Category: Pathophysiology

Support for the microgenderome invites enquiry into sex differences

Abstract:

The microgenderome defines the interaction between microbiota, sex hormones and the immune system. Our recent research inferred support for the microgenderome by showing sex differences in microbiota-symptom associations in a clinical sample of patients with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS).

This addendum expands upon the sex-specific pattern of associations that were observed. Interpretations are hypothesized in relation to genera versus species-level analyses and D-lactate theory. Evidence of sex-differences invites future research to consider sex comparisons in microbial function even when microbial abundance is statistically similar. Pairing assessment of clinical symptoms with microbial culture, DNA sequencing and metabolomics methods will help advance our current understandings of the role of the microbiome in health and disease.

 

Source: Wallis A, Butt H, Ball M, Lewis DP, Bruck D. Support for the microgenderome invites enquiry into sex differences. Gut Microbes. 2017 Jan 2;8(1):46-52. doi: 10.1080/19490976.2016.1256524. Epub 2016 Nov 3. https://www.ncbi.nlm.nih.gov/pubmed/27808584

 

Hypothalamic-Pituitary-Adrenal Hypofunction in Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) as a Consequence of Activated Immune-Inflammatory and Oxidative and Nitrosative Pathways

Abstract:

There is evidence that immune-inflammatory and oxidative and nitrosative stress (O&NS) pathways play a role in the pathophysiology of myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS). There is also evidence that these neuroimmune diseases are accompanied by hypothalamic-pituitary-adrenal (HPA) axis hypoactivity as indicated by lowered baseline glucocorticoid levels.

This paper aims to review the bidirectional communications between immune-inflammatory and O&NS pathways and HPA axis hypoactivity in ME/CFS, considering two possibilities: (a) Activation of immune-inflammatory pathways is secondary to HPA axis hypofunction via attenuated negative feedback mechanisms, or (b) chronic activated immune-inflammatory and O&NS pathways play a causative role in HPA axis hypoactivity.

Electronic databases, i.e., PUBMED, Scopus, and Google Scholar, were used as sources for this narrative review by using keywords CFS, ME, cortisol, ACTH, CRH, HPA axis, glucocorticoid receptor, cytokines, immune, immunity, inflammation, and O&NS.

Findings show that activation of immune-inflammatory and O&NS pathways in ME/CFS are probably not secondary to HPA axis hypoactivity and that activation of these pathways may underpin HPA axis hypofunction in ME/CFS. Mechanistic explanations comprise increased levels of tumor necrosis factor-α, T regulatory responses with elevated levels of interleukin-10 and transforming growth factor-β, elevated levels of nitric oxide, and viral/bacterial-mediated mechanisms.

HPA axis hypoactivity in ME/CFS is most likely a consequence and not a cause of a wide variety of activated immune-inflammatory and O&NS pathways in that illness.

 

Source: Morris G, Anderson G, Maes M. Hypothalamic-Pituitary-Adrenal Hypofunction in Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) as a Consequence of Activated Immune-Inflammatory and Oxidative and Nitrosative Pathways. Mol Neurobiol. 2016 Oct 20. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27766535

 

Elevated Energy Production in Chronic Fatigue Syndrome Patients

Abstract:

Chronic Fatigue Syndrome (CFS) is a debilitating disease characterized by physical and mental exhaustion. The underlying pathogenesis is unknown, but impairments in certain mitochondrial functions have been found in some CFS patients. To thoroughly reveal mitochondrial deficiencies in CFS patients, here we examine the key aspects of mitochondrial function in blood cells from a paired CFS patient-control series. Surprisingly, we discover that in patients the ATP levels are higher and mitochondrial cristae are more condensed compared to their paired controls, while the mitochondrial crista length, mitochondrial size, shape, density, membrane potential, and enzymatic activities of the complexes in the electron transport chain remain intact. We further show that the increased ATP largely comes from non-mitochondrial sources. Our results indicate that the fatigue symptom in this cohort of patients is unlikely caused by lack of ATP and severe mitochondrial malfunction. On the contrary, it might be linked to a pathological mechanism by which more ATP is produced by non-mitochondrial sources.

 

Source: Lawson N, Hsieh CH, March D, Wang X. Elevated Energy Production in Chronic Fatigue Syndrome Patients. J Nat Sci. 2016;2(10). pii: e221. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5065105/ (Full article)

 

Index markers of chronic fatigue syndrome with dysfunction of TCA and urea cycles

Abstract:

Chronic fatigue syndrome (CFS) is a persistent and unexplained pathological state characterized by exertional and severely debilitating fatigue, with/without infectious or neuropsychiatric symptoms, lasting at least 6 consecutive months. Its pathogenesis remains incompletely understood.

Here, we performed comprehensive metabolomic analyses of 133 plasma samples obtained from CFS patients and healthy controls to establish an objective diagnosis of CFS.

CFS patients exhibited significant differences in intermediate metabolite concentrations in the tricarboxylic acid (TCA) and urea cycles. The combination of ornithine/citrulline and pyruvate/isocitrate ratios discriminated CFS patients from healthy controls, yielding area under the receiver operating characteristic curve values of 0.801 (95% confidential interval [CI]: 0.711-0.890, P < 0.0001) and 0.750 (95% CI: 0.584-0.916, P = 0.0069) for training (n = 93) and validation (n = 40) datasets, respectively.

These findings provide compelling evidence that a clinical diagnostic tool could be developed for CFS based on the ratios of metabolites in plasma.

 

Source: Yamano E, Sugimoto M, Hirayama A, Kume S, Yamato M, Jin G, Tajima S, Goda N, Iwai K, Fukuda S, Yamaguti K, Kuratsune H, Soga T, Watanabe Y, Kataoka Y. Index markers of chronic fatigue syndrome with dysfunction of TCA and urea cycles. Sci Rep. 2016 Oct 11;6:34990. doi: 10.1038/srep34990. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5057083/ (Full article)

 

Emotional conflict processing in adolescent chronic fatigue syndrome: A pilot study using functional magnetic resonance imaging

Abstract:

INTRODUCTION: Studies of neurocognition suggest that abnormalities in cognitive control contribute to the pathophysiology of chronic fatigue syndrome (CFS) in adolescents, yet these abnormalities remain poorly understood at the neurobiological level. Reports indicate that adolescents with CFS are significantly impaired in conflict processing, a primary element of cognitive control.

METHOD: In this study, we examine whether emotional conflict processing is altered on behavioral and neural levels in adolescents with CFS and a healthy comparison group. Fifteen adolescent patients with CFS and 24 healthy adolescent participants underwent functional magnetic resonance imaging (fMRI) while performing an emotional conflict task that involved categorizing facial affect while ignoring overlaid affect labeled words.

RESULTS: Adolescent CFS patients were less able to engage the left amygdala and left midposterior insula (mpINS) in response to conflict than the healthy comparison group. An association between accuracy interference and conflict-related reactivity in the amygdala was observed in CFS patients. A relationship between response time interference and conflict-related reactivity in the mpINS was also reported. Neural responses in the amygdala and mpINS were specific to fatigue severity.

CONCLUSIONS: These data demonstrate that adolescent CFS patients displayed deficits in emotional conflict processing. Our results suggest abnormalities in affective and cognitive functioning of the salience network, which might underlie the pathophysiology of adolescent CFS.

 

Source: Wortinger LA, Endestad T, Melinder AM, Øie MG, Sulheim D, Fagermoen E, Wyller VB. Emotional conflict processing in adolescent chronic fatigue syndrome: A pilot study using functional magnetic resonance imaging. J Clin Exp Neuropsychol. 2016 Sep 20:1-14. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27647312

 

The Role of Microbiota and Intestinal Permeability in the Pathophysiology of Autoimmune and Neuroimmune Processes with an Emphasis on Inflammatory Bowel Disease Type 1 Diabetes and Chronic Fatigue Syndrome

Abstract:

BACKGROUND: In steady state conditions intestinal immune homeostasis is maintained by a sophisticated bidirectional dialogue between the microbiota and the intestinal immune system. This “cross talk” is enabled by the presence of highly adapted secretory cells, sampling cells and pattern recognition receptors in the gastric epithelium.

METHODS: Herein we discuss the mechanisms involved in the breakdown of intestinal homeostasis and the development of systemic immune activation and neuroinflammation with a view to discussing the importance of these processes, in tandem with genetic and environmental factors, in the pathophysiology of (auto)immune diseases.Data is presented explaining how immune tolerance is maintained and how it may breakdown.

CONCLUSION: The breakdown of immune homeostasis following the development of gut inflammation, caused for example by gut dysbiosis, and the consequent increased intestinal permeability, is increasingly considered to be the ultimate source of the systemic immune activation and T helper 17/T regulatory cell imbalances, and maybe neurological disturbances, seen in autoimmune diseases such as Type 1 diabetes and inflammatory bowel disease. Increased intestinal permeability and translocation of commensal antigens into the systemic circulation is also a likely cause of the severe fatigue and an almost bewildering range of neurocognitive, neuroimaging and overall symptom presentations seen in patients with a diagnosis of Chronic Fatigue Syndrome.

 

Source: Morris G, Berk M, Carvalho AF, Caso JR, Sanz Y, Maes M. The Role of Microbiota and Intestinal Permeability in the Pathophysiology of Autoimmune and Neuroimmune Processes with an Emphasis on Inflammatory Bowel Disease Type 1 Diabetes and Chronic Fatigue Syndrome. Curr Pharm Des. 2016;22(40):6058-6075. https://www.ncbi.nlm.nih.gov/pubmed/27634186

 

Association of biomarkers with health-related quality of life and history of stressors in myalgic encephalomyelitis/chronic fatigue syndrome patients

Abstract:

BACKGROUND: Myalgic encephalomyelitis chronic fatigue syndrome (ME/CFS) is a common debilitating disorder associated with an intense fatigue, a reduced physical activity, and an impaired quality of life. There are no established biological markerof the syndrome. The etiology is unknown and its pathogenesis appears to be multifactorial. Various stressors, including intense physical activity, severe infection, and emotional stress are reported in the medical history of ME/CFS patients which raises the question whether any physiological and biological abnormalities usually found in these patients could be indicative of the etiology and/or the quality-of-life impairment.

METHODS: Thirty-six patients and 11 age-matched healthy controls were recruited. The following variables that appear to address common symptoms of ME/CFS were studied here: (1) muscle fatigue during exercise has been investigated by monitoring the compound muscle action potential (M-wave); (2) the excessive oxidative stress response to exercise was measured via two plasma markers (thiobarbituric acid reactive substances: TBARS; reduced ascorbic-acid: RAA); (3) a potential inflammatory component was addressed via expression of CD26 on peripheral blood mononuclear cells; (4) quality-of-life impairment was assessed using the London Handicap Scale (LHS) and the Medical Outcome Study Short Form-36 (SF-36). The medical history of each patient, including the presence of stressors such as intense sports practice, severe acute infection and/or severe emotional stress was documented.

RESULTS: We observed that: (1) there were striking differences between cases and controls with regard to three biological variables: post-exercise M-wave, TBARS variations and CD26-expression at rest; (2) each of these three variables correlated with the other two; (3) abnormalities in the biomarkers associated with health-related quality of life: the LHS score was negatively correlated with the exercise-induced TBARS increase and positively correlated with CD26-expression while the pain component of SF-36 was negatively correlated with CD26-expression; (4) the TBARS increase and the M-wave decrease were the highest, and the CD26-expression level the lowest in patients who had been submitted to infectious stressors.

CONCLUSION: In ME/CFS patients, severe alterations of the muscle excitability, the redox status, as well as the CD26-expression level are correlated with a marked impairment of the quality-of-life. They are particularly significant when infectious stressors are reported in the medical history.

 

Source: Fenouillet E, Vigouroux A, Steinberg JG, Chagvardieff A, Retornaz F, Guieu R, Jammes Y. Association of biomarkers with health-related quality of life and history of stressors in myalgic encephalomyelitis/chronic fatigue syndrome patients. J Transl Med. 2016 Aug 31;14:251. doi: 10.1186/s12967-016-1010-x. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5006431/ (Full article)

 

Metabolic features of chronic fatigue syndrome

Abstract:

More than 2 million people in the United States have myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We performed targeted, broad-spectrum metabolomics to gain insights into the biology of CFS.

We studied a total of 84 subjects using these methods. Forty-five subjects (n = 22 men and 23 women) met diagnostic criteria for ME/CFS by Institute of Medicine, Canadian, and Fukuda criteria. Thirty-nine subjects (n = 18 men and 21 women) were age- and sex-matched normal controls. Males with CFS were 53 (±2.8) y old (mean ± SEM; range, 21-67 y). Females were 52 (±2.5) y old (range, 20-67 y). The Karnofsky performance scores were 62 (±3.2) for males and 54 (±3.3) for females.

We targeted 612 metabolites in plasma from 63 biochemical pathways by hydrophilic interaction liquid chromatography, electrospray ionization, and tandem mass spectrometry in a single-injection method. Patients with CFS showed abnormalities in 20 metabolic pathways. Eighty percent of the diagnostic metabolites were decreased, consistent with a hypometabolic syndrome. Pathway abnormalities included sphingolipid, phospholipid, purine, cholesterol, microbiome, pyrroline-5-carboxylate, riboflavin, branch chain amino acid, peroxisomal, and mitochondrial metabolism.

Area under the receiver operator characteristic curve analysis showed diagnostic accuracies of 94% [95% confidence interval (CI), 84-100%] in males using eight metabolites and 96% (95% CI, 86-100%) in females using 13 metabolites. Our data show that despite the heterogeneity of factors leading to CFS, the cellular metabolic response in patients was homogeneous, statistically robust, and chemically similar to the evolutionarily conserved persistence response to environmental stress known as dauer.

 

Source: Naviaux RK, Naviaux JC, Li K, Bright AT, Alaynick WA, Wang L, Baxter A, Nathan N, Anderson W, Gordon E. Metabolic features of chronic fatigue syndrome. Proc Natl Acad Sci U S A. 2016 Sep 13;113(37):E5472-80. doi: 10.1073/pnas.1607571113. Epub 2016 Aug 29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5027464/ (Full article)

Comment

G L Francis 2016 Sep 19 04:58 a.m.

I have read your publication in PNAS titled ‘Metabolic features of chronic fatigue syndrome’ with much interest, this significant contribution has at last provided a definitive publication of a realistic evidence based diagnostic test based on a panel of blood metabolites – this could provide a more robust diagnostic base for future rational treatment studies in ‘CFS’.

Athough there are many more complex and critical questions to be asked, I will keep mine simple. I took particular note of the authors comments “When MTHFD2L is turned down in differentiated cells, less mitochondrial formate is produced and one-carbon units are directed through Methylene-THF toward increased SAM synthesis and increased DNA methylation” (from Figure S6. Mitochondrial Control of Redox, NADPH, Nucleotide, and Methylation Pathways legend). I recently read the paper, ‘Association of Vitamin B12 Deficiency with Homozygosity of the TT MTHFR C677T Genotype, Hyperhomocysteinemia, and Endothelial Cell Dysfunction’ Shiran A et al. IMAJ 2015; 17: 288–292, and wondered whether the gene variations in the individuals described within that publication, could be over represented in your subjects, mind you the size of your study population probably answers my own question; and no doubt many mechanisms that lead to a perturbation of this pathway exist, of which this could conceivable be just one of many, even if a minor contributor. Moreover, there does seem to be a difference between the two papers in terms of the particular pertubations on incidence of cardiovascular disease and outcomes?

 

Potential use of visible and near-infrared spectroscopy for the analysis and diagnosis of chronic fatigue syndrome (Review)

Abstract:

At present, chronic fatigue syndrome (CFS) is diagnosed on the basis of clinical symptoms. Although various psychological, endocrinological and immunological abnormalities of patients with CFS have been reported, no clear consensus exists regarding the symptoms for this disorder. Thus, an objective diagnostic method for CFS is urgently required.

The present study investigated the diagnosis and analysis of CFS using visible and near infrared (Vis NIR) spectroscopy. Previous studies have demonstrated the potential of Vis-NIR spectroscopy for diagnosing CFS by analyzing either serum samples as an invasive approach or thumbs as a non invasive approach.

Analysis of the Vis NIR spectra of blood and thumbs suggested that factors absorbing in this spectral region are altered in patients with CFS compared with healthy individuals. These findings are likely to facilitate the search for biomarkers associated with CFS and to increase our understanding of the pathophysiology of the disorder. The current review aimed to outline the latest studies and discuss the future perspectives for CFS made possible by Vis-NIR spectroscopy.

 

Source: Sakudo A. Potential use of visible and near-infrared spectroscopy for the analysis and diagnosis of chronic fatigue syndrome (Review). Mol Med Rep. 2016 Sep;14(3):1875-9. doi: 10.3892/mmr.2016.5476. Epub 2016 Jul 7. https://www.ncbi.nlm.nih.gov/pubmed/27430297

 

Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a complex, multisystem disorder that can be disabling. CFS symptoms can be provoked by increased physical or cognitive activity, and by orthostatic stress. In preliminary work, we noted that CFS symptoms also could be provoked by application of longitudinal neural and soft tissue strain to the limbs and spine of affected individuals.

In this study we measured the responses to a straight leg raise neuromuscular strain maneuver in individuals with CFS and healthy controls. We randomly assigned 60 individuals with CFS and 20 healthy controls to either a 15 minute period of passive supine straight leg raise (true neuromuscular strain) or a sham straight leg raise. The primary outcome measure was the symptom intensity difference between the scores during and 24 hours after the study maneuver compared to baseline.

Fatigue, body pain, lightheadedness, concentration difficulties, and headache scores were measured individually on a 0-10 scale, and summed to create a composite symptom score. Compared to individuals with CFS in the sham strain group, those with CFS in the true strain group reported significantly increased body pain (P = 0.04) and concentration difficulties (P = 0.02) as well as increased composite symptom scores (all P = 0.03) during the maneuver.

After 24 hours, the symptom intensity differences were significantly greater for the CFS true strain group for the individual symptom of lightheadedness (P = 0.001) and for the composite symptom score (P = 0.005). During and 24 hours after the exposure to the true strain maneuver, those with CFS had significantly higher individual and composite symptom intensity changes compared to the healthy controls.

We conclude that a longitudinal strain applied to the nerves and soft tissues of the lower limb is capable of increasing symptom intensity in individuals with CFS for up to 24 hours. These findings support our preliminary observations that increased mechanical sensitivity may be a contributor to the provocation of symptoms in this disorder.

 

Source: Rowe PC, Fontaine KR, Lauver M, Jasion SE, Marden CL, Moni M, Thompson CB, Violand RL. Neuromuscular Strain Increases Symptom Intensity in Chronic Fatigue Syndrome. PLoS One. 2016 Jul 18;11(7):e0159386. doi: 10.1371/journal.pone.0159386. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948885/ (Full article)