More importantly, the CAS verdict declared the biological passport scheme valid in the eyes of the high court of international sports. The court announced that it "found that the strict application of such [a] program could be considered as a reliable means of detecting indirect doping methods."
The passport concept has also been adopted by the International Association of Athletics Federations (IAAF), the governing body for track and field. In May 2012 the IAAF announced its first suspension based on the testing scheme. Portuguese long-distance runner Hélder Ornelas, who competed in the 2000 and 2008 Olympics, received a four-year ban for abnormalities in blood samples taken in 2009 and 2010. A panel of three hematology experts "unanimously concluded that there was no known reasonable explanation for the abnormalities observed in his blood profile other than the use of a prohibited substance or a prohibited method," according to an IAAF announcement. Ornelas did not appeal the suspension.
The sporting body did not announce what substance or doping method Ornelas was suspected of using, and in fact testers in such cases may never find out what specific tactic the athlete has used to enhance his or her performance. "[ABP] is a game changer because now we don't really care what you're doing to drive up your hemoglobin or play around with your hemoglobin levels, because we're just looking a variation in those levels," Vernec says.
Anti-doping experts view such time-spanning, longitudinal analyses of athletes' biological attributes as an important addition to the anti-doping arsenal. "You can kind of baseline a particular athlete," says pathologist Anthony Butch, the director of the University of California, Los Angeles, Olympic Analytical Laboratory. "They don't vary as much as two different athletes do."
Although the biological passport program is just now edging onto the Olympic stage, the longitudinal analysis of athlete's biological attributes is not entirely new. The U.S. Anti-Doping Agency (USADA)—not part of WADA—for instance, built a 2004 doping case against sprinter Michelle Collins in part on indirect evidence, including years of urine tests that showed "extreme fluctuations" in her testosterone levels. Her unusual pattern of test results, along with e-mail and financial records linking her to a drug lab, led to a four-year suspension from the sport.
The case was notable in part because Collins had never tested positive for a banned substance, but the test results were nonetheless damning when taken together. Even tests that come up clean can turn out to reveal evidence of wrongdoing down the line, notes USADA scientific director Matthew Fedoruk. It is all part of the ever-evolving cat-and-mouse game between anti-doping agencies and drug cheats. "We're trying our best and using a number of different approaches," Fedoruk says.
"I think we have to constantly refine the tool kit," Butch adds. As soon as testers figure out which substances are in use and refine their techniques for detecting them, he says, "the athletes get wise to this and change their modes of use." That is why building a longitudinal profile from test results can be so useful. Butch calls it one facet of "intelligent testing," along with taking athletes' samples at random times out of competition, when a test may not be expected.
With better data from targeted screening and more data from longitudinal monitoring, anti-doping agencies hope that they can gain an edge in the off-the-field competition between drug cheats and drug testers. "Just simply collecting more blood samples and more urine samples is not the answer to this," Butch says. "You have to be smart about when you test and why you test."
Scientists who helped develop the ABP program say that it will be used for several sports during the London games. But just how the passport scheme will work when the International Olympic Committee (IOC) takes over testing efforts from the individual sporting federations and national anti-doping organizations during the competition has yet to be detailed. And its implementation certainly requires more analysis and cross-lab collaboration than conventional, straight-ahead screening of a sample in isolation.