Tyler Hamilton doping case gets weirder and weirder

latimes.com | Hamilton Presses His Case (free reg. required)

So the LA Times has gotten its hands on some of the documents from Tyler Hamilton's case before the US Anti-Doping Agency.

For those joining us late, Tyler Hamilton won the 2004 time trial gold medal, but his blood sample there, and at the Vuelta a España, tested positive for “mixed populations,” or the presence of someone else's red blood cells. His Phonak team dropped him, but he was allowed to keep his gold medal because his "B" sample couldn't be verified. His teammate Santiago Perez was caught by the same test, at the same race, and has been suspended for two years. Hamilton faces the same suspension.

Here's a few of the details that come out in the LA Times story:

Part of Hamilton's defense is that he had a “vanishing twin.” Somewhere around 8 percent of pregnancies start out as multiples, but in many cases, one or more fetuses will be reabsorbed by the mother and the other fetus or fetuses. Hamilton witness David Housman, an MIT professor, pointed out that “cells can pass from one twin to another during the time that they shared a womb together,” and that the vanishing twin might be the source for the other genetic signature found in Hamilton's blood:

“The truth of the matter is they can get there certainly from a fraternal twin who has a different genetic identity and bone marrow stem cells can persist for life. So that's the deal.”

Hamilton's test scores were suspicious. On April 24th, at Liege-Bastogne-Liege, Hamilton's “off score”, a formula based on hemoglobin and reticulocytes (immature red blood cells), was 123.8 (The UCI medical director says its riders average about 90). Then at the Tour de Romandie, only five days later, Hamilton's score had jumped to 132.9, doubly suspicious since the limit is 133. Above that, riders aren't allowed to start a race. His hematocrit was just about pegged, as well: 49.7, where 50.0 is an automatic disqualification, although no presumption of doping is attached to either limit.

UCI officials pointed out that the two numbers are incompatible: The low number of reticulocytes at LBL means that Hamilton was not producing that many new red blood cells, yet five days later, he had a significantly higher red blood cell count.

These results got Hamilton put on the watch list of riders that the UCI monitors more closely. It's worth noting, too, that the UCI didn't perform the test in question on these samples: The homologous blood doping test premiered during the 2004 Tour in July. I would love to know if Hamilton's blood was tested for doping before he dropped out during Stage 13, or if the Olympics were his first test.

USADA witness Ross Brown, who co-developed the doping test, said a transfusion or transfusions were the "only reasonable explanation" for Hamilton's test results, and suggested that he had one around the beginning of 2004, another sometime around midyear, and then might have topped up throughout the year.

Hamilton's legal attack on the doping test's validity rested on two points: 1) There's no threshold in the test: it only shows the presence, not the amount, of someone else's blood cells, and 2) That it proves only the presence of someone else's blood cells, not of a transfusion, and may be subject to false positives, as the “vanishing twin” argument suggests.

The Tugboat defense reappeared, as Haven Hamilton points out to the LA Times reporter that Tyler would never have risked a transfusion after Tugboat's death, which immediately followed a transfusion.

Occam's Razor doesn't look to be cutting Tyler's way here.

Update: Tyler addresses many of the issues of his case in his latest (April 18, 2005) diary entry.