Suspicious Test & Test Suspicions
In a recent interview to the Neue Zuricher Zeitung, Martial Saugy, director of the Anti-Doping Laboratory in Lausanne, described the evolution in time of the EPO test and the criteria that were adopted in order to determine a positive result or to define a "suspicious" one.
The method of the test had already been presented by Wide, Bengtsson, Berglund and Ekblom back in 1995 (Med Sci Sports Exerc, 27: 1569-1576) and was based on the observation that the electric charge of rhEPO is "less negative", with a higher % of "basic bands", compared to endogenous EPO.
The test (immunoelectro-focusing) was further improved by the Chatenay-Malabry Laboratory in 2000 (Nature, 405: 635) and approved by UCI and CIO.
In 2001, an athlete would be declared positive for rhEPO if 80% of the EPO detected in the test presented a "less negative" electric charge.
If this % was between 70 and 80, the test was considered "suspicious", but Saugy himself stated that such result can actually depend from natural causes.
Saugy added that in 2002 the Paris Laboratory raised the "positivity threshold" to 85%, as a consequence of a few "false positive" cases, due to the fact that after extreme efforts there are proteins (non-EPO) found in urine that cross-react with the anti-EPO antibodies utilized in the test.
Moreover, other studies showed that even endogenous EPO could present a "less negative" electric charge due to altogether natural causes, such as altitude exposition or simply the time of the sample being taken: the electric charge is "less negative" in the afternoon and evening than in the morning (Br J Haematol, 76: 121-127, 1990).
In 2004, WADA (TD2004EPO) decreed that the criterion "% of basic bands" was to be abandoned and replaced with a valuation of the number and aspect ("intensity" and "density") of the bands in the basic area.
This standard was approved and perfected by WADA in 2007 (TD2007EPO).
In 2009, WADA itself confirmed the method (TD2009EPO) for alfa and beta epoetins, while for other biosimilar-EPO's there would be the need for additional tests based on different analytical principles (apparent molecular mass), such as SDS-PAGE, with the purpose of confirming the exogenous origin of the checked profile.
From this story, it is rather evident how the criteria that were hurriedly adopted by Anti-Doping Labs in the first years of application of the EPO test, are no longer valid today.
I wonder what those athletes that were sanctioned before 2004 are thinking about this...