Biology Reference
In-Depth Information
the Games. Since darbepoetin alfa was likely to be approved for marketing
before the Games, we were aware that athletes might have access to it at the
time of the Games. Accordingly, we obtained a urine sample from a patient
being treated with darbepoetin alfa. As shown in Figure 1, the electrophero-
gram of this urine sample confirmed [70] that the isoforms of darbepoetin alfa
were more acidic than those of rHuEPO [71] because the former migrated to
the more acidic region of the gel. This sample was important because IOC lab-
oratory regulations require that analyses include a reference standard,a known
positive quality control urine sample, and a known negative quality control
urine sample. The details of the method and the main finding have been
described [69, 70].
During the Games of Salt Lake, our laboratory analyzed 598 urine samples
for the drugs on the IOC List of Prohibited Substances. In addition, 1,222
blood samples were obtained from athletes competing in the endurance sports
of cross-country skiing, biathlon, Nordic combined, long-track speed skating,
and short-track speed skating. These blood samples were tested at the venues
by international sport federations before competition for hemoglobin concen-
trations and reticulocyte counts. If the reticulocyte count exceeded 2% or if the
hemoglobin concentration exceeded 16.5 g% for women or 17.5 g% for men,
the athlete returned after competition and an additional blood and urine sam-
ples were obtained for EPO analysis at the laboratory. Of the 1,222 blood sam-
ples, 133 (10.6%) had reticulocyte counts >2% and eight samples (0.6%) had
increased hemoglobin concentrations [72]. In total, the laboratory received 77
combined blood and urine samples and of these, samples from three athletes
met our criteria for darbepoetin alfa use [72]. All three athletes were cross-
country skiers who had won a total of eight medals.
According to the procedure in effect at these Olympics, before announcing
test results to the public, a committee reviews the laboratory findings and two
hearings are held. The hearings, which are attended by the representatives of
the athlete with or without the athlete, delves into the details of the testing. If
the testing results are upheld, the IOC Executive Board reviews the case and
makes the final decision to announce the findings to the public. In addition, the
athlete has the right to appeal the IOC decision to CAS. As there is little to
lose, most athletes do appeal to CAS. The darbepoetin alfa cases were be adju-
dicated by CAS in late 2002 and early 2003.
Epoetin alfa and darbepoetin alfa detection studies
Because athletes do not reveal their doses or dosing regimen, the only experi-
mental approach to determine how to test for the occurrence of doping is to
administer likely doses and analyze the urine at various times after the last
dose. The early work of Wide et al. [65] established that their gel elec-
trophoresis assay detected urinary rHuEPO for up to 24 hours after adminis-
tering rHuEPO at 60 U/kg/week for seven to nine weeks.
We have used the isolectric focusing method [68-70] to determine the
approximate time-course of detection of epoetin alfa in urine. We gave
