Hepatitis A Antibody-IgM
Label Mnemonic: HABM
Epic Lab Code: LAB621
Downtime Form: A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery
6240 RCP
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
3 mL whole blood from light green top tube or TWO Microtainer® devices for pediatric patients.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
See Interpretive Data
Interpretive Data:
Negative <0.90. IgM anti-HAV not detected. Does not exclude the possibility of exposure to or infection with hepatitis A virus.

Grayzone 0.90-<1.10. Antibodies to IgM anti-HAV may or may not be present. Patients with specimens exhibiting grayzone test results should be retested in two weeks, if clinically indicated.

Positive >1.10. Presumptive evidence of HAV infection.
This assay may be significantly impacted by high-dose biotin (>5 mg dose) taken within previous 12 hours. High concentrations of biotin may lead to falsely decreased results. These concentrations may be found in patients taking over-the-counter supplements with biotin content much higher than nutritional requirements for biotin. Specimens should not be collected until at least 12 hours after the last dose.
Test Limitations:
The assay is unaffected by icterus (bilirubin < 855 μmol/L or < 50 mg/dL), hemolysis (Hb < 0.623 mmol/L or < 1000 mg/dL), lipemia (Intralipid < 2000 mg/dL), and biotin < 205 nmol/L or < 50 ng/mL. In rare cases, interference due to high titers of antibodies to immunological components, streptavidin or ruthenium can occur.

For diagnostic purposes, the results should always be assessed in conjunction with the patient's medical history, clinical examination and other findings. A negative test result does not exclude the possibility of exposure to Hepatitis A virus. Levels of anti-HAV IgM may be below the cutoff in early infection and late after infection. A positive anti-HAV IgM result does not necessarily rule out other hepatitis infections.
Electrochemiluminescence Immunoassay
CPT Code:
See Additional Information:
Biotin Interference with Immunoassays