To study T cells in relation to ME/CFS, the researchers analysed genetic information following symptom provocation. Analysis revealed signs of exhaustion, including altered gene regulation and higher levels of exhaustion markers.

The researchers suggested that ME/CFS leaves “epigenetic scars” on T cells, making T cells more likely to enter a state of exhaustion. Nevertheless, the researchers state that although they gathered strong evidence for T cell exhaustion in ME/CFS, “it remains unknown whether this state is a driver of pathology, or a consequence of prior triggering events”.

Ultimately this research is a starting point and has generated further questions.