Dear All
This is a question for the maths wizards!
I have just had a PCR back at 3.9 log [yes, I'm delighted - best result I've had yet :-) ] but my haematologist says that the lab cannot report over 4 log. He thinks the sensitivity of the lab is 1/100,000. Is this right? Surely if it was 1/100,000 then they could report up to 5 log?? Or is my maths wonky??
Happy New Year to all, and may we all see lots of zeros in 2011!
Janet
Hi Janet... many congratulations on reaching a deeper molecular remission. 4 log (virtually) is fantastic and you should not stress too much about the numbers. I am sure as we go on pcr testing will become more and more sensitive,( some labs do have more sensitivity that others) but in the scheme of things your response is certainly one you should celebrate. Sorry I cannot answer your specific question about further log reductions and how many cells this represents.
Best wishes,
Sandy
Hi Janet, Congratulations from me as well, on the PCR.
There may be two possible issues re PCR at low levels
1. We had a talk in Kings CML group re PCR testing and the Lab rep indicated at below 4 log reduction , at Kings Lab, accuracy of PCR was quite difficult to state accurately. It could be that once the reading goes below 4 log the Lab is reluctant to state values ( although in theory lab can pick up one cell in 100000, the accuracy is not too good).
2. Kings take the start point for their Lab reports at 70000 out of the 100000 cells being leukemic. This means that
1 log reduction goes from 70000 down to 7000
2 log from 7000 to 700
3 log from 700 to 70
4 log from 70 to 7
5 log from 7 to 0.7
This would mean that bottom end of log reductions cannot be measured as reading would be below 1 cell in the 100000 sample.The key point as Sandy states is that 3.9 log reduction is a great place to be, and means relapse is very unlikely!
Regards
Andy
I am consistently being told 0.002% by Hammersmith, which I make a 4.8 log reduction. I guess your maths is right.
John
Hi Janet.... my PCR's tests continue fail to show any presence of bcr/abl- as should be the case post SCT and as I hope it remains in the future.
It would be great to meet up again, as it's been quite a few years since we last met. Are you going to L'pool for the CML seminar?
I will be there this year as it is my home town and I will also take the chance to visit my mum and dad.
BTW for those of you who are attending and are staying over- I really recommend, if the weather is good, that you take the short journey to Crosby Beach- 20/15 minutes drive north from the city centre- to experience Anthony Gormley's 'Sense of Place' installation of up to 100 human (male) figures. It is a wonderous sight and well worth the detour.
Sandy
Hi Sandy - congratulations on the continuing PCRU - maybe I'll get there sometime....sigh...:-)
No, I won't be at the seminar this year - father-in-law is 84 on Friday so there is a family bash on the weekend. It should be good, but it is a shame that the 2 events coincide. Hopefully next year!
Hope you have a great time.
Janet
