Hepatitis B Core Antibody, IgM

Test Code

HBCM

Alias/See Also

Epic: LAB549

Preferred Specimen

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 3 mL

Minimum Volume

0.5 mL

Other Acceptable Specimens

Collection Container: Red top

Instructions

Centrifuge and separate cells after clot formation and within 4 hours of collection.

Transport Container

Plastic vial

Specimen Stability

Room temperature: 3 days
Refrigerated: 7 days
Frozen: >7 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Unlabeled, mislabeled, wrong tube type, hemolyzed, QNS, exceeds specimen/stability requirements.

Methodology

Chemiluminescent microparticle immunoassay

Setup Schedule

Daily

Report Available

Same day

Limitations

If the anti-HBc IgM results are inconsistent with clinical evidence,
additional testing is suggested to confirm the result.
For diagnostic purposes, results should be used in conjunction with
patient history and other hepatitis markers for diagnosis of acute or
chronic infection.
Specimens from heparinized patients may be partially coagulated and erroneous results could occur due to the presence of fibrin. To prevent this phenomenon, draw the specimen prior to heparin therapy.
Specimens from patients with high levels of IgM, e.g. specimens from patients with multiple myeloma, may show depressed values when tested with assay kits that use reagents containing anti-human IgM.

Reference Range

Non-reactive

Clinical Significance

HBV is transmitted through direct contact with blood and body fluids. Modes of transmission include transfusion, needle puncture, contact with open wounds, sexual contact, and mother-infant contact during birth.
Average incubation is 6-8 weeks with a range of 1-6 months. Infection can be asymptomatic, but clinical signs include malaise, fever, gastroenteritis, and icterus. In adults ~95% recover from acute illness, but ~5% become chronic carriers. In neonates, up to 90% develop chronic HBV infection. Chronic HBV infection is associated with hepatocellular carcinoma.
Anti HBc IgM titers increase rapidly and peak during the early stage of infection and fall to low levels as the patient recovers, or becomes a chronic carrier of HBV. The assay is useful in the diagnosis of acute HBV infection, especially at the “core window”, when HbSAg levels fall.

Performing Laboratory

Inova Laboratories

2832 Juniper Street

Fairfax, VA 22031

Last Updated: April 10, 2023
Last Review: N. Wolford, April 10, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.