RÉSUMÉ
Background: occult hepatitis B virus [HBV] infection is characterized by presence of HBV infection with undetectable hepatitis B surface antigen [HBsAg]. Diagnosis of occult HBV infection requires sensitive HBV-DNA PCR assay. Recently it has been shown that occult hepatitis B may be a cause of cryptogenic liver disease. The aim of this study is the investigation of occult HBV infection among patients with cryptogenic liver disease
Methods: 65 consecutive paraffin-embedded liver tissues from cases referred to RCGLD [Research Center for Gastroenterology and Liver Diseases] and THC [Tehran Hepatitis Center] during the years 2001 and 2002 for liver biopsy because - of elevation of alanine aminotransferase [ALT] levels for more than six months were studied. Among these, 12 patients with cryptogenic liver disease were found. Human tissue DNA could be extracted in 7 of 12 patients. In these patients liver biopsies were reviewed and HBV-DNA and HBsAg and HBcAg were assayed in liver tissue by polymerase chain reaction [PCR] and immunohistochemistry [IHC], respectively
Results: histologically, chronic hepatitis, cirrhosis and nonspecific changes were reported. HBVDNA was detectable in 4 patients but IHC was negative in all. The frequency of occult HBV infection was more than 50%
Conclusions: occult HBV infection is common among patients with cryptogenic liver disease. In these patients, HBV-DNA may be detected more frequently among patients with more advanced liver pathology [cirrhosis] and more aggressive clinical course [decompensated cirrhosis]