You must have us confused with Michael Ashenden or Margaret Nelson.Brunswick_kate said:All right sports fans, at the risk of band width a-wasting, time for some people to answer a few simple questions:
1) What is the false-positive rate on the test used by the IOC to determine homologous blood doping?
2) By what means was the false-positive rate on the test determined?
3) Which of the minor blood group antigens were tested?
4) Are those antigens stable in physiologically stressed individuals?
Anybody got answers? I'd love to hear them.
I'll answer #1 indirectly: I don't believe there is any "false positive" because this is a threshold test. They claim that the test has a lower limit of detection of approximately 5% of the total RBC count. So if Hamilton had less than 5% "foreign" RBCs, then he would not have failed the test. As you might have read in the original haemotologica article:
Also,"Ashenden et al" said:False positive results do not appear to present a problem
cyclingnews.com said:There's no way, according to Ashenden, for an individual to have a mixture of red blood cells from different minor blood groups, other than for him to have had a transfusion.
Note from me: the haemotologica article mentions three special cases:cyclingnews.com said:Ashenden is certain the test is reliable, not least because it's based on methods that have long been used to pick up possible problems with sensitivity in patients who have previously had transfusions. "This test has been used in hospitals for 10 years. You either have someone else's blood or you don't. You either have the blood group antigens or you don't."
Answer to #2: read the article. They go into a lot of detail into how they determined their results.Ashenden et al said:hemorrhage between mother and fetus; intrauterine twin-twin transfusion; or in the rare tetragametic chimeras.
The answer to #3 is 12 of them, not declared specifically and on purpose. Since normal blood transfusions are not typed for minor antigens they do not want blood dopers to know specifically which minor antigens, or groups of antigens, or antisera that they use in the test.
The answer to #4 is an emphatic yes, I don't see why you would even ask the question. The antigens are genetically determined. That's like asking "do people with two eyes develop a third after climing Mont Ventoux."Michael Ashenden said:"We haven't declared all the antigens that we test," he says. "Even if they read the article [Haematologica. 2003 Nov;88(11):1284-95] and found a match for the antigens mentioned - one in a million - there is no way they can get a match for the other 'mystery' antigens.
To sum up:
Michael Ashenden said:"We spent a lot of time thinking this through and coming up with a watertight strategy."