A 42-year-old woman comes to the office with worsening fatigue and dark yellow urine. She also has anorexia, nausea, mild abdominal pain, and malaise. The patient is uncertain as to when her symptoms began but felt normal during her vacation 4 weeks ago. She has no known medical problems and does not take any medications. The patient does not use alcohol, tobacco, or illicit drugs. She has had unprotected sexual intercourse with 6 different partners within the past year. The patient does not remember getting a hepatitis B vaccination. Laboratory results are as follows: Which of the following is the most appropriate test to diagnose hepatitis B infection in this patient?

Question

A 42-year-old woman comes to the office with worsening fatigue and dark yellow urine.  She also has anorexia, nausea, mild abdominal pain, and malaise.  The patient is uncertain as to when her symptoms began but felt normal during her vacation 4 weeks ago.  She has no known medical problems and does not take any medications.  The patient does not use alcohol, tobacco, or illicit drugs.  She has had unprotected sexual intercourse with 6 different partners within the past year.  The patient does not remember getting a hepatitis B vaccination.  Laboratory results are as follows:  Which of the following is the most appropriate test to diagnose hepatitis B infection in this patient?

Quizplus · Accepted Answer

11ec25c8_d3f1_d154_bc81_d747fbd7b826_MD0003_00 This patient's new-onset symptoms (eg, fatigue, nausea/abdominal pain, dark urine) and abnormal liver function tests (eg, elevated serum transaminases, hyperbilirubinemia) in the setting of unprotected sex with multiple partners is concerning for acute hepatitis B infection. The first serologic marker to appear in the serum with acute hepatitis B is HBsAg, which appears usually 4-8 weeks after infection. IgM anti-HBc appears shortly thereafter, which is around the time clinical symptoms occur and patients develop elevations in hepatic aminotransferase levels (often >25 times the normal limit). There can be a time lag (weeks to months) between the disappearance of HBsAg and the appearance of anti-HBs, which is termed the window period. IgM anti-HBc may be the only detectable marker for acute hepatitis B infection during this period. As such, HBsAg and anti-HBc are the most appropriate diagnostic tests for acute hepatitis B infection as these are both elevated during initial infection and anti-HBc will remain elevated during the window period. (Choice A) HBcAg is not detectable in serum and is therefore not useful for establishing the diagnosis. (Choice B) HBeAg is a good indicator of infectivity but is a poor test for acute hepatitis B infection as levels typically fall early in the course of the disease. (Choice C) Testing for HBsAg and anti-HBs can miss the diagnosis of acute hepatitis B infection in patients who are in the window period. (Choice E) Although hepatitis B virus DNA may be detectable prior to the appearance of HBsAg or HBeAg, this test is generally not performed to diagnose acute infection. Instead, hepatitis B virus DNA is obtained in patients with chronic hepatitis B to determine candidacy for antiviral therapy or monitor response to treatment. Educational objective: HBsAg and anti-HBc are the most appropriate diagnostic tests for acute hepatitis B infection as they are both elevated during initial infection and anti-HBc will remain elevated during the window period. References: Hepatitis B: diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/20387772) Hepatitis B virus infection. (http://www.ncbi.nlm.nih.gov/pubmed/24954675)

A 42-Year-Old Woman Comes to the Office with Worsening Fatigue