Integrating whole blood transcriptomic collection procedures into the current anti-doping testing system, including long-term storage and re-testing of anti-doping samples [Long-term]

Purpose: Recombinant human erythropoietin administration studies involving “omics” approaches have demonstrated a gene-expression signature that could aid detection of blood doping. However, current anti-doping testing does not involve blood collection into tubes with RNA preservative. This study investigated if whole blood in long-term storage could be used for transcriptomic analysis despite lacking RNA preservation. Methods: Whole blood samples were collected from thirteen male healthy individuals. Long-term storage: whole blood collected into Tempus™ tubes and K2EDTA tubes and subjected to long-term (i.e., -80°C) storage and RNA extracted. After storage, Tempus and K2EDTA tubes were thawed and extracted using Tempus™ Spin RNA Isolation Kit (Life Technologies, Carlsbad, CA, USA). Samples from seven subjects that presented higher RIN value (=7) were selected for RNA_Seq analysis. Results: The experiment provided RNA quality and purity for gene expression analysis. Total of 19239 genes were mapped and the gene expression analysis showed that 658 genes were differentially expressed (which means 3.4% of mapped genes). With 269 being up-regulated and 389 down-regulated. None of the transcripts described in previous studies as biomarkers for blood doping (Durussel et al. 2016; Wang, Durussel, et al. 2017) were differently expressed. Conclusion: RNA quantity, purity and integrity was not significantly compromised from long-term storage in blood storage tubes lacking RNA stabilisation, indicating that transcriptomic/omics analysis could be conducted using anti-doping samples collected or biobanked without RNA preservation. Overall design: Blood samples were collected using K2EDTA tubes or Tempus (control). After long-term storage, blood samples from K2EDTA tubes were transferred into Tempus tube. Both groups (EDTA+Tempus and Tempus) were extracted by using Tempus™ Spin RNA Isolation Kit. The different gene expression between groups was compared.