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Avatar universal

My graph of plotted PCR tests

Link to chart

http://rapidshare.com/files/18966653/Response_rates.pdf.html

I originally posted this in another thread in response to Voltod and a length of treatment formula.  I have plotted a graph that shows the log reduction of viral loads.  I have plotted curves that correspond to the level drop for the different types of people that have been studied. ie RVR and EVR

What is interesting is that the viral load drops linearly on a logrithmic graph. So depending on your blood tests at different dates you can plot your "slope" of viral log drop.

I have plotted my slope and other slopes that correspond to studies that people have published to get a target log drop to correspond to a % of SVR.

1. Rapid viral drop (RVR) or undetected (<50) at week 4
this corresponds to approx 90% SVR.  At week 24!

2. 3 log reduction at week 4 = 75% SVR (48 weeks)

3. Undected at week 12 = 50% SVR (48 wks), 75% (72 weeks)

4. 3 log reduction at wk 12 = 20% SVR (48 weeks), 40% (72 weeks)

5. 2 log reduction at wk 12 = 3% SVR (48 weeks), 15% (72 weeks)

After these graphs are plotted against your tests, you can extrapolate where your viral load will be at the end of treatment and what % of svr these levels correspond to.

You can therefore calculate your odds of SVR depending on how long you treat for.

Amazingly these graphs correspond well to virtually all the studies I have read about. You can easilly see why it is not benifical to continue treatement if you are not undetectable at 24 weeks.  You can see why the RVR people only need 24 weeks the levels drop so quickly etc.

Here is a link to the pdf graph

http://rapidshare.com/files/18966653/Response_rates.pdf.html
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Avatar universal
Hey after looking at my data can tell me what you think about my chances?  

Any insights?
Helpful - 0
Avatar universal
http://rapidshare.com/files/28669739/ViralDrop.pdf.html

This is a graph based on the formula I suggested above and your model.

And, yes, I know that a negative log is a postive number :-) However, I really do NOT believe that a viral load of 1/10,000,000,000,000,000,000,000,000 IU/mL makes any sense. Sorry :-)

BTW, I do understand that you base your reasoning on some of Dr. Cecil's (old) ideas:
http://www.hepatitisdoctor.com/Poster%20present%20Ind%20rx%20vet.html

With all the new data and research in the last 6 years, he probably also moved on form the idea that "estimating the MINIMAL number of treatment days for a sustained response" is of much importance, "...assuming that the average patient has HCV evenly distributed in 5000 cc of space (plasma, liver, spleen plus other spaces), there are still 5000 IU in the patient when the HCV-RNA level is down to 1 IU/mL".

Determining this MINIMAL length of Tx is proven clinically insufficient for achieving real SVR. Back in the day, there was probably some benefit to know that there is some lower limit for length of Tx, under which SVR can not be expected.

However, if you really kill the last virus in your body at 1/100,000 IU/mL, for RVR (week 4) it'll be at week 8. But no one will treat you for 8 weeks only! You need 16 more weeks. Where are they coming from? How the model explains them? Your attempt to solve the model deficiency by digging deeper to 1/10,000,000,000,000,000,000,000,000 IU/mL (so you can reach week 24) is not VERY convincing.

Then for EVR (week 12), your minimal length of Tx is 24 weeks. But you really need 24 more weeks. Where are they coming from? And why is the EVR addition with 8 weeks longer than the RVR addition? How the model explains that? Any additional formula based on different assumptions? Because extrapolating the log of the viral slope to -15 ("just because") won't solve the contradiction.

On the other hand, the model and formula that I proposed is for optimal (NOT minimal) length of Tx. It's based on meta analysis of statistical data for large groups, instead of Newtonian metaphors for the body as a liquid container and the viral elimination as strictly logarithmic on base 10.

Good luck!
Helpful - 0
Avatar universal
For those interested, some previous discussion on this, including some of my thoughts and discussions with Valtod, here: http://www.medhelp.org/forums/Hepatitis/messages/46062.html

While we've come a long way --  and studies like Berg, the short course studies, and models like Drusano are all useful as guides--  "optimal" treatment length is still a bit of an oxymoron because just too many variables involved, some being quite subjective as the amount of risk a given individual is willing to take.

I do not have the math background to comment on Valtod's formula for large groups, but remain skeptical of any formula as it relates to an individual unless the individual conforms very closely to study data which is often not the case.

To paraphrase my esteemed doctor, there is currently no way -- models or tests -- to determine when the virus is gone.

Hopefully, one day soon, there will be such a test, and at that point treatment will be truly individualized and optmized in the sense that people will stop neither a day too soon or too late. Until then, it's a "**** shoot" like many have mentioned, but a crapshoot with odds that we can use to our advantage.

-- Jim

Helpful - 0
179856 tn?1333547362
You are too smart for me.  Wow the best post I've ever seen on here and I just had to tell you.

Unfortunately for me I had an almost 3 log drop by week 4 but it stayed there until after week 12 at the same number and wasn't  = UND until somewhere before 24.

So I'm one of the wierdos who blow a hole in the theory but like I said...wierdo.

thanks Val that was extremely interesting and spoken in an "almost english" i can understand!!!!!!! ;)
Helpful - 0
Avatar universal
""""However, if you really kill the last virus in your body at 1/100,000 IU/mL, for RVR (week 4) it'll be at week 8. But no one will treat you for 8 weeks only! You need 16 more weeks. Where are they coming from? How the model explains them? Your attempt to solve the model deficiency by digging deeper to 1/10,000,000,000,000,000,000,000,000 IU/mL (so you can reach week 24) is not VERY convincing. """""

Voltod,

YOU OBVIOUSLY DID NOT READ MY POST ABOVE THIS!!! :)
Helpful - 0
Avatar universal
Voltod,

Try to remember this is just a theoretical graph to visuallize the slopes of the viral kinetics of various studies I have read about.  This helps one gauge where they are in this complex range of studies.  When looking at the graph some RVR patient's slope goes really low like 1E-18 (at 24 weeks).   Do I think that is an actual measurement of the virus in their body?  

No I dont.  

In reality the patient's viral load probably bounces around in a range that is really close to zero.  Maybe the 1E-3 to 1E-6 range.  But the longer the patient stays close to zero, the the less likely they will relapse.  

This kind of shows that SVR is not only determined by how much time you are undetectable but also the slope or time it takes to get to undetectable.  Similar to your formulas but in graphical form.

Darryl
Helpful - 0
Avatar universal
"""Do these "negative" viral load logs really tell us something meaningful about viral kinetics?""""

These are not negative viral loads!!   A log of 1E -5 is equal to 0.00001 which is way above 0 or negative.

When we are talking about copies of virus in our body we need to distinguish between viral copies in you blood test and in your whole body.  We only have the capability to determine about 5 to 10 copies of virus in a 1 ml amount of serum extracted in a blood test.  The amount of virus detected in your PCR represents a small fraction (1/10,000) of the viral copies in your total body. So say you have 9 copies (which is undetectable with a very sensitive test) you could have approx. 9 X 10,000 or 90,000 copies of virus in your system. That 90,000 needs to get pretty close to zero to get a sustained response. You need another 5 log drop of viral load to be clear.  So hypothetically speaking, the sensitivity of a PCR test to actually tell you if you are clear of the virus would in theory be 0.00001 IU/ml.  Which is way beyond our testing ability.  

Therefore the only way we can estimate our actual whole body viral load is to extrapolate the curve data that is testable.  

So somebody with a starting viral load of 1,000,000 would need an 11 log reduction to clear the virus.  That puts us way down in that graph.  

"""""""Why for faster viral response we have to "dig much deeper", instead of being the other way around?
Why, for example, at week 4 I have to go 10(!) log deeper than at week 12? 10 log is 10 billion!""""""

I would assume that you have to get to at least .000001 IU/ml to have any chance of SVR.  BUT that is if everything goes right.  And in the real world nothing does.   The lower you get in the graph the less likely you will relapse.  
Helpful - 0
Avatar universal
If you want to use the gimmick of "negative" log drop of VL, here is a formula that will calculate it:
N = (2+12/X)L
Where:
L - Log of Pre-Tx VL
X - Week of Log VL = 0 (UND)
N - Negative Log VL when End of Tx

Let's say your Pre-Tx = 100,000, so the Log is L=5. Then
wk 4: N = -5L = -25 (this is a decimal with 25 zeroes) reached at week 24
wk 8: N = -3.5L = -17.5  (this is a decimal with 18 zeroes) reached at week 36
wk 12: N = -3L = -15  (this is a decimal with 15 zeroes) reached at week 48
wk 16: N = -2.75L = -13.75 (this is a decimal with 14 zeroes) reached at week 60
wk 20: N = -2.6L = -13  (this is a decimal with 13 zeroes) reached at week 72

If you draw this on graph paper, you'll get something very similar to Sincebirth's graph.

The question remains: Why this gimmick is necessary when there's a much simpler way to calculate the optimal Length of Tx? And even more importantly: Do these "negative" viral load logs really tell us something meaningful about viral kinetics?

Why for faster viral response we have to "dig much deeper", instead of being the other way around?
Why, for example, at week 4 I have to go 10(!) log deeper than at week 12? 10 log is 10 billion!

As I showed before, I also strongly believe that the viral load decrease is the most important variable for the optimal length of Tx. However, this approach here seems quite removed from the reality, because what actually happens with the viral decay under the horizon of detectability of current tests ( < 5 IU/mL) is anyone's guess.

The concept of 2 phases of viral elimination is more plausible, easier to understand and better supported by data. "The time of elimination of the primary viremia (in the blood) is what the tests measure (as UND), while the time of elimination of the secondary viremia (in the liver and other tissues) should be the length of Tx." And as I suggested, the functional relation between them is probably linear.

It's important to note that although the slope of the viral decay in the blood is not explicitly factored in my model, it is implicitly included in the week of UND variable. Obviously, starting with the same pre-TX VL, a RVR at week 4 suggest much steeper slope (and shorter Tx) than an EVR at week 12.

See http://www.medhelp.org/forums/hepatitis/messages/46062.html

Best wishes!
Helpful - 0
Avatar universal
It is hard to tell what my chances are because it seems that I am not the typical patient.  That is why I had to do this graph.

There just does not seem to be any studies that show chances for people that switched interferons during treatment.  When I switched from Peg-Intron to Pegasis my response was "OK" (not a RVR).  I feel if I had started with Pegasis from the start I would be undetected at week 12.  

Although the graphs says 65% at week 72.  I give my chances 50-50.  My ferritin levels are high (like 600) and that helps the virus rebound.

My data points are the dark points labeled "actual test data"  My slope is extrapolated and is marked "Darryl's exrapolated response to Pegasis" on the graph.  

Yes I am young -- got the ******* disease from a blood transfusion at birth.  But still my liver has endured this for 33 years and may have to do more time if it doesnt work.  
Helpful - 0
Avatar universal
you are so much younger than most of us, you lucky dog! this should be a great boost to your SVR chances. what do you think your adds are?
Helpful - 0
Avatar universal
I also hosted it here:

http://files-upload.com/198755/Responserates.pdf.html
Helpful - 0
173975 tn?1216257775
WOW - thanks for posting your stats.  i take back what i said about being discouraged - you're doing great after switching from pegintron to pegasys.  plus you're still a 'baby' - i'll bet you stay SVR - anyone as DETERMINED as you must be to have come up with that calculation formula - i don't see HOW you can possibly lose!

great work.

CW

I was already old.  now i'm ancient!  :)

I'm having the BEST weekend since i started injecting, 12/23.  Plus i did the neupogen last night as well.

Either i'm so psyched about moving that i can't ALLOW myslef to feel bad (the mindless activity you mentioned a couple of days ago) or i'm gonna crash tomorrow, big time.  i'll let you know.

hey. maybe i found a surefire cure for sx - MOVE!!!  *LOL*

but sorry you're not doing well, today.  When do you do your shot?  (mine is friday)

also, I know the Dr. must have VL results by tomorrow so i'm gonna bug the receptionist on tuesday to tell me what they are.  soon as i find out, i'll post and flag you.

feel better.


wyntre
Helpful - 0
Avatar universal
dont bum out yet, we can grow old together as we fight this hundred years war.
picture this, two old hunched over hep warriors with big spots of missing hair!
itll be fun, in fact, im finally sick again and it feels good to be back on the front lines. it was so boring to feel good! my new religion now reads, it will all work out eventually but in the meantime dont get in a hurry and dont get your hopes up too high. are you feeling like cr*p today or pretty good? i guess theres not much point in complaining until we really fail. always remember that the numbers could be worse and we still have a pretty decent chance. i loved a post from a day or two ago that complained because we never post anything good. this truly made me laugh and so im at least trying to make happier posts.
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Avatar universal
Hey,

I cant get to the "dropload" site?  And "you send it" appears to only be sending to a specific address?
Helpful - 0
Avatar universal
I am a 33 year old male, Geno 1a, with stage 2, starting VL started at 1.78 Million.  My starting weight was 155 lbs.  Now down to 122 lbs.  5'-8" Have been on rescue drugs since week 20.  

I am on week 67 of 72. (cant wait to finish!)

If you noticed on my graph i switched from Peg-Intron to Pegasis at week 16.  I responded fairly well to the pegasis and not at all to the Peg-Intron.  I was undetected at week 28 (<10 copies)  and have been since.  

I really needed this chart because I responded to the Pegasis and needed to decide if it was worth extending to 72 weeks or not.  The usual method of determination (at week of Undetected) would not work for me because of my delayed response.

Raw graphed data points that are the following:


Viral load count - Geno type 1a
Week 0 - 1,780,000
Week 8 - 353,000
Week 12 - 488,000 (went up)
(Changed from PegIntron to Pegasis at week 16)
Week 20 - 15,300
Week 24 - 317
Week 28 Undetectable (below 10)
Week 36 Undetectable (below 10)
Week 48 Undetectable (below 20)
Week 60 Undetctable (below 20)



Helpful - 0
Avatar universal
hi, i can not get it to download from the file site you provided. i did the free register but still can not work. it even came up german! can you send it via "dropload.com" or "yousendit.com", these are both free file services and are much easier to use. i would really like to get this. thanks
Helpful - 0
173975 tn?1216257775
Thanks for the info.

it's a little discouraging to me as i'm 1A, VL 90 at week 16 (did 18 week labs on Thursday) - but you did a great job of presenting the info in an easy-to-understand format.

wyntre

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Avatar universal
I cant figure out how to get to the chart...... i got to the site but what do i do then?   Thanks Anita
Helpful - 0
Avatar universal
Just curious.  What was your initial starting point...grade, stage, VL, 1a or 1b, age, weight, all those goodies. Excellent post by the way. Thanks much.
Helpful - 0
Avatar universal
great work, sincebirth. these are the numbers ive been guessing about.
this is the simplest clearest chart for all of us to see where we are.
i know that many others have probably given these numbers out before, but i could never decipher the results. this chart makes it simple. thanks. would you guess that all 1a cirrohis patients numbers would be skewed slightly down? after all, it is a lower performing subgroup. im at 40% on your chart, i beleive its more like 30% to 35% considering my case of 1a, cirrhohis and med high viral load. any thoughts?
Helpful - 0
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