Hepatitis, Acute

Indications for Testing

New onset of jaundice, anorexia or dark urine
Known exposure to hepatitis
Suspicion of chronic hepatitis (elevated liver enzymes)

Laboratory Testing

Screen for HAV, HBV, and HCV infections concurrently unless specific exposure is known
Panel testing includes HAV IgM, HBV core antibody IgM, HBV surface antigen, and HCV antibody
- Positive HAV antibodies indicate acute HAV
- Positive HBV antibodies and surface antigen indicate acute HBV or chronic hepatitis
  - Repeat surface antigen testing and consider HBV DNA testing
- Positive HCV antibodies indicate acute HCV or chronic hepatitis
  - High positive should be followed with RNA quantitative testing
  - Low positive should be followed with RIBA and/or RNA quantitative testing
HEV testing – if patient is from a high-risk area and hepatitis screening tests are negative
For further evaluation of hepatitis, refer to specific hepatitis algorithms in ARUP Consult

Differential Diagnosis

Viral
- Cytomegalovirus
- Epstein-Barr virus
- Herpes simplex virus
- Varicella-zoster virus
- Hepatitis A, B, C, D, E or G
Toxin exposure
- Alcohol
- Tetrachloride
Nonalcoholic acute steatohepatitis
Drug-induced hepatitis
- Acetaminophen
- Antiseizure medications
- Isoniazid (Nydrazid)
- Oral contraceptives
- Rifampin (Rifadin)
- Sulfonamides
Autoimmune disease
- Systemic lupus erythematosus
- Primary biliary cirrhosis
- Sclerosing cholangitis
- Autoimmune hepatitis
Bacterial infection
Granulomatous
- M. tuberculosis
- Sarcoidosis
Hereditary
- Wilson disease
- Hemochromatosis
- Alpha-1-antitrypsin deficiency
Ischemia
Parasitic
- Liver trematodes
- Toxocara spp

Hepatitis viruses A (HAV), B (HBV) and C (HCV) cause 95% of viral hepatitis cases in the U.S. Less-common hepatitis viruses include D (HDV), E (HEV) and G (HGV or GBV-C).

Epidemiology

Transmission – variable according to virus
- HAV, HEV – fecal-oral
- HBV, HCV, HDV, HGV – IV drug abuse, sexual transmission, blood transfusions

Organism

Diverse group of viruses that share a common ability to cause inflammation and necrosis of the liver
Virus may persist in a chronic state (HBV, HCV, HDV)
- Patients may remain chronic carriers
- May cause the development of cirrhosis

Risk Factors

HAV – children in daycare settings
HBV and HCV
- Sexual transmission from infected partner
- HIV-positive patients
- IV drug abusers
- Hemophiliacs – from blood products
HDV
- IV drug abusers
- Travel to endemic area (Amazon basin, Mediterranean basin, Middle East, South Pacific, Asia, sub-Saharan Africa)
HEV
- Travel to endemic area (Central Asia, Middle East, parts of South America, Africa)

Clinical Presentation

May be difficult to diagnose clinically
Frequently asymptomatic – may have only mild rise in aminotransferases
Mild symptoms – malaise, fever, chills, depressed appetite
Similar symptoms among viral hepatitis types
Jaundice is not a predominant symptom in most patients
Complications – acute liver failure

Treatment

Acute disease – supportive
Chronic disease – reduce or eliminate viral loads

Prevention

Chronic hepatitis is a public health concern for transmission as well as for the development of cirrhosis and hepatocellular carcinoma
Vaccines are available to immunize against HAV and HBV

Tests generally appear in the order most useful for common clinical situations

Test name: Hepatic Function Panel

ARUP #: 0020416

Methodology: Refer to individual components.

Use:

Initial screening for hepatobiliary complications

Panel includes albumin; ALP; AST; ALT; bilirubin, direct; protein, total; and bilirubin, total

Test name: Hepatitis Panel, Acute with Reflex to HBsAg Confirmation

ARUP #: 0020457

Methodology: Qualitative Chemiluminescent Immunoassay/Qualitative Enzyme Immunoassay

Use:

Order when patient has had clinical acute hepatitis of unknown origin for less than 6 months

Panel includes HAV IgM, HBV core antibody IgM, HBV surface antigen, HCV antibody

Positive HAV IgM shows current or recent infection with 98% sensitivity and specificity

Test name: Hepatitis C Virus RNA Quantitative, Real-Time PCR

ARUP #: 0098268

Methodology: Quantitative Real-Time Polymerase Chain Reaction

Use:

Follow-up test for high-positive anti-HCV screen

Limitations:

The limit of quantification for the HCV Quantitative RNA assay is 1.6 log IU/mL (43 IU/mL)

If the assay DID NOT DETECT the virus, the test result will be reported as “<1.6 log IU/mL (<43 IU/mL)”; if the assay DETECTED the presence of the virus but was not able to accurately quantify the number of copies, the test result will be reported as “Not Quantified”

Test name: Hepatitis C Virus Antibody (RIBA), Supplemental

ARUP #: 0020104

Methodology: Qualitative Recombinant Immunoblot Assay

Use:

Follow-up test for low-positive anti-HCV screen

Test name: Hepatitis E Antibody, IgG

ARUP #: 0098655

Methodology: Enzyme-Linked Immunosorbent Assay

Use:

Confirm HEV when other testing is negative

Test name: Hepatitis E Antibody, IgM

ARUP #: 0098656