22 July 2005: Doping fears haunt Tour de France



Organisers of the 2005 Tour de France, which ends in Paris on Sunday, hope that tighter controls and more anti-doping tests will have led to fewer suspensions than in previous years. 

But there are fears that use of banned substances, such as the genetically-engineered glycopeptide hormone erythropoietin (EPO) is still rife in the sport. 'How else can you explain the astronomical rise in speeds this year?' said Ivano Fanini, boss of Italian race team Amore e Vita. 'It can't just be down to favourable tail winds during the first 10 days!'

The biggest scandal to hit the Tour broke in 1998, when the entire Festina race team was suspended for possessing a huge cocktail of illicit performance-enhancing substances. The findings revealed anti-doping officials' long cat-and-mouse game to race down the cheats and the chemists who supply them. 

Two high profile suspensions have already occurred this year - Italian Dario Frigo and Russian Evgeni Petrov - though random testing and snap searches have so far resulted in the majority of competitors and their back-up teams receiving a clean bill of health. 

'The speed of doping detection is getting faster and we are closing in on the clever chemists who supply banned substances,' Bernhard Wuest of Agilent technologies, the company that supplies detection equipment to the international network of labs involved in standardised doping tests, told Chemistry World

The hormone EPO works in the body by raising levels of haematocrit - the percentage of oxygen-carrying red cells in the blood - in response to oxidative stress during exercise. Oxygen-enriched blood then triggers the shut down of further EPO production. The hematocrit for a healthy athletic person averages at 43 per cent. 

A genetically-engineered variant of EPO is used to counter anaemia associated with cancer chemotherapy, AZT treatment for HIV, and chronic renal failure. Dopers cottoned on to drug's performance-enhancing capabilities by the late 1980s. Taking it before a race ensures oxygen-enrichment and peak performance about three weeks later, even though the banned glycopeptide clears rapidly from the blood. This means EPO abuse three to four days before a urine test might still go undetected. 

The sport's governing body, the Swiss-based International Cycling Union (UCI), is aware of the problem and decreed, earlier this year, that cyclists with raised hematocrits of 50 per cent or more would be suspended from racing for two weeks for health reasons. Without a positive urine sample, such a blood test does not itself prove EPO abuse. But sustained high hematocrit levels are intrinsically dangerous, leading to heart and vascular damage.

Dishonest racers and trainers have learnt to juggle EPO regimes to dodge the dope testers. 'Artificial boosting of hematocrit levels a week or more before a race can be maintained by micro-dosing with EPO three-times a week and still go undetected,' said Michel Audran of the organisation Science and Industry Against Blood Doping. This means hematocrit levels can be topped up to just under the UCI's 50 per cent limit, while the low EPO levels can exit the system in under 24 hours, making urine detection difficult. 

Positive testing for synthetic EPO in urine, developed by the Paris-based Laboratoire National de Depistage du Dopage in conjunction with the French government, depends on subtle molecular differences to natural EPO. This leads to variations in the way the molecules behave with antibodies, which alters their performance during a separation technique called gel electrophoresis. 

The tests are expensive and effectively limit how many can be done. 'We just don't have the budget to perform the out-of-competition controls we would like,' said UCI president, Hein Verbruggen, 'But it remains our most powerful weapon against this kind of doping.' 

Back at the race, Fanini disagrees. 'I was censured earlier this year by the UCI when I criticised their 50 per cent haematocrit limit. It's an open invitation to dope,' he said. Once this Tour has ended, the cat-and-mouse game of dopers against detectors will be far from over. Lionel Milgrom