title: Dose-dependent testosterone sensitivity of the steroidal passport and GC-C-IRMS analysis in relation to the UGT2B17 deletion polymorphism.
abstract: The newly implemented Steroid Module of the Athlete Biological Passport has improved doping tests for steroids. A biomarker included in this passport is the urinary testosterone glucuronide to epitestosterone glucuronide (T/E) ratio, a ratio greatly affected by a deletion polymorphism in UGT2B17. Suspect urine doping tests are further analyzed with gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) to determine the origin of the androgen. In this study, we investigated the sensitivity of the steroidal module and the IRMS analysis, in subjects administered with three doses of testosterone enanthate (500, 250, and 125 mg), in relation to the UGT2B17 polymorphism. All subjects carrying the UGT2B17 enzyme reached the traditionally used threshold, a T/E ratio of 4, after all three administered doses, whereas none of the subjects devoid of this enzyme reached a T/E of 4. On the other hand, using the athlete biological passport and IRMS analysis, all three doses could be detected to a high degree of sensitivity. The concentrations of all steroids included in the steroidal module were dose dependently increased, except for epitestosterone which decreased independent of dose. The decrease in epitestosterone was significantly associated with circulatory levels of testosterone post dose (rs =0.60 and p=0.007). In conclusion, these results demonstrate that administration of a single dose of 125-500 mg testosterone enanthate could be detected using the athlete biological passport, together with IRMS. Since IRMS is sensitive to testosterone doping independent of UGT2B17 genotype, also very small changes in the steroidal passport should be investigated with IRMS.
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-141 86, Stockholm, Sweden.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Strahm
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-141 86, Stockholm, Sweden.
authors.forename: Jenny E
authors.initials: JE
authors.lastname: Mullen
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-141 86, Stockholm, Sweden.
authors.forename: Nina
authors.initials: N
authors.lastname: Gårevik
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-141 86, Stockholm, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Ericsson
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-141 86, Stockholm, Sweden.
authors.forename: Jenny J
authors.initials: JJ
authors.lastname: Schulze
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-141 86, Stockholm, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Rane
authors.affiliation: Department of Laboratory Medicine, Division of Clinical Pharmacology, Karolinska Institutet, SE-141 86, Stockholm, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Ekström
mesh_terms: D000328:Adult; D045930:Anabolic Agents / Q000008:administration & dosage / Q000652:urine*; D056352:Athletes; D004300:Doping in Sports; D004334:Drug Administration Schedule; D008401:Gas Chromatography-Mass Spectrometry; D017353:Gene Deletion; D005838:Genotype; D014453:Glucuronosyltransferase / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D050217:Metabolic Detoxication, Phase II; D015778:Minor Histocompatibility Antigens; D058573:Performance-Enhancing Substances / Q000008:administration & dosage / Q000652:urine*; D010641:Phenotype; D011110:Polymorphism, Genetic; D011237:Predictive Value of Tests; D065667:Renal Elimination; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods*; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000652:urine; D013997:Time Factors; D016482:Urinalysis
chemical_list: D045930:Anabolic Agents; D015778:Minor Histocompatibility Antigens; D058573:Performance-Enhancing Substances; C015529:testosterone glucuronate; D013739:Testosterone; C004648:testosterone enanthate; D014453:Glucuronosyltransferase; C500513:UGT2B17 protein, human
keywords: Athlete Biological Passport (ABP); T/E ratio; anabolic androgenic steroids (AAS); isotope ratio mass spectrometry (IRMS); testosterone