As a sort of pre-emptive declaration of conflict of interest, the cyclingnews.com article notes that Mujika is a physiologist and trainer for one of the top pro cycling teams (Euskaltel-Euskadi). He is also a coach for Virginia Berasategui, one of the triathletes who tested positive at Ironman Lanzarote in May, but was later cleared of wrongdoing based on inconsistencies in the laboratory results. So he may have some personal interest in casting doubt on the test.
His report, however, makes extensive reference to an independent evaluation commissioned by WADA, titled Evaluation report of the urine EPO test, written by G. Peltre and W. Thormann and accepted by WADA in March 2003. If you Google the title, you can find several references to the PDF version of the WADA report; unfortunately, WADA appears to have removed it from their web site, since I can't find it there now.
Referring to the WADA report, as well as other sources, Dr. Mujika does raise some alarming points about the urine test for rEPO. Among these:
- The test is not uniformly performed at all accredited laboratories. That is, the procedure for performing the test is slightly different at different labs.
- Laboratories do not measure protein concentration in the urine in the "preconcentration phase" of the test. In some cases intense exercise can induce a condition called proteinuria, which increases the concentration of protein in the urine. This increase in protein concentration can alter the results of the test and may lead to false positives.
- The specificity of the antibodies used to bind to rEPO in the urine test has not been scientifically evaluated. It is possible that the antibodies bind to endogenous (naturally occurring) EPO, and even to other unrelated proteins. Again, this could lead to false positives.
- Despite claims by WADA to the contrary, the rEPO urine test is a quantitative test, not a qualitative tests. That is, the test does not give a simple present-or-absent result, but the test results must be subjected to quantitative pass/fail criteria. Even worse, the criteria that are used are not uniform across all laboratories, and in fact the latest criteria have not been published by WADA, which means that the test cannot be peer-reviewed.
Mujika then goes on to describe several cases where positive test results were subsequently thrown out because of questions about the test.
All of this suggests, in my opinion, that the urinary EPO test should not be used. It is clear that not enough is really known about the test and its limitations; it is also clear that many people don't care that much if the test is imperfect. The managers of the Barcelona anti-doping lab are quoted by Mujika as saying that "the only direct test available on urine has the merit of existing and is definitely needed." That's a rather short list of merits!
As I have stated before, the consequences of a false positive are very severe for the victimized athlete. Any test for EPO must be held to the same strict standards as tests for anabolic agents and other banned substances.