From: WHO guidelines on testing for hepatitis B and C – meeting targets for testing
HOW TO TEST FOR CHRONIC HBV INFECTION AND MONITOR TREATMENT RESPONSE
Which serological assays to use
• For the diagnosis of chronic HBV infection in adults, adolescents and children (>12 months of ageb), a serological assay (in either RDT or laboratory-based immunoassay formatc) that meets minimum quality, safety and performance standardsd(with regard to both analytical and clinical sensitivity and specificity) is recommended to detect hepatitis B surface antigen (HBsAg).
- In settings where existing laboratory testing is already available and accessible, laboratory-based immunoassays are recommended as the preferred assay format.
- In settings where there is limited access to laboratory testing and/or in populations where access to rapid testing would facilitate linkage to care and treatment, use of RDTs is recommended to improve access.
Strong recommendation, low/moderate quality of evidence
Serological testing strategies
• In settings or populations with an HBsAg seroprevalence of ≥0.4%e, a single serological assay for detection of HBsAg is recommended, prior to further evaluation for HBV DNA and staging of liver disease.
• In settings or populations with a low HBsAg seroprevalence of <0.4%e, confirmation of HBsAg positivity on the same immunoassay with a neutralization step or a second different RDT assay for detection of HBsAg may be consideredf.
Conditional recommendation, low quality of evidence
Detection of HBV DNA – assessment for treatment Adapted from existing guidance (WHO HBV 2015 guidelines g )
• Directly following a positive HBsAg serological test, the use of quantitative or qualitative nucleic acid testing (NAT) for detection of HBV DNA is recommended as the preferred strategy and to guide who to treat or not treat.
Strong recommendation, moderate/low quality of evidence
Monitoring for HBV treatment response and disease progression Existing guidance (WHO HBV 2015 guidelines g )
• It is recommended that the following be monitored at least annually:
- ALT levels (and AST for APRI), HBsAgh, HBeAgi, and HBV DNA levels (where HBV DNA testing is available)
- Non-invasive tests (APRI score or transient elastography) to assess for presence of cirrhosis in those without cirrhosis at baseline;
- If on treatment, adherence should be monitored regularly and at each visit.
Strong recommendation, moderate quality of evidence
More frequent monitoring is recommended:
• In persons on treatment or following treatment discontinuation: more frequent on- treatment monitoring (at least every 3 months for the first year) is indicated in: persons with more advanced disease (compensated or decompensated cirrhosisj); during the first year of treatment to assess treatment response and adherence; where treatment adherence is a concern; in HIV-coinfected persons; and in persons after discontinuation of treatment. Conditional recommendation, very low quality of evidence
• In persons who do not yet meet the criteria for antiviral therapy: i.e. persons who have intermittently abnormal ALT levels or HBV DNA levels that fluctuate between 2000 IU/mL and 20,000 IU/mL (where HBV DNA testing is available) and in HIV- coinfected personsh. Conditional recommendation, low quality of evidence