Feasibility of Cell-Free DNA Measurement from the Earlobe during Physiological Exercise Testing

Nils Haller; Aleksandar Tomaskovic; Thomas Stöggl; Perikles Simon; Elmo Neuberger

doi:10.3390/diagnostics12061379

Feasibility of Cell-Free DNA Measurement from the Earlobe during Physiological Exercise Testing

Diagnostics (Basel). 2022 Jun 2;12(6):1379. doi: 10.3390/diagnostics12061379.

Authors

Nils Haller^{1

2}, Aleksandar Tomaskovic¹, Thomas Stöggl^{2

3}, Perikles Simon¹, Elmo Neuberger¹

Affiliations

¹ Department of Sports Medicine, Rehabilitation and Disease Prevention, Johannes Gutenberg University of Mainz, 55099 Mainz, Germany.
² Department of Sport and Exercise Science, University of Salzburg, 5400 Rif, Austria.
³ Red Bull Athlete Performance Center, 5303 Thalgau, Austria.

Abstract

Circulating, cell-free DNA (cfDNA) has been discussed as an upcoming blood-based biomarker in exercise physiology, reflecting important aspects of exercise load. cfDNA blood sampling has evolved from elaborate venous to efficient capillary sampling from the fingertips. In this study, we aimed to evaluate the principal feasibility of cfDNA blood sampling from the earlobe. Therefore, we obtained cfDNA concentrations from the fingertips, earlobe, and the antecubital vein during physiological exercise testing. Significantly higher concentrations were obtained from the earlobe compared to fingertip samples. All of the measurement methods showed good to excellent repeatability (ICCs of 0.85 to 0.93). In addition, the control experiments revealed that repeated sampling from the earlobe but not from the fingertips increased cfDNA at rest. In summary, cfDNA sampling is feasible for all sampling sources. However, at rest, cfDNA collected from the earlobe tend to increase over time in the absence of physical load, potentially limiting this sampling method.

Keywords: cell-free DNA; exercise physiology; liquid biopsy; load monitoring; physiological exercise testing.

Grants and funding

This research received no external funding.