Hi Bobrass, as Splitdog mentioned, two blood tests are recommended at 4 weeks into treatment, then again recommended at the end of treatment, and finally required 12 weeks after the end of treatment (to prove cure). Here are the tests names :
⦁ HCV RNA PCR (Quantitative)
⦁ CBC + CMP
Tests themselves don't cure you so they can all be viewed as optional.
Testing 4 weeks into treatment is when we expect the virus to be undetected (78% of people will be undetected at this time). It can be useful as we know from our data, and VA data that the 22% of patients still detected form 44-50% of the treatment failures so it can be worth considering a small 4 week treatment extension if this is the case.
Psychologically it's nice to see undetected @ 4 weeks. The PCR RNA test is expensive so can be skipped as we also see the ALT and AST in the CMP (Complete Metabolic Panel) fall dramatically - this also show you the meds are working fine and is cheap.
At the end of treatment (EOT) the PCR is not really required - once it is negative it will stay negative. The CMP gives EOT AST/ALT levels which allow us to have a sneak peak once the medications finish. If these numbers stay down all is well.
12 weeks after the tablets finish is the point we call SVR12, standing for Sustained Virological Response. When the tablets finish they wash out of the body almost completely within a week giving any remaining virus 11 weeks to grow back. If it remains undetected we are 99.7% certain that will remain permanent.
At SVR24, 24 weeks after the tablets finish, the virus has has 23 weeks with no drugs to stop it. Undetected at this point is 99.99% certain of being permanent and the 0.01% is probably reinfection.