A 32-year-old man comes to the office to "check up on my liver." He was seen about 2 years ago due to fatigue, anorexia, and jaundice, which developed after sharing needles with another injection drug user. Viral hepatitis serology testing at that time was positive for hepatitis B surface antigen but negative for all other antigens and antibodies, including hepatitis C. The patient has not sought medical care since then and has been asymptomatic. He stopped using injection drugs and is now sober. He does not use tobacco or alcohol and is in a monogamous relationship with his girlfriend. Physical examination is unremarkable. This patient's hepatitis B virus serology testing is most likely to show which of the following?

Question

Quizplus · Accepted Answer

Explanation: The response to acute hepatitis B virus (HBV) infection depends heavily on when in life a patient becomes infected: Patients infected during the perinatal period almost universally progress to chronic HBV infection. Children age 1-5 have an intermediate response, with 50%-80% achieving spontaneous remission. Among healthy adults (as this patient), acute HBV infection is self-limited in >95% of cases. Serological markers help clarify stages of infection. Acute HBV infection is characterized by positive hepatitis B surface antigen (HBsAg), hepatitis B e antigen (an indicator of high infectivity), IgM hepatitis B core antibody (anti-HBc or HBcAb), and detectable HBV DNA. For the majority of patients who contract HBV as an adult and clear the infection, serology typically demonstrates hepatitis B surface antibody (HBsAb or anti-HBs, which provides immunity), IgG anti-HBc, and hepatitis B e antigen antibody (anti-HBe) (Recovery phase in the Table). Anti-HBe can eventually wane and may not be present later. The latter 2 antibodies are markers for prior infection (vaccinated individuals are exposed only to HBsAg) and are also seen in patients with chronic HBV infection. Patients with chronic active infection also have the continued presence of HBsAg in their serum. Serological markers (Choice A) Following acute exposure to HBV, HBsAg alone can be seen 1-2 weeks before the onset of symptoms or the development of other serological markers, as seen in the exhibit. exhibit (Choice C) Because the hepatitis B vaccine is typically made with HBV surface proteins (not core proteins), vaccinated individuals have only positive serology for HBsAb. (Choice D) Patients who have been exposed to HBV have circulating HBcAb (IgM in acute infection and IgG in chronic HBV), and circulating HBsAg signifies the presence of active infection (eg, chronic carrier). (Choice E) The lone presence of IgM HBcAb (and occasionally IgG HBcAb) is usually suggestive of the window period, which occurs after the disappearance of HBsAg but before the appearance of HBsAb. Isolated IgG HBcAb can also be seen when either HBsAb or HBsAg has become undetectable in immune or chronically infected individuals, respectively. Educational objective: Among healthy adults, acute hepatitis B virus infection is self-limited in >95% of cases. In the recovery phase, serology typically demonstrates hepatitis B surface antibody (which provides immunity), IgG hepatitis B core antibody, and hepatitis B e antigen antibody. References: Hepatitis B: diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/20387772)

A 32-Year-Old Man Comes to the Office to "Check Up