Journal of Research in Medical Sciences1735-1995141200902231317ENAssistant Professor, Department of Internal Medicine, Isfahan University of Medical Science, IsfahanMD, Research Center of Gastrointestinal and Liver Disease, Shaheed Beheshti University of Medical Science, Tehran, Iran.Research Center of Gastrointestinal and Liver Disease, Shaheed Beheshti University of Medical Science, TehranMD, Research Center of Gastrointestinal and Liver Disease, Shaheed Beheshti University of Medical Science, TehranFellowship of Gastroentrology, Shaheed Beheshti University of Medical Science, TehranLiver and Gastrointestinal Disease Research Center, Tabriz University of Medical Science, TabrizAssistant Professor, Department of Internal Medicine, Bandar Abas University of Medical Science, Bandar AbasProfessor, Research Center of Gastrointestinal and Liver Disease, Shaheed Beheshti University of Medical Science, Tehran2008072920081219<ul> <li><strong>BACKGROUND</strong>: Occult hepatitis B is defined as presence of HBV DNA in tissue or serum without hepatitis B surface antigen. The aim of this study is to determine frequency of occult hepatitis B among hepatitis C patients in Tehran and compare the route of transmission and liver enzymes between positive and negative HBV DNA patients.</li> <li><strong>METHODS</strong>: In a cross sectional study, serum of 103 hepatitis C cases (79.6% men and 20.4% women) were analyzed for s, x and core genes via a nested polymerase chain reaction technique.</li> <li><strong>RESULTS</strong>: HBV DNA was detectable in serum of 20 patients (19.4%). No significant difference in age, sex and route of transmission were seen in HBV DNA positive and negative patients. In HBV DNA positive and negative groups, mean of AST was 73, 47 (p < 0.05) and mean of ALT was 76 and 36 respectively (p < 0.05).</li> <li><strong>CONCLUSION</strong>: Occult hepatitis B was observed in a considerable number of hepatitis C patients in Tehran. It was associated with elevation in liver enzyme but was not related to route of transmission.</li> <li><strong>KEY WORD</strong>: Occult hepatitis B, hepatitis C, cirrhosis.</li> </ul>http://jrms.mui.ac.ir/index.php/jrms/article/view/1957http://jrms.mui.ac.ir/index.php/jrms/article/download/1957/1232