This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
A patient is diagnosed with Hepatitis B infection. Which of the following markers will always be present in his serum, if he develops chronic hepatitis? 
Select and explain. 
A. HBc Ag, B. Anti HBs Ab, C. HBe Ag, D. Anti HBc Ab
D: Anti HBc Ab
Answer: D: Anti HBc Ab 
Explanation: A patient who has had exposure to HBV will have AntiHBc Ab even when he has moved into the chronic or recurrent stages. IgM anti-HBc reappears during acute recurrences while IgG Anti HBc is found in chronic states. The HBsAg antigen is present in chronic hepatitis B, while the antibody anti-HBs is not. Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition