Hepatitis B Virus: Hepatitis B is caused by infection with the Hepatitis B virus (HBV). The term ‘hepatitis’ simply means inflammation of the liver. Hepatitis may be caused by a virus or a toxin such as alcohol. The incubation period from the time of exposure to onset of symptoms is 6 weeks to 6 months. HBV is found in highest concentrations in blood and in lower concentrations in other body fluids (e.g., semen, vaginal secretions, and wound exudates). HBV infection can be self-limited or chronic. Hepatitis B virus (HBV) infection in a pregnant woman poses a serious risk to her infant at birth. Hepatitis B is spread mainly by exposure to infected blood or body secretions. In infected individuals, the virus can be found in the blood, semen, vaginal discharge, breast milk, and saliva. Hepatitis B is not spread through food, water, or by casual contact.    

Methodology: Taqman Real time PCR assay

Clinical Use:

  • Predict and monitor response to therapy
  • Identify HBV viral load quantitation for epidemiologic and prognostic purposes
  • Assess viral response to treatment as measured by changes in the HBV DNA levels
  • Monitor patients who were infected with HBV prior to liver transplantation
  • Viral loads are predictive of future risk of developing cirrhosis and HCC
  • Monitor patients who were infected with HBV prior to liver transplantation

Screening: Centers for Disease Control recommendations

  • Injection-drug abusers
  • All pregnant women
  • Men who have sex with men
  • Persons who are sources for exposures (needle-stick, sexual assault)
  • Infants born to HBsAg-positive mothers
  • Persons with elevated ALT/AST of unknown etiology
  • Persons needing immunosuppressive therapy (transplant, rheumatology and gastroenterology)
  • HIV-positive persons

Monitoring

  • Monitor chronic disease every 3-6 months
  • HBsAg, HBeAg, anti-HBe, anti-HBs, HBV DNA
  • Genotyping prior to therapy may be helpful
  • Genotype may determine disease progression and response to treatment
Performed:  Every day
Reported: 1-2 days

Specimen Required: Blood, serum, plasma, Collect in: Lavender (EDTA), pink (K2EDTA), or serum separator tube. Stability collection to initiation of testing On Cells: Ambient: 4 hours; after separation from cells: Refrigerated: 48 hours; Frozen at -20°C: 72 hours; Frozen at -70°C: 4 months. Do not thaw avoid repeated freezing and thawing

NOTE-Samples should be collected during the viraemic phase for the presence of viruses during the active infection

Specimen Preparation: Separate serum or plasma from cells within 24 hours.

 

Storage/Transport Temperature: Frozen-20 0C. Refrigerate specimens at 2°C-4°C.

Unacceptable Conditions
:  Heparinized specimens, Hemolysis sample, Quantity not sufficient for analysis, specimen grossly contaminated, specimen too old, frozen whole blood specimen, specimen leaky or tube broken.

 

Interpretation: This test can quantitate/detect Hepatitis B Virus DNA over the range 12-109 IU/mL. However this does not mean that lower copies or higher copies cannot be detected. The lower copies can be detected in some cases. This is a limitation of the currently available extraction systems. The test is intended for use in conjunction with clinical presentation and other markers as an aid in assessing viral response to antiviral treatment as measured by change in HBV DNA levels. Antiviral treatment consisting of interferon (IFN)-alpha, Ganciclovir or lamivudine is now available for chronic hepatitis B. Accurate quantification of HBV DNA is essential for monitoring the efficacy of these antiviral treatments. Early changes in plasma/ serum HBV DNA levels may predict long term response to antiviral therapy. A negative result does not preclude the presence of HBV infection because results depend on adequate/proper patient sample storage and transportation.

Patients suffering from chronic HBV infection typically have intermittent viraemia. Samples collected during the non- viraemic phase may test negative despite the presence of active infection. Hence, in such case’s where HBV PCR is negative despite strong clinical suspicion, a repeat sample collected at an interval of two weeks from the initial sample is strongly recommended to rule out active disease.

Note: The test is intended for use in conjunction with clinical presentation and other laboratory markers as an indicator of disease prognosis.  This test is also used as an aid in assessing viral response to antiretroviral treatment as measured by changes in HBV DNA levels

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