title: Occult hepatitis B virus infection in patients with chronic hepatitis C liver disease.
abstract: BACKGROUND
  Hepatitis B virus (HBV) infections in patients who lack detectable hepatitis B surface antigen (HBsAg) are called occult infections. Although such infections have been identified in patients with chronic hepatitis C liver disease, their prevalence and clinical significance are not known.
  
  
  METHODS
  With the polymerase chain reaction, we searched for HBV DNA in liver and serum samples from 200 HBsAg-negative patients with hepatitis C virus (HCV)-related liver disease (147 with chronic hepatitis, 48 with cirrhosis, and 5 with minimal histologic changes). One hundred of the patients had detectable antibodies to the HBV core antigen (anti-HBc); 100 were negative for all HBV markers. Eighty-three were treated with interferon alfa. We also studied 50 patients with liver disease who were negative both for HBsAg and for HCV markers. In six patients found to have occult HBV infection, we evaluated possible genomic rearrangements through cloning or direct sequencing procedures.
  
  
  RESULTS
  Sixty-six of the 200 patients with chronic hepatitis C liver disease (33 percent) had HBV sequences, as did 7 of the 50 patients with liver disease unrelated to hepatitis C (14 percent, P=0.01). Among the 66 patients, 46 were anti-HBc-positive and 20 were negative for all HBV markers (P<0.001). Twenty-two of these 66 patients (33 percent) had cirrhosis, as compared with 26 of the 134 patients with hepatitis C infection but no HBV sequences (19 percent, P=0.04). HBV sequences were detected in 26 of the 55 patients in whom interferon therapy was ineffective and 7 of the 28 patients in whom interferon therapy was effective (P=0.06). None of the sequenced HBV genomes had changes known to interfere with viral activity and gene expression.
  
  
  CONCLUSIONS
  Occult hepatitis B infection occurs frequently in patients with chronic hepatitis C liver disease and may have clinical significance.
authors.affiliation: Dipartimento di Medicina Interna, Università di Messina, Italy.
authors.forename: I
authors.initials: I
authors.lastname: Cacciola
authors.forename: T
authors.initials: T
authors.lastname: Pollicino
authors.forename: G
authors.initials: G
authors.lastname: Squadrito
authors.forename: G
authors.initials: G
authors.lastname: Cerenzia
authors.forename: M E
authors.initials: ME
authors.lastname: Orlando
authors.forename: G
authors.initials: G
authors.lastname: Raimondo
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D004279:DNA, Viral / Q000032:analysis* / Q000097:blood; D005260:Female; D016679:Genome, Viral; D005838:Genotype; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D006509:Hepatitis B / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood; D006512:Hepatitis B Core Antigens / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000276:immunology; D006515:Hepatitis B virus / Q000235:genetics* / Q000302:isolation & purification; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use; D008099:Liver / Q000737:chemistry / Q000473:pathology; D008103:Liver Cirrhosis / Q000150:complications / Q000821:virology; D008297:Male; D008875:Middle Aged
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D016898:Interferon-alpha