TAQ/PCR and levels of detectability

[katla]

I have a general question of PCR's.
If a test result said HCV RNA TAQ/PCR v2 <25, virus detected, unable to quantitate, I undersatnd what it means. But I'd like to know what the lowest level of virus this test could detect and it doesn't say. It's done by ICON Labs. Does anyone know?

I've read some tests can detect under 25 or under 10...I guess I'd like to learn more about the different tests and levels of detection. Does anyone know or can anyone provide me a link or point me in the direction.

I had trouble finding the info...thanks, kat

[katla]

Thank you everyone, very much!

@gonnabehepcfree- yeah, I was referring to the Electron study 7977+Riba. Sorry I wasn't clear.

@Jimeeboy - I keep checking your journal for the results. Good luck tomorrow!

[UKgirl55]

Don't underestimate yourself Katla. I find you to be VERY knowledgable! Look at how much you want to learn? In fact, I've got to tell you that this whole subject has always baffled me (levels of detectability). As long as I hear the words UD before tx finishes and after tx finishes, that will be fine for me ;-)

[Jimeeboy]

UND.....it still is awesome to here those words Kat.  I feel the same way about the 12 weeks test but I will thoroughly enjoy hearing that I am UND.  I haven't been in over 35 years.  Results for us tomorrow I hope.

[gonnabhepcfree]

How could there be null responders that failed when the trial just really started I believe.  Or are you talking about the other trial with the Nulls that was only 7977 and I think riba.  Congratulations on UND.  I am still a bit reserved myself and next week I will go in for my three month post treatment with 7977 and bms790052.  I feel extremely lucky to have slayed the dragon with no side effects and even should I relapse as least I didn't go through SOC and all that can come with it.  Happy for you!!

[flcyclist]

I was just curious how you knew which test I had.
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You mentioned your test indicated <25, and the Labcorp RT-PCR is the only test I'm aware of with a LOQ of 25 IU/mL.  

katla, you shouldn't feel the slightest bit intimidated on this forum and should feel free to post any question.  There are no bad questions and I think the caring and knowledgable members on the forum will try to assist if they can.  We are all trying to learn, little bits at a time.  

And very good results so far, however, i will not congratulate you yet, lol.   Best of luck to you.  :-)

[orphanedhawk]

I'd like to encourage you to feel free to post here.
You are fortunate to be doing an interferon free trial and doing so well.

Besides the anxiety of being diagnosed, we have members with advanced liver disease, that can affect the mind, and of course, those on interferon treatment, dealing with intense side effects.
It can create an emotional whirlpool around here at times.

BTW: I think your statement about seeing what happens after tx with the new orals, is wise. These are unknown meds though my hepatologist says the new orals will be the future of hep C tx.

[katla]

Thanks all.  I am just trying to learn as much as I can although, to be honest, I'm often afraid to post here since I find it a bit intimidating, even though I know there are many knowledgeable people here. And, I am not the only one who feels this way).

flcyclist- I was just curious how you knew which test I had. Also, that result was day 11. I have since become undetectable on day 14. Please do not congratulate me yet. I'm on a clinical trial GS-7977 and BMS 790052 and as far as I know everyone responds quickly. I believe even the failed null-responders were undetectable early. So the real test is what happens after the 12 weeks.

[flcyclist]

I posted the summary of test below in a recent thread and might help you understand.   As far as I know it is correct, but if not, please feel free to post the correction.  

I believe you had test #2 which has a limit of detection of 7.1.  Since you results were detected, then you are > 7.1, but < 25.   Unfortunately, the lab reports don't list all this information to help us understand.

What # week was this PCR run?

Each of the tests have a limit of detection (LOD) and a limit of quantification (LOQ).

1.   Labcorp NGI QuantaSure: (LOD) 2 IU/mL and (LOQ) 2 IU/mL.

2.   Labcorp Quantitative RT-PCR: (LOD) 7.1 IU/mL and (LOQ) 25 IU/mL.

3.   Abbott RealTime PCR: (LOD) 12 IU/mL and (LOQ) 12 IU/mL.

4.  Quest RT-PCR: (LOD) 7.1 IU/mL and (LOQ) 43 IU/mL.

5.  Quest Quantitative TMA: (LOQ) 5 IU/mL and (LOQ) 5 IU/mL.
The Quest Heptimax test is a two part rollover test using the RT-PCR test (#4) and if lower than 43 IU/mL, then moves on to the TMA test (#5).  You can just do the TMA test to save time and money.

[blondie717]

Hi Kat , I believe (and I could be wrong) that that is the same test that was given me. I think in clinical trials they are using the most sophisticated tests they can use.  Just my guess. I remember they said that the test went from 2 to 25. hope this helps?

[willbb]

Hi kat    

The TAQMAN   you have had can DET. virus over 10iu/ml (being the lowest limit of detection),however it can not quantify it (Count virus) below 25iu/ml

So if the  lab report says DET.. there is still virus but below the level of Quantification of 25....and above 10

Hope that helps

I know there is a site to explain ,,however possibly someone else can post it for you as I have to run  

Best..
Will