The Abbott RealTime HBV assay delivers accurate quantitation of genotypes  A, B, C, D, E, F, G, H and consists of three reagent kits:

• Abbott RealTime HBV Amplification Reagent Kit
• Abbott RealTime HBV Control Kit 
• Abbott RealTime HBV Calibrator Kit

Detection and Quantitation of HBV Genotypes

Linear Range

The upper limit of quantitation (ULQ) for the Abbott RealTime HBV assay is 1 billion IU/mL and the lower limit of quantitation is equivalent to LOD (10 IU/mL for the 0.5 mL sample preparation procedure, 15 IU/mL for the 0.2 mL sample preparation procedure).

Indications and Limitations of Use

Intended Use

Abbott RealTime HBV assay is an in vitro polymerase chain reaction (PCR) assay for use with the Abbott m2000 System DNA reagents and with the Abbott m2000sp and m2000rt instruments for the quantitation of Hepatitis B Virus (HBV) DNA in human serum or plasma (EDTA) from chronically HBV-infected individuals. The assay is intended for use as an aid in the management of patients with chronic HBV infection undergoing anti-viral therapy. The assay can be used to measure HBV DNA levels at baseline and during treatment to aid in assessing response to treatment. The results from the Abbott RealTime HBV assay must be interpreted within the context of all relevant clinical and laboratory findings. Assay performance for determining the clinical stage of HBV infection has not been established. Clinical performance characteristics have been established for individuals treated with adefovir dipivoxil. This assay is not intended for use as a screening test in blood or blood products for HBV or as a diagnostic test to confirm the presence of HBV infection.

Limitations

• Human serum and plasma (EDTA) may be used with the Abbott RealTime HBV assay. The use of other anticoagulants has not been validated for use with the Abbott RealTime HBV assay.
• The use of specimens collected in serum tubes that contain Z-clot activator, or similar types of rapid clot activator, may cause inhibited results in the RealTime HBV assay. 

• In rare cases, a very low level positive result may occur from cross contamination during processing of an adjacent specimen with an extremely high copy number. Carryover rates in representative studies ranged from 0% to 2%. Per treatment guidelines, a 1 log increase is needed in order to impact patient management.  In addition, treatment guidelines require two consecutive elevated measurements to occur before changing patient management.
• A single Entecavir mutation (rtA97V) occurs within the reverse primer. Of all known resistance mutations, it is the only one that occurs within any Abbott RealTime HBV primer or probe sequence. Software simulation predicts that this mutation (rtA97V) would not be expected to interfere with assay results when using RealTime HBV assay conditions.
•  A specimen with a result of “Not Detected” cannot be presumed to be negative for HBV DNA. 
• Drug interference was evaluated using a plasma matrix, and was not evaluated in serum. The listed drugs were tested in pools, and individual drug effects were not assessed.
• The interference studies were performed with an HBV DNA concentration of 2,933 IU/mL (3.47 log IU/mL). Potential interference on HBV DNA concentrations close to the assay LLQ (LLoQ) was not assessed.
• Results from the Abbott RealTime HBV assay should be interpreted in conjunction with other clinical and laboratory findings.  

Warnings and Precautions

The Abbott RealTime HBV assay is not intended for use in the screening of blood, plasma, or tissue donors for HBV, or to be used as a diagnostic test to confirm the presence of HBV infection.