The DEHP/Plasticizer Test

[on3m@n@rmy]

Last friday I was "sealing" some chicken in the frying pan. The frying pan was new. The Spatula was a black plastic. The spatula actually left stains on the frying pan where it had melted; I ate the chicken and it was delicious.

The test must be bullet proof before it's applied. If anything has come out of the Contador enquiry is that it isn't.

If the point is other potential sources of plasticizer may be hard to weed out, thereby making it impossible to form conclusions based on a +ive for plasticizer, I get your drift. BUT I'd be surprised if spatulas (e.g.) contain the same plasticizer used in blood bags. There are many different kinds of plasticizers:
http://en.wikipedia.org/wiki/Plasticizer
Given there are many different kinds, I wonder how specific the plasticizer test is? Does is detect a specific compound, or a group of compounds? If only good down to the group level, that might make a possible scenario like the one you suggested more plausible and difficult to refute.

 

[Galmozzi]

I am not an expert on blood handling, storage, and preparation procedures, but it may well be that the use of bottles will require equipment that is 'non-standard' to a degree that makes shifting quite difficult.

Money still talks, of course. But, if you are counting on the Spanish health care system to store your products for you it could be difficult if the plastic bags are de rigeur. Let alone the fact that it will draw attention to you.

Why does this patient need blood to be treated differently, again?

Anyone know anything about the blood equipment?

Dave.

I was thinking more of the well funded, multi-millionare doper who can afford his own health care system.

I agree with you that the average pro doper will have difficult hurdles due to this but a well funded program will simply adjust.

Then again I am no medical expert, just an observer of past practices in the sport.

 

[Fester]

Don't you think that:

a) the creators of the test will have have considered the possibility other methods of ingestion

b) the creators know considerably more about the issues involved than you (or anyone on here)?

Don't get me wrong, I have a no grasp of the science behind the test. From the article published on said test on this very site:

"Jesús Muñoz-Guerra, described the new method as “an important step in establishing the indirect detection of transfusions. Plasticizers are easy to find, but the difficulty lies in determining at what level the metabolites of a plasticizer signal the use of a transfusion because we can find plastics in everyone’s urine.”

The authors of the paper have recognized this and have themselves stated that the method cannot be used as proof of doping, but is of use when applied in conjunction with other tests and with details available in a rider’s biological passport."

 

[Merckx index]

wait a minute…

didn’t we already establish that the test is too little to late and for all intents and purposes is almost useless...i mean it's of very limited use - like retro testing or catching really stupid ?

I recall reading in this very forum (many months ago in fact !) that as soon as the dopers learn about the plasticizer test they can easily switch to a different type of blood storage containers.

this very forum contained pictures and descriptions of those containers - in existence for decades since the early days of blood banking...

may be we’re losing the fight against dopers because we think they are stupid ?

or is it us who're naive and stupid ?

Right you are. The original point of the thread, I think, was that the timing of this article suggested that it was put out there as evidence against Bert specifically. Whether or not the test can be evaded now that riders know about it is another question. It would certainly force the riders to use other means of storage.Anything not flexible, like a glass bottle, is obviously more cumbersome and more difficult to hide, and IIRC has to be treated so that it doesn't promote clotting.

Given there are many different kinds, I wonder how specific the plasticizer test is? Does is detect a specific compound, or a group of compounds? If only good down to the group level, that might make a possible scenario like the one you suggested more plausible and difficult to refute.

They generally test for the three most common metabolites of DEHP, but in fact any component in plastics, or its metabolites, can be determined. In fact, I was thinking the test might be more powerful if it looked at ratios of metabolites, as that would indicate the kind of plastic. Non-transfusers are exposed to a variety of plastics, and so would have small amounts of many metabolites. Someone transfusing is going to have a large amount of a relatively restricted set of metabolites.

 

[I Watch Cycling In July]

Thinking ahead and assuming the plasticizer test becomes accepted.......

Which organisations have the right to order retrospective tests? Only the UCI? Or can AFLD or WADA demand that samples of riders with suspicious bio-pass values be tested for plasticisers.......?

 

[D-Queued]

I was thinking more of the well funded, multi-millionare doper who can afford his own health care system.

I agree with you that the average pro doper will have difficult hurdles due to this but a well funded program will simply adjust.

Then again I am no medical expert, just an observer of past practices in the sport.

Sure. But that guy has announced his second retirement already.

Fortunately, this can be detected in urine samples.

Even more fortunately, the guy that can afford his own health care system has had some samples stored that could be used for 'Research'.

Dave.

 

[Merckx index]

I have obtained a copy of the Solymos article. Here are what I feel are the salient points:

1) As I noted in an earlier post, the control values are very similar to those reported a year earlier by Segura (Monfort). Though there is some variability in levels among individual subjects, none of the values reaches the very high levels seen after transfusion. In this respect, this report does not support other studies that have found very high levels in some controls. However, this study apparently simply took a single urine sample from each control, and did not consider possible variation over time. Other studies have analyzed several urine samples from subjects taken on different days or different times of the same day, and have also utilized an approach in which all urine excreted over a period of time was analyzed. If Contador or some other rider were forced to defend elevated values, this would be a key point to make.

2) Also in agreement with Segura, Solymos et al. found enormous variability in DEHP metabolite levels in transfused patients. Part of this is due to the time after transfusion urine was obtained for analysis. Generally, the sooner the better. Solymos analyzed several samples at 6 or even 5 hours after transfusion and these generally exhibited the highest levels. This has obvious implications for any test. If an athlete is not tested very soon after transfusion, metabolites levels drop rapidly and soon may not be clearly distinguishable from controls. The highest values appear within 6 hours, so a lot of dopers might avoid a positive just by avoiding being tested for a few hours after transfusion.

3) Much of the variability, though, is found between individual subjects. One subject had values of one metabolite 5-10x higher than that of some other transfused subjects. This again agrees with what Segura’s group found. This might be due to the amount of blood transfused, the length of time of transfusion, the composition of the transfusing equipment, etc. I suspect that if dopers transfused a relatively small amount of blood, in a relatively short amount of time, they would reduce their metabolite levels. As I discussed here last summer, another way to foil the test would be to rinse out the blood bag and other plastic equipment, leaching out some of the DEHP.

4) One of the metabolites, MEHP, does not appear useful for the test. In some transfused subjects, levels of this metabolite were not higher or much higher than many control values. Segura found a few controls with very low levels of all metabolites, and I suspect if Solymos had studied more transfused subjects, they would have found the same thing.

As I think Ferm noted earlier, the authors conclude:

It is emphasized that this assay presents additional data in
the interpretation of the biological passport and it is not
intended to be used separately to proof for blood doping.

 

[JPM London]

Just waking this thread from its slumber...

... I hear the test will be used at the upcoming ski WC in Oslo next week - sorry if it has already been posted.

Anybody who knows more about that?


EDIT:
Doh - Just saw it's been commented on in the skiing thread... Don't mind me, just move on - nothing to see here