Molecular Detection of Hepatitis B Virus Immune Escape Mutants

Molecular detection of Hepatitis B virus immune escape mutants by conventional PCR and sequence analysis.

Serum or plasma sample. Minimum volume required for serum or plasma – 1.0 mL.

Collect blood in serum separator tubes (SST) or EDTA tubes.

Store samples frozen until shipped for testing. Ship frozen on dry ice.

Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.

Suspected Hepatitis B infection. Serology results must show markers consistent with a possible immune or diagnostic escape (i.e., HBsAg negative/DNA positive; HBsAg positive/anti-HBs positive; HBsAg non-confirmatory/discrepant diagnostic results) or the patient is suspected of having an immune escape (post-vaccine breakthrough infection; post-OLT reactivation despite HBIg; etc.).

Completed Molecular and Immuno Diagnostics on Hepatitis requisition including sender name, address and telephone number. Patient name or identifier (referring specimen lab #), date of birth, suspected exposure, test(s) requested and the reason for a suspected immune escape. Type of specimen and date collected. If possible, include the clinical history (particularly vaccine history) and lab results (particularly HBsAg primary and confirmatory S/CO results) that have already been done at local or provincial laboratories.

Conventional PCR followed by sequence analysis. Specific known amino acid substitutions within the antigenic determinant and/or preS deletions may indicate immune escape/loss of HBsAg ex pression.

19 calendar days.

1. Osiowy C. Detection of HBsAg mutants. J Med Virol 2006. 78:S48-S51.
2. Weber B. Diagnostic impact of the genetic variability of the hepatitis B virus surface antigen gene. J Med Virol 2006. 78:S59-S65.