Q&A: Knowledge of Viral Hepatitis

Abnormal liver biochemical and function tests are frequently detected in asymptomatic patients since many screening blood test panels routinely include them. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and bilirubin are biochemical markers of liver injury. Albumin, bilirubin, and prothrombin time are markers of hepatocellular function.

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This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Digestive Health article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
Significance of liver biochemical and function tests
MCQ exam: clinical scenario
MCQ exam: answer
MCQ exam: explanation

Significance of liver biochemical and function tests

Elevations of liver enzymes often reflect damage to the liver or biliary obstruction, whereas an abnormal serum albumin or prothrombin time may be seen in the setting of impaired hepatic synthetic function. The serum bilirubin in part measures the liver's ability to detoxify metabolites and transport organic anions into bile.

MCQ exam: clinical scenario

A lecturer is giving a talk about a ribonucleic acid virus that causes hepatitis. He is describing how this virus requires coinfection with a deoxyribonucleic acid virus to support its replication. This virus has been confined primarily to populations with frequent percutaneous exposures, such as drug addicts and hemophiliacs.

Which virus or viral agent is he talking about?

a) Recombinant hepatitis B vaccine
b) Hepatitis C virus
c) Hepatitis B surface antigen
d) Hepatitis C vaccine
e) Hepatitis D
f) Hepatitis B immune globulin (HBIG)
g) Hepatitis B virus DNA
h) Hepatitis B e antigen
i) Hepatitis A
j) Atopic dermatitis

MCQ exam: answer

The correct answer is E

MCQ exam: explanation

Hepatitis D is a ribonucleic acid (RNA) virus that requires coinfection with hepatitis B (a deoxyribonucleic acid [DNA] virus) to support its replication. Infection with this agent occurs either simultaneously with acute hepatitis B infection or is superimposed on chronic hepatitis B. Like hepatitis B, hepatitis D is transmitted by percutaneous inoculation and intimate contact.

In nonendemic areas, such as the United States and western Europe, hepatitis D has been confined primarily to populations with frequent percutaneous exposures, such as drug addicts and hemophiliacs. In endemic areas, such as the Mediterranean countries, hepatitis D is transmitted primarily through intimate contact. Hepatitis D (delta hepatitis) is being recognized with increasing frequency. Its incubation period is similar to that for hepatitis B, and, when both hepatitis B and hepatitis D infections are acquired simultaneously, a single clinically apparent episode of hepatitis may ensue. There is a slight increase in the risk of fulminant hepatitis when the two infections occur simultaneously, but, in general, the outcome of simultaneous acute hepatitis B and D is no different from the outcome of hepatitis B alone. In contrast, among patients with chronic hepatitis B infection, superimposed hepatitis D may lead to severe, fulminant hepatitis, convert a mild or asymptomatic chronic hepatitis B infection into a severe form of chronic hepatitis (chronic active hepatitis), or accelerate the course of chronic active hepatitis. A diagnosis of delta hepatitis is made by demonstrating the appearance of antibody to hepatitis D (anti-HDV).

Reference(s)
1). UpToDate: Approach to the patient with abnormal liver biochemical and function tests. Available online: https://www.uptodate.com/contents/approach-to-the-patient-with-abnormal-liver-biochemical-and-function-tests