So what are the implications for Week 12 (which I recently referred to in Week 8 Tuesday too)?
The National Institute for Clinical Excellence, NICE, “make recommendations on treatments and care using the best available evidence” to the Department of Health on a wide variety of medical diseases and conditions.
The NHS have accepted their recommendations in Technology Appraisal 75, Interferon alfa (pegylated and non-pegylated) and ribavirin for the treatment of chronic hepatitis C which outlines the treatment criteria, technology, need for research and other medical matters. This policy for treatment has been accepted and adopted as the standard of treatment that HCV+ people have the right to expect from the NHS.
Amongst the many things outlined in this document is the protocol for what happens at Week 12:
For people infected with HCV of genotype 1, 4, 5 or 6, initial treatment should be for12 weeks. Only people showing, at 12 weeks, a reduction in viral load to less than 1% of its level at the start of treatment (at least a 2-log reduction) should continue treatment until 48 weeks. For people in whom viral load at 12 weeks exceeds 1% of its level at the start of treatment, treatment should be discontinued.
In other words, if my viral load has not dropped sufficiently at Week 12 my treatment could be discontinued.
The document also talks about SVR (Sustained Viral Reduction) and how the results of Week 12 indicate the outcome of the treatment:
4.1.2.5 After 12 weeks of treatment, the viral load in people who eventually have an SVR after 24 or 48 weeks - treatment is generally reduced by a factor of 100 or more. That is, for every 1000 copies of the virus in the bif lood at the beginning of treatment, there would be 10 or fewer copies at the end of 12 weeks of treatment. This is known as a 2-log reduction.
4.1.2.6 For genotypes 1, 4, 5 and 6 (together called G1+), only 70-80% have a 2-log reduction at 12 weeks and, of these, about 60% (40-50% of the total group) have an SVR. Of the 20-30% that are non-responders at 12 weeks, few (perhaps 0.5% of those originally treated) go on to have an SVR.
So, as I understand this, 20-30% of patients do not show sufficient reduction in viral load at the Week 12 stage to continue treatment.
Will I be in the 70-80% group or the 20-30% group? This is the significance of Week 12!!
I have to say I am not so worried because I remain optimistic I will be in the group who are responding to the treatment. After all, my Liver Function blood test results show that my liver functions have returned to normal - after having high ALT’s for the past two and half years (probably longer but they weren’t being monitored before that!). So there is evidence that the medications have kicked in sufficiently to stop the attack on my liver and its functions have returned to normal.
But I as I write this I am aware of how much, like other HepC+ people, I have become an ‘amateur expert’ on Hepatitis C.
I support this notion in one respect. Knowledge is power. Understanding the medical information “empowers” me to take responsibility for my health and my treatment. I believe it is important to take “ownership” of my situation as I have said previously.
On the other hand, there reaches a point where I think I want to keep it simple. I don’t understand much about viral loads. I do know there are several ways of measuring them - the Americans have a different standard than the UK. I don’t understand about “changes to log2″. Nor do I really want to.
It reminds me of my days in secondary school Algebra classes when I used to think - what on earth am I learning about logarithms for - what will have to do with the real world? I can honestly say this is the first time since school I have needed to consider logs!
So while I track my other blood test results with interest I think I will adopt a more ‘laissez-faire’ attitude about viral load test results. I also know that the hospital I attend will first test me with a PCR test - the initial test to see if people have the virus. If that is negative, then the viral load blood test - much more expensive to carry out, will not be thought necessary.
I think my ‘laissez-faire’ attitude would disappear if the question of me not continuing treatment arose - but as I said already I am optimistic that the medications are doing their job. They ought to be - I am doing everything I can to support their work!