Hepatitis%20c 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
- Past or current medication use
- Alcohol use
Laboratory Tests
Serological Tests
- Anti-hepatitis C virus (anti-HCV) antibodies are the first-line diagnostic test and are determined via enzyme immunoassay in plasma or serum
- HCV RNA (or HCV core antigen) should be determined to identify viremia or current HCV infection in patients with detected anti-HCV antibodies
- Acute hepatitis C can be reliably diagnosed if recent seroconversion to anti-HCV antibodies (ie a prior negative HCV antibody test becomes positive) can be documented; however, antibody tests often do not become positive until 3 months after infection
- If the clinical suspicion is high, the patient should be tested for HCV RNA (or HCV core antigen) to establish the diagnosis
- Chronic hepatitis C is continued HCV infection of ≥6 months after acquiring the disease and is diagnosed based on the presence of both anti-HCV antibodies and HCV RNA (or HCV core antigen)
- HCV RNA quantitative testing to determine baseline viral load is recommended before starting antiviral therapy
- End of therapy is indicated by undetectable HCV RNA in a sensitive assay (≤15 IU/mL) 12 and 24 weeks after therapy
- Recommended test for assessment of HCV recurrence
- Undetectable HCV core antigen can be an alternative endpoint of therapy in patients with detectable HCV core antigen before therapy
- HCV genotype, including subtyping of genotype 1a/1b, should be determined, if possible (if a non-pangenotypic regimen will be prescribed), in all HCV-infected persons prior to treatment to determine type and duration of therapy and chances of response; predominant genotypes in Asia are:
- Genotypes 1b and 2: East Asia (China, Taiwan, South Korea, Japan)
- Genotype 3: South Asia (India and Pakistan)
- Genotype 3 is considered difficult to treat and is associated with a poor prognosis
- Genotypes 1 and 6: Southeast Asia (Vietnam, Cambodia, Laos, Indonesia, Myanmar, Malaysia, Philippines, Thailand)
- Liver biopsy may be done if it is thought that the results will influence clinical decision, but biopsy is not mandatory to start therapy in patients with genotypes 2 and 3
- Liver biopsy may be obtained to provide prognostic information
- Depending on local health services, the following groups should be tested for chronic HCV infection:
- Persons who have in the recent or remote past used illicit IV/intranasal drugs, men who have sex with men (MSM)
- Persons with conditions associated with high prevalence of HCV infection:
- Positive human immunodeficiency virus (HIV), sexually active individuals taking pre-exposure prophylaxis for HIV, hemophiliacs who received clotting factor prior to 1987, history of hemodialysis, persons who received blood/blood products or organ transplants prior to July 1992, children born to HCV-infected mothers, healthcare workers after needle stick injury or mucosal exposure to HCV-positive blood, current sexual partners of HCV-infected persons, incarcerated individuals
Tests to Rule Out Other Viral Hepatitis
- Hepatitis A: Anti-hepatitis A virus (anti-HAV) IgM; nucleic acid amplification test (NAAT) for HAV RNA may be considered
- Hepatitis B: Hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), hepatitis B e antigen (HBeAg)
- Hepatitis D: Anti-hepatitis D virus (anti-HDV) antibody, HDV RNA test
- Hepatitis E: IgM anti-HEV, IgG anti-HEV in combination with HEV RNA; NAAT for HEV RNA may be considered
- Please see Hepatitis A & E and Hepatitis B disease management charts for further information
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), renal function tests, complete blood count (CBC) with platelets
- Noninvasive tests such as the aminotransferase/platelet ratio index (APRI) or fibrosis-4 (FIB-4) must 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
- Ultrasound of the liver helps identify hepatocellular carcinoma (HCC) and subclinical ascites
Evaluation
Consequences of HCV Infection
- 55-85% of patients who acquire acute hepatitis C will remain HCV infected
- 5-20% of these patients may develop cirrhosis over the next 20-25 years
- HCV-related cirrhosis is associated with risk of developing end-stage liver disease (30% risk over 10 years) as well as HCC
- In patients with persistent infection, the evolution to cirrhosis is the primary concern
- Usually occurs ≥20 years after initial infection and occurs more often in patients at older ages (especially men), those who drink >50 g of alcohol/day, those who are obese or have substantial hepatic steatosis and in those with HIV infection
Antiviral therapy is currently widely accepted for the following hepatitis C patient groups:
- ≥18 years of age
- Normal and abnormal ALT levels
- Liver biopsy showing chronic hepatitis with significant fibrosis or cirrhosis (stage F1 or above)
- HCV genotype 2 or 3 regardless of stage
- Compensated liver disease
- Acceptable hematological and biochemical indices
- If there is a history of depression, the condition is well controlled
- Willing to be treated and conform to patient requirements
- Treated previously for HCV infection
Therapy should be individualized in patients with any of the following:
- Failed prior treatment of either Interferon given alone or in combination with Ribavirin or Peginterferon given alone
- Current PWID or alcoholic but willing to participate in substance abuse program or alcohol support program
- No or mild fibrosis on liver biopsy
- Acute hepatitis C
- Coinfected with HIV
- <18 years of age
- Chronic renal disease
- Decompensated cirrhosis
- Liver transplant recipient
Therapy is contraindicated in patients with any of the following1:
- Major, uncontrolled depressive illness
- Renal, heart or lung transplant recipient
- Autoimmune hepatitis or other condition known to be exacerbated by Interferon and Ribavirin
- Untreated hyperthyroidism
- <3 years of age
- Pregnant or unwilling/unable to comply with adequate contraception
- Severe concurrent disease (eg hypertension, HF, uncontrolled DM, etc)
- Known hypersensitivity to drugs used to treat HCV
- Hepatic decompensation
1Patients have detectable HCV RNA