Effects of blood withdrawal and reinfusion on biomarkers of erythropoiesis

[Tyler'sTwin]

http://www.haematologica.org/cgi/reprint/91/7/1006

 

[JA.Tri]

If data is indicative of blood doping at the 95% confidence level should the "Rule makers" accept that as "prima facie" evidence of blood doping.

I believe no. I note the term "indicative" of blood doping. Therefore futher evidence would seem to be needed to confirm "autologous blood doping".

If so what evidence?... Plasticisers?...Biological Passport Data over an extended period of time? All or a combination of the above (or even more evidence) may be required to prove/demonstrate blood doping.

The research indicates a useful adjunct rather than a definitive test. There is a possibility that a one off result may prove otherwise. That is, a result may be so far outside the expected values, that positive blood doping may be regarded as "proven".

 

[Merckx index]

The subjects in this study had more than a liter of blood removed, and 800 ml. of packed cells, corresponding to 1.5 l. of whole blood, re-infused. This is probably highly unrealistic, as it seems riders generally withdraw/transfuse far smaller amounts, like 300 ml. These smaller amounts would result in far less perturbation of hemodynamic parameters. The only riders withdrawing such large amounts might be those who withdraw during the off-season, with the aim of freezing the blood and using it for multiple transfusions during the season.

Also, following withdrawal, riders most likely use EPO to accelerate replacement of lost RBC. So the window of reduced Hb would be much shorter, and the use of synthetic EPO would probably reduce natural levels of EPO as well. Reticulocyte levels would be increased, but as the authors of this study note, these would only be measured if dramatically reduced Hb levels indicated they should be. So even riders removing a large amount of blood during the off-season might, with some care, reduce their vulnerability to this kind of test.

 

[Orinda8]

I agree with the previous poster that most riders use smaller 250ml amounts of blood;and even when the transfuse they can use frequent 50ml infusions during a race which keeps their hematocrit stable and would not cause a big increase or affect retics so this would allow them to escape detection easily.

 

[Tyler'sTwin]

The subjects in this study had more than a liter of blood removed, and 800 ml. of packed cells, corresponding to 1.5 l. of whole blood, re-infused. This is probably highly unrealistic, as it seems riders generally withdraw/transfuse far smaller amounts, like 300 ml. These smaller amounts would result in far less perturbation of hemodynamic parameters. The only riders withdrawing such large amounts might be those who withdraw during the off-season, with the aim of freezing the blood and using it for multiple transfusions during the season.

Also, following withdrawal, riders most likely use EPO to accelerate replacement of lost RBC. So the window of reduced Hb would be much shorter, and the use of synthetic EPO would probably reduce natural levels of EPO as well. Reticulocyte levels would be increased, but as the authors of this study note, these would only be measured if dramatically reduced Hb levels indicated they should be. So even riders removing a large amount of blood during the off-season might, with some care, reduce their vulnerability to this kind of test.

I'm pretty sure that means packed cells from 800 ml of blood. They can't possibly infuse cells from 1.5l after only withdrawing 1.3l... It also makes sense given the increase in Hb.

Really? Aren't retics measured in every blood-passport test?

 

[Race Radio]

The subjects in this study had more than a liter of blood removed, and 800 ml. of packed cells, corresponding to 1.5 l. of whole blood, re-infused. This is probably highly unrealistic, as it seems riders generally withdraw/transfuse far smaller amounts, like 300 ml. These smaller amounts would result in far less perturbation of hemodynamic parameters. The only riders withdrawing such large amounts might be those who withdraw during the off-season, with the aim of freezing the blood and using it for multiple transfusions during the season.

Also, following withdrawal, riders most likely use EPO to accelerate replacement of lost RBC. So the window of reduced Hb would be much shorter, and the use of synthetic EPO would probably reduce natural levels of EPO as well. Reticulocyte levels would be increased, but as the authors of this study note, these would only be measured if dramatically reduced Hb levels indicated they should be. So even riders removing a large amount of blood during the off-season might, with some care, reduce their vulnerability to this kind of test.

500 ml use to be the norm but supposedly Contador is doing multiple 150 ml transfusions to not trip the Bio passport

 

[Tyler'sTwin]

The effects look pretty short lived, do they not? Pretty much gone after a week...

Also interesting to note that retics lag behind.

 

[Merckx index]

I'm pretty sure that means packed cells from 800 ml of blood. They can't possibly infuse cells from 1.5l after only withdrawing 1.3l... It also makes sense given the increase in Hb.

Really? Aren't retics measured in every blood-passport test?

The packed cells are presumably from all the blood withdrawn, an average of 1.3 l., actually. This amount of whole blood would yield less than 800 ml. of tightly packed cells, but probably the cells were loosely packed, with some serum or even added saline, since the point of separation was only to reduce the volume somewhat. In any case, the amount is far greater than what riders seem to do now. Note this paper was published in 2006, possibly then riders were transfusing more, and have since wised-up.

Yes, the passport measures reticulocytes, but the point is, passport measurements are not made very often. This study indicates that to catch riders, one would have to test very frequently--at least once every week or two--to catch the open window. I don't think passport measurements are made that often, are they? My interpretation was that they were suggesting a simple test just for Hb that could be carried out more frequently, and depending on the results, then go for all the other passport parameters.

But again, it seems to be a moot point.