Killer cell immunoglobulin-like receptor (KIR) alleles suggested to be associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
Ramadan, Donia Jamal, Kichula, Katherine M, Tao, Sudan et al. · Brain, behavior, and immunity · 2025 · DOI
Quick Summary
This study examined specific genetic variations in natural killer (NK) cells—immune cells that help fight infections—in people with ME/CFS compared to healthy people. Researchers found that certain genetic variants were more common in ME/CFS patients while others were less common, suggesting that differences in how NK cells are regulated may play a role in ME/CFS. This supports the idea that immune system dysfunction is involved in the condition.
Why It Matters
This study strengthens evidence that natural killer cell dysfunction is involved in ME/CFS by identifying specific genetic variants associated with the disease. Understanding the genetic basis of immune dysregulation in ME/CFS could lead to new diagnostic biomarkers and targeted treatments aimed at correcting NK cell function.
Observed Findings
Three KIR alleles were significantly more frequent in ME/CFS patients: KIR3DL3*002 (1.43× increased odds), KIR3DL1*020 (2.20× increased odds), and KIR3DL2*009 (1.56× increased odds)
Two KIR alleles were significantly less frequent in ME/CFS patients: KIR3DL3*013 (0.60× odds) and KIR3DL2*010 (0.46× odds)
No significant associations were found between ME/CFS and overall KIR gene content or copy number variations
Allelic haplotype patterns further supported the association with specific inhibitory KIR receptor variants
Inferred Conclusions
Natural killer cell regulatory dysfunction involving inhibitory receptor variants is implicated in ME/CFS pathogenesis
Specific KIR alleles may represent genetic risk or protective factors in ME/CFS susceptibility
Inhibitory KIR receptors warrant further investigation as potential immune dysfunction mechanisms in ME/CFS
Remaining Questions
How do these specific KIR alleles alter the functional capacity and behavior of natural killer cells in ME/CFS patients?
Do these genetic variants interact with environmental triggers (such as infections) to precipitate ME/CFS onset?
Can these genetic variants serve as biomarkers for disease diagnosis or prognosis, and do they correlate with disease severity?
What This Study Does Not Prove
This study shows association, not causation—having these genetic variants does not definitively cause ME/CFS, as genetic predisposition alone may not be sufficient without environmental triggers. The findings cannot yet explain how these genetic differences translate to altered NK cell function in disease. Results are from a Norwegian population and may not generalize to all geographic populations.