There remains strong opposition by some in WADA to a threshold, and for good reason. There is NO level that would indicate with any certainty that the CB came from contaminated meat. The best way to judge, in the absence of actual meat samples, is where the meat was bought. Riders in Mexico, South America and China, have a reasonable chance of eating contaminated meat, and this should be taken into account in their cases (though it shouldn’t by itself get them off; the Mexican soccer players had levels high enough to make contaminated meat fairly unlikely). Riders in Europe really do not have a case on these grounds.
We still don’t know if WADA will bring up the plasticizer results in Bert’s case, but another paper was just published by the Spanish and German groups that published the original studies on DEHP in blood transfusions (abstract below). This latest study presumably would be used to validate DEHP levels as further evidence of transfusion, though the number of subjects, 25, is rather small, and the reported level of significance (< 0.05) not really great enough to rule out false positives. But I haven’t seen the full paper.
Arguably, studies like these are beside the point. There is no question that high levels of DEHP metabolites can result from transfusion of stored blood. The real question is whether such high levels can be found in individuals that did not transfuse. Studies of large numbers of subjects, in the thousands, suggest that a few outliers do exist, but they may have been exposed to DEHP through other environmental sources. If WADA is serious about using this test, they really need to get a fairly precise estimate of the false positive rate. OTOH, since it is not intended as a standalone test, but only supporting evidence of transfusion (and even that is not technically needed, since the burden of proof is supposed to be on the rider to show he didn't dope, not on WADA to show he did), even say 95% certainty that DEHP levels indicated transfusion would be very damning, when added to the evidence that CB-contaminated meat in Spain is so low.
Also note that this study found, as have others, that urine levels of DEHP metabolites dropped off quite rapidly--in this case, they said two days was the effective detection window. IOW, these levels spike following transfusion. Beyond the absolute levels allegedly found in Bert's urine, the report we have is of a spike disappearing within a day or two. If this analysis really is of Bert's samples, this spike would provide further evidence of transfusion, as opposed to background levels.
Transfusion. 2011 Sep 2. doi: 10.1111/j.1537-2995.2011.03331.x. [Epub ahead of print]
Plasticizers excreted in urine: indication of autologous blood transfusion in sports.
Monfort N, Ventura R, Platen P, Hinrichs T, Brixius K, Schänzer W, Thevis M, Geyer H, Segura J.
Source
From the Bioanalysis Research Group, IMIM Hospital del Mar Research Institute and the Universitat Pompeu Fabra, Barcelona, Spain; Department of Sports Medicine and Sports Nutrition, Ruhr University Bochum, Bochum, Germany; and the Institute of Cardiology and Sports Medicine and the Center for Preventive Doping Research, German Sport University, Cologne, Germany.
Abstract
BACKGROUND:
Misuse of autologous blood transfusions in sports remains undetectable. The metabolites of the plasticizer di-(2-ethylhexyl)phthalate (DEHP) were recently proposed as markers of blood transfusion, based on high urinary concentrations of these compounds observed in patients subjected to blood transfusion. This study evaluates DEHP metabolites in urine for detecting autologous blood transfusion.
STUDY DESIGN AND METHODS:
One blood bag was drawn from moderately trained subjects and the red blood cells (RBCs) were reinfused after different storage periods. Group 1 (12 subjects) was reinfused after 14 days, and Group 2 (13 subjects), after 28 days of storage. Urine samples were collected before and after reinfusion for determination of the concentrations of three DEHP metabolites, mono-(2-ethylhexyl)phthalate, mono-(2-ethyl-5-hydroxyhexyl)phthalate, and mono-(2-ethyl-5-oxohexyl)phthalate.
RESULTS:
Concentrations of DEHP metabolites on the days before reinfusion were in agreement with those described after common environmental exposure. A few hours after the reinfusion a significant increase was observed for all metabolites in all volunteers. Concentrations 1 day later were still higher (p < 0.05) than before reinfusion. Variations in urine dilution supported normalization by specific gravity. Concentrations of DEHP metabolites tended to be higher after longer storage times of RBCs.
CONCLUSION:
Autologous transfusion with RBCs stored in plastic bags provokes an acute increase in the urinary concentrations of DEHP metabolites, allowing the detection of this doping malpractice. The window of detection is approximately 2 days. The method might be applied to urine samples submitted for antidoping testing.