Occult HBV infection is defined as the presence of HBV DNA in the liver (with or without detectable or undetectable HBV DNA in the serum) of individuals testing negative for HBsAg. Studies on occult HBV infection in hepatitis C patients have reported highly variable prevalence, because the prevalence of occult HBV infection varies depending on the hepatitis B risk factors and methodological approaches. The most reliable diagnostic approach for detecting occult HBV detection is through examination of liver DNA extracts. HCV has been suspected to strongly suppress HBV replication up to the point where it may be directly responsible for occult HBV infection development. However, more data are needed to arrive at a definitive conclusion regarding the role of HCV in inducing occult HBV infection. Occult HBV infection in chronic hepatitis C patients is a complex biological entity with possible relevant clinical implications. Influence of occult HBV infection on the clinical outcomes of chronic hepatitis C may be considered negative. However, recent studies have shown that occult HBV infection could be associated with the development of hepatocellular carcinoma and contribute to the worsening of the course of chronic liver disease over time in chronic hepatitis C patients. Nevertheless, the possible role of occult HBV infection in chronic hepatitis C is still unresolved and no firm conclusion has been made up until now. It still remains unclear how occult HBV infection affects the treatment of chronic hepatitis C. Therefore, in order to resolve current controversies and understand the pathogenic role and clinical impacts of occult HBV infection in chronic hepatitis C patients, well-designed clinical studies are needed.
Carcinoma, Hepatocellular/complications ; DNA, Viral/analysis ; Hepacivirus/genetics ; Hepatitis B/*complications/*diagnosis/drug therapy ; Hepatitis B virus/genetics ; Hepatitis C, Chronic/*complications/*diagnosis/drug therapy ; Humans ; Interferon-alpha/therapeutic use ; Liver/virology ; Liver Neoplasms/complications

Genetic changes between codons 2209 and 2248 of NS5A of genotype 1b hepatitis C virus (HCV-1b) have been reported to be associated with the sensitivity to interferon-alpha (IFN-alpha). The present study was performed to analyze such relationship in Korean patients with chronic hepatitis C and HCV-1b (n=19), including 12 chronic hepatitis C patients treated with IFN-alpha, 3 chronic hepatitis C patients without treatment as controls, and 4 patients with hepatocellular carcinoma (HCC). Two serum samples, before and after the treatment, were analyzed for the mutations by reverse transcription-polymerase chain reaction, cloning and sequencing. The mutations were identified in 32% (6/19), including five intermediate type (1-3 mutations) and one mutant type (4 or more). In 12 patients treated with IFN-alpha, the number of amino acid substitutions in NS5A2209-2248 was not associated with outcome of the treatment.
Adult ; Aged ; Amino Acid Sequence ; Antiviral Agents/therapeutic use* ; Base Sequence ; Carcinoma, Hepatocellular/virology* ; Carcinoma, Hepatocellular/blood ; Codon ; Female ; Genotype ; Hepatitis C, Chronic/virology* ; Hepatitis C, Chronic/drug therapy* ; Hepatitis C, Chronic/blood ; Hepatitis C-Like Viruses/isolation & purification ; Hepatitis C-Like Viruses/genetics* ; Hepatitis C-Like Viruses/classification ; Human ; Interferon-alpha/therapeutic use* ; Liver Neoplasms/virology* ; Liver Neoplasms/blood ; Male ; Middle Age ; Molecular Sequence Data ; Mutation* ; Prognosis ; Reverse Transcriptase Polymerase Chain Reaction