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Background Hepatitis B surface antigen ( HBsAg) positivity is associated with increased risk for cirrhosis and hepatocellular carcinoma ( HCC). HBsAg seroclearance is thought to be rare in general, but cohort data from US patients are limited. Aim To determine the incidence of HBsAg seroclearance in a real-life US cohort. Methods In total, 4737 patients with chronic hepatitis B from five primary care, gastroenterology and multispecialty centres, and a university medical centre were retrospectively enrolled between 2001 and 2014 with data obtained by manual review of individual patient medical records. Seroclearance was determined by loss of HBsAg seropositivity. Persistent HBsAg was confirmed by direct serology or by proxy with positive hepatitis B e-antigen ( HBeAg) or HBV DNA levels. Results HBsAg seroclearance occurred in 52 patients over 16 844 person-years (0.31% annually, 1.2% overall). Median follow-up was 32 months, and mean age 45 ± 14 years. Incidence of HBsAg seroclearance was higher in non-Asians, age >45, males, and those with baseline HBV DNA ≤10 000 IU/mL. On multivariate Cox proportional modelling, non-Asian ethnicity ( HR 2.8), male sex ( HR 2.1), baseline HBVDNA ≤10 000 ( HR 2.0) and age >45 ( HR 1.8) were significant independent predictors of seroclearance. Conclusion HBsAg seroclearance rates were lower than previously described in this real-life cohort of patients with chronic hepatitis B, especially among Asian, female and younger patients. [ABSTRACT FROM AUTHOR]

Background Chronic hepatitis C ( CHC) infection is a risk factor for both the development of end-stage liver disease and hepatocellular carcinoma ( HCC). Globally, approximately 170 million people are chronically infected with the hepatitis C virus ( HCV), and the majority of these individuals come from the western Pacific and Southeast Asia regions (94.6 million persons combined). CHC is an understudied and underappreciated health problem in many Asian countries and in the US, where Asians represent one of the fastest growing groups of new Americans. Aim To perform a systematic review of the current literature on the epidemiology, diagnosis and screening, clinical characteristics and response to anti-viral therapy of Asians with CHC. Methods Using a PubMed search of 'hepatitis C' and 'Asia,' 341 original manuscripts published in peer-reviewed journals were identified, and 99 were selected based on their relevance. Results Many Asian CHC patients do not have easily identifiable risk factors and may be underdiagnosed. Rates of HCV infection in Asians on community screening in the US are unexpectedly high, and there is a high prevalence of HCV genotype 6 in Southeast Asia and Southern China. HCV-infected Asians tend to present at older age and may have higher risk of HCC; however, they respond better to anti-viral therapy than non-Asians across all HCV genotypes. Conclusions Given the high HCV endemicity in Asia, lack of identifiable risk factors and favourable treatment response rates in Asians, we advocate the screening for HCV infection of all Asians who come from areas where HCV prevalence is ≥2%. [ABSTRACT FROM AUTHOR]

Background The primary and secondary prevention of spontaneous bacterial peritonitis ( SBP) is recommended in high-risk patients with cirrhosis. Several studies evaluating the efficacy of rifaximin for SBP prophylaxis have yielded conflicting results. Rifaximin has the potential advantage of preventing bacterial overgrowth and translocation without the systemic side effects of broad-spectrum antibiotics. Aim To evaluate the efficacy of rifaximin in the primary and secondary prevention of SBP. Methods A literature search using five databases was performed to identify studies on the association between rifaximin and SBP. We performed two meta-analyses: (1) rifaximin compared to systemic antibiotics and (2) rifaximin compared to no antibiotics. Random-effect modelling was conducted to determine overall pooled estimates and 95% confidence intervals ( CIs). Results Five studies with 555 patients (295 rifaximin, 260 systemic antibiotics) compared rifaximin with systemic antibiotics. The pooled odds ratio ( OR) for SBP was 0.45 (95% CI 0.16-1.27; P = .13) in patients receiving rifaximin and strengthened on sensitivity analysis ( OR 0.38, 95% CI 0.19-0.76, P = .01). In the analysis comparing rifaximin with no antibiotics, there were five studies with 784 patients (186 rifaximin, 598 no antibiotics). The OR for SBP was 0.34 (95% CI 0.11-0.99; P < .05) in patients receiving rifaximin. In subgroup analysis, rifaximin reduced the risk of SBP by 47% compared to no antibiotics for primary prophylaxis and by 74% compared to systemic antibiotics for secondary prophylaxis. Conclusion Rifaximin may be effective in preventing SBP in patients with cirrhosis and ascites compared to systemically absorbed antibiotics and compared to placebo. [ABSTRACT FROM AUTHOR]

Background Chronic hepatitis B ( CHB) may lead to cirrhosis, hepatocellular carcinoma and premature death. Elevated alanine transaminase ( ALT) levels ≥ the upper limit of normal ( ULN) are a major determinant for initiating anti-viral therapy; however, ALT levels alone may not be predictive of hepatic fibrosis. Aim To determine the proportion of CHB patients with ALT ≤40 IU/L and liver fibrosis stage ≥2. Secondary goals include subgroup analysis by hepatitis B e antigen ( HBeAg) status, high hepatitis B virus ( HBV) DNA levels, Asian ethnicity, lower ULN of ≤30 IU/L (males) and 19 IU/L (females), and advanced age. Methods Studies identified in EMBASE and MEDLINE (1/1990-6/2012) using the search criteria: 'Hepatitis B'[Mesh] OR 'Hepatitis B virus'[Mesh] OR 'Hepatitis B, Chronic'[Mesh])) AND 'Alanine Transaminase'[Mesh]) and abstracts containing the term 'hepatitis' from recent major U.S. gastroenterology and liver society meetings were considered. Results Among nine studies ( N = 830 patients), a significant proportion (20.7%; 95% CI: 16.2-26.0%) of CHB patients with ALT levels ≤40 IU/L had significant fibrosis irrespective of HBeAg status, high HBV DNA levels, ethnicity or age, although this proportion may be higher in patients older than 30-40 years old. The corresponding proportion was 27.8% even when the newer ULN of 30 IU/L (males) and 19 IU/L (females) was applied. Conclusions Approximately one fifth of CHB patients with ALT ≤40 IU/L may have significant hepatic fibrosis. The approach to such patients should be individualised, as further evaluation and treatment may be appropriate. [ABSTRACT FROM AUTHOR]

Background Prior studies have shown that precore mutations abolish and basal core promoter ( BCP) mutations down-regulate hepatitis B e antigen ( HBeAg) production. Thus, the presence of precore and BCP mutations in HBeAg-positive patients indicates an infection with a mixed viral population of wild-type and precore and/or BCP mutant hepatitis B virus ( HBV). To date, there has been limited study of the prevalence and clinical significance of precore and BCP mutations in patients with HBeAg-positive chronic hepatitis B. Aim To determine the prevalence, predictors and clinical characteristics of mixed wild-type and precore/ BCP HBV infection, through a cross-sectional study, in a US cohort of patients with chronic hepatitis B. Methods We conducted a retrospective study of 828 chronic hepatitis B patients with HBV genotype and mutation panel testing seen at three US gastroenterology and liver clinics from June 2005 to September 2009. Results A majority of our patients (92.3%) were either Vietnamese or Chinese American. In the HBeAg-positive cohort, 17% of patients had precore mutations only, 28% had BCP mutations only and 5% had both BCP and precore mutations. On multivariate analyses, HBV genotype C, increasing age, lower HBV DNA level and an ALT quotient >2 were independent predictors for the presence of precore and/or BCP mutations. Conclusions The current distinction and management recommendations for HBeAg-positive vs. HBeAg-negative patients with chronic hepatitis B should be reassessed. Additional biomarkers and treatment endpoints should be studied for their usefulness in predicting continued viral suppression after treatment discontinuation. [ABSTRACT FROM AUTHOR]

Background One of the most important factors in treatment failure using nucleos(t)ide analogues in chronic hepatitis B is anti-viral resistance. Primary drug resistance refers to amino acid changes in the hepatitis B virus polymerase/reverse transcriptase (rt) that result in reduced susceptibility to anti-viral agents. Pre-existing drug resistance mutations may occur in untreated patients and may affect their treatment outcomes. Aim To determine the prevalence of hepatitis B DNA polymerase mutations in treatment-naïve patients. Methods We used a direct PCR sequencing test to detect DNA polymerase mutations in 472 consecutive treatment-naïve patients at two community gastroenterology clinics in Northern California. Results A majority of patients were Asians (>95%), had either genotype B or C (95%) and had no evidence of cirrhosis or liver cancer (94%). Mean age was 45 ± 13 and mean hepatitis B virus DNA was 5.3 ± 1.8 log10 IU/mL. Most patients did not have any detectable mutations (82.4%). Some (16.7%) had mutations of unknown clinical significance (rtV207M/L/I) and only 4 patients had rtA181A/S, rtA194S or M250I. Conclusions No rtM204V/I or rtN236T mutations were observed in our study. Less than 1% of our patients had mutations that can be associated with primary resistance to existing anti-viral therapies for hepatitis B virus. [ABSTRACT FROM AUTHOR]