Clinically proven mtDNA mutations are not common in those with chronic fatigue syndrome

Abstract:

Background: Chronic Fatigue Syndrome (CFS) is a prevalent debilitating condition that affects approximately 250,000 people in the UK. There is growing interest in the role of mitochondrial function and mitochondrial DNA (mtDNA) variation in CFS. It is now known that fatigue is common and often severe in patients with mitochondrial disease irrespective of their age, gender or mtDNA genotype. More recently, it has been suggested that some CFS patients harbour clinically proven mtDNA mutations.

Methods: MtDNA sequencing of 93 CFS patients from the United Kingdom (UK) and South Africa (RSA) was performed using an Ion Torrent Personal Genome Machine. The sequence data was examined for any evidence of clinically proven mutations, currently; more than 200 clinically proven mtDNA mutations point mutations have been identified.

Results: We report the complete mtDNA sequence of 93 CFS patients from the UK and RSA, without finding evidence of clinically proven mtDNA mutations. This finding demonstrates that clinically proven mtDNA mutations are not a common element in the aetiology of disease in CFS patients. That is patients having a clinically proven mtDNA mutation and subsequently being misdiagnosed with CFS are likely to be rare.

Conclusion: The work supports the assertion that CFS should not be considered to fall within the spectrum of mtDNA disease. However, the current study cannot exclude a role for nuclear genes with a mitochondrial function, nor a role of mtDNA population variants in susceptibility to disease. This study highlights the need for more to be done to understand the pathophysiology of CFS.

Source: Schoeman EM, Van Der Westhuizen FH, Erasmus E, van Dyk E, Knowles CV, Al-Ali S, Ng WF, Taylor RW, Newton JL, Elson JL. Clinically proven mtDNA mutations are not common in those with chronic fatigue syndrome. BMC Med Genet. 2017 Mar 16;18(1):29. doi: 10.1186/s12881-017-0387-6. PMID: 28302057; PMCID: PMC5356238. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5356238/ (Full text)

The Role of Autonomic Function in Exercise-induced Endogenous Analgesia: A Case-control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Healthy People

Abstract:

Background: Patients with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) are unable to activate brain-orchestrated endogenous analgesia (or descending inhibition) in response to exercise. This physiological impairment is currently regarded as one factor explaining post-exertional malaise in these patients. Autonomic dysfunction is also a feature of ME/CFS.

Objectives: This study aims to examine the role of the autonomic nervous system in exercise-induced analgesia in healthy people and those with ME/CFS, by studying the recovery of autonomic parameters following aerobic exercise and the relation to changes in self-reported pain intensity.

Study design: A controlled experimental study.

Setting: The study was conducted at the Human Physiology lab of a University.

Methods: Twenty women with ME/CFS- and 20 healthy, sedentary controls performed a submaximal bicycle exercise test known as the Aerobic Power Index with continuous cardiorespiratory monitoring. Before and after the exercise, measures of autonomic function (i.e., heart rate variability, blood pressure, and respiration rate) were performed continuously for 10 minutes and self-reported pain levels were registered. The relation between autonomous parameters and self-reported pain parameters was examined using correlation analysis.

Results: Some relationships of moderate strength between autonomic and pain measures were found. The change (post-exercise minus pre-exercise score) in pain severity was correlated (r = .580, P = .007) with the change in diastolic blood pressure in the healthy group. In the ME/CFS group, positive correlations between the changes in pain severity and low frequency (r = .552, P = .014), and between the changes in bodily pain and diastolic blood pressure (r = .472, P = .036), were seen. In addition, in ME/CHFS the change in headache severity was inversely correlated (r = -.480, P = .038) with the change in high frequency heart rate variability.

Limitations: Based on the cross-sectional design of the study, no firm conclusions can be drawn on the causality of the relations.

Conclusions: Reduced parasympathetic reactivation during recovery from exercise is associated with the dysfunctional exercise-induced analgesia in ME/CFS. Poor recovery of diastolic blood pressure in response to exercise, with blood pressure remaining elevated, is associated with reductions of pain following exercise in ME/CFS, suggesting a role for the arterial baroreceptors in explaining dysfunctional exercise-induced analgesia in ME/CFS patients.

Source: Oosterwijck JV, Marusic U, De Wandele I, Paul L, Meeus M, Moorkens G, Lambrecht L, Danneels L, Nijs J. The Role of Autonomic Function in Exercise-induced Endogenous Analgesia: A Case-control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Healthy People. Pain Physician. 2017 Mar;20(3):E389-E399. PMID: 28339438. https://www.painphysicianjournal.com/linkout?issn=&vol=20&page=E389 (Full text)

Myalgic encephalomyelitis/chronic fatigue syndrome patients’ reports of symptom changes following cognitive behavioural therapy, graded exercise therapy and pacing treatments: Analysis of a primary survey compared with secondary surveys

Abstract:

Cognitive behavioural therapy and graded exercise therapy are promoted as evidence-based treatments for myalgic encephalomyelitis/chronic fatigue syndrome. This article explores patients’ symptom responses following these treatments versus pacing therapy, an approach favoured by many sufferers. We analyse data from a large cross-sectional patient survey (n = 1428) and compare our findings with those from comparable patient surveys (n = 16,665), using a mix of descriptive statistics and regression analysis modelling.

Findings from analysis of primary and secondary surveys suggest that cognitive behavioural therapy is of benefit to a small percentage of patients (8%-35%), graded exercise therapy brings about large negative responses in patients (54%-74%), while pacing is the most favoured treatment with the lowest negative response rate and the highest reported benefit (44%-82%).

Source: Geraghty K, Hann M, Kurtev S. Myalgic encephalomyelitis/chronic fatigue syndrome patients’ reports of symptom changes following cognitive behavioural therapy, graded exercise therapy and pacing treatments: Analysis of a primary survey compared with secondary surveys. J Health Psychol. 2019 Sep;24(10):1318-1333. doi: 10.1177/1359105317726152. Epub 2017 Aug 29. PMID: 28847166. https://journals.sagepub.com/eprint/hWSxVIBTzDtqisvafkhE/full (Full text)

ME/CFS and the biopsychosocial model: a review of patient harm and distress in the medical encounter

Abstract:

Objective: Despite the growing evidence of physiological and cellular abnormalities in myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS), there has been a strong impetus to tackle the illness utilizing a biopsychosocial model. However, many sufferers of this disabling condition report distress and dissatisfaction following medical encounters. This review seeks to account for this discord.

Methods: A narrative review methodology is employed to synthesize the evidence for potential iatrogenesis.

Results: We identify seven potential modalities of iatrogenesis or harm reported by patients: difficulties in reaching an acceptable diagnosis; misdiagnosis, including of other medical and psychological conditions; difficulties in accessing the sick role, medical care and social support; high levels of patient dissatisfaction with the quality of medical care; negative responses to controversial therapies (cognitive behavioral therapy and graded exercise therapy); challenges to the patient narrative and experience; psychological harm (individual and collective distress).

Conclusion: The biopsychosocial framework currently applied to ME/CFS is too narrow in focus and fails to adequately incorporate the patient narrative. Misdiagnosis, conflict, and harm are observable outcomes where doctors’ and patients’ perspectives remain incongruent. Biopsychosocial practices should be scrutinized for potential harms. Clinicians should consider adopting alternative patient-centred approaches.

Implications for rehabilitation: Patients with ME/CFS may report or experience one or more of the modalities of harms and distress identified in this review. It is important health and rehabilitation professionals seek to avoid and minimize harms when treating or assisting ME/CFS patients. There are conflicting models of ME/CFS; we highlight two divergent models, a biopsychosocial model and a biomedical model that is preferred by patients. The ‘biopsychosocial framework’ applied in clinical practice promotes treatments such as cognitive behavioral therapy and exercise therapy, however, the evidence for their success is contested and many patients reject the notion their illness is perpetuated by dysfunctional beliefs, personality traits, or behaviors. Health professionals may avoid conflict and harm causation in ME/CFS by adopting more concordant ‘patient-centred’ approaches that give greater prominence to the patient narrative and experience of illness.

Source: Geraghty KJ, Blease C. Myalgic encephalomyelitis/chronic fatigue syndrome and the biopsychosocial model: a review of patient harm and distress in the medical encounter. Disabil Rehabil. 2019 Dec;41(25):3092-3102. doi: 10.1080/09638288.2018.1481149. Epub 2018 Jun 21. PMID: 29929450. https://pubmed.ncbi.nlm.nih.gov/29929450/

Relationship Between Exercise-induced Oxidative Stress Changes and Parasympathetic Activity in Chronic Fatigue Syndrome: An Observational Study in Patients and Healthy Subjects

Abstract:

Purpose: Oxidative stress has been proposed as a contributor to pain in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). During incremental exercise in patients with ME/CFS, oxidative stress enhances sooner and antioxidant response is delayed. We explored whether oxidative stress is associated with pain symptoms or pain changes following exercise, and the possible relationships between oxidative stress and parasympathetic vagal nerve activity in patients with ME/CFS versus healthy, inactive controls.

Methods: The present study reports secondary outcomes from a previous work. Data from 36 participants were studied (women with ME/CFS and healthy controls). Subjects performed a submaximal exercise test with continuous cardiorespiratory monitoring. Levels of thiobarbituric acid–reactive substances (TBARSs) were used as a measure of oxidative stress, and heart rate variability was used to assess vagal activity. Before and after the exercise, subjects were asked to rate their pain using a visual analogic scale.

Findings: Significant between-group differences in pain at both baseline and following exercise were found (both, P < 0.007). In healthy controls, pain was significantly improved following exercise (P = 0.002). No change in oxidative stress level after exercise was found. Significant correlation between TBARS levels and pain was found at baseline (r = 0.540; P = 0.021) and after exercise (r = 0.524; P = 0.024) in patients only. No significant correlation between TBARS and heart rate variability at baseline or following exercise was found in either group. However, a significant correlation was found between exercise-induced changes in HRV and TBARS in healthy controls (r = −0.720; P = 0.001).

Implications: Oxidative stress showed an association with pain symptoms in people with ME/CFS, but no exercise-induced changes in oxidative stress were found. In addition, the change in parasympathetic activity following exercise partially accounted for the change in oxidative stress in healthy controls. More research is required to further explore this link.

Source: Andrea Polli, MSc, Jessica Van Oosterwijck, PhD, Jo Nijs, PhD, Greta Moorkens, PhD, Luc Lambrecht, MD, Kelly Ickmans, PhD. Relationship Between Exercise-induced Oxidative Stress Changes and Parasympathetic Activity in Chronic Fatigue Syndrome: An Observational Study in Patients and Healthy Subjects. Clinical Therapeutics. ORIGINAL RESEARCH| VOLUME 41, ISSUE 4, P641-655, APRIL 01, 2019. Published online: January 18, 2019. Accepted: December 14, 2018. DOI: https://doi.org/10.1016/j.clinthera.2018.12.012 https://www.clinicaltherapeutics.com/article/S0149-2918(18)30611-8/fulltext#secsectitle0010 (Full article)

The role of mitochondria in ME/CFS: a perspective

Abstract:

Chronic fatigue syndrome (CFS) also known as Myalgic encephalomyelitis (ME) is a debilitating disease, characterized by the symptom of severe fatigue. ME/CFS is a heterogeneous condition in both clinical presentation and disease duration. A diagnosis of ME/CFS is based on the exclusion of other diseases due to a current lack of known biomarkers for the disease. Patients may be split into categories based on the severity of their illness – mild, moderate and severe. Here we consider some of the recent advances in the understanding of mitochondrial dysfunction and mitochondrial DNA (mtDNA) variation that may have relevance to ME/CFS.

Thus far, we have shown that ME/CFS patients do not harbor proven mtDNA mutations, another exclusion, albeit an important one. As such this group of patients do not fall within the category of patients with mitochondrial disorder. If ME/CFS patients have some form of mitochondrial dysfunction, the form and cause of this dysfunction is a matter of debate. The current data underlines the need to move from small studies to larger endeavors applying multiple methods to well-defined cohorts with samples taken longitudinally.

Source: Cara Tomas & Joanna L Elson (2019) The role of mitochondria in ME/CFS: a perspective, Fatigue: Biomedicine, Health & Behavior, 7:1, 52-58, DOI: 10.1080/21641846.2019.1580855 https://www.tandfonline.com/doi/abs/10.1080/21641846.2019.1580855  (Full text)

Post-COVID-19 Tachycardia Syndrome: A Distinct Phenotype of Post-Acute COVID-19 Syndrome

Abstract:

In this paper we highlight the presence of tachycardia in post-acute COVID-19 syndrome by introducing a new label for this phenomenon—post-COVID-19 tachycardia syndrome—and argue that this constitutes a phenotype or sub-syndrome in post-acute COVID-19 syndrome. We also discuss epidemiology, putative mechanisms, treatment options, and future research directions in this novel clinical syndrome.

Source: Ståhlberg M, Reistam U, Fedorowski A, et al. Post-COVID-19 Tachycardia Syndrome: A Distinct Phenotype of Post-Acute COVID-19 Syndrome [published online ahead of print, 2021 Aug 11]. Am J Med. 2021;S0002-9343(21)00472-1. doi:10.1016/j.amjmed.2021.07.004  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8356730/ (Full text)

Covid and ME/CFS

Announcement:

AMMES has recently added an informational page about COVID-19 and ME/CFS. The page includes physicians’ recommendations regarding the COVID vaccine for people with ME/CFS, patient surveys on how the vaccine has affected them, research articles on long-Covid and ME/CFS, related news items, and tips from doctors on how to treat patients with ME/CFS who contract COVID-19. You can find the page here:  https://ammes.org/covid-19/

Mistaken Identity: Many Diagnoses are Frequently Misattributed to Lyme Disease

Abstract:

Background: Prior studies have demonstrated that Lyme disease is frequently over-diagnosed. However, few studies describe which conditions are misdiagnosed as Lyme disease.

Methods: This retrospective observational cohort study evaluated patients referred for Lyme disease to a Mid-Atlantic academic center between 2000-2013 who lacked evidence for Borrelia burgdorferi infection. The primary outcome is clinically described diagnoses contributing to symptoms. Secondary outcomes included symptom duration and determination whether diagnoses were new or attributed to existing medical conditions.

Results: Of 1261 referred patients, 1061 (84%) had no findings of active Lyme disease, with 690 (65%) receiving other diagnoses resulting in 405 (59%) having newly diagnosed medical conditions, 134 (19%) attributed to pre-existing medical issues, and 151 (22%) had both new and pre-existing conditions. Among the 690 patients, the median symptom duration was 796 days, and a total of 139 discrete diagnoses were made. Infectious disease diagnoses comprised only 3.2%. Leading diagnoses were anxiety/depression 222 (21%), fibromyalgia 120 (11%), chronic fatigue syndrome 77 (7%), migraine disorder 74 (7%), osteoarthritis 62 (6%) and sleep disorder/apnea 48 (5%). Examples of less frequent but non-syndromic diseases newly diagnosed included multiple sclerosis (11), malignancy (8), Parkinson’s disease (8), sarcoidosis (4) or amyotrophic lateral sclerosis (4).

Conclusions: Most patients with long-term symptoms have either new or pre-existing disorders accounting for their symptoms other than Lyme disease, suggesting overdiagnosis in this population. Patients referred for consideration of Lyme disease for chronic symptoms deserve careful assessment for diagnoses other than Borrelia burgdorferi infection.

Source: Kobayashi T, Higgins Y, Melia MT, Auwaerter PG. Mistaken Identity: Many Diagnoses are Frequently Misattributed to Lyme Disease. Am J Med. 2021 Nov 30:S0002-9343(21)00792-0. doi: 10.1016/j.amjmed.2021.10.040. Epub ahead of print. PMID: 34861197. https://www.sciencedirect.com/science/article/pii/S0002934321007920  (Full text)

Investigating Fatigue and Exercise Intolerance in a University Immunology Clinic

Abstract:

Purpose: This manuscript reviews the experience of a University Immunology clinic with the evaluation of patients with idiopathic fatigue and exercise intolerance for the presence of metabolic disorders. Laboratory, biochemical and genetic studies were utilized in the evaluation.

Recent Findings: Of the 372 patients evaluated, 95% were found to have a treatable metabolic disorder. A defect in the glycogen storage pathway was found in 78 patients. Mitochondrial disorders were found in 258 patients. Myoadenylate deaminase deficiency was found in 7 patients. Various congenital myopathies were identified in 11 patients. Inflammatory myopathies were identified in 25 patients, 6 of whom had normal muscle enzymes on the initial evaluation.

Summary: The majority of patients (95%) referred with idiopathic fatigue and exercise intolerance after extensive evaluations were found to have underlying metabolic dysfunction. Frequently associated problems included gastrointestinal dysmotility disorders, recurrent infections, Raynaud’s, migraine headaches and various autoimmune diseases. Most patients showed symptomatic improvement with treatment of their metabolic dysfunction.

Source: Julian L A, Paul I, Molly M, John B, Lucia B. Investigating Fatigue and Exercise Intolerance in a University Immunology Clinic. Arch Rheum & Arthritis Res. 1(1): 2020. ARAR.MS.ID.000505. https://irispublishers.com/arar/fulltext/Investigating-Fatigue-and-Exercise-Intolerance-in-a-University.ID.000505.php (Full study)