Population based evaluation of a multi-parametric steroid profiling on administered endogenous steroids in single low dose

Long-term stability study and evaluation of intact steroid conjugate ratios after the administration of endogenous steroids

The most frequently detected substances prohibited by the World Anti-Doping Agency (WADA) belong to the anabolic steroids class. The most challenging compounds among this class are the endogenous anabolic steroids, which are detected by quantitative measurement of testosterone (T) and its metabolites with a so-called "steroid profiling" method. The current steroid profile is based on the concentrations and ratios of the sum of free and glucuronidated steroids. Recently, our group developed a steroid profiling method for the detection of three free steroids and 14 intact steroid conjugates, including both the glucuronic acid conjugated and sulfated fraction. The study aimed at evaluating the long-term stability of steroid conjugate concentrations and ratios, and the influence of different endogenous steroids on this extended steroid profile. A single dose of oral T undecanoate (TU), topical T gel, topical dihydrotestosterone (DHT) gel, and oral dehydroepiandrosterone (DHEA) was administered to six healthy male volunteers. One additional volunteer with a homozygote deletion of the UGT2B17 gene (del/del genotype) received a single topical dose of T gel. An intramuscular dose of TU was administered to another volunteer. To avoid fluctuation of steroid concentrations caused by variations in urinary flow rates, steroid ratios were calculated and evaluated as possible biomarkers for the detection of endogenous steroid abuse with low doses. Overall, sulfates do not have substantial additional value in prolonging detection times for the investigated endogenous steroids and administration doses. The already monitored glucuronides were overall the best markers and were sufficient to detect the administered steroids.

Athlete Biological Passport: Need and Challenges

The Athlete Biological Passport programme was initiated in 2009 by the World Anti-Doping Agency for making the anti-doping programme more effective and stronger. There are three modules in this ABP programme: haematological, steroidal and endocrinological. Currently, the first two modules have been implemented. The newer products such as recombinant human erythropoietin, recombinant proteins, and peptides are similar to those produced naturally. Hence, detection of these substances even with advanced techniques is difficult. Therefore, the concept of ABP came into existence which is based on longitudinal monitoring of biological markers and their variations over a period of time. The ABP does not rely upon the detection of a particular prohibited substance but it reflects the changes in biological markers collated over an athlete's career. Hence, athletes can be monitored through constant interpretation of the passport data. There are many advantages with the implementation of this programme; however, there are various issues which may lead to false interpretation of passport data that must be taken into consideration.

Steroidomics for highlighting novel serum biomarkers of testosterone doping

Aim: Quantification of testosterone (T) and 5α-dihydrotestosterone serum concentrations proved to be an efficient alternative to urinary steroid profiling for the detection of T doping. In this context, additional serum markers could be discovered by exploratory untargeted steroidomics studies. Results: Endogenous steroid metabolites were monitored by ultra high-performance liquid chromatography coupled to high-resolution mass spectrometry in serum samples collected during a T administration clinical trial. A three-step workflow for accurate review of annotation was used and multifactorial data analysis allowed highlighting promising serum biomarkers. Longitudinal monitoring of selected compounds was performed to assess T abuse detection capabilities. Conclusion: Application of serum steroidomics showed high potential for biomarker discovery of T doping, suggesting longitudinal monitoring of steroid hormones in serum as a significant improvement in detection of endogenous steroids abuse.

Evaluation of sulfate metabolites as markers of intramuscular testosterone administration in Caucasian and Asian populations

The introduction of alternative markers to the steroid profile can be an effective approach to improving the screening capabilities for the detection of testosterone (T) misuse. In this work, endogenous steroid sulfates were evaluated as potential markers to detect intramuscular (IM) T administration. Fourteen sulfate metabolites were quantified using mixed-mode solid-phase extraction and analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine samples after a single IM injection (100 mg) of T cypionate to six Caucasian and six Asian healthy male volunteers were analyzed. Principal component analysis (PCA) was used to characterize the sample cohort and to obtain the most useful markers for discrimination between pre- and post-administration samples. For Caucasian volunteers, a separation between pre- and post-administration samples was observed in PCA, whereas for Asian volunteers no separation was obtained. Seventeen ratios between sulfate metabolites were selected and further considered. Detection times (DTs) of each marker were evaluated using individual thresholds for each volunteer. The best results were obtained using ratios involving T and epitestosterone (E) sulfates in the denominator. The best marker was the ratio androsterone sulfate/testosterone sulfate (A-S/T-S) which prolonged the DT 1.2-2.1 times in respect to those obtained using T/E ratio in all Caucasian volunteers and 1.3-1.5 times in two Asian volunteers. Other ratios between A-S or etiocholanolone sulfate and E-S, and sulfates of etiocholanolone, dehydroandrosterone or epiandrosterone, and T-S were also found adequate. These ratios improve the DT after IM T administration and their incorporation to complement the current steroid profile is recommended.

Sulfate metabolites improve retrospectivity after oral testosterone administration

The detection of testosterone (T) misuse is performed using the steroid profile that includes concentrations of T and related metabolites excreted free and glucuronoconjugated, and the ratios between them. In this work, the usefulness of 14 endogenous steroid sulfates to improve the detection capabilities of oral T administration has been evaluated. Quantitation of the sulfate metabolites was performed using solid-phase extraction and analysis by liquid chromatography-tandem mass spectrometry. Urine samples were collected up to 144 hours after a single oral dose of T undecanoate (120 mg) to five Caucasian male volunteers. Detection times (DTs) of each marker were estimated using reference limits based on a population study and also monitoring the individual threshold for each volunteer. High inter-individual variability was observed for sulfate metabolites and, therefore, better DTs were obtained using individual thresholds. Using individual threshold limits, epiandrosterone sulfate (epiA-S) improved the DT with respect to testosterone/epitestosterone (T/E) ratio in all volunteers. Androsterone, etiocholanolone, and two androstanediol sulfates also improved DTs for some volunteers. Principal component analysis was used to characterize the sample cohort, obtaining 13 ratios useful for discrimination. These ratios as well as the ratio epiA-S/dehydroepiandrosterone sulfate were further examined. The most promising results were obtained using ratios between sulfates of epiA, androsterone, or androstanediol 1 and E, and also sulfates of epiA or androstanediol 1, and dehydroandrosterone. These selected ratios prolonged the DT of oral T administration up to 144 hours, which corresponded to a significantly higher retrospectivity compared to those obtained using concentrations or the conventional T/E ratio.

Metabolic and isotopic signature of short-term DHEA administration in women: Comparison with findings in men

The impact of dehydroepiandrosterone (DHEA) administration has been widely studied for anti-doping purposes in men, whereas only a few studies have been performed in women. In the present study, the impact of DHEA on the steroid profile parameters and their carbon isotopic ratios was explored. Eleven healthy young women and 10 healthy young men received two treatments: One with 100 mg/day of DHEA for 28 days and one with a placebo according to a double-blind crossover protocol. Urine and saliva (only in females) samples were collected before and for 72 hours after each short-term treatment. In all female subjects, concentrations of the urinary parameters of the steroid profile were highly impacted by short-term DHEA administration including epitestosterone (E). Gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) analysis was performed and positive results were observed for E in the four female subjects where E concentration was adequate for such analysis, whereas men results remained negative for E. Last, the ability of the Anti-Doping Administration and Management System (ADAMS) software used for the athlete biological passport to identify such doping was assessed. Of the 11 passports generated for female subjects, 10 were automatically classified as an atypical passport finding (ATPF). For the remaining passport with normal status in one woman, the variability of the concentrations prevented the ADAMS software from adjusting individual limits. The most impacted markers in women were T/E and 5αAdiol/E, with a detection window of 36 hours for 5αAdiol/E. In addition, good correlations were observed for DHEA and T concentrations in urine and saliva in females.

Pregnancy greatly affects the steroidal module of the Athlete Biological Passport

Concentrations of urinary steroids are measured in anti-doping test programs to detect doping with endogenous steroids. These concentrations are combined into ratios and followed over time in the steroidal module of the Athlete Biological Passport (ABP). The most important ratio in the ABP is the testosterone/epitestosterone (T/E) ratio but this ratio is subject to intra-individual variations, especially large in women, which complicates interpretation. In addition, there are other factors affecting T/E. Pregnancy, for example, is known to affect the urinary excretion rate of epitestosterone and hence the T/E ratio. However, the extent of this variation and how pregnancy affect other ratios has not been fully evaluated. Here we have studied the urinary steroid profile, including 19-norandrosterone (19-NA), in 67 pregnant women and compared to postpartum. Epitestosterone was higher and, consequently, the T/E and 5αAdiol/E ratios were lower in the pregnant women. Androsterone/etiocholanolone (A/Etio) and 5αAdiol/5βAdiol, on the other hand, were higher in the first trimester as compared to postpartum (p<0.0001 and p=0.0396, respectively). There was no difference in A/T during pregnancy or after. 19-NA was present in 90.5% of the urine samples collected from pregnant women. In this study, we have shown that the steroid profile of the ABP is affected by pregnancy, and hence can cause atypical passport findings. These atypical findings would lead to unnecessary confirmation procedures, if the patterns of pregnancy are not recognized by the ABP management units.

Evaluation of two glucuronides resistant to enzymatic hydrolysis as markers of testosterone oral administration

Testosterone (T) has traditionally been the most commonly reported doping agent by doping control laboratories. The screening of T misuse is performed by the quantification of six endogenous androgenic steroids and the ratio T/E included in the Athlete Biological Passport (ABP). The inclusion of additional metabolites can improve the screening capabilities of ABP. In this study, the potential of 3α-glucuronide-6β-hydroxyandrosterone (6OH-Andros3G) and 3α-glucuronide-6β-hydroxyetiocholanolone (6OH-Etio3G) as markers of T oral administration was evaluated. These glucuronides have been shown to be resistant to enzymatic hydrolysis and their quantification by means of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was reported as the only way to obtain feasible results. Urine samples were collected from five volunteers before and after the oral administration of 40mg of T undecanoate and were analyzed by a LC-MS/MS method recently developed. Concentration of 6OH-Andros3G and 6OH-Etio3G compounds and those of the glucuronides of T (TG), epitestosterone (EG), androsterone and etiocholanolone were established and different concentration ratios were calculated. The detection windows (DWs) for the T administration obtained by each selected ratio were compared to the one of TG/EG. The results showed that four out of the nine tested markers presented DWs much larger for all volunteers than those obtained by the World Anti-Doping Agency established T/E marker or other alternative markers. The 6OH-Andros3G/EG, 6OH-Etio3G/EG, 6OH-Andros3G/TG and 6OH-Etio3G/TG markers were able to identify the T abuse up to 96h after the administration, extending our detection capability for the misuse up to 84h more than the classic marker. The importance of these markers was also highlighted by their prolonged capacity to detect the T misuse in the case of one volunteer whose TG/EG barely exceeded his individual threshold. As a consequence, the four markers presented in this study seem to have an exceptional potential as biomarkers of T oral administration.

Application of multivariate statistics to the Steroidal Module of the Athlete Biological Passport: A proof of concept study

The Technical Document TD2014EAAS was drafted by the World Anti-Doping Agency (WADA) in order to fight the spread of endogenous anabolic androgenic steroids (EAAS) misuse in several sport disciplines. In particular, adoption of the so-called Athlete Biological Passport (ABP) - Steroidal Module allowed control laboratories to identify anomalous EAAS concentrations within the athletes' physiological urinary steroidal profile. Gas chromatography (GC) combined with mass spectrometry (MS), indicated by WADA as an appropriate technique to detect urinary EAAS, was utilized in the present study to develop and fully-validate an analytical method for the determination of all EAAS markers specified in TD2014EAAS, plus two further markers hypothetically useful to reveal microbial degradation of the sample. In particular, testosterone, epitestosterone, androsterone, etiocholanolone, 5α-androstane-3α,17β-diol, 5β-androstane-3α,17β-diol, dehydroepiandrosterone, 5α-dihydrotestosterone, were included in the analytical method. Afterwards, the multi-parametric feature of ABP profile was exploited to develop a robust approach for the detection of EAAS misuse, based on multivariate statistical analysis. In particular, Principal Component Analysis (PCA) was combined with Hotelling T(2) tests to explore the EAAS data obtained from 60 sequential urine samples collected from six volunteers, in comparison with a reference population of single urine samples collected from 96 volunteers. The new approach proved capable of identifying anomalous results, including (i) the recognition of samples extraneous to each of the individual urine series and (ii) the discrimination of the urine samples collected from individuals to whom "endogenous" steroids had been administrated with respect to the rest of the samples population. The proof-of-concept results presented in this study will need further extension and validation on a population of sport professionals.

Impact of UGT2B17 gene deletion on the steroid profile of an athlete

The measurement of the testosterone to epitestosterone ratio (T/E ratio) in urine is often used as a marker for testosterone administration in the doping control field. This study examines the frequencies of the different expression forms of the UGT2B17 gene, and assesses their effects on this marker in volunteer subjects. The sample for this descriptive study was composed of male and female athletes aged between 16 and 55 years old who practiced different sports disciplines. All participants underwent a sports-medical physical examination, and subsequently provided 10 urine samples consecutively over a period of 48 h. The dependent variable examined was T/E and the main independent variable was the UGT2B17 gene polymorphism. During 1 year, 1410 urine samples were obtained from 141 athletes. The frequencies of the three genotypes were as follows: wt homozygotes (ins/ins) 48.2% (n = 68), mutant homozygotes (del/del) 12.1% (n = 17), and heterozygotes (ins/del) 39.7% (n = 56). Genotype distributions varied significantly (P < 0.001) according to ethnicity, 80% of Asian subjects being homozygous for the gene deletion (del/del) compared to 6.9% of Caucasian subjects. A multivariate analysis adjusted for genotype, age, sex, and sports discipline revealed that athletes with the del/del polymorphism showed a significantly lower mean T/E than heterozygotes (ins/del). In contrast, homozygous athletes for the gene insertion (ins/ins) showed higher mean T/E ratios than heterozygotes (ins/del). UGT2B17 gene deletion has a strong influence on the T/E ratio in urine, which is the most efficient indicator of testosterone prohormone misuse. Others factors studied seem not to have such an impact. The genotyping of UGT2B17 is an important source of information for understanding steroid profiling in the doping control field; therefore it is suggested that it be included in the Athletes Biological Passport.

Untargeted profiling of urinary steroid metabolites after testosterone ingestion: opening new perspectives for antidoping testing

Aim: Antidoping procedures are expected to greatly benefit from untargeted metabolomic approaches through the discovery of new biomarkers of prohibited substances abuse. Results: Endogenous steroid metabolites were monitored in urine samples from a controlled elimination study of testosterone undecanoate after ingestion. A platform coupling ultra-high pressure LC with high-resolution quadrupole TOF MS was used and high between-subject metabolic variability was successfully handled using a multiblock data analysis strategy. Links between specific subsets of metabolites and influential genetic polymorphisms of the UGT2B17 enzyme were highlighted. Conclusion: This exploratory metabolomic strategy constitutes a first step toward a better understanding of the underlying patterns driving the high interindividual variability of steroid metabolism. Promising biomarkers were selected for further targeted study.

Profiling of steroid metabolites after transdermal and oral administration of testosterone by ultra-high pressure liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

The screening of testosterone (T) misuse for doping control is based on the urinary steroid profile, including T, its precursors and metabolites. Modifications of individual levels and ratio between those metabolites are indicators of T misuse. In the context of screening analysis, the most discriminant criterion known to date is based on the T glucuronide (TG) to epitestosterone glucuronide (EG) ratio (TG/EG). Following the World Anti-Doping Agency (WADA) recommendations, there is suspicion of T misuse when the ratio reaches 4 or beyond. While this marker remains very sensitive and specific, it suffers from large inter-individual variability, with important influence of enzyme polymorphisms. Moreover, use of low dose or topical administration forms makes the screening of endogenous steroids difficult while the detection window no longer suits the doping habit. As reference limits are estimated on the basis of population studies, which encompass inter-individual and inter-ethnic variability, new strategies including individual threshold monitoring and alternative biomarkers were proposed to detect T misuse. The purpose of this study was to evaluate the potential of ultra-high pressure liquid chromatography (UHPLC) coupled with a new generation high resolution quadrupole time-of-flight mass spectrometer (QTOF-MS) to investigate the steroid metabolism after transdermal and oral T administration. An approach was developed to quantify 12 targeted urinary steroids as direct glucuro- and sulfo-conjugated metabolites, allowing the conservation of the phase II metabolism information, reflecting genetic and environmental influences. The UHPLC-QTOF-MS(E) platform was applied to clinical study samples from 19 healthy male volunteers, having different genotypes for the UGT2B17 enzyme responsible for the glucuroconjugation of T. Based on reference population ranges, none of the traditional markers of T misuse could detect doping after topical administration of T, while the detection window was short after oral TU ingestion. The detection ability of the 12 targeted steroids was thus evaluated by using individual thresholds following both transdermal and oral administration. Other relevant biomarkers and minor metabolites were studied for complementary information to the steroid profile, including sulfoconjugated analytes and hydroxy forms of glucuroconjugated metabolites. While sulfoconjugated steroids may provide helpful screening information for individuals with homozygotous UGT2B17 deletion, hydroxy-glucuroconjugated analytes could enhance the detection window of oral T undecanoate (TU) doping.

Profiling of urinary formestane and confirmation by isotope ratio mass spectrometry

Formestane (F, androst-4-en-4-ol-3,17-dione) is an irreversible aromatase inhibitor with the ability to suppress the estrogen production from anabolic steroids. Consequently, F is mentioned on the World Anti-Doping Agency (WADA) prohibited list and because studies have shown that F is produced endogenously in small amounts, a threshold for urinary excreted F of 150 ng/mL was introduced. Lower concentrations could be due to endogenous production and need further investigation to prove the exact origin through determination of the carbon isotope ratio. However, because the current screening methods are a lot more sensitive, F is detected in practically every urine sample. A strict implementation of this WADA rule would imply that almost every urine sample needs additional investigation to verify an exogenous or endogenous origin. The main aim of this study was to propose and introduce a lower concentration limit of 25 ng/mL beneath which the detected F is considered as being endogenous and no further investigation is needed. The data presented in this paper suggests that this threshold provides a good balance between a sufficiently large detection window and not having to perform isotope ratio mass spectrometry (IRMS) analyses on negative urine samples.

Monitoring the endogenous steroid profile disruption in urine and blood upon nandrolone administration: An efficient and innovative strategy to screen for nandrolone abuse in entire male horses

Nandrolone (17β-hydroxy-4-estren-3-one) is amongst the most misused endogenous steroid hormones in entire male horses. The detection of such a substance is challenging with regard to its endogenous presence. The current international threshold level for nandrolone misuse is based on the urinary concentration ratio of 5α-estrane-3β,17α-diol (EAD) to 5(10)-estrene-3β,17α-diol (EED). This ratio, however, can be influenced by a number of factors due to existing intra- and inter-variability standing, respectively, for the variation occurring in endogenous steroids concentration levels in a single subject and the variation in those same concentration levels observed between different subjects. Targeting an efficient detection of nandrolone misuse in entire male horses, an analytical strategy was set up in order to profile a group of endogenous steroids in nandrolone-treated and non-treated equines. Experiment plasma and urine samples were steadily collected over more than three months from a stallion administered with nandrolone laurate (1 mg/kg). Control plasma and urine samples were collected monthly from seven non-treated stallions over a one-year period. A large panel of steroids of interest (n = 23) were extracted from equine urine and plasma samples using a C18 cartridge. Following a methanolysis step, liquid-liquid and solid-phase extractions purifications were performed before derivatization and analysis on gas chromatography-tandem mass spectrometry (GC-MS/MS) for quantification. Statistical processing of the collected data permitted to establish statistical models capable of discriminating control samples from those collected during the three months following administration. Furthermore, these statistical models succeeded in predicting the compliance status of additional samples collected from racing horses.

Development of a GC/C/IRMS method--confirmation of a novel steroid profiling approach in doping control

In doping control, an athlete can only be convicted with the misuse with endogenous steroids like testosterone (T), if abnormal values of steroid metabolites and steroid ratios are observed and if the subsequent analysis with isotope ratios mass spectrometry (IRMS) confirms the presence of exogenously administered androgens. In this work, we compare the results of a novel steroid profiling approach with the performance an in-house developed IRMS method. The developed IRMS has the advantage over other methods to be relatively short in time and with target compounds androsterone, etiocholanolone, 5β-androstane 3α,17β-diol and 5α-androstane 3α,17β-diol. Pregnanediol was used as an endogenous reference compound (ERC). Reference limits for the IRMS values were established and applied as decision limits for the evaluation of excretion urine from administration with oral T, T-gel, dihydrotestosterone (DHT) - gel and dehydroepiandrosterone (DHEA). Results indicated the importance of both androstanediols as important IRMS markers where relative values compared to an ERC (Δδ(13)C) yielded better detection accuracy than absolute δ(13)C-values. The detection times of all administered endogenous steroids were evaluated using the proposed thresholds. The results of traditional steroid profiling and a new approach based upon minor steroid metabolites monitoring introduced in a longitudinal framework were evaluated with IRMS. With traditional steroid profiling methods, 95% of the atypical samples could be confirmed whereas an additional 74% of IRMS confirmed was provided by a new biomarkers strategy. These results prove that the other steroid profiling strategies can improve the efficiency in detection of misuse with endogenous steroids.

Impact of the emergence of designer drugs upon sports doping testing

Historically, dope-testing methods have been developed to target specific and known threats to the integrity of sport. Traditionally, the source of new analytical targets for which testing was required were derived almost exclusively from the pharmaceutical industry. More recently, the emergence of designer drugs, such as tetrahydrogestrinone that are specifically intended to evade detection, or novel chemicals intended to circumvent laws controlling the sale and distribution of recreational drugs, such as anabolic steroids, stimulants and cannabinoids, have become a significant issue. In this review, we shall consider the emergence of designer drugs and the response of dope-testing laboratories to these new threats, in particular developments in analytical methods, instrumentation and research intended to detect their abuse, and we consider the likely future impact of these approaches.

Alternative markers for the long-term detection of oral testosterone misuse

The screening of testosterone misuse in the doping control field is normally performed by the measurement of the ratio between the concentrations of testosterone and epitestosterone excreted as glucuronides (T/E). Despite the satisfactory results obtained with this approach, the measurement of T/E presents some limitations like the long-term detection of oral testosterone administration. Recently, several testosterone metabolites released after basic treatment of the urine have been reported (androsta-1,4-dien-3,17-dione, androsta-4,6-dien-3,17-dione, 17β-hydroxy-androsta-4,6-dien-3-one and 15-androsten-3,17-dione). In the present work, the usefulness of these metabolites for the detection of oral testosterone misuse has been evaluated and compared with the conventional T/E measurement. For this purpose, 173 urine samples collected from healthy volunteers were analysed in order to obtain reference concentrations for the four metabolites released after alkaline treatment. On the other hand, urine samples collected from five volunteers before and after testosterone undecanoate administration were also analysed. Concentrations of androsta-4,6-dien-3,17-dione and 17β-hydroxy-androsta-4,6-dien-3-one showed a similar behaviour as the T/E, allowing the detection of the misuse for several hours after administration. More promising results were obtained by quantifying androsta-1,4-dien-3,17-dione and 15-androsten-3,17-dione. The time in which the concentrations of these analytes could be differentiated from the basal level was between 3 and 6 times longer than the obtained with T/E, as a result, an improvement in the detection of testosterone abuse can be achieved. Moreover, several ratios between these compounds were evaluated. Some of them improved the detection of testosterone misuse when comparing with T/E. The best results were obtained with those ratios involving androsta-1,4-dien-3,17-dione.

OMICS-strategies and methods in the fight against doping

During the past decade OMICS-methods not only continued to have their impact on research strategies in life sciences and in particular molecular biology, but also started to be used for anti-doping control purposes. Research activities were mainly reasoned by the fact that several substances and methods, which were prohibited by the World Anti-Doping Agency (WADA), were or still are difficult to detect by direct methods. Transcriptomics, proteomics, and metabolomics in theory offer ideal platforms for the discovery of biomarkers for the indirect detection of the abuse of these substances and methods. Traditionally, the main focus of transcriptomics and proteomics projects has been on the prolonged detection of the misuse of human growth hormone (hGH), recombinant erythropoietin (rhEpo), and autologous blood transfusion. An additional benefit of the indirect or marker approach would also be that similarly acting substances might then be detected by a single method, without being forced to develop new direct detection methods for new but comparable prohibited substances (as has been the case, e.g. for the various forms of Epo analogs and biosimilars). While several non-OMICS-derived parameters for the indirect detection of doping are currently in use, for example the blood parameters of the hematological module of the athlete's biological passport, the outcome of most non-targeted OMICS-projects led to no direct application in routine doping control so far. The main reason is the inherent complexity of human transcriptomes, proteomes, and metabolomes and their inter-individual variability. The article reviews previous and recent research projects and their results and discusses future strategies for a more efficient application of OMICS-methods in doping control.

Influence of multiple injections of human chorionic gonadotropin (hCG) on urine and serum endogenous steroids concentrations

Since it is established that human chorionic gonadotropin (hCG) affects testosterone production and release in the human body, the use of this hormone as a performance enhancing drug has been prohibited by the World Anti-Doping Agency. Nowadays, the only validated biomarker of a hCG doping is its direct quantification in urine. However, this specific parameter is subjected to large inter-individual variability and its determination is directly dependent on the reliability of hCG immunoassays used. In order to counteract these weaknesses, new biomarkers need to be evidenced. To address this issue, a pilot clinical study was performed on 10 volunteers submitted to 3 subsequent hCG injections. Blood and urine samples were collected during two weeks in order to follow the physiological effects on related compounds such as the steroid profile or hormones involved in the hypothalamo-pituitary axis. The hCG pharmacokinetic observed in all subjects was, as expected, prone to important inter-individual variations. Using ROC plots, level of testosterone and testosterone on luteinizing hormone ratio in both blood and urine were found to be the most relevant biomarker of a hCG abuse, regardless of inter-individual variations. In conclusion, this study showed the crucial importance of reliable quantification methods to assess low differences in hormonal patterns. In regard to these results and to anti-doping requirements and constraints, blood together with urine matrix should be included in the anti-doping testing program. Together with a longitudinal follow-up approach it could constitute a new strategy to detect a hCG abuse, applicable to further forms of steroid or other forbidden drug manipulation.

A pilot study on subject-based comprehensive steroid profiling: novel biomarkers to detect testosterone misuse in sports

CONTEXT

Until now, the testosterone/epitestosterone (T/E) ratio is the main marker for the detection of testosterone (T) misuse in athletes. As this marker can be influenced by a number of confounding factors, additional steroid profile parameters indicating T misuse can provide substantiating evidence of doping with endogenous steroids. The evaluation of a steroid profile is currently based upon population statistics. As large inter-individual variations exist, a paradigm shift towards subject-based references is ongoing in doping analysis.

OBJECTIVE

Proposition of new biomarkers for the detection of testosterone in sports using extensive steroid profiling and an adaptive model based upon Bayesian inference.

SUBJECTS

Six healthy male volunteers were administered with testosterone undecanoate. Population statistics were performed upon steroid profiles from 2014 male Caucasian athletes participating in official sport competition.

DESIGN

An extended search for new biomarkers in a comprehensive steroid profile combined with Bayesian inference techniques as used in the athlete biological passport resulted in a selection of additional biomarkers that may improve detection of testosterone misuse in sports.

RESULTS

Apart from T/E, 4 other steroid ratios (6α-OH-androstenedione/16α-OH-dehydroepiandrostenedione, 4-OH-androstenedione/16α-OH-androstenedione, 7α-OH-testosterone/7β-OH-dehydro-epiandrostenedione and dihydrotestosterone/5β-androstane-3α,17β-diol) were identified as sensitive urinary biomarkers for T misuse. These new biomarkers were rated according to relative response, parameter stability, detection time and discriminative power.

CONCLUSION

Newly selected biomarkers were found suitable for individual referencing within the concept of the Athlete's Biological Passport. The parameters showed improved detection time and discriminative power compared to the T/E ratio. Such biomarkers can support the evidence of doping with small oral doses of testosterone.

Quantification of glucuronidated and sulfated steroids in human urine by ultra-high pressure liquid chromatography quadrupole time-of-flight mass spectrometry

The urinary steroid profile is constituted by anabolic androgenic steroids, including testosterone and its relatives, that are extensively metabolized into phase II sulfated or glucuronidated steroids. The use of liquid chromatography coupled to mass spectrometry (LC-MS) is an issue for the direct analysis of conjugated steroids, which can be used as urinary markers of exogenous steroid administration in doping analysis, without hydrolysis of the conjugated moiety. In this study, a sensitive and selective ultra high-pressure liquid chromatography coupled to quadrupole time-of-flight mass spectrometer (UHPLC-QTOF-MS) method was developed to quantify major urinary metabolites simultaneously after testosterone intake. The sample preparation of the urine (1 mL) was performed by solid-phase extraction on Oasis HLB sorbent using a 96-well plate format. The conjugated steroids were analyzed by UHPLC-QTOF-MS(E) with a single-gradient elution of 36 min (including re-equilibration time) in the negative electrospray ionization mode. MS(E) analysis involved parallel alternating acquisitions of both low- and high-collision energy functions. The method was validated and applied to samples collected from a clinical study performed with a group of healthy human volunteers who had taken testosterone, which were compared with samples from a placebo group. Quantitative results were also compared to GC-MS and LC-MS/MS measurements, and the correlations between data were found appropriate. The acquisition of full mass spectra over the entire mass range with QTOF mass analyzers gives promise of the opportunity to extend the steroid profile to a higher number of conjugated steroids.