Hepatitis B Virus Quantitation by PCR

Mnemonic

HBV QNT

Synonym

HBV - Hep B - Hepatitis B Titer - HBV Quant PCR - HBV quantitative - HBV Viral Load - Hep B DNA - Nucleic Acid Amplification Test (NAT or NAAT) - Viral load monitoring

Guidelines

This test is intended for use as an aid in the management of patients with chronic HBV infection undergoing anti-viral therapy. This test can be used to measure HBV DNA levels at baseline and during treatment to aid in assessing response to therapy.

This test is not intended for use as a screening test for the presence of HBV in blood or blood products or as a diagnostic test to confirm the presence of HBV infection.

Specimen Collection Requirements

Collect

Plasma or serum collected from lavender (EDTA) or serum separator top tubes (SST).

Handling

Separate plasma or serum from whole blood within 24 hours of collection.
Transfer 3.0 mL plasma or serum into plastic aliquot tube and freeze immediately.

Preferred Volume

3.0 mL

Minimum Volume

1.5 mL

Transport

Frozen

Rejection Criteria

Heparinized specimens, specimens past stability, specimens with inadequate volume for testing, or specimens tested first in non-molecular labs.

Stability

On cells – Ambient or refrigerated: 24 hours.
After separation from cells – Ambient: 3 days; Refrigerated: 7 days; Frozen: 6 weeks.

Testing Information

Note

Critical sterile. Samples cannot be shared with other laboratory departments unless molecular testing is performed first.

Performed

Mon - Fri, batched two times per week.

Reported

2-5 days

Method

Method: Quantitative Polymerase Chain Reaction

Clinical Specificity: 100% with a confidence limit of 99.40% (A total of 1296 samples were tested)

Analytical Specificity: No cross reactivity was observed in samples spiked with other common pathogenic viruses, bacteria, or yeast

Limit of Detection: 16.4 IU/mL

Quantitative Range: 20 – 170,000,000 IU/mL (1.3 - 9.2 Log IU/mL)
1 IU/mL of HBV DNA is approximately 5.82 copies/mL

A negative result (“Not Detected”) does not rule out the presence of HBV below the limit of detection of the assay or the presence of inhibitory substances. HBV viral loads detected at less than 20 IU/mL are not quantitated. Assay is the FDA approved Roche AmpliPrep/COBAS®TaqMan® HBV Test, v2.0.

Reference Values

Reference Values

Not Detected

Comments

Though rare, mutations in the highly conserved regions of the viral genome covered by the COBAS® AmpliPrep/COBAS® TaqMan HBV Test, v2.0 primers and/or probes may result in under-quantification of or failure to detect the virus.

Due to inherent differences between quantitative methodologies, it is recommended that prior to changing methodologies a new baseline is established before making clinical decisions.

CPT Codes

87517

Last Updated: Thursday, May 9, 2019 11:53:11 AM

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