All,
I am keen to find out if anyone has explored the meaning of a PCR of undetectable .
August 2016 my PCR was 0.266 and the latest dated 2017 is 0.000 undetectable ;that is after being on high dose Glivec of 600mg daily.For a while we lost our molecular remission but have now regained it in a very very deep manner.
It seems that there are limits to the degree to which the PCR test might detect the extent of the residual leukaemic cells in the bone marrow and that we will never be fully clear of the disease.There appear to be certain markers such as
log 3 reduction or 0.1 % or 1000 times smaller or 1 in a 1000,
log 4 reduction or 0.01% or 10,000 times smaller or 1 in 10,000
log 5 reduction is 0.001 or 100,000 times smaller or 1 in 100,000
log 6 reduction is I understand 0.000 or 1,000,000 times smaller or 1 in 1,000,000 but at this level Bcr/Abl transcripts are currently undetectable
So my query is are we only able to as far as log 5 with any reliability and so does log 6 exist
The other issue is that there will always be some residual levels of leukaemic cells in the bone marrow.The meaning of undetectable is 1 in 1 million residual cells.
One author suggested that there are 3 trillion cells in total in the bone marrow so in equivalence terms 1 in a million means that there are still one million residual cells in total in the marrow even if a reading shows undetectable.
However it seems that if one maintains a score of undetectable one is unlikely to have a re -occurrence of the disease and unlikely ever to lose ones remission
Any comments?
John
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