TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: HCVDX    
Hepatitis C Virus (HCV) Antibody with Reflex to HCV RNA by PCR, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosis of recent or chronic hepatitis C virus infection in symptomatic patients

 

This test is not offered as a screening or confirmatory test for hepatitis C virus (HCV) for blood, human cells, or tissue donors.

 

This test profile is not useful for detection or diagnosis of acute HCV, since HCV antibodies may not be detectable until after 2 months following exposure and HCV RNA testing is not performed on specimens with negative anti-HCV screening test results. Initial testing using: HCVQN / Hepatitis C Virus (HCV) RNA Detection and Quantification by Real-Time Reverse Transcription-PCR (RT-PCR), Serum is recommended for detection of HCV infection in such patients.

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If hepatitis C virus (HCV) antibody screen is reactive, then HCV RNA by reverse transcription-polymerase chain reaction (RT-PCR) will be performed at an additional charge.

  

See Hepatitis C: Testing Algorithm for Screening and Diagnosis in Special Instructions.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Hepatitis C virus (HCV) is recognized as the cause of most cases of posttransfusion hepatitis and is a significant cause of morbidity and mortality worldwide. In the United States, HCV infection is quite common, with an estimated 2.4 million chronic HCV carriers.

 

Laboratory testing for HCV infection usually begins by screening for the presence of HCV antibodies in serum, using an FDA-approved screening test. Specimens that are repeatedly reactive by screening tests should be confirmed with HCV tests with higher specificity, such as direct detection of HCV RNA by reverse transcription-PCR (RT-PCR) or HCV-specific antibody confirmatory tests.

 

HCV antibodies are usually not detectable during the first 2 months following infection, but they are usually detectable by the late convalescent stage (>6 months after onset) of infection. These antibodies do not neutralize the virus and they do not provide immunity against this viral infection. Decrease in the HCV antibody level in serum may occur after resolution of infection.

 

Current screening serologic tests to detect antibodies to HCV include EIA and chemiluminescence immunoassay. Despite the value of serologic tests to screen for HCV infection, several limitations of serologic testing exist:

-There may be a long delay (up to 6 months) between exposure to the virus and the development of a detectable HCV antibody

-False-reactive screening test result can occur

-A reactive screening test result does not distinguish between past (resolved) and present HCV infection

-Serologic tests cannot provide information on clinical response to anti-HCV therapy

 

Reactive screening test results should be followed by a supplemental or confirmatory test, such as nucleic acid test for HCV RNA or HCV antibody confirmatory test. Nucleic acid tests provide a very sensitive and specific approach for the direct detection of HCV RNA.

 

See Hepatitis C: Testing Algorithm for Screening and Diagnosis in Special Instructions.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

See Viral Hepatitis Serologic Profiles in Special Instructions.

Interpretation Provides information to assist in interpretation of the test results

Reactive hepatitis C virus (HCV) antibody screening results with signal-to-cutoff (S/CO) ratios of below 8.0 are not predictive of the true HCV antibody status and additional testing is recommended to confirm anti-HCV status.

Reactive results with S/CO ratios of 8.0 or greater are highly predictive (95% or greater probability) of the true anti-HCV status, but additional testing is needed to differentiate between past (resolved) and chronic hepatitis C.

 

A negative screening test result does not exclude the possibility of exposure to or infection with HCV. Negative screening test results in individuals with prior exposure to HCV may be due to low antibody levels that are below the limit of detection of this assay or lack of reactivity to the HCV antigens used in this assay. Patients with acute or recent HCV infections (<3 months from time of exposure) may have false-negative HCV antibody results due to the time needed for seroconversion (average of 8 to 9 weeks). Testing for HCV RNA using HCVQN / Hepatitis C Virus (HCV) RNA Detection and Quantification by Real-Time Reverse Transcription-PCR (RT-PCR), Serum is recommended for detection of HCV infection in such patients.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

A single negative hepatitis C virus (HCV) RNA test result together with a reactive HCV antibody screen result with a S/CO ratio of 8.0 or greater do not rule out the possibility of chronic HCV infection. Repeat testing for HCV RNA in 1 to 2 months is recommended in patient at risk for chronic hepatitis C.

 

Infants born to HCV-infected mothers may have false-reactive HCV antibody test results due to transplacental passage of maternal HCV IgG antibodies. HCV antibody testing is not recommended until at least 18 months of age in these infants.

 

Performance characteristics have not been established for the following types of serum specimen:

-Individuals under 10 years of age

-Grossly icteric (total bilirubin level of >20 mg/dL)

-Grossly lipemic (triolein level of >3000 mg/dL)

-Grossly hemolyzed (hemoglobin level of >500 mg/dL)

-Presence of particulate matter

-Cadaveric specimens

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Centers for Disease Control and Prevention: Testing for HCV infection: an update of guidance for clinicians and laboratorians. MMWR Morb Mortal Wkly Rep 2013;62(18):362-365

2. American Association for the Study of Liver Diseases and Infectious Diseases Society of America: HCV guidance: Recommendations for testing, managing, and treating hepatitis C. Available at www.hcvguidelines.org/full-report-view

Special Instructions Library of PDFs including pertinent information and forms related to the test