Require help with technicalities of Ashenden article

[asdfgh101]

Preamble:

I tend to immerse myself in clinic reading whenever a particular issue (Contador positive, Landis/Hamilton accusations, UK Postal) piques my interest. Consequently my knowledge is functional rather than comprehensive and am seeking clarification on several issues.

Questions:

Ashenden addresses the problem with attempting to maintain haemoglobin levels via simultaneously transfusing red blood cells and plasma. Could this not be remedied through the use of an exchange transfusion?

It is stated that with correct timing and titration epo can be utilised as a masking agent for blood infusion by normalising reticulocyte levels. Out of competition testing necessitates a corresponding protocol for concealing blood withdrawl. Is this acheived through a post-withdrawl suspension of the micro-dosing of epo?

Regarding the adverse analytical finding of clenbuterol in Contador's blood sample; are we to deduce a flaw in the screening processs (inability to detect a concentration of 50 picograms)?

 

[Cavalier]

I can't answer all of the questions, and remotely pretend to be able to answer with the expertise Mike Ashenden could, but:

Ashenden addresses the problem with attempting to maintain haemoglobin levels via simultaneously transfusing red blood cells and plasma. Could this not be remedied through the use of an exchange transfusion?

The problem is that this is both time-consuming (due to low volume of withdrawal + then infusion) and requires a substantial amount of stored blood to complete. Given how often someone would need to do this to gain consistency in behaviour and resultant gains it's unfeasible.

I'll postscript that by saying my understanding of the practice isn't remotely at expert level so I comment with the proviso I could be corrected.

 

[lean mean &green]

Preamble:

I tend to immerse myself in clinic reading whenever a particular issue (Contador positive, Landis/Hamilton accusations, UK Postal) piques my interest. Consequently my knowledge is functional rather than comprehensive and am seeking clarification on several issues.

Questions:

#1 Ashenden addresses the problem with attempting to maintain haemoglobin levels via simultaneously transfusing red blood cells and plasma. Could this not be remedied through the use of an exchange transfusion?

#2 It is stated that with correct timing and titration epo can be utilised as a masking agent for blood infusion by normalising reticulocyte levels. Out of competition testing necessitates a corresponding protocol for concealing blood withdrawl. Is this acheived through a post-withdrawl suspension of the micro-dosing of epo?

#3 Regarding the adverse analytical finding of clenbuterol in Contador's blood sample; are we to deduce a flaw in the screening processs (inability to detect a concentration of 50 picograms)?

To #1... If I understand you correctly, and I think I do, exchange transfusion is a dead end. Once Hb concentrations have been altered/increased to gain competitive advantage and plasma levels altered/increased to avoid detection the body will attempt to correct for these unnatural levels no matter what method is used. The increased volume will trigger baroreceptors/kidneys/urine production in an attempt to return to homeostasis. Natural erythropoiesis slows to a crawl (see below). Maintaining plasma levels would be a constant struggle but there are much simpler ways of accomplishing this "correction".

To #2... You are mostly correct, assuming a very simple pattern of donation and reinsfusion EPO use would essentially stop following a withdraw. Synthetic EPO and natural erythropoiesis together could likely push retics too high.

To #3... I don't understand your question. Some labs, for better or worse, can and did detect concentrations even below 50 pg/dL. I'm drawing a few inferences from what MA has said but I believe he thinks the clenbuterol finding originated from a plasma transfusion. This, in my quasi-expert view, makes perfect sense.

 

[asdfgh101]

I am assuming that the withdrawn plasma was screened prior to the transfusion.

 

[lean mean &green]

I am assuming that the withdrawn plasma was screened prior to the transfusion.

I think I understand you better now, you mean the athlete's own screening process. There's really know way to know. I doubt that they screen their own samples, it would be expensive and there's no need to - they know what substances they're taking and how long the window of detection is for every drug/method.

There's a chance that Contador's team made a mistake in not waiting long enough for clenbuterol to clear before withdrawing blood/plasma but I don't think so.

The levels suggest to me that it was a calculated risk. IOW they never expected samples to be tested at such a low concentration let alone that the UCI/NADO would follow through on such a thing and it very nearly played out that way.