Central sensitisation in chronic fatigue syndrome and fibromyalgia; a case control study

Abstract:

Introduction: Chronic fatigue syndrome (CFS) and fibromyalgia (FM) are both complex conditions that are challenging to treat. This may be related to an incomplete understanding of their pathophysiology, itself obfuscated by their heterogeneity. The symptomatic overlap between them and their common comorbidity suggests a shared vulnerability, which might be explained by central sensitisation.

Methods: 19 CFS cases, 19 FM cases and 20 age and sex matched healthy controls (HC) were recruited primarily from secondary care clinics in London. Those with other pain disorders, psychiatric diagnoses and those taking centrally acting or opiate medications were excluded. Participants were asked to abstain from alcohol and over the counter analgaesia 48 h prior to assessment by static and dynamic quantitative sensory tests, including measures of temporal summation (TS) and conditioned pain modulation (CPM).

Results: CS, as defined by the presence of both enhanced TS and inefficient CPM, was present in 16 (84%) CFS cases, 18 (95%) FM cases, and none of the HC (p < 0.001). Pressure pain thresholds were lower in CFS (Median222kPaIQR 146-311; p = 0.04) and FM cases (Median 189 kPa; IQR 129-272; p = 0.003) compared to HC (Median 311 kPa; IQR 245-377). FM cases differed from HC in cold-induced (FM = 22.6 °C (15.3-27.7) vs HC = 14.2 °C (9.0-20.5); p = 0.01) and heat-induced (FM = 38.0 °C (35.2-44.0) vs HC = 45.3 °C (40.1-46.8); p = 0.03) pain thresholds, where CFS cases did not.

Conclusion: Central sensitisation may be a common endophenotype in chronic fatigue syndrome and fibromyalgia. Further research should address whether central sensitisation is a cause or effect of these disorders.

Source: Bourke JH, Wodehouse T, Clark LV, Constantinou E, Kidd BL, Langford R, Mehta V, White PD. Central sensitisation in chronic fatigue syndrome and fibromyalgia; a case control study. J Psychosom Res. 2021 Sep 21;150:110624. doi: 10.1016/j.jpsychores.2021.110624. Epub ahead of print. PMID: 34600309. https://pubmed.ncbi.nlm.nih.gov/34600309/

A Comprehensive Examination of Severely Ill ME/CFS Patients

One in four myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients are estimated to be severely affected by the disease, and these house-bound or bedbound patients are currently understudied. Here, we report a comprehensive examination of the symptoms and clinical laboratory tests of a cohort of severely ill patients and healthy controls.
The greatly reduced quality of life of the patients was negatively correlated with clinical depression. The most troublesome symptoms included fatigue (85%), pain (65%), cognitive impairment (50%), orthostatic intolerance (45%), sleep disturbance (35%), post-exertional malaise (30%), and neurosensory disturbance (30%). Sleep profiles and cognitive tests revealed distinctive impairments. Lower morning cortisol level and alterations in its diurnal rhythm were observed in the patients, and antibody and antigen measurements showed no evidence for acute infections by common viral or bacterial pathogens.
These results highlight the urgent need of developing molecular diagnostic tests for ME/CFS. In addition, there was a striking similarity in symptoms between long COVID and ME/CFS, suggesting that studies on the mechanism and treatment of ME/CFS may help prevent and treat long COVID and vice versa.
Source: Chang C-J, Hung L-Y, Kogelnik AM, Kaufman D, Aiyar RS, Chu AM, Wilhelmy J, Li P, Tannenbaum L, Xiao W, Davis RW. A Comprehensive Examination of Severely Ill ME/CFS Patients. Healthcare. 2021; 9(10):1290. https://doi.org/10.3390/healthcare9101290 https://www.mdpi.com/2227-9032/9/10/1290/htm  (Full text)

Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice

Abstract:

Fatigue is a persistent and debilitating symptom following radiation therapy for prostate cancer. However, it is not well-understood how radiation targeted to a small region of the body can lead to broad changes in behavior. In this study, we used targeted pelvic irradiation of healthy male mice to test whether inflammatory signaling mediates changes in voluntary physical activity levels.

First, we tested the relationship between radiation dose, blood cell counts, and fatigue-like behavior measured as voluntary wheel-running activity. Next, we used oral minocycline treatments to reduce inflammation and found that minocycline reduces, but does not eliminate, the fatigue-like behavioral changes induced by radiation. We also used a strain of mice lacking the MyD88 adaptor protein and found that these mice also showed less fatigue-like behavior than the wild-type controls. Finally, using serum and brain tissue samples, we determined changes in inflammatory signaling induced by irradiation in wild-type, minocycline treated, and MyD88 knockout mice.

We found that irradiation increased serum levels of IL-6, a change that was partially reversed in mice treated with minocycline or lacking MyD88. Overall, our results suggest that inflammation plays a causal role in radiation-induced fatigue and that IL-6 may be an important mediator.

Source: Wolff BS, Alshawi SA, Feng LR, Juneau PL, Saligan LN. Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice. Brain Behav Immun Health. 2021 May 19;15:100264. doi: 10.1016/j.bbih.2021.100264. PMID: 34589770; PMCID: PMC8474574. https://pubmed.ncbi.nlm.nih.gov/34589770/

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A neurological entity?

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a disorder of unknown physiopathology with multisystemic repercussions, framed in ICD-11 under the heading of neurology (8E49). There is no specific test to support its clinical diagnosis. Our objective is to review the evidence in neuroimaging and dysautonomia evaluation in order to support the neurological involvement and to find biomarkers serving to identify and/or monitor the pathology.
The symptoms typically appear acutely, although they can develop progressively over years; an essential trait for diagnosis is “central” fatigue together with physical and/or mental exhaustion after a small effort. Neuroimaging reveals various morphological, connectivity, metabolic, and functional alterations of low specificity, which can serve to complement the neurological study of the patient. The COMPASS-31 questionnaire is a useful tool to triage patients under suspect of dysautonomia, at which point they may be redirected for deeper evaluation. Recently, alterations in heart rate variability, the Valsalva maneuver, and the tilt table test, together with the presence of serum autoantibodies against adrenergic, cholinergic, and serotonin receptors were shown in a subgroup of patients.
This approach provides a way to identify patient phenotypes. Broader studies are needed to establish the level of sensitivity and specificity necessary for their validation. Neuroimaging contributes scarcely to the diagnosis, and this depends on the identification of specific changes. On the other hand, dysautonomia studies, carried out in specialized units, are highly promising in order to support the diagnosis and to identify potential biomarkers. ME/CFS orients towards a functional pathology that mainly involves the autonomic nervous system, although not exclusively.
Source: Gandasegui IM, Laka LA, Gargiulo P-Á, Gómez-Esteban J-C, Sánchez J-VL. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Neurological Entity? Medicina. 2021; 57(10):1030. https://doi.org/10.3390/medicina57101030 https://www.mdpi.com/1648-9144/57/10/1030 (Full article available as PDF file)

Clinical Profile and Aspects of Differential Diagnosis in Patients with ME/CFS from Latvia

Abstract:

Background and objectives: There is still an uncertainty regarding the clinical symptomatology and the diagnostic criteria in terms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), as different diagnostic criteria exist. Our aim is to identify the core symptoms of ME/CFS in the outpatient setting in Riga; to distinguish symptoms in patients with ME/CFS and those with symptoms of fatigue; and to investigate patient thoughts on the onset, symptoms, treatment and effect of ME/CFS.

Materials and methods: Total of 65 Caucasian patients from an ambulatory care setting were included in the study. Questionnaires, specialist evaluation of the patients and visual analogue scale (VAS) measurements were used to objectify the findings.

Results: The study showed that ME/CFS with comorbidities is associated with a more severe disease. A negative correlation was found regarding an increase in age and number of current symptoms, as well as an increase in VAS score and the duration of fatigue and age in the ME/CFS without comorbidities group.

Conclusions: Comorbidities tend to present with a more severe course of ME/CFS. Fatigue, myalgia, arthralgia and sleep disturbances tend to be more prevalent in the ME/CFS patients compared to the non-ME/CFS patients. VAS score has a tendency to decrease with age and duration of fatigue. Nonsteroidal anti-inflammatory drugs are the most commonly used pharmacological drug class that reduces ME/CFS symptoms.

Source: Krumina A, Vecvagare K, Svirskis S, Gravelsina S, Nora-Krukle Z, Gintere S, Murovska M. Clinical Profile and Aspects of Differential Diagnosis in Patients with ME/CFS from Latvia. Medicina (Kaunas). 2021 Sep 11;57(9):958. doi: 10.3390/medicina57090958. PMID: 34577881. https://pubmed.ncbi.nlm.nih.gov/34577881/

An Audit of UK Hospital Doctors’ Knowledge and Experience of Myalgic Encephalomyelitis

Abstract:

Background and Objectives: There is some evidence that knowledge and understanding of ME among doctors is limited. Consequently, an audit study was carried out on a group of hospital doctors attending a training event to establish how much they knew about ME and their attitudes towards it.

Materials and Methods: Participants at the training event were asked to complete a questionnaire, enquiring about prior knowledge and experience of ME and their approaches to diagnosis and treatment. A total of 44 completed questionnaires were returned. Responses were tabulated, proportions selecting available options determined, 95% confidence limits calculated, and the significance of associations determined by Fisher’s exact test.

Results: Few respondents had any formal teaching on ME, though most had some experience of it. Few knew how to diagnose it and most lacked confidence in managing it. None of the respondents who had had teaching or prior experience of ME considered it a purely physical illness. Overall, 91% of participants believed ME was at least in part psychological. Most participants responded correctly to a series of propositions about the general epidemiology and chronicity of ME. There was little knowledge of definitions of ME, diagnosis, or of clinical manifestations. Understanding about appropriate management was very deficient. Similarly, there was little appreciation of the impact of the disease on daily living or quality of life. Where some doctors expressed confidence diagnosing or managing ME, this was misplaced as they were incorrect on the nature of ME, its diagnostic criteria and its treatment.

Conclusion: This audit demonstrates that most doctors lack training and clinical expertise in ME. Nevertheless, participants recognised a need for further training and indicated a wish to participate in this. It is strongly recommended that factually correct and up-to-date medical education on ME be made a priority at undergraduate and postgraduate levels. It is also recommended that this audit be repeated following a period of medical education.

Source: Hng KN, Geraghty K, Pheby DFH. An Audit of UK Hospital Doctors’ Knowledge and Experience of Myalgic Encephalomyelitis. Medicina (Kaunas). 2021 Aug 27;57(9):885. doi: 10.3390/medicina57090885. PMID: 34577808. https://pubmed.ncbi.nlm.nih.gov/34577808/

Complement Component C1q as a Potential Diagnostic Tool for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Subtyping

Abstract:

Background: Routine blood analytics are systematically used in the clinic to diagnose disease or confirm individuals’ healthy status. For myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a disease relying exclusively on clinical symptoms for its diagnosis, blood analytics only serve to rule out underlying conditions leading to exerting fatigue. However, studies evaluating complete and large blood datasets by combinatorial approaches to evidence ME/CFS condition or detect/identify case subgroups are still scarce.

Methods: This study used unbiased hierarchical cluster analysis of a large cohort of 250 carefully phenotyped female ME/CFS cases toward exploring this possibility.

Results: The results show three symptom-based clusters, classified as severe, moderate, and mild, presenting significant differences (p < 0.05) in five blood parameters. Unexpectedly the study also revealed high levels of circulating complement factor C1q in 107/250 (43%) of the participants, placing C1q as a key molecule to identify an ME/CFS subtype/subgroup with more apparent pain symptoms.

Conclusions: The results obtained have important implications for the research of ME/CFS etiology and, most likely, for the implementation of future diagnosis methods and treatments of ME/CFS in the clinic.

Source: Castro-Marrero J, Zacares M, Almenar-Pérez E, Alegre-Martín J, Oltra E. Complement Component C1q as a Potential Diagnostic Tool for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Subtyping. J Clin Med. 2021 Sep 15;10(18):4171. doi: 10.3390/jcm10184171. PMID: 34575280. https://pubmed.ncbi.nlm.nih.gov/34575280/

Evaluation of Immune Dysregulation in an Austrian Patient Cohort Suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe multi-systemic disease characterized by debilitating fatigue that is not relieved by rest. The causes of the disease are still largely unexplained, and no causative treatment is currently available. Changes in the immune response are considered as fundamental in the development of ME/CFS. Thus, we aimed to evaluate the immunological profile of ME/CFS patients in a retrospective data analysis.

As part of the routine workup for ME/CFS patients, a differential blood count, leukocyte subtyping, and quantification of immunoglobulins and IgG subclasses, as well as a complement analysis, was performed. Out of 262 ME/CFS patients, 64.9% had a reduction or deficiency in at least one of the listed immune parameters. In contrast, 26.3% showed signs of immune activation or inflammation. A total of 17.6% of the ME/CFS patients had an unclassified antibody deficiency, with IgG3 and IgG4 subclass deficiencies as the most common phenotypes. Reduced MBL (mannose-binding lectin) levels were found in 32% of ME/CFS patients, and MBL deficiency in 7%.

In summary, the present results confirmed the relevance of immune dysfunction in ME/CFS patients underlining the involvement of a dysfunctional immune response in the disease. Thus, immune parameters are relevant disease biomarkers, which might lead to targeted therapeutic approaches in the future.

Source: Lutz L, Rohrhofer J, Zehetmayer S, Stingl M, Untersmayr E. Evaluation of Immune Dysregulation in an Austrian Patient Cohort Suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Biomolecules. 2021 Sep 14;11(9):1359. doi: 10.3390/biom11091359. PMID: 34572574. https://pubmed.ncbi.nlm.nih.gov/34572574/

Turning a Corner in ME/CFS Research

This collection of research papers addresses fundamental questions concerning the nature of myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS), the problem of disbelief and lack of knowledge and understanding of the condition among many doctors and the origins of this problem, and its impact on patients and their families. We report briefly the growing knowledge of the underlying pathological processes in ME/CFS, and the development of new organizations, including Doctors with ME, the US ME/CFS Clinical Coalition and EUROMENE, to address aspects of the challenges posed by the illness. We discuss the implications of COVID-19, which has much in common with ME/CFS, with much overlap of symptoms, and propose a new taxonomic category, which we are terming post-active phase of infection syndromes (PAPIS) to include both.
This collection of papers includes a number of papers reporting similar serious impacts on the quality of life of patients and their families in various European countries. The advice of EUROMENE experts on diagnosis and management is included in the collection. We report this in light of guidance from other parts of the world, including the USA and Australia, and in the context of current difficulties in the UK over the promulgation of a revised guideline from the National Institute for Health and Care Excellence (NICE). We also consider evidence on the cost-effectiveness of interventions for ME/CFS, and on the difficulties of determining the costs of care when a high proportion of people with ME/CFS are never diagnosed as such.
The Special Issue includes a paper which is a reminder of the importance of a person-centred approach to care by reviewing mind–body interventions. Finally, another paper reviews the scope for prevention in minimizing the population burden of ME/CFS, and concludes that secondary prevention, through early detection and diagnosis, could be of value.
Source: Pheby DFH, Friedman KJ, Murovska M, Zalewski P. Turning a Corner in ME/CFS Research. Medicina. 2021; 57(10):1012. https://doi.org/10.3390/medicina57101012  https://www.mdpi.com/1648-9144/57/10/1012 (Full article available as PDF file)

Induced pluripotent stem cells as suitable sensors for fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Fibromyalgia (FM) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are devastating metabolic neuroimmune diseases that are difficult to diagnose because of the presence of numerous symptoms and a lack of specific biomarkers. Despite patient heterogeneity linked to patient subgroups and variation in disease severity, anomalies are found in the blood and plasma of these patients when compared with healthy control groups. The seeming specificity of these “plasma factors”, as recently reported by Ron Davis and his group at Stanford University, CA, United States, and observations by our group, have led to the proposal that induced pluripotent stem cells (iPSCs) may be used as metabolic sensors for FM and ME/CFS, a hypothesis that is the basis for this in-depth review.

Aim: To identify metabolic signatures in FM and/or ME/CFS supporting the existence of disease-associated plasma factors to be sensed by iPSCs.

Methods: A PRISMA (Preferred Reported Items for Systematic Reviews and Meta-analysis)-based systematic review of the literature was used to select original studies evaluating the metabolite profiles of FM and ME/CFS body fluids. The MeSH terms “metabolomic” or “metabolites” in combination with FM and ME/CFS disease terms were screened against the PubMed database. Only original studies applying omics technologies, published in English, were included. The data obtained were tabulated according to the disease and type of body fluid analyzed. Coincidences across studies were searched and P-values reported by the original studies were gathered to document significant differences found in the disease groups.

Results: Eighteen previous studies show that some metabolites are commonly altered in ME/CFS and FM body fluids. In vitro cell-based assays have the potential to be developed as screening platforms, providing evidence for the existence of factors in patient body fluids capable of altering morphology, differentiation state and/or growth patterns. Moreover, they can be further developed using approaches aimed at blocking or reversing the effects of specific plasma/serum factors seen in patients. The documented high sensitivity and effective responses of iPSCs to environmental cues suggests that these pluripotent cells could form robust, reproducible reporter systems of metabolic diseases, including ME/CFS and FM. Furthermore, culturing iPSCs, or their mesenchymal stem cell counterparts, in patient-conditioned medium may provide valuable information to predict individual outcomes to stem-cell therapy in the context of precision medicine studies.

Conclusion: This opinion review explains our hypothesis that iPSCs could be developed as a screening platform to provide evidence of a metabolic imbalance in FM and ME/CFS.

Source: Monzón-Nomdedeu MB, Morten KJ, Oltra E. Induced pluripotent stem cells as suitable sensors for fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome. World J Stem Cells. 2021 Aug 26;13(8):1134-1150. doi: 10.4252/wjsc.v13.i8.1134. PMID: 34567431; PMCID: PMC8422931. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8422931/ (Full article)