Whole blood gene expression in adolescent CFS: altered B cell differentiation and survival, 2017, Nguyen et al

https://pubmed.ncbi.nlm.nih.gov/28494812/
Whole blood gene expression in adolescent chronic fatigue syndrome: an exploratory cross-sectional study suggesting altered B cell differentiation and survival

Chinh Bkrong Nguyen 1 2, Lene Alsøe 3, Jessica M Lindvall 4, Dag Sulheim 5, Even Fagermoen 6, Anette Winger 7, Mari Kaarbø 8, Hilde Nilsen 3, Vegard Bruun Wyller 9 10

Abstract
Background: Chronic fatigue syndrome (CFS) is a prevalent and disabling condition affecting adolescents. The pathophysiology is poorly understood, but immune alterations might be an important component. This study compared whole blood gene expression in adolescent CFS patients and healthy controls, and explored associations between gene expression and neuroendocrine markers, immune markers and clinical markers within the CFS group.

Methods: CFS patients (12-18 years old) were recruited nation-wide to a single referral center as part of the NorCAPITAL project. A broad case definition of CFS was applied, requiring 3 months of unexplained, disabling chronic/relapsing fatigue of new onset, whereas no accompanying symptoms were necessary. Healthy controls having comparable distribution of gender and age were recruited from local schools. Whole blood samples were subjected to RNA sequencing.

Immune markers were blood leukocyte counts, plasma cytokines, serum C-reactive protein and immunoglobulins. Neuroendocrine markers encompassed plasma and urine levels of catecholamines and cortisol, as well as heart rate variability indices. Clinical markers consisted of questionnaire scores for symptoms of post-exertional malaise, inflammation, fatigue, depression and trait anxiety, as well as activity recordings.

Results: A total of 29 CFS patients and 18 healthy controls were included. We identified 176 genes as differentially expressed in patients compared to controls, adjusting for age and gender factors. Gene set enrichment analyses suggested impairment of B cell differentiation and survival, as well as enhancement of innate antiviral responses and inflammation in the CFS group. A pattern of co-expression could be identified, and this pattern, as well as single gene transcripts, was significantly associated with indices of autonomic nervous activity, plasma cortisol, and blood monocyte and eosinophil counts. Also, an association with symptoms of post-exertional malaise was demonstrated.

Conclusion: Adolescent CFS is characterized by differential gene expression pattern in whole blood suggestive of impaired B cell differentiation and survival, and enhanced innate antiviral responses and inflammation. This expression pattern is associated with neuroendocrine markers of altered HPA axis and autonomic nervous activity, and with symptoms of post-exertional malaise. Trial registration Clinical Trials NCT01040429.

 

That final author is the BPS Wyller.

(crosspost) Note the definition of CFS - 3 months of unexplained fatigue of new onset.

The paper notes that previous attempts at relating gene expression to clinical symptoms of CFS have struggled, and that it might be because things are rather complicated. So, they decided to have a go.
A total of 29 CFS patients and 18 healthy controls, a mixed gender sample, and a ridiculously wide definition of the illness. They actually say this:

What could possibly go wrong?

 

Cortisol - my favourite measure
Plasma cortisol mol/L

Patients Mean 334 Standard deviation 151
Controls Mean 349 Standard deviation 202

Look at the difference between the means, relative to the standard deviations for the samples. There is no difference, nothing at all to suggest that the cortisol levels of the young patients are unusual. The P value of 0.782 clearly indicates there is no significant difference. (Of course, it's highly debatable whether all the patients have (ME/)CFS.)

 

Really the only notable biochemical findings are for norepinephrine and epinephrine (also known as adrenalin).
First some background:

Plasma norepinephrine pmol/L - Normal range 414 to 10,049 pmol/L
Patients 2067 Standard deviation 835 - so entirely normal
Controls 1530 Standard deviation 358

Plasma epinephrine pmol/L - Normal range 0 to 764.3 pmol/L
Patients 362 Standard deviation 131 - also entirely normal
Controls 284 Standard deviation 74

Patients have just slightly higher levels than the controls, but maybe they also have low blood pressure. And the data collection was all done between 7.30 am and 9 am, so I am sure some people were firing on adrenalin (and probably quite a lot of coffee, which increases both epinephrine and norepinephrine) to get to the clinic. But, even so, the levels were normal.

This study makes all sorts of complicated models trying to associate gene expression with biochemical markers that are entirely unremarkable. From a tiny sample of people who may or may not have ME/CFS. (The study says 11 of the 29 people with 'CFS' met the CCC criteria, but, as Andy says, the authors don't seem to have grasped the concept of PEM, so, who knows.)

This study claimed to be, and has been cited as, evidence of HPA axis issues in ME/CFS.

That's a load of baloney - this study is not evidence of abnormal neuroendocrine levels in ME/CFS. Nor is it evidence of a causal relationship between 'neuroendocrine changes and immune alterations [37]'. Or of anything to do with HPA axis issues.

Ref [37] is a paper by Wyller et al 'Can sustained arousal explain chronic fatigue syndrome?'. Looks like he was determined to find a positive answer to that question, regardless of the data.

 

I think a good way would be for one of the international ME/CFS charities (e.g. the World ME Alliance) to make guidelines for ME/CFS research, with criteria and standard outcomes and requirements to have people with ME/CFS involved in the study design, and have all the national charities promote those with their national research funding bodies.