7 replies to this topic

[JoshLee]

So I was doing some research this morning on lab procedures and came across some info that is a little frustrating.......My first PCR came back as having increased a little bit....Less than 1 fold. My Onc. has decided to run Fish, Cytogenetics, Mutations Test and re-test the PCR.  My numbers have been pretty good. WBC-4.0, RBC-4.2, ANC-2.4, Hb-14.4, and Plt 100 (slowly coming back up over two week intervals from 60-78-100). I was a little shocked a majorly bummed out to hear about the pcr, especially when my raw numbers have been good. WBC holding and everything else slowly rising. I feel fantastic and have so much energy.....The clinic I go to is pretty small. When I got my first PCR test done, I noticed the lab tech was using two long red topped tubes. Aren't lavendure and green tops usually used for PCR testing? They redrew my tests on Thursday.....No red tubes to be found....Am I missing something? Who knows how much this even matters, but it's still confusing.

[Happycat]

Josh,

I'm certainly too new to be a lot of help here, but how many months since starting treatment has it been before you got the PCR test?  I thought they didn't do them for a while anyway because they don't mean that much in the real early stages.

Traci

[JoshLee]

Hi Happy Cat,

      I was Dx Dec 23rd of 2010, but didn't start Tasigna until February 5th. I was on Hydro in the mean time. I also had a two week break to let my platelets recover. So....Probably 2 months and 3 weeks before my first PCR. The increase was only slight....Like a 1 fold increase, so well within the margine of error. My onc. had told me that he should have just done a Fish at this point, but was instructed to do a PCR. I am so "green" to all of this, but I just want to make sure I am getting this stuff right from the beginning. The clinic I go to is really small and I know the lab techs rarely have to look up a PCR test. She did use the wrong tube, but I doubt it made a huge difference....My onc. is now doing a Fish, Cytogentics, a mutation test, and another PCR (none of them with a red tube this time). My onc. said he would "be surprised" if I wasn't responding to therapy. He doesn't have a lot of experience with CML, so I hope he is right. I should be hearing about the Fish on Monday or Tuesday. I really hope that I am healing. Thanks for asking.

[Trey]

Leukemia PCRs MUST be done using ONLY a lavender top tube (which uses EDTA as a preservative).  Red top tubes are for viral PCRs, but not leukemia and not for blood.  A red top tube would render the test invalid.  If you saw a red top tube, ignore the results.  Green top tubes are for FISH tests.

[rickpister]

Trey,

Is it a red-top tube or tiger-top (red and gray marble)?  I don't recall ever having a red-top tube but I have had the tiger-top, green-top, and lavender-top tubes.

[Trey]

Tiger Top and Red Top tubes are different.  Red Top has no preservatives or additives, but Tiger Top has a gel separator additive.  Lavendar Top (also called Purple Top) has EDTA preservative.  Green has Heparin preservative.  The tests are picky about what additives are used.  If you are having a PCR done, a Lavender Top tube must be used.  See below:

http://www.austincc.edu/mlt/phb_tubes

[gunner]

Also, for those not familiar with the process:

The PCR test must be run within 24 to 36 hours from the time of blood collection (depending on the lab). If your sample has to be couriered out to have the testing done, then you probably want to do the following:

Find out when the blood needs to be drawn such that it does not sit overnight before being sent to the lab.

Schedule your blood draws early in the week (so that the sample doesn't sit at the lab over the weekend).

Check the results for when the test was run and compare that to when the blood was drawn. (Verify that it was within 36 hours).

If I am going to have blood drawn for a PCR test, I want it drawn before 2 pm, and preferably on a Tuesday. Early on I had a 'PCRU' result come back, but it was zero because it had set around for 10 days or so before they run the test. The front desk likes to give out the story that 'it can take two weeks or more for the results'. The results are usually back at the office within four days, but it may sit in the doctor's approval pile for a week. This last time I visited the Onc I requested that we do labs 2 weeks before the appointment, rather than at the same time. That way she has the results from the PCR before meeting with me.

[Trey]

Just to over-emphasize the issue: never have a PCR blood draw on Friday, because the blood sample will likely sit around all weekend waiting to be processed on Monday and the result will be invalid.