Quantitative PCR sensitivity 3200 copies/ml?

[ameer]

Our doctor said that the their Quantitative PCR test sensitivity goes as low as 3200 copies per ml. How much is that if we convert it into IU/ml? and how good is it?

[jmjm530]

I'm not up to speed on extended treatment protocols for geno 2's and 3's if detectible at 12 weeks. I would ask your doctor (or research) what your odds of SVR would be if detectible at 12 weeks with extended treatment. I would then weigh this against the risks of extended treatment (more side effects, etc) taking into consideration how much liver damage you have. If you don't have a lot of liver damage and figure your odds of success are low, then stopping treamtment and waiting for newer drugs seems like a reasonable option to me. You might also want to post this hypothetical question here, but try and independently research out any answers you get (by looking/asking for study data and/or with your doctor)  which is always wise in any internet discussion group.

All the best.

-- Jim

[ameer]

JIM,

You are very right because what i found is that the QUALIT PCR is way more sensitive compared to QUANT PCR in my country. (QUANT= 3200 copies/ml, QUALT = 100 to 200 copies/ml).

So it makes sense that why the doctor should stick to QUALIT PCR during the treatment and QUANT only @ pre-treatment. Because after all while you are on treatment, all you want is to get cleared by the most sensitive test. Yep.

The only question is that if you are detectible @ week 12 by QUALIT PCR, how would you make the decision to continue or discontinue the treatment?

I hope i will get cleared by week 12 but if not, then my plan is to continue till week 16 and do a QUALIT PCR and see if i can be un-detectible. If I am, then i will treat for next 16 weeks means total period of 32 weeks. Am i on right track?

[jmjm530]

In terms of treatment, I'd focus on your Viral Load tests and not your antibody tests.

I was pretty clear in my first answer to you but now I'm joining the ranks of the confused :)

What I'm guessing is that in your country the quantitative PCR is not very sensitive as it only goes to 615 IU/ml. Is this correct?

If correct, than I understand why your doctor would prefer to do a qualitative at week 12 which is more sensitive. Do you know the sensitivity of the qualitative? If not, ask him.

As to using the tests for determining length of treatment, my understanding is that a shortened treatment is only indicated if you were non-detectible at week 4, which you were not. The use of a 12-week VL as your doctor suggests does not follow that protocol. So, if it were me, I'd treat for 24 weeks even if you show non-detectible at 12 weeks.

Should you be detectible at 12 weeks, then you might even have to treat longer than the 24, but I'm really not all that familiar with the extended protocols for geno 3's.

Hope this helps some.

-- Jim

[ameer]

Sorry, it got a bit confusing but this is the actual story. Geno 3 and its been 10 syringes so far..............

- Qualitative PCR @ 4 weeks detectible
- the doctor said that he would go for a qualitative PCR again @ week 12.
- He is not a big fan of QUANT pcr, he follows a simple protocol for geno 3 and that is, if u r undetectible @ week 4, he will treat you for 16 weeks and if u r undetectible by week 12, he will treat you for 24 weeks.

So in our case he is saying, do a qualitative pcr @ week 12 and if undetectible, get a 24 week treatment.

But my question to him is that if its detectible @ week 12, how would you make a decision about further treatment when you dont have the viral load (QUANTITATIVE PCR).

and i need an advice from your guys. DO i make sense?

[cuteus]

ameer, in your case, as a geno 3, it does not matter if you have log drops of any sort, if you are still positive for the virus, I have not read many studies that say that going longer than 24 wks will give you a higher shot at SVR, maybe someone has seen them?
let's hope you are negative at wk 12, by qualitative, if not negative, then tx might not be working and needs to be changed or stopped.
I hope someone has studies where going longer than 24 wks actually shows a higher SVR. Let's just hope that you are negative right now.

[ameer]

Adding................Just for my curiosity, we did ELISA @
pre-treatment stage and @ week 10, since its anyways a quick and inexpensive test.

Pre-treatment ELISA test result         = 85 Reactive
and after 10 syringes ELISA test result = 25 Reactive

The way how i am taking these results is that, my blood antibodies against the HC Virus has reduced considerably which means that the Peg+Rib treatment is killing the virus.

Am i drawing a right conclusion?

[NYgirl]

I'm so confused.

[cuteus]

I am confused, I thought you had a qualitative PCR at 12 wk? did you have both?

[jmjm530]

The formula's I've seen are copies/ml = IU/ml x 2.7 (PCR technology)
(or)
IU/ml = copies/ml x 5.2 (bDNA technology)
-------------------------
My guess it's the latter and therefore the test your doc mentions has a sensitivity of 615 IU/ml using bDNA technology.

bDNA technology gives you  a very accurate test and therefore often used pre-treatment both to confirm a positive antibody test as well as to compute viral load. I had same test (sensitivity 3200 copies/615 IU/ml) prior to treating and after the first week of treatment.

That said, I suggest you talk to your doctor about a more sensitive test once treatment actually begins. For example for your 12 week test and also for your 4 week test if your doctor tests that early, which is now recommended by many. You will want a test that goes down to at least 50 IU/ml, or preferably down to 5 IU/ml. One very available test that goes down to 5 IU/ml is the HEPTIMAX test by Quest Diagnostic Labs.

All the best moving forward.

-- Jim