Funded by the Centers for
Disease Control and Prevention
- Acute flare or exacerbation of hepatitis B: Intermittent elevations in hepatic aminotransferases that can occur in chronic hepatitis B, usually more than twice the baseline value and as high as 10 times the upper limit of normal.
- Alanine aminotransferase (serum), upper limit of normal: The upper limit of normal ALT should be considered 30 U/L for men and 19 U/L in women with chronic hepatitis B. This threshold is relevant for both treatment and biopsy decisions when managing this infection. See case, “Deciding to Initiate Antiviral Therapy in Patients with Chronic Hepatitis B Virus Infection.”
- Anti-hepatitis B core antibody (anti-HBc), total: The antibody directed against hepatitis B core antigen - see below under Core antibody for details. Total anti-HBc refers to presence of either IgG or IgM and test result does not discriminate between the subclasses. Its presence in the blood indicates prior or current hepatitis B infection. It does not confer protection against HBV.
- Anti-hepatitis B surface antibody (anti-HBs): The antibody directed against hepatitis B surface antigen. When present at titers that exceed 10 IU, it confers protective immunity against HBV.
- APRI: The Aspartate aminotransferase (AST)-to-Platelet Ratio Index is a simple non-invasive means of estimating hepatic fibrosis. Its performance characteristics vary depending on the cutoff used and population studied. One meta-analysis found that an APRI threshold of 1.0 was 76% sensitive and 72% specific for detecting hepatitis C-associated cirrhosis. The accuracy of the APRI appears to be less for HIV-hepatitis C coinfected patients.