Test Catalog

Test ID: HAIGG    
Hepatitis A IgG Antibody, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Detection of previous exposure or immunity to hepatitis A infection

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Hepatitis A virus (HAV) is endemic throughout the world, occurring most commonly, however, in areas of poor hygiene and low socioeconomic conditions. The virus is transmitted primarily by the fecal-oral route, and it is spread by close person-to-person contact and by food- and water-borne epidemics. Outbreaks frequently occur in overcrowded situations and in high-density institutions and centers, such as prisons and health care or day care centers. Viral spread by parenteral routes (eg, exposure to blood) is possible but rare, because infected individuals are viremic for a short period of time (usually <3 weeks). There is little or no evidence of transplacental transmission from mother to fetus or transmission to newborn during delivery.

 

In most cases, antibodies to HAV (anti-HAV) are detectable by the time that symptoms occur, usually 15 to 45 days after exposure. Initial antibodies consist almost entirely of the IgM subclass. HAV-specific IgM antibody level in serum usually falls to an undetectable level by 6 months after acute infection. HAV-specific IgG antibody level in serum rises quickly once the virus is cleared and may persist for many years.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Unvaccinated: negative

Vaccinated: positive

See Viral Hepatitis Serologic Profiles in Special Instructions.

Interpretation Provides information to assist in interpretation of the test results

This assay detects the presence of hepatitis A virus (HAV)-specific IgG antibody in serum. 

 

A negative result indicates the absence of HAV-specific IgG antibody, implying no past exposure or immunity to HAV infection.

 

A positive result indicates the presence of HAV-specific IgG antibody from either vaccination or past exposure to hepatitis A virus.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Passively acquired IgG antibody from recent immune globulin administration or transfusion may result in transiently positive test results.

 

The presence of heterophilic antibodies, cytomegalovirus (CMV)-specific antibodies, or human antimouse antibodies (in patients who have received preparations of mouse monoclonal antibodies for diagnosis or therapy) in serum may interfere with the assay and cause erroneous results (false-positive or false-negative).

 

Performance characteristics have not been established for the following specimen characteristics:

-Grossly icteric (total bilirubin level of >20 mg/dL)

-Grossly hemolyzed (hemoglobin level of >500 mg/dL)

-Grossly lipemic (triolein level >3,000 mg/dL)

-Containing particulate matter

-Cadaveric specimens

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Centers for Disease Control and Prevention: Prevention of hepatitis A through active or passive immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep 2006;55(RR7):1-23

2. Nainan OV, Xia G, Vaughan G, Margolis HS: Diagnosis of hepatitis A infection: a molecular approach. Clin Microbiol Rev 2006;19:63-79

3. de Paula VS: Laboratory diagnosis of hepatitis A. Future Virology 2012;7(5):461-472

Special Instructions Library of PDFs including pertinent information and forms related to the test