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PCR tests – is this via a bone marrow sample or blood ?

Hi all, only 2 months in since Dx so unsure on the next stage, read quite a lot however a question please as seem to have seen conflicting info. I am unsure how a PCR test is done. I thought it was via a bone marrow aspiration every three months, however I also seem to read it is done via a normal blood sample ?

Am I right that Cytogenetic response is looking at the 20 cells or so under the microscope for no signs of the Leukaemia, and then I gather once achieved PCR tests are done there after as microscope will not find them ?

Thanks    Nigel

Hello Nigel,

PCR tests are normally only carried out once your bcr/abl level is below 30/35%, & is done from blood taken at one of your regular blood checks. Until your bcr/abl falls to this level the count is done by a method call FISH, which is done via a bone marrow biopsy. Personally speaking, I have never had a problem with a bone marrow test, & found them relatively painless & hassle free. I have now had 7, so please don't worry to much about them.

If you haven't seen your doctor by the time of the next meeting at Hammersmith, Prof Goodman will be just the man to answer any questions, or you can always look on cml facts page at the front of the site. E mail me later if you have any more question.

Bob

Pcr tests the molecular level of disease....i.e when you can no longer detect PH+ cells by FISH or cytogenetics then they will switch to doing pcr testing from you peripheral blood. You shoulc not need to endure biopsy or aspirates other than the one at diagnosis unless there is reason to doubt the FISH (also done from peripheral blood)

Generally PCR is a sensitive (and therefore complex) test to do. There is no point in doing it until your levels have reduced so low that bcr/abl levels (the cell signalling protein produced by the PH+ cell and driver of this disease) can only be detected on the molecular level.

If you have an optimal response to imatinib you should hope to be at this sort of low level by 6 -12 months from start of therapy.

Sandy