HBV DNA levels were determined at baseline. The presence of 3TC-resistant mutations was confirmed by direct sequencing whenever biochemical breakthrough developed. RESULTS: The distribution of HBV genotype B and C in 40 patients receiving 3TC therapy were 60% and 40%, respectively. The mean interval to detect 3TC-resistant strain was 19.6 +/-1.7 months. By using multivariate analysis, HBV genotype B and higher pre-treatment HBV DNA level were independently associated with earlier detection of 3TC-resistant strains. In addition, genotype B was significantly associated with development of 3TC resistance within the first 12 months of 3TC therapy compared with genotype C (odds ratio 8.27; P=0.004). CONCLUSIONS: Compared with HBV genotype C, genotype B appears to have an earlier biochemical resistance to 3TC than genotype C. Therefore, more frequent monitoring of viral load or genotypical resistance might be needed for patients with HBV genotype B infection receiving 3TC therapy, especially during the first year.

High serum adiponectin correlates with advanced liver disease in patients with chronic hepatitis B virus infection.

PURPOSE: Adiponectin possesses anti-inflammatory and insulin-sensitizing properties. Little is known about the role of adiponectin in hepatitis B-related liver disease. METHODS: Serum adiponectin and hepatitis B viral factors were cross-sectionally assayed in 280 patients with chronic hepatitis B virus (HBV) infection including 120 patients with chronic HBV infection, 40 patients with cirrhosis, and 120 patients with hepatocellular carcinoma (HCC); 116 healthy adults were used as controls. The dynamics of serum adiponectin level was also studied longitudinally in 25 patients with hepatitis B e antigen (HBeAg) seroconversion (SC). RESULTS: We found that serum adiponectin level in patients with chronic HBV infection was similar to that in healthy controls and was significantly lower than patients with cirrhosis and HCC. In univariate analysis, high serum adiponectin level significantly correlated with the presence of HBV-related cirrhosis or HCC, abnormal serum ALT level, and HBV genotype C. Multivariate analysis revealed that high serum adiponectin level significantly correlated with the development of HCC. Serum adiponectin levels remained stationary in patients experiencing HBeAg SC. CONCLUSIONS: Our findings suggest that HBV infection itself does not affect adiponectin levels. Serum adiponectin level correlates with the progression of HBV-related liver diseases but not with the development of HBeAg SC.

Ribavirin enhances interferon signaling via stimulation of mTOR and p53 activities.

Cellular mechanisms involving the enhancement of interferon (IFN) signaling by ribavirin remain poorly understood. Here, we identified a novel role of ribavirin in the communication between p53 and the mammalian target of rapamycin (mTOR) signaling. Ribavirin activates p53 by stimulating mTOR and promoting the interaction between mTOR and p53. Activated p53 stimulates the transcription of IFN regulatory factor 9 and subsequently enhances IFN signaling. Furthermore, ribavirin-induced activation of mTOR and p53 enhances IFN-dependent signaling for the IFN-alpha/ribavirin combined treatment. We conclude that ribavirin enhances activities of mTOR and p53, which may account for its antiviral and antitumor effects.

Association of baseline viral factors with response to lamivudine therapy in chronic hepatitis B patients with high serum alanine aminotransferase levels.

BACKGROUND: With the exception of alanine aminotransferase (ALT) level, baseline factors predictive of therapeutic response to lamivudine in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) remain unknown. We thus studied the influence of pre-therapy viral factors on end-of-treatment responses to lamivudine. METHODS: A total of 116 treatment-naive HBeAg-positive CHB patients who had pre-therapy ALT level >5x the upper limit of normal (ULN) and received lamivudine for 12-18 months were enrolled. HBeAg seroclearance and combined HBeAg seroclearance, ALT normalization and undetectable hepatitis B virus DNA at the end of therapy were defined as primary and secondary endpoints, respectively. Pre-therapy viral factors including viral load, genotype, precore (PC) stop codon status, basal core promoter status and pre-S deletion were determined to correlate with therapeutic endpoints. RESULTS: The frequency of patients with detectable PC stop codon mutation (G1896A), basal core promoter mutation (A1762T/G1764A) and pre-S deletion at baseline was 22.4%, 21.6% and 12.1%, respectively. After the end of 12-18 months of lamivudine therapy, the overall HBeAg seroclearance rate was 56.0%. Patients with HBeAg seroclearance had a higher prevalence of baseline PC stop codon mutation than those without (30.8% versus 11.8%; P=0.015). By using multivariate analyses, the odds ratio of patients with the PC stop codon mutation to develop HBeAg seroclearance was 3.33 (P=0.024). The presence of the PC stop codon mutation also correlated with the combined response. CONCLUSIONS: For lamivudine-treated HBeAg-positive CHB patients with pre-therapy ALT levels >5xULN, the PC stop codon mutation could predict a higher HBeAg seroclearance rate at the end of 12-18 months of therapy.

Association of lipid profiles with hepatitis C viral load in chronic hepatitis C patients with genotype 1 or 2 infection.

OBJECTIVES: Metabolic profiles correlate with hepatitis C virus (HCV) infection and are known to be predictors of virologic responses in chronic hepatitis C patients on interferon-based treatment. However, little is known about the differential association of lipid profiles with hepatitis C viral load between genotype 1 and 2 infections. The aim of this study was to evaluate the impact of lipid profiles on HCV RNA levels in patients with genotypes 1 and 2. METHODS: A total of 531 chronic hepatitis C patients infected patients with HCV genotype 1 or 2 were consecutively enrolled. Univariate and multivariate approaches were used to estimate the associations between demographic, metabolic, and viral variables and HCV RNA levels. RESULTS: Higher serum triglyceride, total cholesterol, and low-density lipoprotein levels correlated with higher HCV RNA levels. In multivariate analysis, genotype 1 infection, severe hepatitis activity, milder hepatic fibrosis, higher homeostasis model assessment of insulin resistance (HOMA-IR) index and triglyceride levels are associated with higher HCV viral loads (P<0.05). Subanalysis on patients with lower body mass index values showed higher HCV viral load was associated with higher HOMA-IR index and total cholesterol level (P<0.05). After stratification by HCV genotype, lipid profiles were significantly associated with HCV viral load in genotype 2 infection (P<0.05), but not genotype 1 infection. CONCLUSIONS: A proportional relationship is found between serum lipid profiles and hepatitis C viral load in patients with genotype 2 infection; however, whether manipulation of lipid profiles would improve the response to current anti-HCV therapy is to be determined in further studies.

Factors affecting early viral load decline of Asian chronic hepatitis C patients receiving pegylated interferon plus ribavirin therapy.

BACKGROUND: Early viral load decline following pegylated interferon-alpha2a and ribavirin therapy is an important predictor of the treatment responses in chronic hepatitis C (CHC) patients, thus, it is essential to evaluate the influence of host and viral factors on early viral load decline. METHODS: Clinical and serial virological data were collected from 145 consecutive Asian CHC patients with pegylated interferon-alpha2a plus ribavirin therapy. A dose of pegylated interferon-alpha2a was administered at week 1 and then weekly with daily oral ribavirin for 24 or 48 weeks. Genotyping and quantification of hepatitis C virus (HCV) RNA were done using molecular methods. RESULTS: A total of 81 patients were infected with HCV genotype 1,61 with genotype 2 and 3 with both genotypes 1 and 2. At the end of follow-up, 110 patients attained sustained virological response (SVR). In multivariate analyses, body mass index (BMI) and genotype were related to viral load decline at day 2, baseline viral load and high-density lipoprotein (HDL) cholesterol levels were correlated with viral load decline between days 2 and 28. Genotype, baseline viral load, alanine aminotransferase (ALT) levels and BMI independently predicted rapid virological response, whereas only genotype 2, lower baseline viral load and more substantial viral load decline at day 28 predicted a higher SVR. CONCLUSIONS: HCV genotype, baseline viral load, pretreatment BMI, HDL and ALT levels have a significant effect on early viral load decline of Asian CHC patients with interferon-based therapy. Only HCV genotype, baseline viral load and viral load decline at day 28 can independently predict SVR.

Hepatitis B virus basal core promoter mutation and DNA load correlate with expression of hepatitis B core antigen in patients with chronic hepatitis B.

BACKGROUND: Expression of intrahepatic hepatitis B core antigen (HBcAg) is related to the immunopathogenesis of hepatitis B virus (HBV) infection. This study investigated the role that HBV genotype and basal core promoter (BCP) mutation play in the expression of HBcAg. METHODS: A total of 70 hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis (genotype B in 52 patients and genotype C in 18 patients; BCP mutation T1762/A1764 in 16 patients) were enrolled. Clinical, virologic, and histologic features were compared with regard to localization and expression of intrahepatic HBcAg. The effects that HBV genotype and BCP mutation T1762/A1764 had on expression of HBcAg were further evaluated by in vitro assays. RESULTS: Cytoplasmic, mixed cytoplasmic/nuclear, and nuclear localization of intrahepatic HBcAg was found in 38 (56.7%), 25 (37.3%), and 4 (6.0%) patients, respectively; HBcAg was not discernible in 3 patients. A total of 58 (82.9%) of these patients expressed a high level of HBcAg. In multivariate analysis, cytoplasmic localization of HBcAg correlated only with a low HBV load in serum (P = .045) and BCP mutation (P = .04). A high expression level of HBcAg also correlated with a high HBV load in serum (P = .015) and with BCP wild-type sequence (P = .037). In vitro assays indicated that the HBV BCP mutant strain had lower subcellular expression of HBcAg than did the BCP wild-type strain. CONCLUSIONS: HBV BCP mutation and HBV load, but not genotype, contribute to the expression of intrahepatic HBcAg.