Reliability of HCV Antibody testing (false negatives?)

[Andromedae]

Dear Dr.  Dietrich,
  I have to start out by saying how much I appreciate your participation here.   I know that you hear it many times but you should hear it many more - it is very much appreciated.  you are a rare gem.

  My question is how accurate the HCV antibody tests are - specifically how possible is it to have a false negative?

   I was diagnosed with HCV in 12/07 after someone finally having noticed elevated ALT/AST levels (ALT 120 - 150)  for 12 months and ordered an antibody test.  I was given an HCV antibody test in 03/06 (18 months earlier) and tested negative.  I was given the first test (the negative one) after complaining of bouts of extreme fatigue that had reoccurred for years as well as accompanying occasional mental "fuzziness".  Those bouts of fatigue (three or four over 15 years) lasted from 3-6 weeks and then went completely away and I would feel great again.  I had an MRI done in '05 to test for MS plaques which showed negative.

  I was in the military as a medical paraprofessional from '76-81.  I was 1. given gamma globulin once   2. had air gun injectors used on me twice, 3. had two needle sticks on me while I was working in the medical field.

  So what I am asking is this Doctor, I was a potential risk, having several exposure risks, and had experienced several HCV-like symptoms over the years  BUT an HCV antibody test showed negative in early '06.  So I am wondering how accurate that test might be?  

  On more thing - prior to '06 two blood tests showed my ALT levels were around 19 - in  early '07 they jumped to 150.

  Does any of this make sense to you?  What are the odds that the antibody test in '06 was a false negative?

Thank you for your time. Doctor.

[Douglas Dieterich, MD]

No lab test is 100% perfect and you should both repeat the HCV antibody and also the PCR as well as HBV test. But the previous answer is likely correct now. Fatty liver is more commonly the cause of elevated enzymes as we age. If there is any doubt about any lab tests just repeat it! ALT of 150 is not good no matter what is causing it and you need to follow it up. Good luck! DTD