Which is the first antibody detected in serum after infection with hepatitis B virus (HBV)?

The first antibody detected in serum after infection with hepatitis B virus (HBV) is indeed Anti-HBc IgM. This antibody appears shortly after the onset of symptoms and indicates that the patient is experiencing an acute infection.

Anti-HBc IgM is produced in response to the core antigens of the virus and serves as an important marker for early detection of HBV infection. Its presence confirms that the individual is in the acute phase of hepatitis B, since it generally emerges before other antibodies, such as Anti-HBs or Anti-HBe, which indicate later stages of infection or recovery.

Anti-HBs is associated with recovery and immunity following infection or vaccination, appearing later than Anti-HBc IgM. Similarly, Anti-HBe usually appears once the viral replication begins to decline and is associated with either recovery from acute hepatitis or the chronic phase of the infection.

In summary, the key marker for identifying early HBV infection is Anti-HBc IgM, making it the correct answer to this question.