ANTI-HBc IgM Test
Overview
The ANTI-HBc IgM test detects Immunoglobulin M (IgM) antibodies against the Hepatitis B core antigen (HBc) in a person’s blood serum. This test is used primarily to diagnose acute or recent Hepatitis B infection. It is one of the earliest antibodies to appear after infection with the Hepatitis B virus (HBV) and typically indicates an active or recent HBV infection.

Purpose of the Test
The ANTI-HBc IgM test is used to:

Detect acute Hepatitis B infection

Differentiate between acute and chronic HBV when combined with other tests

Diagnose recent reactivation of chronic HBV

Identify infection during the "window period" (a time when other markers like HBsAg may be negative)

Sample Type
Serum (from a blood sample)

Understanding the Results
Positive (Reactive):

Indicates recent or acute infection with HBV

May also appear during reactivation of chronic HBV

Negative (non-reactive):

No recent HBV infection

May still have chronic infection or past exposure; further testing is needed

🧪 Important: This test is most useful early in the infection or during the "window period", when other hepatitis B markers may not yet be present.

When Is It Ordered?
Doctors may order the ANTI-HBc IgM test when:

A patient has symptoms of hepatitis (e.g., fatigue, jaundice, abdominal pain)

Hepatitis B infection is suspected but HBsAg and anti-HBs tests are negative

There's a need to distinguish between acute and chronic HBV

Reactivation of HBV is suspected (especially in immunosuppressed patients)

Preparation & Procedure
Preparation: No special preparation is needed

Procedure: A blood sample is drawn, and the serum is tested in the lab for anti-HBc IgM antibodies

Follow-Up Testing
If ANTI-HBc IgM is positive, your healthcare provider may recommend:

HBsAg (Hepatitis B surface antigen) – confirms current infection

Anti-HBs (Hepatitis B surface antibody) – indicates recovery or immunity

HBV DNA testing – checks for the amount of virus in the blood

Liver function tests (LFTs) – assess liver damage

Conclusion
The ANTI-HBc IgM test is a valuable diagnostic tool for identifying acute Hepatitis B infection, especially in the early stages or during the window period. A positive result suggests recent exposure to HBV and helps guide appropriate treatment and monitoring. Always follow up with your healthcare provider for additional testing and interpretation.