how likely is a false NEGATIVE

no one answered my other question so let me ask this. Someone told me that HCV antibodies can "hide" from your blood test for years. I just can't believe that to be true. If possible exposure was many many years ago- and recently tested non reactive for HCV antibody- can it seriously be "hiding"????

[pjhep80]

no... im pretty sure no anyway...

the virus can hide from the drugs but if you tested non-reactive you dont have it

[Bill1954]

False negative EIA tests are a possibility; I don’t have specifics for that question, although they might be available on the internet. Serial EIA testing as well as RIBA testing are considered conclusive for HCV exposure; and if appropriate, an HCV serum RNA test by PCR can acurately determine whether a person has contracted the actual virus.

Most of us in here have been diagnosed with active HCV RNA, and don’t concern ourselves with the intricacies of antibody testing, hence the lack of response to your questions.

The following link from the U.S. CDC discusses S/CO ratios per your last post:

http://www.cdc.gov/hepatitis/HCV/LabTesting.htm#section2

Best of luck to you—

Bill

[Bill1954]

Also from the U.S. CDC:

http://www.cdc.gov/hepatitis/HCV/HCVfaq.htm#section3

“How soon after exposure to HCV can anti-HCV be detected?
HCV infection can be detected by anti-HCV screening tests (enzyme immunoassay) 4–10 weeks after infection. Anti-HCV can be detected in >97% of persons by 6 months after exposure.

How soon after exposure to HCV can HCV RNA be detected by PCR?
HCV RNA appears in blood and can be detected as early as 2–3 weeks after infection.

Under what circumstances is a false-positive anti-HCV test result likely?
False-positive anti-HCV tests appear more often when persons at low risk for HCV infection (e.g., blood donors) are tested. Therefore, it is important to confirm a positive anti-HCV test with a supplemental test, such as RIBA (recombinant immunoblot assay), as most false positive anti-HCV tests are reported as negative on supplemental testing. More information is available from the Guidelines for Laboratory Testing and Result Reporting of Antibody to Hepatitis C Virus.

Under what circumstances might a false-negative anti-HCV test result occur?
Persons with early HCV infection might not yet have developed antibody levels high enough that the test can measure. In addition, some persons might lack the (immune) response necessary for the test to work well. In these persons, further testing such as PCR for HCV RNA may be considered.”

[jmjm530]

If you think your test was a false negative, have it repeated. If you have reason to believe you may have hepatitis C and don't trust the antibody test, you can get what is called a PCR, or viral load test. If that tests negative, you don't have hepatitis C. The exception being, if you were just very recently exposed.

[copyman]

Samples with high S/CO ratios (>9.9) confirm positive (95%), but <5 out of 100 might represent false-positive. Further testing i.e. PCR will differentiate active from resolved infection. Best of luck

[nygirl7]

Re: PCR fales positives.....

False negative numbers I think for the most part don't make sense. For example after I had finished treatment successfully for 72 weeks my test came back a numbemr 60.;  The doctor knew this wasn't a real number because after that time period it would have been much higher at least in the 100s of thousands.

I retested and it was false.

So if you ask the number, you could be able to tell that way if PERHAPS it was a false positive on a PCR test.
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Otherwise with a hep reaction test - you would have to have it rerun or do the PCR but that is a more expensive test that they probably wouldn't do till later. I hope that made sense but wanted to make sure you understood.