MKSAP Quiz: diagnostics for viral hepatitis
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A 44-year-old man was recently found to have abnormal serologic test results for viral hepatitis when he attempted to donate blood. The patient is asymptomatic. He used injection drugs and drank alcohol excessively for two years 25 years ago but has not used either drugs or alcohol since. Medical history is otherwise unremarkable, and he takes no medications.
Physical examination discloses a BMI of 23, no stigmata of chronic liver disease, and a normal-sized liver.
Laboratory studies
Abdominal ultrasonography is normal.
Which of the following diagnostic studies should be done next?
A. Hepatitis B e antigen (HBeAg)
B. Hepatitis B virus DNA (HBV DNA)
C. Hepatitis C virus RNA (HCV RNA)
D. IgM antibody to hepatitis A virus (IgM anti-HAV)
MKSAP Answer and Critique
The correct answer is C) Hepatitis C virus RNA (HCV RNA). This item is available online to MKSAP 14 subscribers in the Gastroenterology and Hepatology section, Item 12.
Answer and Critique
This patient has elevated serum aminotransferase values and positive antibodies to hepatitis C virus (anti-HCV). In a patient with a history of injection drug use, these findings are highly suggestive of hepatitis C, and an HCV RNA study should be done to confirm the presence of viremia.
Positive tests for antibody to hepatitis B surface antigen (anti-HBs) and IgG antibody to hepatitis B core antigen (IgG anti-HBc) are consistent with immunity from prior infection, and determination of hepatitis B e antigen (HBeAg) and HBV DNA is therefore not necessary. Testing for IgM antibody to hepatitis A virus (IgM anti-HAV) is not indicated because acute hepatitis A tends to cause systemic symptoms, jaundice, and more marked elevations in serum aminotransferase values.
Key Point
- Elevated serum aminotransferase values and a positive assay for antibody to hepatitis C virus (anti-HCV) in a patient with risk factors for HCV are highly suggestive of the presence of hepatitis C. Patients with a positive assay for antibody to hepatitis C virus (anti-HCV) should be tested for HCV RNA to determine if viremia is present.