Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

HCV
80190
Negative
See Viral Hepatitis Serologic Profiles in Special Instructions.
Clinical References: 1. Carithers RL, Marquardt A, Gretch DR: Diagnostic testing for hepatitis C.
Semin Liver Dis 2000;20(2):159-171 2. Germer JJ, Zein NN: Advances in the molecular diagnosis of
hepatitis C and their clinical implications. Mayo Clin Proc 2001;76(9):911-920 3. Pawlotsky JM: Use
and interpretation of virological tests for hepatitis C. Hepatology 2002;36:S65-S73 4. Alter MJ, Kuhnert
WL, Finelli L: Centers for Disease Control and Prevention: guidelines for laboratory testing and result
reporting of antibody to hepatitis C virus. MMWR Morb Mortal Wkly Rep 2003;52(No. RR-3):1-14
Hepatitis C Antibody Screen, Serum
Clinical Information: Hepatitis C virus (HCV) is recognized as the cause of most cases of
post-transfusion hepatitis and is a significant cause of morbidity and mortality worldwide. In the United
States, HCV infection is quite common, with an estimated 3.5 to 4 million chronic HCV carriers.
Laboratory testing for HCV infection usually begins by screening for the presence of HCV antibodies
(anti-HCV) in serum, using an FDA-approved anti-HCV screening test. Specimens that are repeatedly
reactive by screening tests should be confirmed by more HCV-specific tests, such as direct detection of
HCV RNA by reverse transcriptase-PCR (RT-PCR) or strip recombinant immunoblot assay (RIBA)
using recombinant HCV-specific antigens. HCV antibodies are usually not detected during the first 2
months following infection and are almost always 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. Loss of HCV antibodies may occur several years following resolution of
infection. Current screening serologic tests to detect HCV antibodies 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 detectable HCV antibodies. -False-reactive screening test
results can occur. -A reactive screening test result does not distinguish between past (resolved) and
chronic 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 RIBA for HCV antibodies or nucleic acid tests for HCV RNA. Nucleic acid tests provide a very
sensitive and specific approach for the direct detection of HCV RNA. The following algorithms are
available in Special Instructions: -Viral Hepatitis Serologic Profiles -Recommended Approach to the
Diagnosis of Hepatitis C -Alternative Approaches to the Diagnosis of Hepatitis C
Useful For: Screening for past (resolved) or chronic hepatitis C
Interpretation: Reactive hepatitis C virus (HCV) antibody screening results with signal-to-cutoff
(S/CO) ratios of or =8.0 are highly
predictive (> or =95% probability) of the true anti-HCV status, but additional testing is needed to
differentiate between past (resolved) and chronic hepatitis C. To confirm results of HCV antibody
screening test and to guide further management of patients, specimens should be tested by 1 of the
following supplemental tests: -HCVQU Hepatitis C Virus (HCV) RNA Detection and Quantification by
Real-Time Reverse Transcription-PCR (RT-PCR), Serum for patients with known risk factors for HCV
infection. Presence of HCV RNA in a given specimen indicates acute or chronic hepatitis C.
-RIBA/80181 Hepatitis C Virus Antibody Confirmation by Recombinant Immunoblot Assay (RIBA),
Serum for patients with minimal or no risk factors for HCV infection. A positive RIBA result confirms
the presence of HCV IgG antibodies, but it does not 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 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 (