I thought this was helpful in understanding vl

[drummerman]

http://www.webmd.com/hepatitis/c-hcv-viral-load#1

Course this is from the olden days by the vl information is still pertinent.

One part I did not quite understand:
"Dr. Pearlman: After treatment, [patients] have a "sustained virologic response" or SVR. That is defined as undetectable viral load by PCR to under 50 IU/mL for 24 weeks after treatment is completed. If that is the case, that is an SVR. SVR means it's 98% certain you are cured"

So if I can keep getting >15 or ....even >50 I am considered as close to "cured" as you can get?

One thing I  am confused about is a PCR (polymerase chain reaction technology) a quantitative test or a qualitative test.  I assuming it it the former since it gives us a number.  Is that correct?

Also it talks about the copies that float in 1ml of blood as rna building blocks , not total viruses.... just wondering if all of these eventually link up and form a virus particle of if some die just get eaten up by our own immune system defenses. 

anyway, I thought it was very helpful and cleared up somethings going through my head.

dm

[gnatcatcher]

dm, thanks for the link. Another quote in the article may answer your first question: "Dr. Pearlman: We often talk about viral load numbers, but we really look at this in terms of logarithms. A '1 log' change is a 10-fold difference. Significant changes in viral load are a 2-log difference or a 100-fold change. This can be deceptive. If you have a viral load of 800,000 and it drops to 400,000, that seems like a big drop. But it's only changed by a factor of two. A change from 800,000 to 8,000 would be significant. This is important when we look at response to treatment. Twelve weeks after starting treatment, we see if a person's viral load has dropped 2 logs or more from baseline. If it has not, we are almost sure the treatment is not going to work."
   So, as to your first question, this article seems to be saying that measurements earlier than 24 weeks after treatment (for the old treatments, or earlier than 12 weeks after treatment for the latest treatments) are only useful to the doctor-authors to show whether there's been a 2-log drop (100-fold change) in VL to indicate that the treatment has good odds of eliminating the Hep C. This probably explains why my treatment center tests VL only 4 weeks into treatment and then again 12 weeks after the end of treatment. I think it also explains why someone detected at the end of a 12-week treatment can still reach SVR12, as several people on this forum have done.
   As to your second question, here's a very informative link: http://www.clevelandclinicmeded.com/online/monograph/hepc/page2.htm  Note especially: "Although qualitative HCV RNA assays are more sensitive, they do not provide a quantitative value for the viral load. In fact, many laboratories do not offer qualitative testing any more." In other words, both types of the test exist. Qualitative just tells you that you have it or you don't, but it does so very accurately (sensitively); quantitative tells you approximately how much you have. Some years ago, my PCP used to order both, but more recently he ordered only the HCV RNA quantitative (as the article says, the HCV RNA qualitative may not still be available).
 
Gnatty

[drummerman]

Thanks Gnat!

very helpful.

so 800,000 to 8000 is a 2 log drop and you can tell this because 2 digits have been dropped from the end?

Also, they talked about how high viral loads are no indication of liver damage but can be more difficult to show a reaction.  I wonder if that is still true with the new meds ... mine was in the high category and plummeted.   Next blood draw is next Monday... hope it is still down.

thanks for your help!  Its difficult to bend my mind around this since I learned so much about the old tx and now everything has changed so much.  I thought it never would and it seemed like it took awhile but looking back it wasn't that long at all, and even better meds on the way!

dm

[gnatcatcher]

. . . so 800,000 to 8000 is a 2 log drop and you can tell this because 2 digits have been dropped from the end? . . .

Yes. You yourself went from 10,783,000 to <15, which is almost a 6 log drop, so the treatment is doing great things for you. Here's an easy way to check: Ask Google log 10783000. Google answers 7.03273960521. Ask Google log 15. Google answers 1.17609125906. The first answer is almost 6 times more than the second. (Keep in mind, too, that any number from 1 to 14 is <15. The HCV PCR quantitative test you had can't accurately count viral loads less than 15, which is why it says <15.)
   On your next blood draw, your doctor won't be concerned by small changes to the VL, ALT, or AST. It's probably because you are on Riba that you are having another test so soon -- based on what I've read in the forums by people on Riba, sometimes adjustments to the amount of Riba are necessary because of other blood results.
   Gnatty

[drummerman]

Thanks Gnat!

I thought was a pretty good drop and the nurse seemed pleased and excited.

dm

[KimInTheForest]

I thought was a pretty good drop and the nurse seemed pleased and excited.

dm

Fantastic drop, dm. Good work!

kim

[drummerman]

thanks kim!
dm