Hepatitis A Antibody, IgM
Code:17009|CPT:86709|LOINC:13950-1
| Includes | Hep A Ab, IgM |
|---|
Analysis details
Methodology
- Immunochemiluminometric assay (ICMA)
Expected Turnaround Time
1 day
Special Instructions
- If taking biotin supplements, stop for at least 72 hours before the blood draw to reduce assay interference.
- Do not smoke during the 30 minutes prior to specimen collection.
How to use
The Hepatitis A Antibody, IgM test (anti-HAV IgM; HAV IgM antibody) aids in diagnosing acute or recent hepatitis A by qualitatively identifying HAV-specific IgM in serum. It is ordered for individuals with signs of acute hepatitis, new-onset jaundice, or unexplained transaminase elevations when HAV is a consideration. Because false-positive reactivity is more likely in low-pretest-probability settings, use is recommended for symptomatic patients or those with epidemiologic suspicion rather than for routine screening.
Limitations
Acute hepatitis A produces hepatocellular injury with alanine aminotransferase (ALT) and aspartate aminotransferase (AST) elevations that are often several-fold above the upper reference limit; serum bilirubin may also be increased. Serologic confirmation relies on HAV-specific antibodies: IgM indicates acute or recent infection, while IgG appears during convalescence and persists thereafter. This assay is not cleared or approved by the FDA for screening blood or plasma donors. Performance characteristics have not been established for immunocompromised or immunosuppressed patients, cord blood, patients less than 2 years of age, or cadaveric specimens.
| Unit | qualitative | ||||
|---|---|---|---|---|---|
| Reference interval |
| ||||
| Indications | Workup of a prolonged clinical course of hepatitis A (protracted HAV) |
Possible Causes of Abnormal Results
Increased levels
- hiv infection
- systemic lupus erythematosus
- thyroiditis
Specimen Requirements
| Specimen | Serum |
|---|---|
| Container | Gold/Tiger Top (SST, Gel Separator) |
| Volume | 1 mL (min 0.4 mL) |
| Storage Instructions | Room temperature, Refrigerated, Frozen |
References
Nelson NP, Weng MK, Hofmeister MG, et al. Prevention of Hepatitis A Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020. MMWR Recomm Rep. 2020;69(5):1-38. PubMed: 32614811.
Workowski KA, Bolan GA; Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines, 2015. MMWR Recomm Rep. 2015;64(RR-03):1-137. PubMed: 26042815.
Balayan MS, Zamyatina NA. Viral hepatitis A and E. In: Pokrovsky VI, Onishchenko GG, Cherkassky BL, eds. Evolution of Infectious Diseases in Russia in the 20th Century. Moscow: Meditsina; 2003:51-63.
Ryan KJ, Ray CG, eds. Sherris Medical Microbiology. 4th ed. New York: McGraw-Hill; 2004:541-544. ISBN: 0838585299.
Murray PR, Rosenthal KS, Pfaller MA. Medical Microbiology. 5th ed. Elsevier Mosby; 2005.
Musana KA, Yale SH, Abdulkarim AS. Tests of liver injury. Clin Med Res. 2004;2(2):129-131. doi:10.3121/cmr.2.2.129. PMID: 15931347.