Hepatitis B Virus DNA Quantification by bDNA, Serum
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Hepatitis B virus (HBV) is a causative agent of viral hepatitis, with >50% of those infected developing symptoms of acute hepatitis (jaundice, nausea, anorexia, malaise, and fatigue). Progression to chronic hepatitis B, which occurs in 5% of adults and up to 90% of newborns, is of great public health concern. There are an estimated 300 million chronic carriers of HBV worldwide. Up to 25% of these chronically infected individuals subsequently develop cirrhosis and liver failure or hepatocellular carcinoma. HBV is found in the blood and other body fluids of those with acute or chronic HBV infection, and person-to-person transmission of HBV infection occurs via sexual contacts, childbirth (with HBV-infected mothers), shared use of contaminated needles, or organ transplantation.
While serologic markers are routinely used to determine the diagnosis of acute and chronic HBV infection, they often do not reflect the true disease progression. Presence of detectable HBV DNA levels in serum is an accurate marker of active viral replication. During the convalescent phase of acute hepatitis B, detectable HBV DNA levels persisting for longer than 8-week duration may indicate progression to chronic hepatitis B. In patients with chronic hepatitis B, HBV DNA levels in serum correlate with risk of cirrhosis and hepatocellular carcinoma. Thus, the ability to detect HBV DNA in serum has prognostic value for the outcome of acute and chronic HBV infection.
Effective antiviral treatment is available for patients with chronic hepatitis B and include interferon-alpha, nucleoside analogs (lamivudine, entecavir, telbivudine), and a nucleotide analog (adefovir). Goals of anti-HBV therapy are to reduce serum HBV viral load to undetectable level and to achieve hepatitis B surface antigen (HBsAg) seroconversion (anti-HBs positivity).
See The Laboratory Approach to the Diagnosis and Monitoring of Hepatitis B Infection in Publications.
Quantification of hepatitis B virus (HBV) DNA levels in serum of patients with confirmed chronic HBV infection (known to have detectable HBV DNA in serum)
Monitoring progression of chronic HBV infection and responses to anti-HBV therapy
This assay has a quantification range of 357 to 17,900,000 IU/mL (2.55-7.25 log IU/mL). Results are reported as integers in IU/mL (rounded to 3 significant figures) and log IU/mL.
A result of <357 IU/mL (or <2.55 log IU/mL) indicates that either the specimen contains no detectable hepatitis B virus (HBV) DNA or the HBV DNA level is below the lower limit of quantification for this assay.
A result of >17,900,000 IU/mL (or >7.25 log IU/mL) indicates that the HBV DNA level is above the upper limit of quantification for this assay.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Due to the potential for false-positive results, this assay should NOT be used for initial detection of hepatitis B virus (HBV) DNA in patients with suspected chronic HBV infection. Laboratory evaluation of HBV status should begin with HBV serological marker tests, including hepatitis B surface antigen.
A result of <357 IU/mL (<2.55 log IU/mL) does not rule out the presence of HBV DNA in the specimen.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Servoss JC, Friedman LS: Serologic and molecular diagnosis of hepatitis B virus. Clin Liver Dis 2004;8:267-281
2. Valsamakis A: Molecular testing in the diagnosis and management of chronic hepatitis B. Clin Microb Rev 2007;20(3):426-439
3. Chevaliez S, Bouvier-Alias M, Laperche S, et al: Performance of version 2.0 of the Cobas AmpliPrep/Cobas TaqMan Real-Time PCR Assay for Hepatitis B Virus DNA Quantification. J Clin Microbiol 2010;48:3641-3647
4. Vivekanandan P, Singh MV: Molecular methods in the diagnosis and management of chronic hepatitis B. Expert Rev Mol Diagn 2010;10(7):921-935