Analysis of RBC‐microparticles in stored whole blood bags – a promising marker to detect blood doping in sports?

Indirect biomarkers of blood doping: A systematic review

The detection of blood doping represents a current major issue in sports and an ongoing challenge for antidoping research. Initially focusing on direct detection methods to identify a banned substance or its metabolites, the antidoping effort has been progressively complemented by indirect approaches. The longitudinal and individual monitoring of specific biomarkers aims to identify nonphysiological variations that may be related to doping practices. From this perspective, the identification of markers sensitive to erythropoiesis alteration is key in the screening of blood doping. The current Athlete Biological Passport implemented since 2009 is composed of 14 variables (including two primary markers, i.e., hemoglobin concentration and OFF score) for the hematological module to be used for indirect detection of blood doping. Nevertheless, research has continually proposed and investigated new markers sensitive to an alteration of the erythropoietic cascade and specific to blood doping. If multiple early markers have been identified (at the transcriptomic level) or developed directly in a diagnostics' kit (at a proteomic level), other target variables at the end of the erythropoietic process (linked with the red blood cell functions) may strengthen the hematological module in the future. Therefore, this review aims to provide a global systematic overview of the biomarkers considered to date in the indirect investigation of blood doping.

Whispers in the Blood: Leveraging MicroRNAs for Unveiling Autologous Blood Doping in Athletes

The prevalence of autologous blood transfusions (ABTs) presents a formidable challenge in maintaining fair competition in sports, as it significantly enhances hemoglobin mass and oxygen capacity. In recognizing ABT as a prohibited form of doping, the World Anti-Doping Agency (WADA) mandates stringent detection methodologies. While current methods effectively identify homologous erythrocyte transfusions, a critical gap persists in detecting autologous transfusions. The gold standard practice of longitudinally monitoring hematological markers exhibits promise but is encumbered by limitations. Despite its potential, instances of blood doping often go undetected due to the absence of definitive verification processes. Moreover, some cases remain unpenalized due to conservative athlete-sanctioning approaches. This gap underscores the imperative need for a more reliable and comprehensive detection method capable of unequivocally differentiating autologous transfusions, addressing the challenges faced in accurately identifying such prohibited practices. The development of an advanced detection methodology is crucial to uphold the integrity of anti-doping measures, effectively identifying and penalizing instances of autologous blood transfusion. This, in turn, safeguards the fairness and equality essential to competitive sports. Our review tackles this critical gap by harnessing the potential of microRNAs in ABT doping detection. We aim to summarize alterations in the total microRNA profiles of erythrocyte concentrates during storage and explore the viability of observing these changes post-transfusion. This innovative approach opens avenues for anti-doping technologies and commercialization, positioning it as a cornerstone in the ongoing fight against doping in sports and beyond. The significance of developing a robust detection method cannot be overstated, as it ensures the credibility of anti-doping efforts and promotes a level playing field for all athletes.

Age-Markers on the Red Blood Cell Surface and Erythrocyte Microparticles may Constitute a Multi-parametric Strategy for Detection of Autologous Blood Transfusion

BACKGROUND

Autologous blood transfusion is one of the illicit strategies, banned by the World Anti-Doping Agency, to increase the levels of hemoglobin, with a consequent improvement in the delivery of oxygen to tissues. At present, this practice is detectable exclusively by the individual, longitudinal monitoring of hematological biomarkers, as in the hematological module of the Athlete Biological Passport; but this indirect approach may suffer from different confounding factors. We are presenting a multi-parametric, analytical strategy to detect autologous blood transfusions by targeting the modification of the red blood cells during storage. We focused on the assessment of "storage lesions", targeting (i) membrane proteins: Glycophorin-A and Band 3 complex, (ii) biomarkers of oxidative stress: Peroxiredoxin-2, (iii) biomarkers of senescence: CD47 and Phosphatidylserine, (iv) erythrocytes microparticles.

RESULTS

All of the above markers were monitored, by immunological and flow cytofluorimetric methods, on samples of stored whole blood collected at different time intervals, and on fresh blood samples, collected for official doping control tests, mixed "ex vivo" to simulate an autotransfusion. Although anonymized before the delivery to the laboratory, it was possible to mix samples belonging to the same subject based on the "athlete biological passport" code. Our results showed that the irreversible alteration of RBCs morphology, the loss of membrane integrity, the occurrence of hemolysis phenomena, and, more in general, the "aging" of the erythrocytes during storage are closely related to: (i) the reduced concentration, on the erythrocyte membrane, of Band 3 protein (decrease of 19% and of 39% after 20 and 40 days of storage respectively) and of glycophorin A (- 47% and - 63% respectively); (ii) the externalization of phosphatidyl serine (with a five-fold increase after 20 days and a further 2× increase after 40 days); (iii) the reduced concentration of CD47; and (iv) increased levels of erythrocyte microparticles.

CONCLUSIONS

The most promising method to detect the presence of transfused blood in whole blood samples can be based on a multi-parametric strategy, considering jointly both protein expression on RBCs membranes and micro-vesiculation phenomena.

Red blood cell derived extracellular vesicles during the process of autologous blood doping

The purpose of this pilot study was to investigate the effects of the transfusion of one erythrocyte concentrate on the number of circulating red blood cell extracellular vesicles (RBC-EVs) and their clearance time. Six, healthy volunteers donated their blood and were transfused with their RBC concentrate after 35-36 days of storage. One K₂ EDTA and one serum sample were collected before donation, at four timepoints after donation and at another six timepoints after transfusion. RBC-EVs were analyzed on a Cytek Aurora flow cytometer. A highly significant increase (p < 0.001) of RBC-EVs from an average of 60.1 ± 19.8 (10³ /μL) at baseline to 179.3 ± 84.7 (10³ /μL) in the first 1-3 h after transfusion could be observed. Individual differences in the response to transfusion became apparent with one volunteer showing no increase and another an increased concentration at one timepoint after donation due to an influenza infection. We concluded that in an individualized passport approach, increased RBC-EVs might be considered as additional evidence when interpreting suspicious Athletes Biological Passport (ABPs) but for this additional research related to sample collection and transport processes as well as method development and harmonization would be necessary.

Untargeted Metabolomics Identifies a Novel Panel of Markers for Autologous Blood Transfusion

Untargeted metabolomics was used to analyze serum and urine samples for biomarkers of autologous blood transfusion (ABT). Red blood cell concentrates from donated blood were stored for 35−36 days prior to reinfusion into the donors. Participants were sampled at different time points post-donation and up to 7 days post-transfusion. Metabolomic profiling was performed using ACQUITY ultra performance liquid chromatography (UPLC), Q-Exactive high resolution/accurate mass spectrometer interfaced with a heated electrospray ionization (HESI-II) source and Orbitrap mass analyzer operated at 35,000 mass resolution. The markers of ABT were determined by principal component analysis and metabolites that had p < 0.05 and met ≥ 2-fold change from baseline were selected. A total of 11 serum and eight urinary metabolites, including two urinary plasticizer metabolites, were altered during the study. By the seventh day post-transfusion, the plasticizers had returned to baseline, while changes in nine other metabolites (seven serum and two urinary) remained. Five of these metabolites (serum inosine, guanosine and sphinganine and urinary isocitrate and erythronate) were upregulated, while serum glycourdeoxycholate, S-allylcysteine, 17-alphahydroxypregnenalone 3 and Glutamine conjugate of C6H10O2 (2)* were downregulated. This is the first study to identify a panel of metabolites, from serum and urine, as markers of ABT. Once independently validated, it could be universally adopted to detect ABT.

Olympic anti-doping laboratory: the analytical technological road from 2016 Rio De Janeiro to 2021 Tokyo

The summer Olympic Games is the major mega sports event since the first modern era Olympiad, held in Athens, Greece in 1896. International Olympic Committee (IOC) has the responsibility of the organization of the summer and winter Games ensuring the broadcast in all corners of earth. The World Anti-Doping Agency (WADA) is the responsible organization of the fight against doping in sports. IOC and WADA support the event's country WADA Accredited Laboratory to incorporate the maximum of the new analytical technologies to become applicable during the event's antidoping testing. The current study reviewed the last 5 years progresses of the antidoping system with emphasis on the laboratory field.

Whole Blood Storage in CPDA1 Blood Bags Alters Erythrocyte Membrane Proteome

Autologous blood transfusion (ABT) has been frequently abused in endurance sport and is prohibited since the mid-1980s by the International Olympic Committee. Apart from any significant performance-enhancing effects, the ABT may pose a serious health issue due to aging erythrocyte-derived "red cell storage lesions." The current study investigated the effect of blood storage in citrate phosphate dextrose adenine (CPDA1) on the red blood cell (RBC) membrane proteome. One unit of blood was collected in CPDA1 blood bags from 6 healthy female volunteers. RBC membrane protein samples were prepared on days 0, 14, and 35 of storage. Proteins were digested in gel and peptides separated by nanoliquid chromatography coupled to tandem mass spectrometry resulting in the confident identification of 33 proteins that quantitatively change during storage. Comparative proteomics suggested storage-induced translocation of cytoplasmic proteins to the membrane while redox proteomics analysis identified 14 proteins prone to storage-induced oxidation. The affected proteins are implicated in the RBC energy metabolism and membrane vesiculation and could contribute to the adverse posttransfusion outcomes. Spectrin alpha chain, band 3 protein, glyceraldehyde-3-phosphate dehydrogenase, and ankyrin-1 were the main proteins affected by storage. Although potential biomarkers of stored RBCs were identified, the stability and lifetime of these markers posttransfusion remain unknown. In summary, the study demonstrated the importance of studying storage-induced alterations in the erythrocyte membrane proteome and the need to understand the clearance kinetics of transfused erythrocytes and identified protein markers.