The role of low-grade inflammation in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) – associations with symptoms

Abstract:

BACKGROUND: Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) often present with a range of flu-like symptoms resembling sickness behavior as well as widespread pain and concentration deficits. The aim of this study was to explore the association between inflammatory markers previously shown to be related to fatigue severity in ME/CFS and common ME/CFS symptoms post-exertional fatigue, impaired cognitive processing, musculoskeletal pain and recurrent flu-like symptoms, and the moderating effect of sex on these associations.

METHODS: 53 adult patients diagnosed with ME/CFS at a specialist clinic were included in the study. Fasting blood plasma was analyzed using the Olink Proseek Multiplex Inflammation panel (β-NGF, CCL11, CXCL1, CXCL10, IL-6, IL-7, IL-8, IL-10, IL-18, TGF-α, TGF-β-1 and SCF) and BioRad Human Cytokine Type 1 assay (TNF-α). Participants rated the average severity of symptoms (0-10) based on the 2011 International Consensus Criteria of ME/CFS during a structured clinical interview. Associations between inflammatory markers and symptom severity were analyzed using bivariate correlations and moderated regression analyses bootstrapped with 5000 repetitions.

RESULTS AND CONCLUSIONS: Only β-NGF was associated with the fatigue severity measure. However, higher levels of CCL11, CXCL10, IL-7, TNF-α and TGF-β-1 were significantly associated with higher levels of impaired cognitive processing and musculoskeletal pain, and sex was a significant moderator for CXCL10, IL-7 and TGF-β-1. Future studies should investigate the relationship between inflammatory markers and key symptoms in ME/CFS in a longitudinal design in order to explore if and for whom low-grade inflammation may contribute to illness development.

Copyright © 2019. Published by Elsevier Ltd.

Source: Jonsjö MA, Olsson GL, Wicksell RK, Alving K, Holmström L, Andreasson A. The role of low-grade inflammation in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) – associations with symptoms. Psychoneuroendocrinology. 2019 Dec 26;113:104578. doi: 10.1016/j.psyneuen.2019.104578. [Epub ahead of print] https://www.sciencedirect.com/science/article/pii/S0306453019313198?via%3Dihub (Full article)

Post-exertional malaise is associated with greater symptom burden and psychological distress in patients diagnosed with Chronic Fatigue Syndrome

Abstract:

OBJECTIVE: Post-exertional malaise (PEM) is often considered a cardinal symptom of Chronic Fatigue Syndrome (CFS). There is no gold standard diagnostic method for CFS, however, and the Centers for Disease Control (CDC) Fukuda case definition does not require PEM. Research has identified differences in symptom burden between patients according to PEM, but whether it is associated with psychological distress has not been investigated.

METHODS: The CDC CFS Inventory, Fatigue Symptom Inventory, Profile of Mood States, Center for Epidemiologic Studies Depression Scale, Perceived Stress Scale, and subscales of the Sickness Impact Profile were administered to 261 patients diagnosed with the Fukuda criteria. PEM status (loPEM/hiPEM) was determined via self-reported post-exertional fatigue severity. Analyses of covariance (ANCOVA), controlling for age and gender, assessed cross-sectional group differences, and cross-sectional linear regressions using the continuous PEM severity predictor paralleled these analyses.

RESULTS: hiPEM patients reported greater symptom intensity, frequency, and interference than loPEM counterparts (p’s < .001). hiPEM patients also reported greater social disruption, depressive symptoms, and mood disturbance (p’s ≤ .011). Groups did not differ in recent negative life experiences, perceived stress, or demographic variables. The results of regression analyses mirrored those of ANCOVAs.

CONCLUSION: This study replicates the association between PEM and symptom burden and additionally associates PEM with psychological distress; psychological distress could, however, be a consequence of symptom burden. Differences between hiPEM and loPEM CFS patients highlight the heterogeneity of diagnoses resulting from the Fukuda criteria. It is also possible that PEM identifies particularly distressed patients for whom psychological intervention would be most beneficial.

Copyright © 2019 Elsevier Inc. All rights reserved

Source: May M, Milrad SF, Perdomo DM, Czaja SJ, Fletcher MA, Jutagir DR, Hall DL, Klimas N, Antoni MH. Post-exertional malaise is associated with greater symptom burden and psychological distress in patients diagnosed with Chronic Fatigue Syndrome. J Psychosom Res. 2019 Dec 16;129:109893. doi: 10.1016/j.jpsychores.2019.109893. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31884303

Rethinking ME/CFS Diagnostic Reference Intervals via Machine Learning, and the Utility of Activin B for Defining Symptom Severity

Abstract:

Biomarker discovery applied to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a disabling disease of inconclusive aetiology, has identified several cytokines to potentially fulfil a role as a quantitative blood/serum marker for laboratory diagnosis, with activin B a recent addition. We explored further the potential of serum activin B as a ME/CFS biomarker, alone and in combination with a range of routine test results obtained from pathology laboratories.

Previous pilot study results showed that activin B was significantly elevated for the ME/CFS participants compared to healthy (control) participants. All the participants were recruited via CFS Discovery and assessed via the Canadian/International Consensus Criteria. A significant difference for serum activin B was also detected for ME/CFS and control cohorts recruited for this study, but median levels were significantly lower for the ME/CFS cohort.

Random Forest (RF) modelling identified five routine pathology blood test markers that collectively predicted ME/CFS at ≥62% when compared via weighted standing time (WST) severity classes. A closer analysis revealed that the inclusion of activin B to the panel of pathology markers improved the prediction of mild to moderate ME/CFS cases. Applying correct WST class prediction from RFA modelling, new reference intervals were calculated for activin B and associated pathology markers, where 24-h urinary creatinine clearance, serum urea and serum activin B showed the best potential as diagnostic markers. While the serum activin B results remained statistically significant for the new participant cohorts, activin B was found to also have utility in enhancing the prediction of symptom severity, as represented by WST class.

Source: Lidbury BA, Kita B, Richardson AM, Lewis DP, Privitera E, Hayward S, de Kretser D, Hedger M. Rethinking ME/CFS Diagnostic Reference Intervals via Machine Learning, and the Utility of Activin B for Defining Symptom Severity. Diagnostics (Basel). 2019 Jul 19;9(3). pii: E79. doi: 10.3390/diagnostics9030079. https://www.mdpi.com/2075-4418/9/3/79 (Full article)

Inflammation correlates with symptoms in chronic fatigue syndrome

It is not unusual for patients who say they are sick to have normal results on standard laboratory testing. The physician often concludes that there is no “real” illness and that the patients’ symptoms likely stem from a psychological disorder. An alternative conclusion, often honored in the breach, is that the standard laboratory tests are measuring the wrong things.

Chronic fatigue syndrome (CFS)―also called myalgic encephalomyelitis/chronic fatigue syndrome―is such an illness. Often, the condition begins suddenly, following an “infectious-like” illness.

For years, patients do not return to full health. The illness waxes and wanes, and at its worst leads patients to be bedridden or unable to leave their homes. A report from the National Academies estimates that CFS affects up to 2.5 million people in the United States and generates direct and indirect expenses of $17–24 billion annually (1). The most widely used case definition (2) consists only of symptoms. This, along with typically normal results on standard laboratory tests, has raised the question of whether there are any “real” objective, biological abnormalities in CFS. In PNAS, Montoya et al. report the latest evidence that there are such abnormalities.

Indeed, research over the past 30 y has discovered pathology involving the central nervous system (CNS) and autonomic nervous system (ANS), energy metabolism (with associated oxidative and nitrosative stress), and the immune system, as described in a detailed review (4). This Commentary will briefly summarize the evidence, providing citations only to work published since this review. I will then place the report by Montoya et al. (3) in context, and speculate about the pathophysiology of the illness.

Source: Anthony Komaroff. Inflammation correlates with symptoms in chronic fatigue syndrome. PNAS  2017 ; published ahead of print August 15, 2017 doi: 10.1073/pnas.1712475114  http://www.pnas.org/content/early/2017/08/14/1712475114.extract

Cytokine signature associated with disease severity in chronic fatigue syndrome patients

Abstract:

Although some signs of inflammation have been reported previously in patients with myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), the data are limited and contradictory. High-throughput methods now allow us to interrogate the human immune system for multiple markers of inflammation at a scale that was not previously possible.

To determine whether a signature of serum cytokines could be associated with ME/CFS and correlated with disease severity and fatigue duration, cytokines of 192 ME/CFS patients and 392 healthy controls were measured using a 51-multiplex array on a Luminex system. Each cytokine’s preprocessed data were regressed on ME/CFS severity plus covariates for age, sex, race, and an assay property of newly discovered importance: nonspecific binding.

On average, TGF-β was elevated (P = 0.0052) and resistin was lower (P = 0.0052) in patients compared with controls. Seventeen cytokines had a statistically significant upward linear trend that correlated with ME/CFS severity: CCL11 (Eotaxin-1), CXCL1 (GROα), CXCL10 (IP-10), IFN-γ, IL-4, IL-5, IL-7, IL-12p70, IL-13, IL-17F, leptin, G-CSF, GM-CSF, LIF, NGF, SCF, and TGF-α. Of the 17 cytokines that correlated with severity, 13 are proinflammatory, likely contributing to many of the symptoms experienced by patients and establishing a strong immune system component of the disease. Only CXCL9 (MIG) inversely correlated with fatigue duration.

Source: Montoya JG, Holmes TH, Anderson JN, Maecker HT, Rosenberg-Hasson Y, Valencia IJ, Chu L, Younger JW, Tato CM, Davis MM. Cytokine signature associated with disease severity in chronic fatigue syndrome patients. Proc Natl Acad Sci U S A. 2017 Jul 31. pii: 201710519. doi: 10.1073/pnas.1710519114. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28760971

Mitochondrial DNA variants correlate with symptoms in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

BACKGROUND: Mitochondrial dysfunction has been hypothesized to occur in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a disease characterized by fatigue, cognitive difficulties, pain, malaise, and exercise intolerance. We investigated whether haplogroup, single nucleotide polymorphisms (SNPs), or heteroplasmy of mitochondrial DNA (mtDNA) were associated with health status and/or symptoms.

METHODS: Illumina sequencing of PCR-amplified mtDNA was performed to analyze sequence and extent of heteroplasmy of mtDNAs of 193 cases and 196 age- and gender-matched controls from DNA samples collected by the Chronic Fatigue Initiative. Association testing was carried out to examine possible correlations of mitochondrial sequences with case/control status and symptom constellation and severity as reported by subjects on Short Form-36 and DePaul Symptom Questionnaires.

RESULTS: No ME/CFS subject exhibited known disease-causing mtDNA mutations. Extent of heteroplasmy was low in all subjects. Although no association between mtDNA SNPs and ME/CFS vs. healthy status was observed, haplogroups J, U and H as well as eight SNPs in ME/CFS cases were significantly associated with individual symptoms, symptom clusters, or symptom severity.

CONCLUSIONS: Analysis of mitochondrial genomes in ME/CFS cases indicates that individuals of a certain haplogroup or carrying specific SNPs are more likely to exhibit certain neurological, inflammatory, and/or gastrointestinal symptoms. No increase in susceptibility to ME/CFS of individuals carrying particular mitochondrial genomes or SNPs was observed.

 

Source: Billing-Ross P, Germain A, Ye K, Keinan A, Gu Z, Hanson MR. Mitochondrial DNA variants correlate with symptoms in myalgic encephalomyelitis/chronic fatigue syndrome. J Transl Med. 2016 Jan 20;14:19. doi: 10.1186/s12967-016-0771-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4719218/ (Full article)

 

What is in a name? Comparing diagnostic criteria for chronic fatigue syndrome with or without fibromyalgia

Abstract:

The current study had two objectives. (1) to compare objective and self-report measures in patients with chronic fatigue syndrome (CFS) according to the 1994 Center for Disease Control (CDC) criteria, patients with multiple sclerosis (MS), and healthy controls, and (2) to contrast CFS patients who only fulfill CDC criteria to those who also fulfill the criteria for myalgic encephalomyelitis (ME), the 2003 Canadian criteria for ME/CFS, or the comorbid diagnosis of fibromyalgia (FM).

One hundred six participants (48 CFS patients diagnosed following the 1994 CDC criteria, 19 MS patients, and 39 healthy controls) completed questionnaires assessing symptom severity, quality of life, daily functioning, and psychological factors. Objective measures consisted of activity monitoring, evaluation of maximal voluntary contraction and muscle recovery, and cognitive performance. CFS patients were screened whether they also fulfilled ME criteria, the Canadian criteria, and the diagnosis of FM.

CFS patients scored higher on symptom severity, lower on quality of life, and higher on depression and kinesiophobia and worse on MVC, muscle recovery, and cognitive performance compared to the MS patients and the healthy subjects. Daily activity levels were also lower compared to healthy subjects. Only one difference was found between those fulfilling the ME criteria and those who did not regarding the degree of kinesiophobia (lower in ME), while comorbidity for FM significantly increased the symptom burden.

CFS patients report more severe symptoms and are more disabled compared to MS patients and healthy controls. Based on the present study, fulfillment of the ME or Canadian criteria did not seem to give a clinically different picture, whereas a diagnosis of comorbid FM selected symptomatically worse and more disabled patients.

 

Source: Meeus M, Ickmans K, Struyf F, Kos D, Lambrecht L, Willekens B, Cras P, Nijs J. What is in a name? Comparing diagnostic criteria for chronic fatigue syndrome with or without fibromyalgia. Clin Rheumatol. 2016 Jan;35(1):191-203. doi: 10.1007/s10067-014-2793-x. Epub 2014 Oct 14. https://www.ncbi.nlm.nih.gov/pubmed/25308475

 

Impact of the fibromyalgia in the chronic fatigue syndrome

Abstract:

BACKGROUND AND OBJECTIVE: Different studies have showed association of the chronic fatigue syndrome (CFS) with other pathologies, including fibromyalgia (FM). The objective of this study is to analyze whether there are differences in the clinic and in the assessment of fatigue in CFS patients associated or not with FM.

PATIENTS AND METHODS: A cross-sectional, single-site observational study was undertaken on a consecutive cases of a register of CFS patients at CFS Unit in Vall d’Hebron Hospital, Barcelona, from January 2008 until March 2011. The variables analyzed were FM comorbidity, sleep and fatigue characteristics and cognitive, neurological and autonomic symptoms. Questionnaires of fatigue impact scale, fatigue strength and impact on quality of life SF-36 were evaluated.

RESULTS: We included 980 CFS patients (mean age: 48±9 years; 91% women). Fibromyalgia was present in 528 patients (54%). The level of fatigue (P=.001) and pain (P<.001) was higher in FM patients. Patients with CFS and FM had more prevalence of sleep-related phenomena. The percentage of patients and the degree of severity of cognitive symptoms, neurological and autonomic dysfunction was higher in FM patients (P<.001). FM patients scored higher on the fatigue impact scale (P<.001) and showed worse results in the quality of life questionnaire (P<.001).

CONCLUSIONS: FM co-morbidity worse clinical parameters, fatigue and the perception of quality of life in CFS patients.

Copyright © 2013 Elsevier España, S.L. All rights reserved.

 

Source: Faro M, Sáez-Francàs N, Castro-Marrero J, Aliste L, Collado A, Alegre J. Impact of the fibromyalgia in the chronic fatigue syndrome. Med Clin (Barc). 2014 Jun 16;142(12):519-25. doi: 10.1016/j.medcli.2013.06.030. Epub 2014 Jan 2. [Article in Spanish] https://www.ncbi.nlm.nih.gov/pubmed/24387955

 

A Chronic Fatigue Syndrome (CFS) severity score based on case designation criteria

Abstract:

BACKGROUND: Chronic Fatigue Syndrome case designation criteria are scored as physicians’ subjective, nominal interpretations of patient fatigue, pain (headaches, myalgia, arthralgia, sore throat and lymph nodes), cognitive dysfunction, sleep and exertional exhaustion.

METHODS: Subjects self-reported symptoms using an anchored ordinal scale of 0 (no symptom), 1 (trivial complaints), 2 (mild), 3 (moderate), and 4 (severe). Fatigue of 3 or 4 distinguished “Fatigued” from “Not Fatigued” subjects. The sum of the 8(Sum8) ancillary criteria was tested as a proxy for fatigue. All subjects had history and physical examinations to exclude medical fatigue, and ensure categorization as healthy or CFS subjects.

RESULTS: Fatigued subjects were divided into CFS with ≥4 symptoms or Chronic Idiopathic Fatigue (CIF) with ≤3 symptoms. ROC of Sum8 for CFS and Not Fatigued subjects generated a threshold of 14 (specificity=0.934; sensitivity=0.928). CFS (n=256) and CIF (n=55) criteria were refined to include Sum8≥14 and ≤13, respectively. Not Fatigued subjects had highly skewed Sum8 responses. Healthy Controls (HC; n=269) were defined by fatigue≤2 and Sum8≤13. Those with Sum8≥14 were defined as CFS-Like With Insufficient Fatigue Syndrome (CFSLWIFS; n=20). Sum8 and Fatigue were highly correlated (R(2)=0.977; Cronbach’s alpha=0.924) indicating an intimate relationship between symptom constructs. Cluster analysis suggested 4 clades each in CFS and HC. Translational utility was inferred from the clustering of proteomics from cerebrospinal fluid.

CONCLUSIONS: Plotting Fatigue severity versus Sum8 produced an internally consistent classifying system. This is a necessary step for translating symptom profiles into fatigue phenotypes and their pathophysiological mechanisms.

 

Source: Baraniuk JN, Adewuyi O, Merck SJ, Ali M, Ravindran MK, Timbol CR, Rayhan R, Zheng Y, Le U, Esteitie R, Petrie KN. A Chronic Fatigue Syndrome (CFS) severity score based on case designation criteria. Am J Transl Res. 2013;5(1):53-68. Epub 2013 Jan 21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3560481/ (Full article)

 

Metacognitions and negative emotions as predictors of symptom severity in chronic fatigue syndrome

Abstract:

OBJECTIVE: Chronic fatigue syndrome (CFS) describes a condition that is primarily characterized by fatigue and flu-like symptoms that are not alleviated by rest. This study investigated the relationship among metacognitions, negative emotions, and symptom severity in CFS.

METHODS: A total of 96 patients who had received a diagnosis of CFS according to the Oxford Criteria completed a battery of self-report measures that consisted of the Depression Anxiety Stress Scales, the 30-Item Metacognitions Questionnaire, the Chalder Fatigue Questionnaire (CFQ), and the RAND 36-Item Short-Form Health Survey-Physical Functioning.

RESULTS: Correlation analyses showed that negative emotions and metacognitions were positively correlated with measures of symptom severity and that metacognitions were a better predictor of symptom severity than anxiety and depression. Hierarchical regression analyses indicated that (1) lack of cognitive confidence predicted both mental and physical factors of the CFQ and physical functioning independently of negative emotions and (2) beliefs about the need to control thoughts predicted the mental factor of the CFQ independently of negative emotions and lack of cognitive confidence.

CONCLUSION: The data support the potential application of the metacognitive model of psychological disorder to understanding CFS.

Copyright © 2011 Elsevier Inc. All rights reserved.

 

Source: Maher-Edwards L, Fernie BA, Murphy G, Wells A, Spada MM. Metacognitions and negative emotions as predictors of symptom severity in chronic fatigue syndrome. J Psychosom Res. 2011 Apr;70(4):311-7. doi: 10.1016/j.jpsychores.2010.09.016. Epub 2010 Nov 18. https://www.ncbi.nlm.nih.gov/pubmed/21414450