The Bad Science
By: Michele Ferrari
Published: 22 Sep 2012
In a recent article (http://downthebackstretch.blogspot.co.uk/2012/09/its-all-about-blood.html) Robin Parisotto, Md., commenting on some USADA blood tests of Lance Armstrong claimed that those "blood values are undoubtedly indicative of blood manipulation".
Parisotto based his certainty on the following observations:
- a decrease in Hb from 14.9 to 13.0 g/dl from 30/04/2009 to 31/05/2009, without the expected (by the Author) increase in reticulocytes
- a subsequent rise in Hb to 16.0 g/dl on 16/06/2009, without the same expected increase in reticulocytes.
Parisotto, one of the fathers of the Biological Passport (Haematologica 2003, 88 :333-344) and a member of the panel of experts judging the blood profiles of athletes, defined the above scenario "consistent with a deceleration in red cell production following auto-bleed and re-infusion", i.e. a drawing of blood followed by a subsequent re-infusion, accompanied by microdoses of rhEPO to mask the expected response in reticulocytes.
Apparently, from what we read in the article, the blood drawing would have taken place during the Giro d' Italia (!) and the re-infusion would have happened 19 days before the start of the Tour de France!
Parisotto shows two graphs, displaying the trends in Hb and reticulocytes, which are in perfect "Biological Passport style", i.e. without chronological references, showing the values in simple numerical sequence of execution.
There is no reference in the graphs to events that may have interfered/affected the considered parameters, such as STAGE RACES or ALTITUDE sojourns.
- the value of Hb=13.0 was taken the last day of the Giro, dated 05/31/2009, preceded by a Hb=13.6 dated 18/05/2009 and a Hb=14.8 at the start of the Italian race (7/05/2009), a decrease of 12.2% (from 14.8 to 13.0) fully compatible with what is reported in the literature with regards to cyclists involved in stage races (Int J Sports Med 2009, 30:130-138): Hb decreases by an average of 11.5% from the beginning to the end of the event, with individual drops ranging between 7% and 20.5%.
This reduction is mainly due to an increase in PLASMA VOLUME and it is therefore normal for reticulocytes not to have increased...
Consequently, it is INCORRECT to approach a value of Hb at the end of the Giro with a later one, taken out of competition, moreover collected at altitude (Aspen, 2400m above sea level)
- the values of Hb=16.0 in the samples reported as numbers 14 and 15 were collected on two consecutive days (16/06/2009 and 17/06/2009) at altitude.
The Athletes Hematological Passport Interpretation Technical Document (2.09) recommends the adoption of correction factors in Hb values for athletes who reside in or have stayed at altitude in the two weeks prior to collection. For altitudes between 2000 and 2500m the correction factor is 0.8: therefore Hb=16.0 becomes 15.2.
This value is perfectly in line with the results of the ten samples taken out of competition from 15/10/08 to 04/30/2009, which show an average value of Hb=14.8.
The same Hb z-score for samples 14 and 15 is equal to 0.75, when altitude is correctly taken into account.
I remind you that this parameter is indicative of suspicion of doping when it is >3.19 (a value that corresponds to a 99.9% probability).
The values at altitude of Hb=16.0 in June 2009 are further confirmed by the sample taken on 12/08/2009, always collected in Aspen, with Hb=16.1; a value that Parisotto refrained from showing, but that can easily be found in the same source quoted by the australian Author (cyclingnews.com, July 13th, 2012), along with 37 other blood samples reported by USADA.
More from Other :
Graham Watson: 20 Years of Cycling Photographs