Hepatitis Testing

General

Synonym/Acronym:
hepatitis A (HAV): (antibody) anti-HAV; hepatitis B (HBV): (antigens) HBsAg, HBeAg, HBcAg; and (antibodies) anti-HBe, anti-HBc, anti-HBs; hepatitis C (HCV): (antibody) anti-HCV; hepatitis D (HDV): (antibody) anti-HDV (delta hepatitis); hepatitis E (HEV): (antibody) anti-HEV.

Rationale
To test blood for the presence of antibodies that would indicate a past or current hepatitis infection.

Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings
Method: Enzyme immunoassay, chemiluminescent immunoassay, line immunoassay for HAV, HBV, HCV, HDV, HEV; polymerase chain reaction (reverse transcriptase polymerase chain reaction, nucleic acid amplification test [NAAT], next-generation sequencing [NGS]) may also be used for some quantitative hepatitis markers where indicated. Normal findings for the various markers depend on various circumstances that include vaccination status and resolution of infection with or without treatment (see table).

Hepatitis antigen and antibody markers can be reported qualitatively (negative or positive using a signal to cutoff ratio or s/c) or quantitatively (international units/mL [IU/mL]). The cutoff values for negative, indeterminate, or positive vary between laboratories based on variations in test kits; therefore, reference ranges for quantitative assays may differ. The testing laboratory’s final report will provide guidance on interpretation of test results for both types of assays. Note: In 2011, the Advisory Committee on Immunization Practices recommended that for quantitative postvaccination anti-HBS testing, a method able to reliably detect protective levels of antibody, levels greater than 10 mIU/mL, should be used.

Following is a “simplified” explanation of how the various markers are used and reported. Note: A single test result should not be interpreted without considering related test results or other circumstances. Qualitative test methods often use a signal to cutoff ratio (s/c) to determine negative and positive findings; quantitative methods generally report in IU/mL, U/mL, or mIU/mL.

Test Name/Test Use Result
Hepatitis A
Anti-HAV, IgM (qualitative)/Identify acute HAV infectionNegative (indicating absence of Hepatitis A antibody)
Hepatitis B
HBSAg (qualitative)/Screen for HBV infectionNegative (indicating absence of Hepatitis B antigen)
HBSAg (quantitative)/Monitor response to antiviral therapy; evaluate the progression of infection and degree of correlation between quantitative HBSAg levels, which reflect the amount of viral DNA being converted to viral antigen, and quantitative HBV DNA, which reflects viral load or degree of viral replicationUndetected or less than the lower reportable limit (quantification) of the assay (IU/mL) (indicating absence of Hepatitis B antigen
Anti-HBc, total (qualitative) and IgM/Total antibody: indicates absence of HBV infection; IgM: indicates absence of acute or recent HBV infection—will be positive during the “core window” when HBSAG and anti-HBS are undetectableNegative (indicating absence of Hepatitis B core antibody)
HBcAg (quantitative)/Monitor response to therapy for chronic HBV infection in clinical scenarios where results of other markers are inconclusiveLess than the lower reportable limit (quantification) of the assay (U/mL) (indicating absence of Hepatitis B core antibody)
Anti-HBS (qualitative)/Identify past exposure/infection, vaccine efficacy, or recovery from HBV infection with development of antibodiesUnvaccinated: Negative (indicating absence of Hepatitis B antibody); Vaccinated: Positive (indicating presence of Hepatitis B antibody)
Anti-HBS (quantitative)/Identify past exposure/infection, vaccine efficacy, or recovery from HBV infection with natural development of antibodiesUnvaccinated: Less than 5 mIU/mL (indicating absence of Hepatitis B antibody); Vaccinated: Greater than 10 mIU/mL (indicating presence of Hepatitis B antibody)
HBV DNA (quantitative)/Monitor viral load/replication; monitor response to therapy for chronic HBV infection in clinical scenarios where results of other markers are inconclusiveUndetected or less than the lower reportable limit (quantification) of the assay (IU/mL) (indicating absence of Hepatitis B viral DNA)
HBV genotyping/Identify resistance to antiviral drugsEncoding regions of the HBV DNA are sequenced, and sequence variations related to drug resistance are reported
Hepatitis C
Anti-HCV (qualitative)/Screen for HCV infectionNegative (indicating absence of Hepatitis C antibody)
HCV RNA (quantitative)/Identify or confirm HCV infection, monitor viral load and disease progression, determine response to antiviral therapyUndetected or less than the lower reportable limit (quantification) of the assay (IU/mL) (indicating absence of Hepatitis C viral RNA)
Test Name/Test Use Result
Hepatitis C
HCV genotype/Provide information for selection of appropriate retroviral therapy by classifying the genotypes identifiedUndetected or less than the lower reportable limit (quantification) of the assay (IU/mL) (indicating absence of Hepatitis C viral DNA)
HCV genotype antiviral drug resistance/Resistance-associated substitutions (sequence variations) in the viral RNA are identified to provide information for selection of appropriate retroviral therapyInterpretive report is provided by the testing laboratory
Hepatitis D
HDVAg (qualitative)/Identify concurrent HDV/HBV infectionNegative (indicating absence of Hepatitis D antigen)
Anti-HDV (qualitative), total (IgG and IgM)/Identify concurrent HDV/HBV infectionNegative (indicating absence of Hepatitis D antibody)
Hepatitis E
anti-HEV (qualitative), IgG/Identify past HEV infectionNegative (indicating absence of Hepatitis E antibody, IgG)
anti-HEV (qualitative), IgM/Identify acute or recent HEV infectionNegative (indicating absence of Hepatitis E antibody, IgM)
HEV DNA (quantitative)/Confirm HEV infection and monitor HEV viral loadUndetected (indicating absence of Hepatitis E viral DNA)

Critical Findings and Potential Interventions
Specific infectious organisms are required to be reported to local, state, and national departments of health. Lists of specific organisms may vary among facilities. State health departments provide information regarding reportable diseases, which can be accessed at each state health department website. The Centers for Disease Control and Prevention (CDC) provides information regarding national notifiable diseases at https://ndc .services.cdc.gov/search-results-year/.

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