Hepatitis B IgM
Anti-hepatitis B core antibodies (anti-HBc) are mostly IgM. They appear shortly after the symptoms begin to show, in the initial acute phase of infection. These antibodies may persist for about six months after the acute phase and are detectable after the disappearance of HBsAg and before the appearance of hepatitis B surface antibody (anti-Hbs). Therefore, anti-HBc IgM is an important serological marker of a recent HBV infection.
Why is the test ordered?
The test is useful in detecting the presence of the hepatitis B virus in the window period that shows negative results for both hepatitis B surface antigen (HBsAg) and anti-HBs. The test also differentiates an acute, chronic or a past hepatitis B infection with the positive anti-HBc. The test may be useful in the diagnosis of acute hepatitis B infection.
How is the sample collected?
A blood sample is collected from a vein in the arm.
How to prepare for the test?
Some drugs and dietary supplements may affect the test results and therefore, patients are advised not to consume any such supplements – particularly biotin and vitamin B7, for up to 24 hours before taking the test. It is always better to inform the doctor about all the medicines and supplements one is taking prior to the test.