Question

A 62 yr old male presents to the physician with abnormal results from a routine physical. Liver enzymes were elevated by 3 times the normal upper limit. Patient denies alcohol or drug use and is not taking any medications. He gives no history of jaundice. His past medical history is unremarkable except for hospitalization for a bleeding stomach ulcer. He required surgery and was transfused 4 units of blood. He recovered from this episode without complications. On examination the patient has no sign of jaundice or hepatosplenomegaly. Ruling out all other causes the physician suspects an infectious etiology for the laboratory findings.

1. What group of viruses are the most likely cause of this infection?

2. If you were to confirm the infection, what type of serological information might be needed to provide the physician with an accurate diagnosis of the a. State of their infection (acute, chronic) and b. whether they would be infectious? Be very thorough.

3. How do you tell the difference between someone who has been vaccinated against this virus and someone who has contracted the virus?

Answer 1

1. The most likely cause of infection here is hepatotrophic viruses like Hepatitis B virus.

Points in favour of diagnosis

Liver enzymes were elevated.

No history of alcohol usage / drug abuse

No history of any medications

H/o surgery and blood transfusions.

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2. The serological tests for diagnosis are : HBsAg, IgM Anti HBC , and Total Anti HBC

The first marker to appear in blood is the HBsAg. The IgM Anti HBC levels now rises and remains elevated for 3 to 4 months. The total Anti HBC levels remain elevated for lifetime after an infection.

So, the markers during acute infection are HBsAg and IgM HBC

If the patient recovers from illness, the HBsAg and IgM HBC levels declines but the total Anti HBC levels and Anti HBs levels remain elevated as a marker of remote infection.

However, in chronic infections, the levels of HBsAg and total Anti HBC levels are elevated, along with Anti HBs

The infectivity of a person with Hepatitis B depends upon the level of the HBV DNA levels and the HBeAg levels. High titres of HBV DNA or HBeAg are associated with high infectivity.

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3. The levels of Anti- HBS rises months after the initial infection and remains elevated thereafter. Here, the levels of Anti HBS and Anti HBC are elevated, as described above.

However following immunisation with HBV vaccine, the levels of Anti HBS alone are elevated without elevation of Anti HBC.