In patients with HBeAg-positive chronic hepatitis B, 48 weeks of 10 mg or 30 mg of adefovir dipivoxil per day resulted in histologic liver improvement, reduced serum HBV DNA and alanine aminotransferase levels, and increased the rates of HBeAg seroconversion. The 10-mg dose has a favorable risk-benefit profile for long-term treatment. No adefovir-associated resistance mutations were identified in the HBV DNA polymerase gene.

Background & Aims: Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is a

In patients with HBeAg-negative chronic hepatitis B, 48 weeks of adefovir dipivoxil treatment resulted in significant histologic, virologic, and biochemical improvement, with an adverse-event profile similar to that of placebo. There was no evidence of the emergence of adefovir-resistant HBV polymerase mutations.

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I nfection with hepatitis B virus (HBV) causes acute and chronic hepatitis and is strongly associated with the development of cirrhosis and hepatocellular carcinoma. Immediately after infection of hepatocytes, the viral DNA is transferred to the nucleus, where the viral polymerase is removed, and the double-stranded, open circular DNA is converted to a covalently closed circular DNA molecule (cccDNA). During chronic HBV infection (CH-B), cccDNA accumulates in hepatocyte nuclei, apparently at a level of about 5-50 copies per cell, where it persists as a minichromosome and functions as the template for the transcription of viral genes. 1 The RNA pregenome, in addition to producing capsid and polymerase proteins, becomes encapsidated and is reverse-transcribed. A particularity of the hepadnavirus life cycle is that DNA-containing nucleocapsids can either recycle back to the nucleus to amplify and maintain the pool of cccDNA or become enveloped and secreted into the blood, where new viral particles can spread to other hepatocytes. 2,3 Because cccDNA is the transcriptional template of the virus, it is required for maintenance of HBV infection.Evidence from the woodchuck hepatitis virus system indicated that the pool of cccDNA persisted even when viral production was strongly reduced by the presence of nucleoside analogues. 4,5 Woodchuck studies 6,7 and recent

In patients with HBeAg-negative chronic hepatitis B, the benefits achieved from 48 weeks of adefovir dipivoxil were lost when treatment was discontinued. In patients treated for 144 weeks, benefits were maintained, with infrequent emergence of viral resistance.

Estimates of the prevalence of chronic hepatitis B (CHB) in the United States differ significantly, and the contribution of foreign-born (FB) persons has not been adequately described. The aim of this study was to estimate the number of FB persons in the United States living with CHB by their country of origin. We performed a systematic review for reports of HBsAg seroprevalence rates in 102 countries (covering PubMed from 1980 to July 2010). Data from 1,373 articles meeting inclusion criteria were extracted into country-specific databases. We identified 256 seroprevalence surveys in emigrants from 52 countries (including 689,078 persons) and 1,797 surveys in the general populations of 98 countries (including 17,861,035 persons). Surveys including individuals with lower or higher risk of CHB than the general population were excluded. Data were combined using meta-analytic methods to determine country-specific pooled CHB prevalence rates. Rates were multiplied by the number of FB living in the United States in 2009 by country of birth from the U.S. Census Bureau to yield the number of FB with CHB from each country. We estimate a total of 1.32 million (95% confidence interval: 1.04-1.61) FB in the United States living with CHB in 2009; 58% migrated from Asia and 11% migrated from Africa, where hepatitis B is highly endemic. Approximately 7% migrated from Central America, a region with lower CHB rates, but many more emigrants to the United States. This analysis suggests that the number of FB persons living with CHB in the United States may be significantly greater than previously reported. Assuming 300,000-600,000 U.S.-born persons with CHB, the total prevalence of CHB in the United States may be as high as 2.2 million. (HEPATOLOGY 2012;56:422-433)