부산대학교 도서관

Four phases of chronic hepatitis B virus [1] infection have been identified: immune tolerant, immune active, inactive, and hepatitis B surface antigen (HBsAg) clearance. These phases are defined by using a combination of hepatitis B “e” antigen (HBeAg) status, alanine aminotransferase (ALT) level, and HBV DNA level. To determine the extent of liver inflammation and fibrosis needed to decide whether antiviral therapy is necessary often requires a liver biopsy. Recent studies have found that levels of HBsAg can also be used to determine the phase of HBV and can even predict persons who may remain in the inactive phase over time. Non invasive markers including transient elastography can detect a proportion of those with a high probability of severe fibrosis and mild disease but are not yet helpful to determine the status of most chronically infected persons.