Fevang, Børre, Wyller, Vegard Bruun Bratholm, Mollnes, Tom Eirik et al. · Frontiers in immunology · 2021 · DOI
This study tracked 200 teenagers with mononucleosis (caused by Epstein-Barr virus) for 6 months to understand why some developed chronic fatigue. Researchers found that teenagers who developed chronic fatigue showed persistent signs of immune system activation and inflammation, particularly elevated levels of RANTES (a signaling protein) and other inflammatory markers, both at the start of illness and 6 months later.
This longitudinal study provides immunological evidence that ME/CFS developing after EBV infection involves persistent immune dysregulation, specifically T-cell activation and chronic inflammation. Identifying biomarkers like RANTES and elevated CRP in the CF+ group may help researchers develop targeted treatments and clinicians better predict which acute EBV patients will develop chronic fatigue.
This study does not prove that elevated RANTES or inflammation directly causes chronic fatigue—only that they are associated with it. It does not establish whether these immune abnormalities are the primary driver of fatigue, a consequence of reduced physical activity, or a marker of other underlying processes. The study also does not clarify whether these findings apply to adult-onset ME/CFS or non-EBV-triggered cases.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Spotted an error in this entry? Report it →