WBR0134
| Author | PageAuthor::Hardik Patel |
|---|---|
| Exam Type | ExamType::USMLE Step 3 |
| Main Category | MainCategory::Community Medical Health Center, MainCategory::Primary Care Office |
| Sub Category | SubCategory::Gastrointestinal, SubCategory::Hepatology, SubCategory::Infectious Disease |
| Prompt | [[Prompt::A 35-year-old patient you see routinely in the clinic has elevated liver function tests. ALT is 92, AST is 86, and the total bilirubin and alkaline phosphatase are normal. The patient has no past history of hepatitis, taking medications, or excessive drinking. You order hepatitis serology. The results are as follows:
Positive: HBsAg and anti-HBc. Negative: anti-HBs, anti-HBc IgM, anti-HAV, and anti-HCV What is your interpretation based on these findings?]] |
| Answer A | AnswerA::The patient has acute hepatitis B. |
| Answer A Explanation | [[AnswerAExp::The patient does not have acute hepatitis B because the IgM antibody to hepatitis B core is negative, and the total antibody to hepatitis B core is positive. Antibody to hepatitis B core occurs prior to the development of antibody to hepatitis B surface. IgM is found in acute infections; primarily IgG is seen in chronic infections.]] |
| Answer B | AnswerB::The patient needs a test for IgM antibody to hepatitis A virus to rule out acute hepatitis A. |
| Answer B Explanation | [[AnswerBExp::This is not a presentation of acute hepatitis A, which usually has very high transaminases. The antibody to hepatitis A virus occurs after a month and is associated with high transaminases. Hepatitis A vaccine is indicated for patients with chronic liver disease.]] |
| Answer C | AnswerC::The patient needs a test for hepatitis C antigen to exclude acute hepatitis C. |
| Answer C Explanation | AnswerCExp::Investigating for other causes of hepatitis is not necessary as the diagnosis of chronic hepatitis B is already established. |
| Answer D | AnswerD::The patient has chronic hepatitis B. |
| Answer D Explanation | AnswerDExp::The patient has chronic hepatitis B. The presence of antibody to hepatitis B core with a positive hepatitis B surface antigen is indicative of chronic infection. |
| Answer E | AnswerE::The patient needs a quantitative hepatitis B viral load analysis. |
| Answer E Explanation | AnswerEExp::A quantitative hepatitis B viral load might be useful to evaluate for potential antiviral therapy. |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::The patient has chronic hepatitis B. The presence of antibody to hepatitis B core with a positive hepatitis B surface antigen is indicative of chronic infection. Any patient who is hepatitis B surface antigen positive is at risk for delta hepatitis. This patient would be at risk for delta hepatitis by virtue of having a positive hepatitis B surface antigen. There is no level of transaminases, even normal transaminases, which would preclude antiviral therapy. The level of viral production indicated by the hepatitis B quantitative viral load, along with an assessment of the underlying liver pathology, is the best indication of need for treatment. As mentioned earlier, the antibody to hepatitis B would show the patient is less infectious and likely have a lower viral load. Educational Objective: |
| Approved | Approved::Yes |
| Keyword | |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |