Methods to increase oxygen transfer

Transcription

1 IMIM-UPF PRBB Methods to increase oxygen transfer Jordi Segura Accredited Antidoping Laboratory, Municipal Institute for Medical Research IMIM-UPF, Biomedical Research Park PRBB, Barcelona; IOC Medical Commission, Games Group, Lausanne, IOC International Symposium Rome,, 14 october 2006

2 Haemoglobin content and exercise Δ max VO2 % Δ Hb conc. % Ref. Ekblom B, Goldbarg AN, Gullbring B. Response to exercise after blood loss and reinfusion. J Appl Physiol 1972 Aug;33(2):

3 1984 OG Los Angeles: first acknowledgement that blood transfusion could be common practice in some sport disciplines (cyclism) 1985 Amgen: Introduction of recombinant erythropoietin, 1990 s UCI and FIS: Indirect markers (health prevention) hematocrit hemoglobin 1994 OG Lillehammer: first control during OG of blood transfusion 1998 Doping crisis: availability of EPO during the Tour de France 2000 First EPO detection methods: direct and indirect markers 2000 RSR13 : Giro of Italy, one participant had available RSR13, first evidence that haemoglobin modifiers maybe misused in sport practice 2001 Masking agents: Plasma expanders HES (hydroxy-ethyl starch) 2002 Darbepoetin (NESP) used at OG Salt Lake City 2004/2006 Transfussions OG Athens and Vuelta. Puerto affair.

4 World Anti-Doping Agency (WADA) Level 1: World Anti-Doping Code International Standards Level 2: Testing Laboratory TUE List Models of Best Practice Level 3: Rules and Regulations: IFs, NADOs, NOCs, EOs Results Management Education Programs National Anti- Doping Programs

5 The World Anti-Doping Code The 2005 Prohibited List PROHIBITED SUBSTANCES S1. Anabolic Agents S2. Hormones and Related Substances S3. Beta-2 Agonists S4. Agents with antioestrogenic activity S5. Diuretics and other masking agents S6. Stimulants S7. Narcotics S8. Cannabinoids S9. Glucocorticosteroids PROHIBITED METHODS M1. Enhancement of oxygen transfer M2. Chemical and physical manipulation M3. Gene Doping SUBSTANCES PROHIBITED IN PARTICULAR SPORTS P1. Alcohol P2. Beta blockers

6 The World Anti-Doping Code The 2005 Prohibited List S2 Hormones and related substances Erhytropoietin S5 Diuretics and Masking Agents Plasma expanders M1 Enhancement of Oxygen transfer Blood doping (autologous, homologous or heterologous blood or red blood cell products) Enhancers of uptake, transport or delivery of oxygen (perfluorochemicals, efaproxiral, modified haemoglobin products) M3 Gene Doping

7 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

8 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

9 Old methods revisited Hamilton blood tests show 'inconsistencies' By Andrew Hood September 20, 2004 Tyler Hamilton is denying media reports of blood tampering that have been detected in two samples taken since he won the Olympic time trial gold medal last month. The Vuelta a España was rocked overnight following reports that the UCI informed Phonak team doctor Iñaki Arratibel that blood samples taken Aug. 19 and Sept. 18 showed traces of mixed blood cells. Follow-up tests were scheduled for later Tuesday. Phonak confirmed those reports, but said Hamilton has denied any wrong-doing. Phonak officials have scheduled a press conference at the team's headquarters in Zurich on Tuesday afternoon.

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11 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

12 α α Fe Fe Fe Fe β β

13 HBOCs (Haemoglobin Based Oxygen Carriers) α1α2 β1 β2 Crosslinked tetrameric Hb α1 α2 β1 β2 bis(3,5 dibromosalicyl)fumarate pyridoxal-5-phosphate o-adenosine-5'-triphosphate Recombinant Hb α1 and α2 fused α1 α2 β1 β2 α1 α2 β1 β2 α1 α2 glutaraldehyde o-adenosine β1 β2 α Fe α Fe Crosslinked polyhb α1 α2 2,3-DPG β1 β2 α1 α2 2,3-DPG β1 β2 α1 α2 2,3-DPG β1 α1 α2 2,3-DPG β1 β2 β2 α1 α2 2,3-DPG β1 α1 α2 2,3-DPG β1 β2 β2 Encapsulated Hb Fe β β Tetrameric Hb Fe Oxygent TM PolyHeme TM HBOC 201 TM Hemolink TM HemAssist TM PHP TM α1 α2 β1 α1 α2 β1 β2 β2 polyoxoethylene polyethylene glycol dextran Conjugated Hb α1 α2 β1 β2 α1 α2 β1 Conjugated polyhb β2

14 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

15 RSR-13 (EFAPROXIRAL) Allosteric modifier of Hb Increases maximum oxygen uptake (VO 2 max) High urinary concentrations O O O OH N H (Breidbach, Catlin et al. 2001; Ventura, Segura et al. 2003)

16 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

17 PFCs (Perfluorocarbons) Synthetic hydrocarbon analogues. High solubility of O 2 e.g. PERFLUBRON (perfluoro-octyl bromide) CF 3 -CF 2 - CF 2 - CF 2 - CF 2 - CF 2 - CF 2 - CF 2 Br PROPERTIES OF PFCs: H 2 O Perflubron Boiling point ( C)( Density at 25 C C (g/ml) 1 1,93 Viscosity (centistokes at 25 C) 1 1,10 O 2 solubility at 37 C C (ml gas/100 ml liquid) 3 53 CO 2 solubility at 37 C C (ml gas/100 ml liquid) LIPOSOME EMULSION PFC Lipid bilayer

18 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

19 hepo (natural) BIOLOGICAL ACTIVITY Stem cell (bone marrow) BFU-E GM-CSF IL-3 Burst-forming unit erythroid EPO receptor transferrin receptor ( Tfr ) EPO CFU-E Hemoglobin synthesis proerythroblast Colony-forming unit erythroid Fe (transferrin) normoblast enucleation stfr reticulocyte reticulocyte erythrocyte stfr blood Bone marrow

20 rhepo PHARMACEUTICAL PRODUCT (recombinant): - Recombinant product obtained by expressing the human EPO gen in different cell lines: CHO, BHK, etc. - Commercially available since 1985 as EPOETIN ALFA - Epoetin Alfa glycoform profile ALFA EPOADE EPOGEN EPREX ESPO GLOBUREN PROCRIT EPOPEN (Sankyo) (Amgen) (Jansern-Cilag) (Kirin) (Dompé) (Ortho Biotech) (Esteve) - Epoetin Omega glycoform profile OMEGA EPOMAX HEMAX (Elanex) (Elanex) - Epoetin Beta glycoform profile BETA EPOCH (Chugai) EPOGIN (Chugai) MAROGEN (Chugai) RECORMON (Boehringer M.) ERANTIN (Boehringer M.) NEORECORMON (Roche) EPOPEN (Pensa) - Epoetin Delta glycoform profile DELTA DYNEPO (Aventis-TKT)

21 rhepo INDIRECT MARKERS blood serum (Parisotto et al. 2000)

22 rhepo INDIRECT MARKERS (Parisotto et al. Haematologica 2000; 85: ) - ON MODEL : ON score = RetHct Hct EPO stfr %macrocytes - OFF MODEL : OFF score = RetHct Hct EPO REEVALUATION OF MARKERS: - ON MODEL : ON score = Hb ln (EPO) (Gore CJ et al. Haematologica 2003; 88: ) - OFF MODEL : OFF score = Hb 60 (ret%) 1/2

23 rhepo DIRECT MARKERS Electrophoretic detection in urine Wide et al., 1995

24 EPO CHEMICAL PROPERTIES - Glycoprotein (mw: ~ 30 kda) polipeptidic chain 60% Glicosidic chains 40% 4 glycosidic chains: Asn 24, 38, 83 Ser 126 -different sugar composition -many isoforms with different charges: MICROHETEROGENEITY

25 rh EPO DIRECT MARKERS (urine) 5.21 ph 4.42 Marker Line 3.77 Standard of uhepo (sigma) Std rhepo β Std rhepo α uepo in a real Negative urine Positive urines Std uhepo (NIBSC) Std rhepo α+β Std rhepo ω Lasne, de Ceaurriz, et al, 2000 Pascual, Segura, et al, 2004

26 Mimetics and analogues according to the WADA Prohibited List ANALOGUE An analogues is defined as a substance derived from the modification or alteration of the chemical structure of another substance while retaining a similar pharmacological effect

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28 NESP (Darbepoetin alfa): Hyperglycosilated rhepo DIRECT MARKERS (urine) SENSITIVE DETECTION ph 6 ph 2 Std hepo (NIBSC) rhepo α+β rhepo ω NESP

29 Mimetics and analogues according to the WADA 2004 Prohibited List MIMETIC A mimetic is defined as a substances with pharmacological effect similar to that of another substance, regardless of the fact that it has a different chemical structure

30 SEP ( Synthetic Erythropoiesis protein ) DEVELOPMENT: Gryphon Therapeutics (San Francisco, USA) Blood Reseach Institute (Milwaukee, USA) CHEMICAL PROPERTIES: - Chemically synthesized. - Nearly identical to the EPO protein back-bone. - Substitute oligosaccarides by a precision-length,negatively charged polymers

31 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

32 Are false positives possible by hypobaric hypoxia? 16 highly trained male triathletes participated in a randomised controlled trial Hypobaric chamber 2 groups: NORM (N=8) training at sea level HYPO (N=8) training at sea level with resting in the hypobaric chamber

33 HYPO group followed hypobaric exposure in resting conditions Simulated altitude (m) Pre Time (days) Post Post 1 wk t 8 t 33 t 46 t 8 t 33 Treadmill test Field test Blood and urine samples collection Post 2 wk NORM group remained in normobaric conditions

34 3 Are false positives possible (eg. by hypobaric hypoxia?) Outcome Both ON/OFF scores and endogenous EPO isoforms were slightly modified, BUT NEVER ENOUGH to produce any false positive result Segura J, Rodriguez F et al, 2005

35 Ways to increase oxygen transport and delivery Blood transfusions Modified haemoglobins Allosteric modifiers of haemoglobin Perfluorocarbons rhuepo, mimetics and analogues Altitude training - hypoxic houses Gene therapy with EPO genes

36 Gene therapy with EPO Monkeys injected with a virus carrying the gene for EPO

37 Conclusions Artifical increase of oxygen transport and release is a powerful form of doping in sport. Modified haemoglobins, perfluorocarbons and efrapoxiral will be easily detectable and probably will not represent a major real challenge. Doping substances have expanded towards engineered analogues and mimetics of endogenous substances. Sophisticated methodology is needed to evidence the presence of those substances in biological fluids, particularly to differentiate synthetic or recombinant analogues from the naturally occurring hormones. New expertise has been incorporated to doping control to cope with the new challenges.

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