Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome

Abstract:

Symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are common in rheumatic diseases, but no studies report the frequency of these in early systemic sclerosis. There are no known biomarkers that can distinguish between patients with ME/CFS, although mitochondrial abnormalities are often demonstrated.

We sought to assess the prevalence of ME/CFS in limited cutaneous SSc (lcSSc) patients early in their disease (<5 years from the onset of non-Raynaud’s symptoms) and to determine if alterations in mitochondrial electron transport chain (ETC) transcripts and mitochondrial DNA (mtDNA) integrity could be used to distinguish between fatigued and non-fatigued patients.

All SSc patients met ACR/EULAR classification criteria. ME/CFS-related symptoms were assessed through validated questionnaires, and the expression of ETC transcripts and mtDNA integrity were quantified via qPCR.

SSc patients with ME/CFS could be distinguished from non-fatigued patients through ETC gene analysis; specifically, reduced expression of ND4 and CyB and increased expression of Cox7C. ND4 and CyB expression correlated with indicators of disease severity.

Further prospective and functional studies are needed to determine if this altered signature can be further utilized to better identify ME/CFS in SSc patients, and whether ME/CFS in early SSc disease could predict more severe disease outcomes.

Source: van Eeden C, Redmond D, Mohazab N, Larché MJ, Mason AL, Cohen Tervaert JW, Osman MS. Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome. International Journal of Molecular Sciences. 2023; 24(15):12057. https://doi.org/10.3390/ijms241512057 https://www.mdpi.com/1422-0067/24/15/12057 (Full text)

Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue

Abstract:

Fatigue is a common reason that patients seek medical care. Only a fraction of these patients meet criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). To determine if ME/CFS is just a more extreme form of fatigue, or a qualitatively different condition, we assessed whether risk factors for ME/CFS and for Severe Fatigue were similar.

An email questionnaire that inquired about symptoms of Severe Fatigue and ME/CFS was completed by 41,802 US female nurses from whom detailed medical and lifestyle information had been collected since 1989: 102 met criteria for ME/CFS, 522 had Severe Fatigue, and 41,178 individuals were without significant chronic fatigue.

We used Cox proportional hazards regression to estimate the Hazard Ratio (HR) of Severe Fatigue and of ME/CFS with each of several potential risk factors, according to the level of exposure to each risk factor. The risk of Severe Fatigue was significantly increased among participants who were older, had a higher BMI in adulthood, used hormone therapy, had increased alcohol intake and decreased caffeine intake.

In contrast, these risk factor associations were not seen in people with ME/CFS. A self-reported past history of acute infectious mononucleosis was associated with a non-significantly increased Hazard Ratio of later ME/CFS (HR 1.77, 0.87–3.61) and, to a lesser extent, of Severe Fatigue (HR 1.28, 0.98–1.66). The different contribution of various risk factors to Severe Fatigue and ME/CFS suggests that ME/CFS has a qualitatively different underlying biology from the more common state of Severe Fatigue.

Source: Palacios, N., Molsberry, S., Fitzgerald, K.C. et al. Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue. Sci Rep 13, 2469 (2023). https://doi.org/10.1038/s41598-023-29329-x https://www.nature.com/articles/s41598-023-29329-x (Full text)

The utility of patient-reported outcome measures among patients with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

PURPOSE: Debilitating fatigue is a core symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS); however, the utility of patient-reported symptom outcome measures of fatigue for ME/CFS patients is problematic due to ceiling effects and issues with reliability and validity. We sought to evaluate the performance of three patient-reported symptom measures in a sample of ME/CFS patients and matched controls.

METHODS: Two hundred and forty ME/CFS patients and 88 age, sex, race, and zip code matched controls participated in the study. Participants completed the Multidimensional Fatigue Inventory-20, DePaul Symptom Questionnaire, and RAND SF-36.

RESULTS: The general and physical fatigue subscales on Multidimensional Fatigue Inventory-20, as well as the role of physical health on the RAND SF-36, demonstrated questionable or unacceptable internal consistency and problematic ceiling effects. The DePaul Symptom Questionnaire demonstrated excellent internal reliability, and less than 5 % of participants were at the ceiling on each subscale. The post-exertional malaise subscale on the DePaul Symptom Questionnaire demonstrated excellent clinical utility as it was able to differentiate between ME/CFS patients and controls (OR 1.23, p < .001) and predicted ceiling effects on other patient-reported outcome subscales. A score of 20 on the post-exertional malaise subscale of the DePaul Symptom Questionnaire optimally differentiated between patients and controls.

CONCLUSIONS: Significant ceiling effects and concerns with reliability and validity were observed among Multidimensional Fatigue Inventory-20 and RAND SF-36 subscales for ME/CFS patients. The DePaul Symptom Questionnaire addresses a number of concerns typically identified when using patient-reported outcome measures with ME/CFS patients; however, an improved multidimensional patient-reported outcome tool for measuring ME/CFS-related symptoms is warranted.

 

Source: Murdock KW, Wang XS, Shi Q, Cleeland CS, Fagundes CP, Vernon SD. The utility of patient-reported outcome measures among patients with myalgic encephalomyelitis/chronic fatigue syndrome. Qual Life Res. 2016 Sep 6. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27600520

 

Fatigue Scales and Chronic Fatigue Syndrome: Issues of Sensitivity and Specificity

Abstract:

Few studies have explored issues of sensitivity and specificity for using the fatigue construct to identify patients meeting chronic fatigue syndrome (CFS) criteria. In this article, we examine the sensitivity and specificity of several fatigue scales that have attempted to define severe fatigue within CFS. Using Receiver Operating Characteristic (ROC) curve analysis, we found most scales and sub-scales had either significant specificity and/or sensitivity problems.

However, the post-exertional subscale of the ME/CFS Fatigue Types Questionnaire (Jason, Jessen, et al., 2009) was the most promising in terms of specificity and sensitivity. Among the more traditional fatigue scales, Krupp, LaRocca, Muir-Nash, and Steinberg’s (1989) Fatigue Severity Scale had the best ability to differentiate CFS from healthy controls. Selecting questions, scales and cut off points to measure fatigue must be done with extreme care in order to successfully identify CFS cases.

 

Source: Jason LA, Evans M, Brown M, Porter N, Brown A, Hunnell J, Anderson V, Lerch A. Fatigue Scales and Chronic Fatigue Syndrome: Issues of Sensitivity and Specificity. Disabil Stud Q. 2011 Winter;31(1). Pii: 1375. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3181109/ (Full article)

 

The Chronic Fatigue Syndrome Activities and Participation Questionnaire (CFS-APQ): an overview

Abstract:

Chronic fatigue syndrome (CFS) is characterized by severe fatigue and a reduction in activity levels. The purpose of this study was to provide an overview of design, reliability, and validity of the CFS Activities and Participation Questionnaire (CFS-APQ).

The CFS-APQ was constructed based on a retrospective analysis of the Karnofsky Performance Status Questionnaire and the Activities of Daily Living Questionnaire (n = 141). In a reliability study of 34 participants the test-retest reliability coefficient of the CFS-APQ was 0.95. In two different studies, the Cronbach alpha coefficient for internal consistency varied between 0.87 (n = 88) and 0.94 (n = 47). The CFS-APQ was administered to 47 patients who listed 183 activities that had become difficult due to their chronic symptoms, and 157 (85.8%) answers matched the content of the CFS-APQ.

The outcome of a cross-sectional study (n = 88) studying the correlations between the Medical Outcomes Short Form 36 Health Status Survey subscale scores and the CFS-APQ supported the validity of the CFS-APQ. The CFS-APQ scores correlated with a behavioural assessment of the patients’ performance of activities encompassed by the questionnaire (r = 0.29-0.55; n = 63), and correlated with exercise capacity parameters (r = 0.26-0.39; n = 77) obtained during a maximal exercise capacity stress test. Finally, the CFS-APQ correlated with visual analogue scales for pain (r = 0.51) and fatigue (r = 0.50; n = 47).

It is concluded that the CFS-APQ generates reliable and valid data, and can be used as a clinical measure of disease severity in patients with CFS. Future studies should aim at examining the sensitivity of the CFS-APQ.

 

Source: Nijs J, Vaes P, De Meirleir K. The Chronic Fatigue Syndrome Activities and Participation Questionnaire (CFS-APQ): an overview. Occup Ther Int. 2005;12(2):107-21. http://www.ncbi.nlm.nih.gov/pubmed/16136868

 

The feeling of fatigue–fatigue severity by unidimensional versus composite questionnaires

Abstract:

The authors’ purpose in this study was to compare the perception of fatigue severity as measured by different fatigue questionnaires. The authors evaluated 3 groups of patients in a cross-sectional study: chronic fatigue syndrome (CFS, n = 20), non-CFS fatigue (n = 20), and familial Mediterranean fever (FMF n = 25). In addition, the authors tracked 7 patients with CFS longitudinally for severity of fatigue.

The severity of fatigue-related symptoms was assessed with 2 questionnaires: the unidimensional Chalder’s Fatigue Severity Scale (CH) and the composite Fatigue Impact Scale (FI) which has 3 subscales–cognitive, physical, and social–and a total score.

In the cross-sectional study, correlations between CH and FI cognitive scores were r = .78 (p < .0001), CH versus FI physical scores r = .603 (p < .0001), CH versus FI social scores r = .66 (p < .0001), and CH versus FI total scores r = .74 (p < .0001).

In the longitudinal survey of CFS patients, the authors compared 30 questionnaires revealing correlations of CH versus FI cognitive scores r = .64 (p = .0004), CH versus FI physical r = .68 (p = .0001), CH versus FI social r = .87 (p < .0001), and CH versus FI total r = .90 (p < .0001).

Fatigue severity as assessed by the unidimensional CH scale and the composite FI scale is comparable. The simple CH scale may be adequate for the assessment of the feeling of fatigue, in general, and for monitoring the severity of fatigue in CFS, in particular.

 

Source: Naschitz JE, Rozenbaum M, Shaviv N, Fields MC, Enis S, Babich JP, Manor H, Yeshurun D, Sabo E, Rosner I. The feeling of fatigue–fatigue severity by unidimensional versus composite questionnaires. Behav Med. 2004 Winter;29(4):167-72. http://www.ncbi.nlm.nih.gov/pubmed/15369197