LabCorp vs Quest for VL sensitivity

[apache1]

LabCorp wins hands down for VL testing sensitivity.
LabCorps best HCV test is more than twice as sensitive as Quest best hcv test.

That being said, I use Quest Heptimax and like it for the ease of use and the good local labs.
Plus the Heptimax is probably good enough for HCV.... <5 Heptimax  vs  <2 labCorp
Now for testing occult, or low level infections, imo thats best done with LabCorp, especially for HBV

For HBV Quest surprises me they are not competitive in the same universe as LabCorp.
So did not include Quests best HBV VL test of 100 copies per m/l  to
LabCorps HBV 1-2 COPIES per m/l

Hope this helps some pick the appropriate test for their needs.

jmo
apache

[Marc1955]

No argument with your findings. What I'd be curious to know is whether these ultra sensitive tests have any real impact on treatment. I've never been able to get an answer to that. When the standard treatment protocols were established, I believe the cutoff was 50 iu/ml. My hepatologist says that from a treatment point of view, you simply work with whatever test the patient is administered. Is there a real context where a 5 iu/ml cutoff vs. a 2 iu/ml cutoff makes a difference? I don't think any of us know the answer to that.

[apache1]

Your right Marc, most of the old protocols were based on < 50 tests.
But a lot of the newer studies you see now are using  < 10 or < 15 testing. Some < 2

For HBV occult, or low level infections, which are not uncommon, LabCorp testing is far superior.
I hope not, but maybe in the future we will see the same with HCV low level or occult now that the  < 2, < 5  tests are more available?

In the last HCV occult Study debate we had in this forum, the patients were all between 8-400 copies per m/l. The < 2 LabCorp testing would do a better job of testing for those levels.

Now as you say, not really sure of the clinical value of knowing you have a low level infection. But at least you will know.
Also the very low relapse rate for SVR might even be lower for the ones without a very low level RNA load such as they found in the occult studies.

One thing to remember, while < 5 or < 2 sounds very low, that is only for 1m/l of blood.
iirr there is 1800 m/l of circulating serum, so it is very possible that with a < 2 test per 1 m/l of serum, it is UND,... but in 10 m/L you find 1 or 2 virion or 2iu/20ml. That means 2000+ virions are circulating still when you came up UND with a < 2iu/ml test.
Just something to think about.

What I am suggesting here is as long as one is testing why not use the most sensitive test available to them when appropriate. The deal my BCBS ins has with Quest charges the same for all VL tests, pcr < 50 or Heptimax <5, so why not get the better test?

jmo
apache