Hepatitis%20a%20-and-%20e Diagnosis
History
Important Points in the Clinical History of Patients with Suspected Viral Hepatitis
- Contacts with jaundiced patients
- IV drug use
- History of blood transfusion
- Surgery or hospitalizations
- Family history of chronic liver disease
- Occupation
- Food and water sources
Laboratory Tests
Serological Tests
Hepatitis A
- Anti-hepatitis A virus (HAV) IgM has high sensitivity and specificity and is a marker of acute infection
- This test remains positive for ≥6 months
- Anti-HAV should be tested in patients <50 years
Hepatitis E
- IgM anti-HEV, IgG anti-HEV in combination with hepatitis E virus (HEV) RNA indicate acute hepatitis E infection
- Detection of HEV antigen by enzyme immunoassays may also be used to diagnose both acute and chronic infections
- HEV genotype should be determined, if possible, in all HEV-infected persons prior to treatment to determine type and duration of therapy and chances of response; predominant genotypes worldwide are:
- Genotype 1: Africa and Asia
- Genotype 2: Mexico, West Africa
- Genotype 3: Developed countries
- Genotype 4: China, Taiwan, Japan
Tests to Rule Out Other Viral Hepatitis
- Hepatitis B: Hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), hepatitis B e antigen (HBeAg)
- Hepatitis C: Anti-hepatitis C virus (anti-HCV) antibody, HCV RNA test, HCV core antigen
- Hepatitis D: Anti-hepatitis D virus (anti-HDV) antibody, HDV RNA test
- Please see Hepatitis B and Hepatitis C disease management charts for further information
Nucleic Acid Amplification Test (NAAT)
- Eg conventional reverse transcription polymerase chain reaction (RT-PCR), real-time RT-PCR, transcription-mediated amplification methods, genotyping for HAV RNA or HEV RNA may be considered
- HEV RNA is detected from serum and stool of infected patients by NAAT-based assays
Immunohistochemistry
- HEV ORF2 protein immunohistochemistry can be used to establish a histopathologic diagnosis of hepatitis E
Other Recommended Lab Tests in Patients Suspected of Viral Hepatitis
- Liver function tests (LFTs)
- Aspartate aminotransferase (AST) and alanine aminotransferase (ALT)
- Serum bilirubin, alkaline phosphatase (ALP)
- Prothrombin time (PT), international normalized ratio (INR), complete blood count (CBC) with platelets, renal function tests
- Noninvasive tests such as the aminotransferase/platelet ratio index (APRI) or FIB4 may be used to assess the degree of hepatic fibrosis when resources are limited prior to initiating HCV therapy
- Transient elastography may be an option for patients with contraindications to liver biopsy
Evaluation
Features of Hepatic Decompensation
- Mental dullness, hepatic encephalopathy, bilateral asterixis, ascites, clinical deterioration
- Serum bilirubin >2.5x upper limit of normal, PT is 3 seconds longer than control or INR >1.5
Biochemical or Clinical Improvement
- Repeat liver function test and serum/stool HEV RNA detection will show normalization if patient responded to treatment or infection subsided spontaneously
- Repeat anti-HAV IgM after 1 week may be used to determine if acute or recent infection has resolved
- Refer to a specialist if tests are still positive for infection and with disease persistence or progression