6 replies to this topic

[valiantchong]

HI,

Would appreciate if anyone here could help me to shed some light on my old PCR result interpretation, why the count of BCR-ABL1 read 0.2 ? why not 1 ?

I checked my old PCR result and puzzle of my print out results was :

Sample Type: Peripheral Blood

Test BCR-ABL 1 Major Fusion Quantatitative 1-step RT-PCR

Results

Control Gene [ABL1] copy number : 51,500

BCR-ABL1 gene copy number : [0.2]    -> I do not understand why 0.2 here how does a gene could be counted as 0.2 and not 1 ?? Please help

% BCR-ABL1 ratio : - %

IRIS international scale : - %

Interpretation Section :

BCR-ABL1 fusion transcript is below limit of detection in Peripheral Blood.

When BCR-ABL1 fusion transcript is not detected and ABL1 copy number is >= 26,514 is can be considered as CMR

QUESTION:

What is  BCR-ABL1 gene copy number [0.2] means ? ? does it means there are 0.2 BCR-ABL1 detected in 51,500 ?? If this is true why 0.2 and NOT 1 ? How to quantified 0.2 gene detected ??

Anyone please help me to explain ,,, Thank you in advance...

[Trey]

V.C.,

Good to hear from you again. 

The answer is a math puzzle.  The PCR result does not show "how many" leukemic BCR-ABL genes (cell DNA fragments) were found, or else the lowest number above zero would be 1 as you suggest.   Rather, the result is given as a percentage of BCR-ABL to another non-leukemic gene (usually ABL1 by itself without the BCR) called a control gene normally found in white blood cells.  So in your case there were 110 BCR-ABL found, and 51,500 ABL1, so 110 divided by 51,500 is about .002 which is a ratio.  The ratio is then converted to a percentage by taking .002 x 100 = .2%  So your PCR found approx 110 BCR-ABL in the sample.

[valiantchong]

Hi Trey,

Glad to hear from you too, thank you for answering. One more question, why the ratio is my case in the Results section indicated as "-%" as in the print out ? Since referring to  your answer is 0.2% but in my case the indicated "gene copy number = [0.2] " not the %.

Results:

% BCR-ABL1 ratio : "- %" (not 0.2% as it should be?)

IRIS international scale : - %

Please help out Trey... Thanks again

FYI, my results after this results is always indicate as "-%" and the BCR-ABL1 gene no of copy also = - but at reference at lower ABL1 copy of over 38,000 copies.

I did asked the doc. what is 0.2 means however I did not have a satisfactory answer, I was told it no BCR-ABL1 gene detected.

I was wondering is it due to error or something...

Thank you.

[Trey]

Maybe your Onc changed labs.  You are correct to say that there cannot be .2 BCR-ABL genes detected since they must be whole numbers.  That is why the .2 must either be the ratio or percentage.  I assume it is the percentage because of the way you wrote it.  If it is a ratio,  the percentage result would be 20%, which seems unlikely given what you have said otherwise.   

Your Onc should be able to explain it to you or else ask the lab for clarification. 

[valiantchong]

Thanks for your answer this result was 2011 about 2 years ago... it still puzzle me... I cannot understand too, but my doc says not detected but she did not explain what is 0.2 means..

Well and I do not want to re-open the old case again.. since all my results after this is "-".  Which I hope many - to come....

I did ask my doc to reduce my dosage but my doc seems to be very unhappy with my quest...But I took it personally... Now I am at 200g - 300g, most of the days I take 200g till now, I am sure last 6 months was still "=". Now I am trying to reduce to 200mg without my knowledege and I know this is a big risk to me...

But I feel much better after reduced from 400mg, my cramp is much much less and my GI issue also must less...

Just cross my fingers and hope for the best... bless all of us...hoping for the cure..

Thank you again Trey...

[Trey]

The reduced dosage should work well, but keep monitoring. 

[pamsouth]

VAliant,

""But I feel much better after reduced from 400mg, my cramp is much much less and my GI issue also must less...

Just cross my fingers and hope for the best... bless all of us...hoping for the cure.""

Been on Gleevec since 2005.  Took a Gleevec Break for 8 weeks do to other health issues and taking antibiotics and pain pills.  Also tried Sprycel 50mg, for a few days and it was terrible for me, felt like I was at death door, went thru that when starting on Gleevec 8 years ago, don't care to try that again.  I think at my age 65 years and taking these meds for 8 years has had some toxic long term side effects.  Kidney GFR at stage 3, and severe lower abodomen pain, but it goes away when not taking Gleevec. If I switch to antoher TKI just swapping side effects, as they all have toxic effects of some kind.  Getting to old to be jumping around on TKI's to much stress.  Anyhow when I went back on Gleevec two months agok I  talked my onc into lowering dose to 300mg.  However got my PCR in the mail today and it was 25.629, hopefully the next one, in 3 months will be better, as I am sure after being off Gleevec for 2 months it will take some time to get back where I was before I stopped.  What ever the results,  I don't intend on raising my dosage or changing TKI

s.  .  If my onc throws a fit and/or refusing to refil my scripts or see me, I guess I will just go without, I don't know.  Have been to other oncologist but they all want standard or close to standard dose, and I don't intend on ever going on a high dose of anything again or my CBC counts be on the sever low side.  At 65 years old I'm looking for a quality of life.  Although these drugs may be killing the CML,  the mother stem cells is still spitting them out, as fast as the TKI 's are killing them.  I feel like these drugs are slowing poisioning my body and killing my major organs.  Think if I take lower dose, I would feel better and slow down the process of my other health issues.  Don't think it is  possible to reverse kidney or liver damage, at least not in my case.  There are no reall long term statistics on low dose especially for my age, so how do they know//   They study these drugs for a short time and push them out so quickly., that I feel like they are still in a clinical trial.  Well Gleevec has been out the longest, so at least there is some data there, but don't think there are any real studies on low dosage.  For those who don't mind it, that is Ok, but I do, but it seems you can't fight with the drug companies and their protocol.  None of them want to lower your dosage, to much money lost.

PamSouth

PamSouth

PamSouth