HCV and PCR testing

[Keith Appleyard]

The original test used to screen you detected antibody to Hepatitis C 
Virus (HCV). This antibody is a marker of HCV infection at some time in 
the past which caused you to produce the antibody in the first place to 
fight off the original episode of infection. 

The test result is normally confirmed by carrying out another form of 
test for antibody called a Rapid ImmunoBlot Assay (RIBA). The original 
test simply says that you have antibody. The RIBA is capable of showing 
that you have different types of antibody directed against different 
proteins from the virus and thereby more specifically confirms the 
original result.

However, antibody only tells us about YOUR body's immune response to the 
virus and tells us nothing about the response of the virus to you.

Did it survive from the original infection or was it eliminated?
If it survived and is still in your liver is it still active?
If so how active?

These and other questions can only be resolved by looking for the virus 
itself. PCR (Polymerase Chain Reaction) is a test that looks for viral 
genetic material in your circulating peripheral blood supply. If it is 
found (a positive PCR result) then the virus is still active and 
producing new viral material. If positive the amount can be quantitated 
to see how much viral genetic material is present, from this the level of 
activity of the virus can be deduced, i.e the more viral genetic 
material=the stronger the PCR result=the more active the virus.

As a more active virus is generally bad news for the patient this 
information is important for your doctor's. From this knowledge they can 
better inform you - the patient - of the future possibilities and also 
better decide how, and when they should treat you and how well the 
treatment is working.

Only the lab that carried out your PCR can tell you accurately what your 
value means. This is because PCR results carried out at different sites 
can vary due to the way that the individual lab carries out the test. 
Only the lab concerned with their own experience can tell you what their 
result means.

No reflection on your physician but if I were you I'd contact them direct 
to get an unequivocal answer as the test is specialised and sometimes the 
meaning of the results is difficult for other doctors to understand.

Good Luck!

-- 
Keith Appleyard BSc, Senior Scientific Officer, Virology
Ninewells Hospital and Medical School, Dundee DD1 9SY,
U.K, e-mail k.appleyard at dundee.ac.uk
Tel: U.K 01382 632559 Fax: U.K 01382 641907