Network Analysis of Symptoms Co-Occurrence in Chronic Fatigue Syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a heterogenous disorder of multiple disabling symptoms with complex manifestations. Network analysis is a statistical and interrogative methodology to investigate the prevalence of symptoms (nodes) and their inter-dependent (inter-nodal) relationships. In the present study, we explored the co-occurrence of symptoms in a cohort of Polish CFS patients using network analysis.

A total of 110 patients with CFS were examined (75 females). The mean age of the total sample was 37.93 (8.5) years old while the mean duration of symptoms in years was 4.4 (4). Post-exertional malaise (PEM) was present in 75.45% of patients, unrefreshing sleep was noted in 89.09% and impaired memory or concentration was observed in 87.27% of patients. The least prevalent symptom was tender cervical or axillary lymph nodes, noted in 34.55% of the total sample.

Three of the most densely connected nodes were the total number of symptoms, sore throat and PEM. PEM was positively related with impairment in memory or concentration. Both PEM and impairment in memory or concentration presence are related to more severe fatigue measured by CFQ and FIS. PEM presence was positively related with the presence of multi-joint pain and negatively with tender lymph nodes and muscle pain. Sore throat was related with objective and subjective autonomic nervous system impairment. This study helps define symptom presentation of CFS with the pathophysiology of specific systems and links with multidisciplinary contemporary molecular pathology, including comparative MRI.

Source: Kujawski S, Słomko J, Newton JL, Eaton-Fitch N, Staines DR, Marshall-Gradisnik S, Zalewski P. Network Analysis of Symptoms Co-Occurrence in Chronic Fatigue Syndrome. Int J Environ Res Public Health. 2021 Oct 13;18(20):10736. doi: 10.3390/ijerph182010736. PMID: 34682478; PMCID: PMC8535251. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8535251/ (Full text)

Potential Implications of Mammalian Transient Receptor Potential Melastatin 7 in the Pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Review

Abstract:

The transient receptor potential (TRP) superfamily of ion channels is involved in the molecular mechanisms that mediate neuroimmune interactions and activities. Recent advancements in neuroimmunology have identified a role for TRP cation channels in several neuroimmune disorders including amyotropic lateral sclerosis, multiple sclerosis, and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). ME/CFS is a debilitating disorder with an obscure aetiology, hence considerable examination of its pathobiology is warranted. Dysregulation of TRP melastatin (TRPM) subfamily members and calcium signalling processes are implicated in the neurological, immunological, cardiovascular, and metabolic impairments inherent in ME/CFS.

In this review, we present TRPM7 as a potential candidate in the pathomechanism of ME/CFS, as TRPM7 is increasingly recognized as a key mediator of physiological and pathophysiological mechanisms affecting neurological, immunological, cardiovascular, and metabolic processes. A focused examination of the biochemistry of TRPM7, the role of this protein in the aforementioned systems, and the potential of TRPM7 as a molecular mechanism in the pathophysiology of ME/CFS will be discussed in this review. TRPM7 is a compelling candidate to examine in the pathobiology of ME/CFS as TRPM7 fulfils several key roles in multiple organ systems, and there is a paucity of literature reporting on its role in ME/CFS.

Source: Du Preez S, Cabanas H, Staines D, Marshall-Gradisnik S. Potential Implications of Mammalian Transient Receptor Potential Melastatin 7 in the Pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Review. Int J Environ Res Public Health. 2021 Oct 12;18(20):10708. doi: 10.3390/ijerph182010708. PMID: 34682454; PMCID: PMC8535478. https://pubmed.ncbi.nlm.nih.gov/34682454/ (Full text)

Impact of Life Stressors on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Symptoms: An Australian Longitudinal Study

Abstract:

(1) Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex, multifaceted illness. The pathomechanism, severity and progression of this illness is still being investigated. Stressors have been implicated in symptom exacerbation for ME/CFS, however, there is limited information for an Australian ME/CFS cohort. The aim of this study was to assess the potential effect of life stressors including changes in work, income, or family scenario on symptom severity in an Australian ME/CFS cohort over five months;

(2) Methods: Australian residents with ME/CFS responded to questions relating to work, income, living arrangement, access to healthcare and support services as well as symptoms experienced;

(3) Results: thirty-six ME/CFS patients (age: 41.25 ± 12.14) completed all questionnaires (response rate 83.7%). Muscle pain and weakness, orthostatic intolerance and intolerance to extreme temperatures were experienced and fluctuated over time. Sleep disturbances were likely to present as severe. Work and household income were associated with worsened cognitive, gastrointestinal, body pain and sleep symptoms. Increased access to healthcare services was associated with improved symptom presentation;

(4) Conclusions: life stressors such as work and financial disruptions may significantly contribute to exacerbation of ME/CFS symptoms. Access to support services correlates with lower symptom scores.

Source: Balinas C, Eaton-Fitch N, Maksoud R, Staines D, Marshall-Gradisnik S. Impact of Life Stressors on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Symptoms: An Australian Longitudinal Study. Int J Environ Res Public Health. 2021 Oct 11;18(20):10614. doi: 10.3390/ijerph182010614. PMID: 34682360; PMCID: PMC8535742.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8535742/ (Full text)

Diffusion tensor imaging reveals neuronal microstructural changes in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis/Chronic fatigue syndrome (ME/CFS) patients suffer from a variety of physical and neurological complaints indicating the central nervous system plays a role in ME/CFS pathophysiology. Diffusion tensor imaging (DTI) has been used to study microstructural changes in neurodegenerative diseases. In this study, we evaluated DTI parameters to investigate microstructural abnormalities in ME/CFS patients.

We estimated DTI parameters in 25 ME/CFS patients who met Fukuda criteria (ME/CFSFukuda ), 18 ME/CFS patients who met International Consent Criteria (ICC) (ME/CFSICC ) only, and 26 healthy control subjects (HC). In addition to voxel-based DTI-parameter group comparisons, we performed voxel-based DTI-parameter interaction-with-group regressions with clinical and autonomic measures to test for abnormal regressions.

Group comparisons between ME/CFSICC and HC detected significant clusters (a) with decreased axial diffusivity (p=0.001) and mean diffusivity (p=0.01) in the descending cortico-cerebellar tract in the midbrain and pons, and (b) with increased transverse diffusivity in the medulla. The mode of anisotropy was significantly decreased (p=0.001) in a cluster in the superior longitudinal fasciculus region. Voxel-based group comparisons between ME/CFSFukuda and HC did not detect significant clusters. For ME/CFSICC and HC, DTI parameter interaction-with-group regressions were abnormal for the clinical measures of information processing score, SF36 physical, sleep disturbance score, and respiration rate in both grey and white matter regions.

Our study demonstrated that DTI parameters are sensitive to microstructural changes in ME/CFSICC and could potentially act as an imaging biomarker of abnormal pathophysiology in ME/CFS. The study also shows that strict case definitions are essential in investigation of the pathophysiology of ME/CFS.

Source: Thapaliya K, Marshall-Gradisnik S, Staines D, Barnden L. Diffusion tensor imaging reveals neuronal microstructural changes in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Eur J Neurosci. 2021 Aug 6. doi: 10.1111/ejn.15413. Epub ahead of print. PMID: 34355438. https://pubmed.ncbi.nlm.nih.gov/34355438/

The effect of IL-2 stimulation and treatment of TRPM3 on channel co-localisation with PIP 2 and NK cell function in myalgic encephalomyelitis/chronic fatigue syndrome patients

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a serious multifactorial disorder. The origin remains ambiguous, however reduced natural killer (NK) cell cytotoxicity is a consistent immunological feature of ME/CFS. Impaired transient receptor potential melastatin 3 (TRPM3), a phosphatidylinositol dependent channel, and impaired calcium mobilisation have been implicated in ME/CFS pathology. This investigation aimed to examine the localisation of TRPM3 at the NK cell plasma membrane and co-localisation with phosphatidylinositol 4,5-bisphosphate (PIP2). The effect of IL-2 priming and treatment using pregnenolone sulfate (PregS) and ononetin on TRPM3 co-localisation and NK cell cytotoxicity in ME/CFS patients and healthy controls (HC) was also investigated.

Methods: NK cells were isolated from 15 ME/CFS patients and 15 age- and sex-matched HC. Immunofluorescent technique was used to determine co-localisation of TRPM3 with the NK cell membrane and with PIP2 of ME/CFS patients and HC. Flow cytometry was used to determine NK cell cytotoxicity. Following IL-2 stimulation and treatment with PregS and ononetin changes in co-localisation and NK cell cytotoxicity were measured.

Results: Overnight treatment of NK cells with PregS and ononetin resulted in reduced co-localisation of TRPM3 with PIP2 and actin in HC. Co-localisation of TRPM3 with PIP2 in NK cells was significantly reduced in ME/CFS patients compared with HC following priming with IL-2. A significant increase in co-localisation of TRPM3 with PIP2 was reported following overnight treatment with ononetin within ME/CFS patients and between groups. Baseline NK cell cytotoxicity was significantly reduced in ME/CFS patients; however, no changes were observed following overnight incubation with IL-2, PregS and ononetin between HC and ME/CFS patients. IL-2 stimulation significantly enhanced NK cell cytotoxicity in HC and ME/CFS patients.

Conclusion: Significant changes in co-localisation suggest PIP2-dependent TRPM3 function may be impaired in ME/CFS patients. Stimulation of NK cells with IL-2 significantly enhanced cytotoxic function in ME/CFS patients demonstrating normal function compared with HC. A crosstalk exists between IL-2 and TRPM3 intracellular signalling pathways which are dependent on Ca2+ influx and PIP2. While IL-2R responds to IL-2 binding in vitro, Ca2+ dysregulation and impaired intracellular signalling pathways impede NK cell function in ME/CFS patients.

Source: Eaton-Fitch N, Cabanas H, du Preez S, Staines D, Marshall-Gradisnik S. The effect of IL-2 stimulation and treatment of TRPM3 on channel co-localisation with PIP2 and NK cell function in myalgic encephalomyelitis/chronic fatigue syndrome patients. J Transl Med. 2021 Jul 15;19(1):306. doi: 10.1186/s12967-021-02974-4. PMID: 34266470.  https://pubmed.ncbi.nlm.nih.gov/34266470/

A preliminary investigation of nutritional intake and supplement use in Australians with myalgic encephalomyelitis/chronic fatigue syndrome and the implications on health-related quality of life

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, multisystem illness without a currently recognized pharmacological treatment. Dietary supplementation and modification have been posited as potential management strategies; however, their efficacy is controversial.

Objective: This study aimed to assess the nutritional intake and supplement use of Australian ME/CFS patients and the perceived effect on health-related quality of life (HRQoL) for the first time in an Australian patient population.

Design: Between February 2019 and January 2020, ME/CFS patients across Australia volunteered in this cross-sectional study in response to online advertisements. Eligible respondents were invited to complete three online self-administered questionnaires investigating their supplement use, nutritional intake, and HRQoL. The study participants’ supplement use and nutritional intake were summarized and compared with the population data returned from the Australian Health Survey (2011-2012). Multiple linear regression analysis was also performed to determine the effect of participants’ supplement use and nutrient intake on HRQoL.

Results: Twenty-four eligible ME/CFS patients (54.2% meeting the International Consensus Criteria, 79.2% female, mean age = 43.4 ± 10.5 years) completed the online questionnaires. Supplement use was highly prevalent among the study sample (87.5%) and considerably more common when compared with population data (31.9%). Daily total fats and caffeine intakes were significantly higher among ME/CFS patients when compared with the Australian population (P = 0.009 and P = 0.033, respectively), whereas daily intakes of total carbohydrates and alcohol were significantly lower (both P < 0.001). No consistent trends between nutrition and supplement use with patients’ HRQoL could be identified.

Conclusions: The daily diet and supplement use of ME/CFS patients appear to vary considerably from those of the general Australian population. Although the role of nutritional intake and supplement use on ME/CFS patients’ HRQoL remains unclear, dietary changes and the use of supplements appear to be of value to ME/CFS patients.

Keywords: chronic fatigue syndrome (CFS); health-related quality of life (HRQoL); myalgic encephalomyelitis (ME); nutrition; nutritional intake; supplements.

Source: Weigel B, Eaton-Fitch N, Passmore R, Cabanas H, Staines D, Marshall-Gradisnik S. A preliminary investigation of nutritional intake and supplement use in Australians with myalgic encephalomyelitis/chronic fatigue syndrome and the implications on health-related quality of life. Food Nutr Res. 2021;65:10.29219/fnr.v65.5730. Published 2021 Jun 7. doi:10.29219/fnr.v65.5730 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8254462/ (Full text)

Potential Therapeutic Benefit of Low Dose Naltrexone in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Role of Transient Receptor Potential Melastatin 3 Ion Channels in Pathophysiology and Treatment

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating multi-systemic chronic condition of unknown aetiology classified as an immune dysfunction syndrome and neurological disorder. The discovery of the widely expressed Transient Receptor Potential Melastatin 3 (TRPM3) as a nociceptor channel substantially targeted by certain opioid receptors, and its implication in calcium (Ca2+)-dependent Natural Killer (NK) cell immune functions has raised the possibility that TRPM3 may be pharmacologically targeted to treat characteristic symptoms of ME/CFS. Naltrexone hydrochloride (NTX) acts as an antagonist to the mu (μ)-opioid receptor thus negating its inhibitory function on TRPM3.

Based on the benefits reported by patients on their symptoms, low dose NTX (LDN, 3.0–5.0 mg/day) treatment seems to offer some potential benefit suggesting that its effect may be targeted towards the pathomechanism of ME/CFS. As there is no literature confirming the efficacy of LDN for ME/CFS patients in vitro, this study investigates the potential therapeutic effect of LDN in ME/CFS patients. TRPM3 ion channel activity was measured after modulation with Pregnenolone sulfate (PregS) and ononetin in NK cells on 9 ME/CFS patients taking LDN and 9 age- and sex-matched healthy controls using whole-cell patch-clamp technique.

We report that ME/CFS patients taking LDN have restored TRPM3-like ionic currents in NK cells. Small ionic currents with a typical TRPM3-like outward rectification were measured after application of PregS, a TRPM3-agonist, in NK cells from patients taking LDN. Additionally, PregS-evoked ionic currents through TRPM3 were significantly modulated by ononetin, a TRPM3-antagonist, in NK cells from ME/CFS patients taking LDN.

These data support the hypothesis that LDN may have potential as a treatment for ME/CFS by characterising the underlying regulatory mechanisms of LDN treatment involving TRPM3 and opioid receptors in NK cells. Finally, this study may serve for the repurpose of marketed drugs, as well as support the approval of prospective randomized clinical studies on the role and dose of NTX in treating ME/CFS patients.

Source: Helene Cabanas, Katsuhiko Muraki, Natalie Eaton-Fitch, Donald Ross Staines and Sonya Marshall-Gradisnik. Potential Therapeutic Benefit of Low Dose Naltrexone in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Role of Transient Receptor Potential Melastatin 3 Ion Channels in Pathophysiology and Treatment. Front. Immunol. | https://doi.org/10.3389/fimmu.2021.687806 https://www.frontiersin.org/articles/10.3389/fimmu.2021.687806/full (Full text)

Systematic Review of Sleep Characteristics in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

(1) Background-Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multifaceted illness characterized by profound and persistent fatigue unrelieved by rest along with a range of other debilitating symptoms. Experiences of unrefreshing and disturbed sleep are frequently described by ME/CFS patients. This is the first systematic review assessing sleep characteristics in ME/CFS. The aim of this review is to determine whether there are clinical characteristics of sleep in ME/CFS patients compared to healthy controls using objective measures such as polysomnography and multiple sleep latency testing.

(2) Methods-the following databases-Pubmed, Embase, Medline (EBSCO host) and Web of Science, were systematically searched for journal articles published between January 1994 to 19 February 2021. Articles that referred to polysomnography or multiple sleep latency testing and ME/CFS patients were selected, and further refined through use of specific inclusion and exclusion criteria. Quality and bias were measured using the Joanna Briggs Institute checklist.

(3) Results-twenty observational studies were included in this review. The studies investigated objective measures of sleep quality in ME/CFS. Subjective measures including perceived sleep quality and other quality of life factors were also described.

(4) Conclusions-Many of the parameters measured including slow- wave sleep, apnea- hypopnea index, spectral activity and multiple sleep latency testing were inconsistent across the studies. The available research on sleep quality in ME/CFS was also limited by recruitment decisions, confounding factors, small sample sizes and non-replicated findings. Future well-designed studies are required to understand sleep quality in ME/CFS patients.

Source: Maksoud R, Eaton-Fitch N, Matula M, Cabanas H, Staines D, Marshall-Gradisnik S. Systematic Review of Sleep Characteristics in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Healthcare (Basel). 2021 May 11;9(5):568. doi: 10.3390/healthcare9050568. PMID: 34065013. https://pubmed.ncbi.nlm.nih.gov/34065013/

A systematic review of nutraceutical interventions for mitochondrial dysfunctions in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating illness, characterised by persistent fatigue that is unrelieved by rest, in combination with a range of other disabling symptoms. There is no diagnostic test nor targeted treatment available for this illness. The pathomechanism also remains unclear. Mitochondrial dysfunctions have been considered a possible underlying pathology based on reported differences including structural and functional changes in ME/CFS patients compared to healthy controls. Due to the potential role that mitochondria may play in ME/CFS, mitochondrial-targeting nutraceutical interventions have been used to potentially assist in improving patient outcomes such as fatigue. The aim of this systematic review is to appraise literature assessing these nutraceuticals as a possible intervention for treating ME/CFS.

Methods: A systematic search of Pubmed, Embase, Medline (EBSCO host) and Web of Science (via Clarivate Analytics) for journal articles published between January 1995 and 10th November 2020 was conducted. Articles assessing nutraceutical interventions and ME/CFS patient outcomes were retrieved. Using specific inclusion and exclusion criteria, the list of articles was further refined. Quality was measured using the Rosendal scale.

Results: Nine intervention studies were included in this review. The studies investigated patient symptom severity changes such as altered fatigue levels in response to mitochondrial-targeting nutraceuticals. Improvements in fatigue levels were observed in six of the nine studies. Secondary outcomes assessed include biochemical, psychological, and quality of life parameters.

Conclusion: There is insufficient evidence on the effectiveness of mitochondria- targeting nutraceuticals in ME/CFS patients. Future well-designed studies are required to elucidate both the involvement of mitochondria in the pathomechanism of ME/CFS and the effect of mitochondrial-modifying agents on illness severity.

Source: Maksoud R, Balinas C, Holden S, Cabanas H, Staines D, Marshall-Gradisnik S. A systematic review of nutraceutical interventions for mitochondrial dysfunctions in myalgic encephalomyelitis/chronic fatigue syndrome. J Transl Med. 2021 Feb 17;19(1):81. doi: 10.1186/s12967-021-02742-4. PMID: 33596913; PMCID: PMC7890871. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-021-02742-4  (Full text)

The Economic Impacts of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in an Australian Cohort

Abstract:

Objectives: This study aims to estimate direct and indirect health economic costs associated with government and out-of-pocket (OOP) expenditure based on health care service utilization and lost income of participants and carers, as reported by Australian Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patient survey participants.

Design: A cost of illness study was conducted to estimate Australian cost data for individuals with a ME/CFS diagnosis as determined by the Canadian Consensus Criteria (CCC), International Consensus Criteria (ICC), and the 1994 CDC Criteria (Fukuda).

Setting and participants: Survey participants identified from a research registry database provided self-report of expenditure associated with ME/CFS related healthcare across a 1-month timeframe between 2017 and 2019.

Main outcome measures: ME/CFS related direct annual government health care costs, OOP health expenditure costs, indirect costs associated with lost income and health care service use patterns.

Results: The mean annual cost of health care related expenditure and associated income loss among survey participants meeting diagnostic criteria for ME/CFS was estimated at $14.5 billion. For direct OOP and Government health care expenditure, high average costs were related to medical practitioner attendance, diagnostics, natural medicines, and device expenditure, with an average attendance of 10.6 referred attendances per annum and 12.1 GP visits per annum related specifically to managing ME/CFS.

Conclusions: The economic impacts of ME/CFS in Australia are significant. Improved understanding of the illness pathology, diagnosis, and management, may reduce costs, improve patient prognosis and decrease the burden of ME/CFS in Australia.

Source: Close S, Marshall-Gradisnik S, Byrnes J, Smith P, Nghiem S, Staines D. The Economic Impacts of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in an Australian Cohort. Front Public Health. 2020 Aug 21;8:420. doi: 10.3389/fpubh.2020.00420. PMID: 32974259; PMCID: PMC7472917. https://www.frontiersin.org/articles/10.3389/fpubh.2020.00420/full (Full text)