EPO test problems

Erythropoietin or EPO is a hormone produced by the kidneys which stimulates the production of red blood cells. Synthetic EPO is produced right here in my hometown of Longmont, Colorado at Amgen. Amgen uses rDNA-modified hamster ovaries to produce synthetic EPO. This synthetic EPO (under the brand name EPOGEN) is used to enhance red blood cell production during chemotherapy and kidney dialysis. Cyclist Lance Armstrong took synthetic EPO during his cancer treatment in 1996.

Because EPO occurs naturally in the blood, the test for synthetic EPO depends on slight differences in the way the two kinds of EPO behave in an electrical field. To test for EPO, a preparation of urine is placed on the edge of a blotter, then subjected to the pull of an electrical field, leaving deposits in certain patterns that resemble a tiger's stripes. Some bands are more associated with recombinant EPO, some more with the natural substance. But there is considerable overlap as well.

For some people, this testing technique reeks of black magic. Cyclingnews just published a new critique of the testing method. According to Cyclingnews:

* False EPO positives can arise from proteinuria, if an athlete produces certain types of proteins after intense exercise that the test picks up.
* The antibody used is not specific enough, meaning that it will identify non-EPO proteins as EPO.
* Different labs can give different results for the same sample, sometimes calling a negative a positive, and vice versa.
* There can be a large variability in results, even when the same lab does the testing
* WADA changed the test criteria from quantitative to qualitative wihtout any scientific validation.
* A new "two-dimensional" EPO test is undergoing validation studies at the moment to iron out the flaws of the first one.
* WADA doesn't believe that it can be sued by athletes who wrongly tested positive. It maintains that the test has given valid results in the past.

The article is fairly technical and doesn't lend itself to a quick scan, but that's all I've had a chance to do before posting this article. Somebody who's a little more familiar with medical terminology or the testing please feel free to weigh in with your comments.