Labcorp QuantaSure vs Quest Heptimax

[Valtod]

Contrary to what some NPs and even GIs think, Labcorp QuantaSure is NOT the same test as Quest Diagnostics Heptimax.

QuantaSure is a 1 step PCR (polymerase chain reaction) test using Roche's TaqMan.
Assay range: 10 - 100,000,000 IU/mL.
http://labcorp.com/pdf/One_Source_Infectious_Disease_Reference_Guide_1394.pdf

On the other hand, Heptimax (CPT Code: 87522) is a 2 STEP test.
Step 1: Roche's TaqMan PCR test.
Step 2: If the HCV RNA level is below 50 IU/mL, then the sample is ASSAYED AGAIN using the TMA (transcription mediated amplification) Bayer Diagnostics method.
Assay range: 5 - 50,000,000 IU/mL.
http://questdiagnostics.com/hcp/intguide/jsp/showintguidepage.jsp?fn=TH_HEPTIMAX.htm

Although Labcorp and Quest claim comparable sensitivity for their HCV RNA tests, several studies showed that significant percentage of PCR negative patients turn out to be TMA positive. One recent study found that 12.5%(!) of patients who showed clear by PCR at end of treatment had detectible virus when measured by TMA. Naturally, nearly every one of those with detectible virus by TMA relapsed when treatment was withdrawn.

http://www.natap.org/2005/HCV/122805_04.htm
"How Should TMA Be Used" - Martina Gerottoa et al.; Journal of Hepatology. Jan 2006

http://www.hivandhepatitis.com/2006roberts/hcv/081106_c.html
"HCV RNA detection by TMA" - Morishima et al.; Hepatology 44(2):360-367. August 2006

[jmjm530]

Just add that if anyone is still confused -- or their doctors are -- you can always just order  "Heptimax" from Quest Diagnositics before, during or after treatment. It was designed as a one-test for all contingencies and appears to live up to its billing. All the doc has to do is write "Heptimax" on the rx form and you can bring it to any Quest Lab. Very little room for confusion.

With LabCorp, on the other hand, it's very important to have the correct test code for some of their tests as people here have reported getting other than what was requested. Also Quantasure, the very sensitive one, has sort of a grey area where its two components don't exactly connect and this has resulted in some intepreation confusion here in the past.

My personal choice is  Quest's Heptimax for pre treatment and during treatment until you become UND.
After becoming UND during treatment and then post treatment then switch to Quest's "HCV RNA QUALITATVE TMA" which is sometimes abbreviated
"HCV RNA QUAL TMA"

or again, just "Heptimax" if you want one test for all instances.

[apache1]

Excellent thread...good job bringing it back up portman!
As you said, I also am interested if any new tests have been developed.
Have heard that the tma test are more prone to false positives, is this true ?

Thanks jim and valtod for the info...just what i was looking for in my next VL test.
The <50 I got at 4 weeks has me wondering if i might be at 15 or 30 or ....

Don't get me wrong i am happy the nurse calls me undetectable, but is <50 really undetectable

Thanks to all the excellent members here that make this forum a wealth of info.

[portann]

I forgot to say my doctor's policy is to only use an in-house qualitiative test to 50 at week twelve and if the virus is undetected, not to test aagain until week 48,  with the same test, sensitivity to 50. That is why I've decide to simply travel to a private lab out of town and do this for my own peace of mind, in the event of break-through.

[portann]

Here's a thread from last year about viral load testing. Jmjm's last post in the thread provides a fabulous, easy-to-understand list about the testing options.

I'm wondering if there are any updates or developments about viral load testing since you posted this in 2007 and if it's stood the test of time? Is there any reason to not have LabCorp's UltraQual at 24 weeks if I'm doing this privately and have only had in-house testing to 50 at week 12, which showed clearance? My doctor's policy is to not test at 24, if cleared at 12. Based on the input here, I think I should run off at week 24 and test privately. I'd like to confirm that an UltraQual may be my best option.

[jmjm530]

Thought I'd arrange a  menu by stages during treatment for the two labs discussed.

BEFORE TREATMENT:
1) Heptimax (Quest Diagnostics) (5 IU/ml-50 million IU/ml)
2) Quantasure Plus (LabCorp) (10 IU/ml-100 million IU/ml)

DURING TREATMENT ONCE VIRAL LOAD IS BELOW  2,000,000 IU/ml
1) Heptimax (Quest)  
2) Quantasure (LabCorp)  (2 IU/ml-2 million IU/ml)
3) Quantasure Plus (LabCorp)

AFTER NON-DETECTIBLE VIA ANY OF THE ABOVE TESTS:
1) Heptimax (Quest) (
2) HCV RNA QL TMA (Quest) (<5 IU/ml)
2) Quantasure (LabCorp)  
3) Quantasure Plus (LabCorp) (
4) UltraQual (LabCorp)     (<2-3 IU/ml)

[jmjm530]

LabCorp offers two very sensitive quantitative tests using PCR technology. The first, discussed above is Quantasure which has a dynamic range of 2-2,000,000 IU/ml. The second is Quantasure Plus with a dynamic range of 10-100,000,000 IU/ml.

Because Quantasure Plus has a wider dynamic range, it would be the best test to use for initial viral load screenings. Quantasure, on the other hand, might be a good choice after the viral load has dropped below 2,000,000 IU/ml. Heptimax has a dynamic range of 5 - 50,000,000 IU/ml and therefore could be used both before, during and after treatment. All three tests are considered very sensitive.


http://www.labcorp.com/pdf/HCV_QuantaSure_Plus_LabFacets_1285.pdf

http://www.labcorp.com/datasets/labcorp/html/chapter/mono/id004600.htm

[jmjm530]

I don't think it was your intention to infer that because the testing technologies are different between Heptimax and Quantasure, that one test is better or more reliable than the other. However, in case anyone read it that way, here is some clarification.

It's true that a study showed a certain per cent of PCR negatives ended up being TMA positive, however the PCRs used in that study were less sensitive (50 IU/ml I believe) than the PCR used by LabCorp (2 or 3 IU/ml). The point of that study therefore had more to do with test sensitivities than test technologies.

So in the case of LabCorp, they appear to use a very sensitive PCR that goes down to 2-3 IU/ml. Heptimax, on the other hand, uses a two-step process (described above) that goes down to 5 IU/ml.  

Both appear to do pretty much the same thing and I don't think anyone could go wrong with either.

-- Jim