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 2.4 million chronic HCV carriers.

HCV antibodies are usually not detectable during the early months following infection, but they are almost always detectable by the late convalescent stage (>6 months after onset of acute infection). These antibodies do not neutralize the virus, and they do not provide immunity against this viral infection. Loss of HCV antibodies may occur many years following resolution of infection.

Despite the value of serologic tests to screen for HCV infection, several limitations of serologic testing are known:

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

-False-reactive screening test results 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 antiviral therapy.

Positive screening serologic test results should be followed by a confirmatory or supplemental test, such as line immunoassay (HCVL / Hepatitis C Virus Antibody Confirmation, Serum) for HCV antibodies or a nucleic acid test for HCV RNA. Although nucleic acid tests provide a very sensitive and specific approach to directly detect HCV RNA in a patient's blood, they are not suitable for use in testing cadaveric blood specimens due to interference of heme with the nucleic acid amplification processes.