Anyone know how to work out the international score/ scale for PCR ?

It is interesting reading other people's posts, as I look at their scores I wonder if they are the IS score or the 'raw' score as my consultant described it to me. If everyone is using raw scores my last PCR at 9 months (manged to root out my notes!) was 0.256 which seems so much higher and more comparable to others than the 0.08 I was given. Which score is everyone using? Am I the only one finding this confusing? I know my score is down which is all I wish for but it is like one exam board giving you one grade and another giving you a different grade, which do I use?
Maybe I am really thinking about this too much!!
Emma x

not meaning to hijack the thread, however, my question is relevant:

Per one of my previous posts, i have found myself in a peculiar situation. In the US, my labs (non-IS)were giving a result of BCR-ABL:ABL Ratio of <0.000 after 8 months - so there's me thinking PCR-U (CMR) and incredibly happy with my response.

Came back to the UK and have had 0.179 followed by 0.11 3 months apart (I am assuming IS % as i've not seen the printed results). That apparent response is not so good, considering i've had 18 months on Tasigna. I now don't even know if i hit MMR let alone CMR.

I fully expected there to be differences between the two labs; however, I am amazed at the massive difference between the UK and US results. I understand non-IS labs use their own baseline and IS labs use a standardized baseline of BCR-ABL in untreated patients.

Em, your question makes me wonder if I am being given raw results or IS from my UK clinic.

Sandy, you seem to think all results should be delivered expressed as IS in the UK; can you offer any pertinent (read accurate) questions for us to ask or explanations to ensure we can all compare apples with apples? i.e. what units are raw results offered in? how are the conversions calculated?

Chris (confused from Bristol)

Hi Chris,

well I am confused too!
In my previous post to Emma, when I said that all UK labs have converted to the IS I should have said...all labs that are attached to the expert centres.... i.e Hammersmith, Liverpool, Newcastle, Leeds, Glasgow etc.
for the pcr's that are taken at general haematology depts I assumed they would now send the samples for testing to one of the expert centre labs..

a result using the IS can also be expressed as a log reduction

So, a bcr/abl result of 0.1% would be equivalent to a 3 log reduction from a baseline of 100% PH+.

I think that in the EU MOST expert centres work to the lS.... however, this is not the case in the US -just like you say. It is a problem and I will try to find a way of confirming my own understanding- which is not expert by any means- ;o)

Best wishes,

Sandy