The biological passport.

The gatekeepers of fair sport have a whole new way to identify doping: the "athlete biological passport." An approach that has evolved over the last several years, it is an electronic record of test results of the lingering effects of banned substances in the body, rather than the substances themselves. Like a valid passport required for entry into foreign countries, a valid (clean) biological passport is now required for many athletes to gain entry into elite competitions. Hopes are high among sports federations and antidoping agencies that the biological passport will close some of the biggest loopholes that have let cheaters slip into the Olympics, the Tour de France, and other major events. Standard sports doping tests look for drugs like designer steroids or synthetic erythropoietin (EPO), a hormone injected to increase endurance by increasing oxygen in the blood. One gaping loophole in such tests is that some drugs, like EPO, can only be detected in the body for a few days. But the effects of the drugs last for a week or more, increasing the odds that users will get caught. Another loophole is that banned substances, for a variety of reasons, are sometimes impossible to detect: they can be designed to elude specific tests, new substances can be made for which there are no tests, and a genetic trait--missing copies of a gene called UGT2B17, which makes testosterone soluble in urine--renders testosterone doping invisible to conventional urine tests. (The absence of this gene is strongly related to ethnicity: 81 percent of Asians, 22 percent of Africans, and 10 percent of Caucasians are missing both copies.) Looking for the physiological footprints left by such drugs, rather than the particular culprits, should reduce these problems. A handful of sports federations have used the biological passport on a trial basis, but it is becoming more widespread because the World Anti-Doping Agency, which leads the international effort against banned sports enhancement, just released guidelines on its use. The U.S. Anti-Doping Agency and similar groups in the United Kingdom and Norway have adopted the passport for elite athletes in those countries. Under WADA's guidelines, testing occurs unannounced several times a year throughout an athlete's career. Initial readings establish a normal baseline for each athlete. Variations consistent with use of EPO, illicit blood transfusions, and other methods of increasing blood oxygen can trigger an investigation. To prevent false positives, information is collected about legitimate activities that can affect the readings, such as blood donation during the previous six months, medications or supplements taken, and training. Already, the passport has led to investigations of a speed skating champion and five cyclists. Last year, the speed skater, Claudia Pechstein, was found guilty of doping and was banned by the International Skating Federation from competing for two years (although she won an appeal in a Swiss court, which allowed her to compete in the Olympic Oval in Utah last December). At press time, cases against the five cyclists were pending with the International Cycling Union. David Howman, director general of WADA, hopes that the biological passport will reduce the false negatives that plague the fight against sports doping. …