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PCR lab sensitivity

Is PCR reading increase from 0.022% to 0.041% in 3 months significant enough to change dosage or is it within lab variability limits?

The variability of PCR results at these low levels is easily +/- 50%. This increase is more than that, but the result is still well below 0.1%. If you have been tracking around 0.02% for a while, my inclination would be not to change now, but at your next test (when is that?) if there is a continuing upward trend in that result, then a discussion with your specialist on some change is appropriate. What TKI are you taking, at what dose?

(By the way, before I retired I ran an internationally accredited toxicology lab for some years so I know a fair bit about this stuff).

Best wishes

Alastair

Hi
Most haematologists would consider any pcr less than 0.1% is in totally safe territory and also any fluctuations between 0.1 and undetectable would be ignored.In addition if they would be considering any switch of tki it would be based on a trend upwards over a significant period of time and of course well above 0.1.
If you think it through every tki has side effects some of which are specific to you and every new tki you take on will have side effects for you some of which you may not be able to tolerate.Example imatinib is well known for bringing about muscular skeletal effects -irritating but not life threatening;Dasatinib has side effects of pleural effusions for 20 % of patients on the drug and many cannot tolerate their lungs periodically filling up with fluid or having a long needle inserted on a regular basis to drain the fluid.
Alistair will be very aware of the sensitivity of the PCR test in different labs and also as one goes down to very low levels.
Good luck
John