“Our findings support the hypothesis that immune dysregulation underlies ME/CFS pathology” concludes a paper written by a team of researchers including Prof. Maureen Hanson.
The study recruited 93 people who met both the Institute of Medicine and Canadian Consensus Criteria for ME/CFS, and 75 sedentary controls. The methods used by the research team were complex, but when participants were compared with the sedentary controls, results suggested differences in genetic material relating to:
- Cytokine response: Cytokines are involved in triggering inflammation when the body needs to fight infection or repair tissue, they are also responsible for stopping the inflammatory response when it is no longer needed.
- B cell function: B cells are a type of white blood cell that plays a central role in a subsystem of the overall immune system known as the adaptive (or acquired) immune system.
- mRNA stability: a factor which is essential for determining the functionality cells – in this study, mRNA stability related particularly to the activation of T cells, which are a type of white blood cell that play a key role in the immune system.
- Transcriptional regulation: the biological process that coordinates cellular activity.
- Cellular stress: the adverse effects on a cell caused by environmental factors, such as oxidative stress, that disrupt normal function
- Oxygen transportation: The movement of oxygen around the body, either dissolved in blood, or bound to a protein (haemoglobin) found in red blood cells.
Analysis also highlighted key biological processes relating to the immune system which were associated with ME/CFS:
- Dysregulated cytokine signalling: This may lead to poor control of inflammation in the body.
- Immune cell activation: The process in which the defence cells in the body are switched on to address threats such as infection.
- The JAK-STAT signalling pathway: A chain of interactions between proteins in a cell that is involved in a number of processes including cell division, cell death, and immunity.
Interestingly, despite the small sample size when comparing males and females with ME/CFS, the team found an indication of sex-based differences in immune responses among those with ME/CFS.
The researchers note that, in addition to the small sample size, the study was limited as it did not consider how post exertional malaise (PEM) may impact the findings – The study team suggest that future studies should extend the work they have done by collecting samples from people with ME/CFS during PEM.
ME Research UK notes that while the healthy controls in the current study were sedentary, it is not clear how the team ensured that those with ME/CFS study were not experiencing PEM; even if they too were in a sedentary state, PEM can be triggered by many different types of exertion – social, emotional, sensory – not just physical activity.
