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PCR differences between labs

I'm not particularly concerned about this result, but it's a little odd and was wondering if anyone had similar experiences in the past?

My PCR results have been a bit less than stellar, hovering around the 0.5-1% territory for much of the last 8 or 9 months. It stays pretty stubbornly at around the 0.4% mark as the low point. The suspicion is that some of this is due to the fact that I have to take proton pump inhibitors which are affecting the metabolism of dasatinib in my system - we're hoping to take a surgical route to fix the problem which causes me to need the PPIs, so hopefully that issue will go away soon. I ought to find out the surgical (or not!) plan tomorrow.

But, on my most recent trip to clinic my latest PCR from Barts was 0.4% (not unexpected) but the result from Hammersmith (blood samples from the same day) came back as 0.04% - i.e. in MMR. There is a full log difference between the results. Weird, no?

The doctor thought that the Hammersmith sample may have degraded as it took a little while to get the blood sample over there and didn't seem to have too much faith in it.

In happier news, I am now going to be supplied dasatinib from the NHS, with my privately sourced dasatinib supply coming to an enforced end next week. It's a relief that all that has gone through, as I didn't really fancy having to change TKI for an economic, rather than medical reason.

David.

I've had differences between labs - my PCR is done by Hammersmith every 6 months as part of Spirit2, while the alternate ones are done here in Edinburgh. The Hammersmith ones have generally been better recently (around 0.01, rather than 0.04) so I tend to believe them! Not a very great difference anyway.
Olivia

Hi David,

first, good news that you will now be secure in your access to dasatinib.

HH lab results. Hammersmith have one of the most sensitive PCR methods globally, so if their result is lower then I would welcome that.

As for the sample being degraded, HH would not have reported a result if they had not had a good enough sample to do so... i.e an adequate amount of the control (ABL) gene in the sample. If it was delayed in being sent from Barts then I would question why as this can and does affect a result because the cells are already dying and therefore there is less mRNA to extract.
You should be able to find out from your doctor if there were adequate ABL (the control gene that HH uses) transcripts in that particular sample.

Hope you can get some resolution on PPI issue, it may well be affecting the uptake of the TKI.

Best.. Sandy

Hi Sandy,

I'm not so sure about the Hammersmith result. To be honest, I'm not too bothered - lets see what the next ones come in at and take stock! I can't really take a full log difference too seriously. There must be a muck-up somewhere.

Anyway, on the PPI front it's been confirmed that I will have a Nissen Fundoplication. I'm looking forward to it as it will (hopefully!) mean no more PPIs and help with the dasatinib uptake. It might even make me feel better, since the acid reflux isn't too pleasant to begin with.

I'll continue to post here about my experience with the Nissen and CML and the TKIs, not for my own benefit really - but I suspect it might be useful for others to search upon in the future. When I looked into it, I found next to nothing about CML and a Nissen ... why would you?

David.