what is rt pcr and tma vl test?

my 4 week was <43....they said between 0 and 42.....so i am suppose to tx for 48 weeks...my 8 week was und...my 12 week will be taken this week...i'm cc 2/2.......thanks billy

[flcyclist]

These are 2 different tests used to measure your viral load.  The TMA is a more sensitive.  See the following.

RT-PCR = Hepatitis C Viral RNA, Quantitative Real-Time PCR ; Linear range: 43 to 69,000,000 IU/mL

http://www.questdiagnostics.com/hcp/intguide/jsp/showintguidepage.jsp?fn=TS_HCV_RNA_QuantPCR.htm

TMA = Hepatitis C Viral RNA, Quantitative Transcription-Mediated Amplification (TMA) ;  Linear range: 5 to 7,500 IU/mL

[working dog]

so does that mean i should have taken a less sensitive test to only tx for 24 weeks?...i must have something wrong....billy

[can-do-man]

No matter what test you would have done you still would not have been und.

[lynda607]

More than likely, your RT PCR level of detection was between 7.1 and 42 IU/mL.  Somewhere in between there HCV RNA was detected but they couldn't put it couldn't be quantified because the level of quantification is 43 IU/mL or above.

Vertex specifically states on the prescribing guide that PCR should have a level of detection to 10 IU/mL.  

If you had a PCR performed with an LOD of 50 or 43 IU/mL it wouldn't pick up any remaining low level virus if present below those numbers and would report HCV RNA undetected.  So not only is that non-compliant with the Vertex prescribing because of the higher LOD but it's inaccurate and the 4 week PCR would not truly be undetected so that disqualifies the patient for a 24 week treatment duration.  It kind of like kidding yourself, don't you think?

If your treatment becomes too hard and you can't do the 48 weeks Billy, don't do it but you can't change the rules.  There is a reason why Vertex recommends a sensitive PCR.

[working dog]

so i sure must have missed something when yodennis had <43 and was undetectable...billy

[lynda607]

He doesn't know if he was truly undetectable, he only did the RT PCT part of the Heptimax test.  His test did not say detectable or undetectable, it just said under 43 IU/mL but the LOD of the first part of the Heptimax test is 43 or above.

Like he said, he's not sure whether or not he is truly UND but that's what he's going with.  Your test specifically said you were not UND.  What you choose to do with that info and how you plan on moving forward is strictly up to you.

[GINGERPAL]

I thought the Quest  'Heptimax'  test automatically tested the TMA part if the patient's VL results were under 43.

[flcyclist]

It does.  But for some reason yodennis indicated they just did the first part of the test, RT-PCR, not the TMA this time.  

[GINGERPAL]

maybe the tma test part can still be done if the patient's blood sample is still available.

[scoleman]

Unfortunately, treatment with triple therapy is so new that some of the doc's out there don't know about the more sensitive PCR tests such as Heptimax and NGI Quantasure.  

The Heptimax is actually 2 tests.  The first test is the COBAS(R) AmpliPrep/ COBAS(R) Taqman (R) HCV test kit made by Roche Molecular.  This test is the usual one my doc prescribed until I asked for the 2 part Heptimax test from Quest Diagnostics.  The second part of the Heptimax test is a TMA PCR test.  This test is more sensitive because it makes copies of the HCV RNA as well as copying that HCV RNA into DNA.  I like molecular biology.

Sherry