Q:

What tests should be ordered for suspected acute viral hepatitis?

A:

A standard panel for acute hepatitis should include:

Hepatitis A Antibody, IgM
Hepatitis B Surface Antigen
Hepatitis B Core Antibody, IgM
Hepatitis C Antibody

Acute Hepatitis A

Hepatitis A is an RNA virus that causes an acute self-limiting illness characterized by jaundice, fever, anorexia and diarrhea. An acute infection can be determined with the detection of hepatitis A virus (HAV) IgM antibodies, which appear early in the course of infection. Rheumatoid factor can occasionally cause false-positive results.

Hepatitis B is a DNA virus consisting of a nucleocapsid core and an outer protein coat, which contains the surface antigen (HBsAg).

Symptomatic acute hepatitis develops in 25% of infected persons. An active hepatitis B virus (HBV) infection can be confirmed by the presence of HBsAg, which is the first serologic marker to appear. Typically, HBsAg is no longer detectable 1 to 3 months after onset of jaundice and rarely persists longer than 6 months.

Hepatitis B core antibodies (IgM) can be used to establish acute infection in a smaller number of patients (fewer than 5%) whose HBsAg is below detectable limits.

Hepatitis C is a small, single-stranded RNA virus. Infections are typically asymptomatic. For patients who develop acute hepatitis, the symptoms are generally milder than in acute infection with HAV or HBV.

Hepatitis C virus (HCV) antibodies are generally non-protective, but serve as markers of chronic infection. If the acute panel is entirely negative, HCV RNA testing should be considered.