2020 – Page 19 – American ME and CFS Society

An Isolated Complex V Inefficiency and Dysregulated Mitochondrial Function in Immortalized Lymphocytes from ME/CFS Patients

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is an enigmatic condition characterized by exacerbation of symptoms after exertion (post-exertional malaise or “PEM”), and by fatigue whose severity and associated requirement for rest are excessive and disproportionate to the fatigue-inducing activity. There is no definitive molecular marker or known underlying pathological mechanism for the condition.

Increasing evidence for aberrant energy metabolism suggests a role for mitochondrial dysfunction in ME/CFS. Our objective was therefore to measure mitochondrial function and cellular stress sensing in actively metabolizing patient blood cells.

We immortalized lymphoblasts isolated from 51 ME/CFS patients diagnosed according to the Canadian Consensus Criteria and an age- and gender-matched control group. Parameters of mitochondrial function and energy stress sensing were assessed by Seahorse extracellular flux analysis, proteomics, and an array of additional biochemical assays.

As a proportion of the basal oxygen consumption rate (OCR), the rate of ATP synthesis by Complex V was significantly reduced in ME/CFS lymphoblasts, while significant elevations were observed in Complex I OCR, maximum OCR, spare respiratory capacity, nonmitochondrial OCR and “proton leak” as a proportion of the basal OCR. This was accompanied by a reduction of mitochondrial membrane potential, chronically hyperactivated TOR Complex I stress signaling and upregulated expression of mitochondrial respiratory complexes, fatty acid transporters, and enzymes of the β-oxidation and TCA cycles. By contrast, mitochondrial mass and genome copy number, as well as glycolytic rates and steady state ATP levels were unchanged.

Our results suggest a model in which ME/CFS lymphoblasts have a Complex V defect accompanied by compensatory upregulation of their respiratory capacity that includes the mitochondrial respiratory complexes, membrane transporters and enzymes involved in fatty acid β-oxidation. This homeostatically returns ATP synthesis and steady state levels to “normal” in the resting cells, but may leave them unable to adequately respond to acute increases in energy demand as the relevant homeostatic pathways are already activated.

Source: Missailidis D, Annesley SJ, Allan CY, Sanislav O, Lidbury BA, Lewis DP, Fisher PR. An Isolated Complex V Inefficiency and Dysregulated Mitochondrial Function in Immortalized Lymphocytes from ME/CFS Patients.Int J Mol Sci. 2020 Feb 6;21(3). pii: E1074. doi: 10.3390/ijms21031074. https://www.mdpi.com/1422-0067/21/3/1074 (Full text)

Can the light of immunometabolism cut through “brain fog”?

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a highly debilitating disease with heterogeneous constitutional and neurological complaints. Infection-like symptoms often herald disease onset, but no pathogen or immune defect has been conclusively linked.

In this issue of the JCI, Mandarano et al. illuminate bioenergetic derangements of ME/CFS T cell subsets. CD4+ and CD8+ T cells had impaired resting glycolysis. CD8+ cells additionally showed activation-related metabolic remodeling deficits and decreased mitochondrial membrane potential; a subset had increased resting mitochondrial mass. Immune senescence and exhaustion paradigms offer only partial explanations. Hence, unique mechanisms of disrupted immunometabolism may underlie the complex neuroimmune dysfunction of ME/CFS.

Source: Hornig M. Can the light of immunometabolism cut through “brain fog”? J Clin Invest. 2020 Feb 10. pii: 134985. doi: 10.1172/JCI134985. [Epub ahead of print] https://www.jci.org/articles/view/134985

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: a quantitative, controlled study using Doppler echography

Abstract:

Objective: The underlying hypothesis in orthostatic intolerance (OI) syndromes is that symptoms are associated with cerebral blood flow (CBF) reduction. Indirect CBF measurements (transcranial Doppler flow velocities), provide inconsistent support of this hypothesis. The aim of the study was to measure CBF during a 30 min head-up tilt test (HUT), using Doppler flow imaging of carotid and vertebral arteries, in individuals with chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), a condition with a high prevalence of OI.

Methods: 429 ME/CFS patients were studied: 247 had a normal heart rate (HR) and blood pressure (BP) response to HUT, 62 had delayed orthostatic hypotension (dOH), and 120 had postural orthostatic tachycardia syndrome (POTS). We also studied 44 healthy controls (HC). CBF measurements were made at mid-tilt and end-tilt. Before mid-tilt, we administered a verbal questionnaire to ascertain for 15 OI symptoms.

Results: End-tilt CBF reduction was 7% in HC versus 26% in the overall ME/CFS group, 24% in patients with a normal HR/BP response, 28% in those with dOH, and 29% in POTS patients (all P<.0005). Using a lower limit of normal of 2SD of CBF reduction in HC (13% reduction), 82% of patients with normal HR/BP response, 98% with dOH and 100% with POTS showed an abnormal CBF reduction. There was a linear correlation of summed OI symptoms with the degree of CBF reduction at mid-tilt (P<.0005).

Conclusions: During HUT, extracranial Doppler measurements demonstrate that CBF is reduced in ME/CFS patients with POTS, dOH, and even in those without HR/BP abnormalities.

Significance: This study shows that orthostatic intolerance symptoms are related to CBF reduction, and that the majority of ME/CFS patients (90%) show an abnormal cerebral flow reduction during orthostatic stress testing. This may have implications for the diagnosis and treatment of ME/CFS patients.

Source: C. (Linda) M.C.van Campen, Freek W.A. Verheugt, Peter C. Rowe, Frans C.Visser. Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: a quantitative, controlled study using Doppler echography. Clinical Neurophysiology Practice. Available online 8 February 2020. https://doi.org/10.1016/j.cnp.2020.01.003 https://www.sciencedirect.com/science/article/pii/S2467981X20300044 (Full text)

Assessing diagnostic value of microRNAs from peripheral blood mononuclear cells and extracellular vesicles in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating multisystemic disease of unknown etiology, affecting thousands of individuals worldwide. Its diagnosis still relies on ruling out medical problems leading to unexplained fatigue due to a complete lack of disease-specific biomarkers. Our group and others have explored the potential value of microRNA profiles (miRNomes) as diagnostic tools for this disease. However, heterogeneity of participants, low numbers, the variety of samples assayed, and other pre-analytical variables, have hampered the identification of disease-associated miRNomes.

In this study, our team has evaluated, for the first time, ME/CFS miRNomes in peripheral blood mononuclear cells (PBMCs) and extracellular vesicles (EVs) from severely ill patients recruited at the monographic UK ME biobank to assess, using standard operating procedures (SOPs), blood fractions with optimal diagnostic power for a rapid translation of a miR-based diagnostic method into the clinic.

Our results show that routine creatine kinase (CK) blood values, plasma EVs physical characteristics (including counts, size and zeta-potential), and a limited number of differentially expressed PBMC and EV miRNAs appear significantly associated with severe ME/CFS (p < 0.05). Gene enrichment analysis points to epigenetic and neuroimmune dysregulated pathways, in agreement with previous reports. Population validation by a cost-effective approach limited to these few potentially discriminating variables is granted.

Source: Almenar-Pérez E, Sarría L, Nathanson L, Oltra E. Assessing diagnostic value of microRNAs from peripheral blood mononuclear cells and extracellular vesicles in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Sci Rep. 2020 Feb 7;10(1):2064. doi: 10.1038/s41598-020-58506-5. https://www.nature.com/articles/s41598-020-58506-5 (Full text)

Legitimizing myalgic encephalomyelitis/chronic fatigue syndrome: Indications of change over a decade

Abstract:

This commentary identifies recent scientific and clinical milestones that appear to have increased legitimization of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). These milestones include government-funded reports recognizing the seriousness of ME/CFS, new initiatives for biomedical research sponsored by the US National Institutes of Health, official endorsement of the ME/CFS name, publication of practitioner primers, and the launch of a new peer-review fatigue journal. These positive developments are tempered by ongoing illness challenges including patient stigma, absence of diagnostic markers, a lack of established treatments, and a dearth of researchers and knowledgeable, interested clinicians.

Source: Fred Friedberg (2020) Legitimizing myalgic encephalomyelitis/chronic fatigue syndrome: indications of change over a decade, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2020.1718292

Treating medically unexplained symptoms via improving access to psychological therapy (IAPT): major limitations identified

Abstract:

BACKGROUND: Improving Access to Psychological Therapies is a UK Government funded initiative to widen access to psychological treatment for a range of common mental health complaints, such as depression and anxiety. More recently, the service has begun to treat patients with medically unexplained symptoms. This paper reports on a review of treatment protocols and early treatment data for medically unexplained symptoms, specifically the illness myalgic encephalomyelitis/chronic fatigue syndrome.

MAIN TEXT: A series of seven core problems and failings are identified, including an unproven treatment rationale, a weak and contested evidence-base, biases in treatment promotion, exaggeration of recovery claims, under-reporting of drop-out rates, and a significant risk of misdiagnosis and inappropriate treatment.

CONCLUSIONS: There is a pressing need for independent oversight of this service, specifically evaluation of service performance and methods used to collect and report treatment outcomes. This service offers uniform psycho-behavioural therapy that may not meet the needs of many patients with medically unexplained health complaints. Psychotherapy should not become a default when patients’ physical symptoms remain unexplained, and patients should be fully informed of the rationale behind psychotherapy, before agreeing to take part. Patients who reject psychotherapy or do not meet selection criteria should be offered appropriate medical and psychological support.

Source: Geraghty K, Scott MJ. Treating medically unexplained symptoms via improving access to psychological therapy (IAPT): major limitations identified. BMC Psychol. 2020 Feb 5;8(1):13. doi: 10.1186/s40359-020-0380-2. https://bmcpsychology.biomedcentral.com/articles/10.1186/s40359-020-0380-2 (Full article)

Associations of occupational stress, workplace violence and organizational support on chronic fatigue symptoms among nurses

Abstract:

AIMS: Chronic fatigue syndrome is an agnogenic disease worldwide. Nurses are at a high risk of chronic fatigue syndrome. However, no research has been done to examine the associations of workplace violence, organizational support and occupational stress with chronic fatigue syndrome among Chinese nurses. This study aimed to examine effects of these factors on chronic fatigue syndrome in this occupational group.

DESIGN: Cross-sectional. All participants voluntarily completed a questionnaire survey.

METHODS: The study was conducted in Liaoning province from December 2017 to January 2018. Self-administered questionnaires were distributed to 1200 nurses, including Effort-Reward-Imbalance, Workplace Violence Scale, Survey of Perceived Organizational Support, together with age, gender, marital status, education levels, physical activities, job rank, monthly income and weekly working hours. Complete responses were obtained from 1080 (90%) participants. Chronic fatigue syndrome was diagnosed by doctors according to the Centers for Disease Control and Prevention criteria. Multivariable logistic regression was performed to examine these independent risk factors.

RESULTS: The prevalence of chronic fatigue syndrome was 6.76%. The results of logistic regression analysis showed that nurses who experienced serious higher levels of overcommitment, workplace violence and less organizational support were more likely to be classified as chronic fatigue syndrome.

CONCLUSION: There was a high prevelence of chronic fatigue syndrome. Lower workplace violence, more organizational support and lower overcommitment could be effective resources for reducing chronic fatigue syndrome.

IMPACT: Workplace violence, organizational support and occupational stress were related to chronic fatigue syndrome, which helped to explain why Chinese nurses suffered higher prevelance of chronic fatigue syndrome. Overcommitment explained chronic fatigue syndrome better than Effort/Reward Ratio, so intrinsic stress played a more critical role than extrinsic stress in chronic fatigue syndrome. Chinese nurses suffered serious sleep disorders and impairment of concentration and memory. These symptoms might also atributed to serious occupational stress, unsafe and unsupportive working environment. Creating a safe and supportive working emvironment, releiving intrinsic occupational stress should be considered as an institutional strategy to early prevent chronic fatigue syndrome.

Source: Li M, Shu Q, Huang H, Bo W, Wang L, Wu H. Associations of occupational stress, workplace violence and organizational support on chronic fatigue symptoms among nurses. J Adv Nurs. 2020 Feb 3. doi: 10.1111/jan.14312. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/32011012

Maximal handgrip strength can predict maximal physical performance in patients with chronic fatigue

Abstract:

BACKGROUND: Maximal handgrip strength is used to predict exercise performance in healthy older subjects and in patients with chronic obstructive pulmonary disease, breast cancer or cirrhosis. Our objective was to evaluate the ability of maximal handgrip strength to predict maximal exercise performance in patients with chronic fatigue.

METHODS: Sixty-six patients with myalgic encephalomyelitis/chronic fatigue syndrome and 32 patients with chronic fatigue but no diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome were included. The maximal physical performance was measured on a cycle ergometer to measure the peak oxygen uptake and the maximal work rate. We searched for linear regressions between maximal handgrip strength and maximal performances.

FINDINGS: No significant differences in slopes and ordinates of regression lines were noted between patients with or without a diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome, allowing to pool the data. Maximal handgrip strength was significantly and positively correlated with peak oxygen uptake and maximal work rate in all patients with chronic fatigue.

INTERPRETATION: We conclude that handgrip strength can predict maximal exercise performance in patients with chronic fatigue.

Source: Jammes Y, Stavris C, Charpin C, Rebaudet S, Lagrange G, Retornaz F. Maximal handgrip strength can predict maximal physical performance in patients with chronic fatigue. Clin Biomech (Bristol, Avon). 2020 Jan 9;73:162-165. doi: 10.1016/j.clinbiomech.2020.01.003. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31986462

Health-related quality of life in patients with myalgic encephalomyelitis/chronic fatigue syndrome: an Australian cross-sectional study.

Abstract:

BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious and debilitating disorder associated with significant disruptions in daily life including. This study aimed to examine the impact of sociodemographic and patient symptom characteristics on health-related quality of life (HRQoL) of Australians with ME/CFS.

METHODS: Self-reported data collected from 480 individuals diagnosed with ME/CFS were obtained between August 2014 and August 2018. This cross-sectional survey analysed sociodemographic, symptom characteristics and HRQoL according to the 36-Item Health Survey (SF-36). Multivariate linear regression models were used to determine ME/CFS symptoms associated with eight domains of HRQoL.

RESULTS: Reported HRQoL was significantly impaired in ME/CFS patients across all domains compared with the general population. Scores were the lowest for physical role (4.11 ± 15.07) and energy/fatigue (13.54 ± 13.94). Associations with females, higher body mass index (BMI), employment status, cognitive difficulties, sensory disturbances and cardiovascular symptoms were observed in the physical functioning domain. Impaired pain domain scores were associated with high BMI, annual visits to their general practitioner, flu-like symptoms and fluctuations in body temperature. Reduced well-being scores were associated with smoking status, psychiatric comorbidity, cognitive difficulties, sleep disturbances and gastrointestinal difficulties.

CONCLUSION: This study provides evidence that ME/CFS has a profound and negative impact on HRQoL in an Australian cohort.

Source: Eaton-Fitch N, Johnston SC, Zalewski P, Staines D, Marshall-Gradisnik S. Health-related quality of life in patients with myalgic encephalomyelitis/chronic fatigue syndrome: an Australian cross-sectional study. Qual Life Res. 2020 Jan 22. doi: 10.1007/s11136-019-02411-6. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31970624

Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome

Abstract:

STUDY OBJECTIVES: Physiological dearousal characterized by an increase in parasympathetic nervous system activity is important for good-quality sleep. Previous research shows that nocturnal parasympathetic activity (reflected by heart rate variability [HRV]) is diminished in individuals with chronic fatigue syndrome (CFS), suggesting hypervigilant sleep. This study investigated differences in nocturnal autonomic activity across sleep stages and explored the association of parasympathetic activity with sleep quality and self-reported physical and psychological wellbeing in individuals with CFS.

METHODS: Twenty-four patients with medically diagnosed CFS, and 24 matched healthy control individuals participated. Electroencephalography and HRV were recorded during sleep in participants’ homes using a minimally invasive ambulatory device. Questionnaires were used to measure self-reported wellbeing and sleep quality.

RESULTS: Sleep architecture in patients with CFS differed from that of control participants in slower sleep onset, more awakenings, and a larger proportion of time spent in slow-wave sleep (SWS). Linear mixed-model analyses controlling for age revealed that HRV reflecting parasympathetic activity (normalized high frequency power) was reduced in patients with CFS compared to control participants, particularly during deeper stages of sleep. Poorer self-reported wellbeing and sleep quality was associated with reduced parasympathetic signaling during deeper sleep, but not during wake before sleep, rapid eye movement sleep, or with the proportion of time spent in SWS.

CONCLUSIONS: Autonomic hypervigilance during the deeper, recuperative stages of sleep is associated with poor quality sleep and self-reported wellbeing. Causal links need to be confirmed but provide potential intervention opportunities for the core symptom of unrefreshing sleep in CFS.

Source: Fatt SJ, Beilharz JE, Joubert M, Wilson C, Lloyd AR, Vollmer-Conna U, Cvejic E. Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome. J Clin Sleep Med. 2020 Jan 15;16(1):19-28. doi: 10.5664/jcsm.8114. Epub 2019 Nov 27. https://www.ncbi.nlm.nih.gov/pubmed/31957647