Characterization of subgroups of myalgic encephalomyelitis/chronic fatigue syndrome based on disease onset, symptoms and biomarkers

Abstract:

Myalgic encephalomyelitis, also called chronic fatigue syndrome (ME/CFS), is an acquired multisystem disease. The core symptoms include fatigue, exercise intolerance and pain as well as cognitive, autonomic and immunological manifestations. The diagnosis of ME/CFS is based on clinical criteria. Specific biomarkers do not currently exist, but studies suggest a role for soluble cluster of differentiation 26 (sCD26) and autoantibodies (AAK) against G protein-coupled receptors (GPCR). In many cases, the disease begins as a result of infections. 

The aim of this work was to determine the pathophysiological significance of potential biomarkers, assuming different development mechanisms in patients with infection-associated disease onset compared to those with other triggers. In a first study, sCD26, also called dipeptidyl peptidase-4 (DPP-4) due to its enzymatic activity, was analyzed and compared in the serum of 205 ME/CFS patients and 98 controls. This was followed by a comprehensive correlation analysis between sCD26 and clinical and laboratory parameters for ME/CFS patients, separated by type of disease onset. In addition, CD26 expression on lymphocyte subpopulations was determined for 12 patients and 12 controls. 

In another study, a correlation analysis was carried out between AAK against vasoregulatory GPCR and symptoms in 116 ME/CFS patients, separated by type of disease onset. It was shown that in ME/CFS patients with infection-associated disease onset, sCD26 correlated with numerous immunological and metabolic parameters, the changes of which have also been described in connection with DPP-4 inhibitors. In addition, there were inverse correlations with AAK against alpha1-adrenergic and M3-acetylcholine receptors. 

In this subgroup, the second study found correlations between numerous GPCR-AAK and the severity of fatigue, muscle pain and cognitive symptoms as well as greater functional impairment relevant to everyday life. None of these correlations were found in patients without infection-associated disease onset. 

Here, sCD26 correlated inversely with orthostatically induced heart rate increases and AAK against alpha- and beta-adrenergic receptors with the severity of orthostatic symptoms. Different correlation patterns between AAK against GPCR and symptoms allow us to assume that in patients with ME/CFS, an altered function of the AAK or its receptors or signaling pathways has occurred as a result of an infection. The association of sCD26 and GPCR-AAK also indicates the dysregulation of other parts of the immune system with potentially pathological consequences. The differences presented compared to patients with non-infectious genesis suggest two definable subgroups.

Source: Szklarski, Marvin. Characterization of subgroups of myalgic encephalomyelitis/chronic fatigue syndrome based on disease onset, symptoms and biomarkers. Charité – University Medicine Berlin, dissertation. https://refubium.fu-berlin.de/handle/fub188/40276

How post-infection status could lead to the increasing risks of chronic fatigue syndrome and the potential mechanisms: A 17-year population based Cohort study

Abstract:

Background: Serological studies have suggested that viruses and atypical pathogens are associated with CFS, but no study has focused on typical and common pathogens. This study aims to assess the association of infections with a variety of common pathogens with the risk of CFS and provide evidence for the hypothesis that infection triggers CFS.

Methods: The nested case-control study identified 2,000,000 adult patients from a nationwide population-based health insurance claims database from January 1, 2000, to December 31, 2017. Each case with a diagnosis of infection by pathogens was matched with one control using a propensity score. Patients with more than one potential pathogen, younger than 20 years old, or with a history of CFS or infection with certain pathogens before the index date were excluded. Univariate and multivariate Cox proportional hazard models were applied to estimate the HR, aHR, and corresponding 95% CI. The multivariate analysis had adjustments for age, sex, comorbidities, and medication confounders.

Results: A total of 395,811 cases with 1: 1 matched controls were included (58.2% female; mean age [standard deviation], 44.15 [17.02]). Among these, the aHR of the pathogen cohort was 1.5 (95% CI, 1.47 to 1.54). Pathogens were positively correlated with CFS, including influenza, candida and others.

Conclusion: The findings of this study demonstrate the association between CFS and infection with common pathogens, including bacteria, virus and fungi.

Source: Hsun Chang; Chien-Feng Kuo; Teng-Shun Yu; Liang-Yin Ke; Chung-Lieh Hung; Shin-Yi Tsai. How post-infection status could lead to the increasing risks of chronic fatigue syndrome and the potential mechanisms: A 17-year population based Cohort study. Research Square, August 30, 2023. https://assets.researchsquare.com/files/rs-3289981/v1/55890598-6f0d-4f73-a9f4-5349e07baac0.pdf (Full text)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A preliminary survey among patients in Switzerland

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a multi-factorial systemic chronic debilitating disease of poorly understood etiology and limited systematic evidence. The questionnaire and interview-based survey included 169 ME/CFS patients from the Swiss ME/CFS association. The majority of patients were females (72.2%), single (55.7%) and without children (62.5%). Only one third were working (full/part-time). The mean onset of ME/CFS was 31.6 years of age with 15% of patients being symptomatic before their 18th birthday.

In this cohort, patients had documented ME/CFS for a mean 13.7 years, whereby half (50.3%) stated their condition was progressively worsening. Triggering events and times of disease onset were recalled by 90% of the participants. An infectious disease was associated with a singular or part of multiple events by 72.9% and 80.6%, respectively.

Prior to disease onset, a third of the patients reported respiratory infections; followed by gastro-intestinal infections (15.4%) and tick-borne diseases (16.2%). Viral infections were recalled by 77.8% of the respondents, with Epstein Barr Virus being the most commonly reported agent. Patients self-reported an average number of 13 different symptoms, all described specific triggers of symptoms exacerbation and 82.2% suffered from co-morbidities.

This study collated clinically relevant information on ME/CFS patients in Switzerland, highlighting the extent of disease severity, the associated factors negatively affecting daily life activities and work status as well as potential socio-economic impact.

Source: Rea Tschopp; Rahel S. König; Protazy Rejmer; Daniel H. Paris. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): A preliminary survey among patients in Switzerland. Heliyon, Volume 9, Issue 5, e15595, May 2023. https://www.cell.com/heliyon/fulltext/S2405-8440(23)02802-5 (Full text)

A Proposed New Model to Explain the Role of Low Dose Non-DNA Targeted Radiation Exposure in Chronic Fatigue and Immune Dysfunction Syndrome

Abstract:

Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS) is considered to be a multidimensional illness whose etiology is unknown. However, reports from Chernobyl, as well as those from the United States, have revealed an association between radiation exposure and the development of CFIDS. As such, we present an expanded model using a systems biology approach to explain the etiology of CFIDS as it relates to this cohort of patients. This paper proposes an integrated model with ionizing radiation as a suggested trigger for CFIDS mediated through UVA induction and biophoton generation inside the body resulting from radiation-induced bystander effects (RIBE).
Evidence in support of this approach has been organized into a systems view linking CFIDS illness markers with the initiating events, in this case, low-dose radiation exposure. This results in the formation of reactive oxygen species (ROS) as well as important immunologic and other downstream effects. Furthermore, the model implicates melanoma and subsequent hematopoietic dysregulation in this underlying process. Through the identification of this association with melanoma, clinical medicine, including dermatology, hematology, and oncology, can now begin to apply its expansive knowledge base to provide new treatment options for an illness that has had few effective treatments.
Source: Cocchetto A, Seymour C, Mothersill C. A Proposed New Model to Explain the Role of Low Dose Non-DNA Targeted Radiation Exposure in Chronic Fatigue and Immune Dysfunction Syndrome. International Journal of Molecular Sciences. 2023; 24(7):6022. https://doi.org/10.3390/ijms24076022 https://www.mdpi.com/1422-0067/24/7/6022 (Full text)

Towards a Better Understanding of the Complexities of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex condition arising in susceptible people, predominantly following viral infection, but also other stressful events. The susceptibility factors discussed here are both genetic and environmental although not well understood.

While the dysfunctional physiology in ME/CFS is becoming clearer, understanding has been hampered by different combinations of symptoms in each affected person.

A common core set of mainly neurological symptoms forms the modern clinical case definition, in the absence of an accessible molecular diagnostic test. This landscape has prompted interest in whether ME/CFS patients can be classified into a particular phenotype/subtype that might assist better management of their illness and suggest preferred therapeutic options.

Currently, the same promising drugs, nutraceuticals, or behavioral therapies available can be beneficial, have no effect, or be detrimental to each individual patient. We have shown that individuals with the same disease profile exhibit unique molecular changes and physiological responses to stress, exercise and even vaccination.

Key features of ME/CFS discussed here are the possible mechanisms determining the shift of an immune/inflammatory response from transient to chronic in ME/CFS, and how the brain and CNS manifests the neurological symptoms, likely with activation of its specific immune system and resulting neuroinflammation.

The many cases of the post viral ME/CFS-like condition, Long COVID, following SARS-CoV-2 infection, and the intense research interest and investment in understanding this condition, provide exciting opportunities for the development of new therapeutics that will benefit ME/CFS patients.

Source: Tate WP, Walker MOM, Peppercorn K, Blair ALH, Edgar CD. Towards a Better Understanding of the Complexities of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID. International Journal of Molecular Sciences. 2023; 24(6):5124. https://doi.org/10.3390/ijms24065124 (Full text)

What Causes ME/CFS: The Role of the Dysfunctional Immune System and Viral Infections

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) remains an enigmatic highly disabling and complex long-term condition with a wide range of aetiologies and symptoms.

A viral onset is commonly mentioned by patients and several bodily systems are ultimately disturbed. The parallel with long-covid is clear.

However, immune dysregulation with impaired NK cell dysfunction and tendency to novel autoimmunity have been frequently reported. These may contribute to reactivation of previous acquired viruses/retroviruses accompanied by impaired endocrine regulation and mitochondrial energy generation.

The unpredictable nature of seemingly unconnected and diverse symptoms that are poorly responsive to several allopathic and alternative therapies then contributes to an escalation of the illness with secondary dysfunction of multiple other systems. Treatment of established ME/CFS is therefore difficult and requires multi-specialty input addressing each of the areas affected by the illness.

Source: Amolak S Bansal, Aletta D Kraneveld, Elisa Oltra and Simon Carding. What Causes ME/CFS: The Role of the Dysfunctional Immune System and Viral Infections. Journal of Immunology and Allergy 2022;3(2):1-15. https://maplespub.co.in/assets/images/files/doc_1663924267.pdf (Full text)

Orthostatic Symptoms and Reductions in Cerebral Blood Flow in Long‐Haul COVID‐19 Patients: Similarities with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Background and Objectives: Symptoms and hemodynamic findings during orthostatic stress have been reported in both long-haul COVID-19 and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), but little work has directly compared patients from these two groups. To investigate the overlap in these clinical phenotypes, we compared orthostatic symptoms in daily life and during head-up tilt, heart rate and blood pressure responses to tilt, and reductions in cerebral blood flow in response to orthostatic stress in long-haul COVID-19 patients, ME/CFS controls, and healthy controls.
Materials and Methods: We compared 10 consecutive long-haul COVID-19 cases with 20 age- and gender-matched ME/CFS controls with postural tachycardia syndrome (POTS) during head-up tilt, 20 age- and gender-matched ME/CFS controls with a normal heart rate and blood pressure response to head-up tilt, and 10 age- and gender-matched healthy controls. Identical symptom questionnaires and tilt test procedures were used for all groups, including measurement of cerebral blood flow and cardiac index during the orthostatic stress.
Results: There were no significant differences in ME/CFS symptom prevalence between the long-haul COVID-19 patients and the ME/CFS patients. All long-haul COVID-19 patients developed POTS during tilt. Cerebral blood flow and cardiac index were more significantly reduced in the three patient groups compared with the healthy controls. Cardiac index reduction was not different between the three patient groups. The cerebral blood flow reduction was larger in the long-haul COVID-19 patients compared with the ME/CFS patients with a normal heart rate and blood pressure response.
Conclusions: The symptoms of long-haul COVID-19 are similar to those of ME/CFS patients, as is the response to tilt testing. Cerebral blood flow and cardiac index reductions during tilt were more severely impaired than in many patients with ME/CFS. The finding of early-onset orthostatic intolerance symptoms, and the high pre-illness physical activity level of the long-haul COVID-19 patients, makes it unlikely that POTS in this group is due to deconditioning. These data suggest that similar to SARS-CoV-1, SARS-CoV-2 infection acts as a trigger for the development of ME/CFS.
Source: Campen CMCv, Rowe PC, Visser FC. Orthostatic Symptoms and Reductions in Cerebral Blood Flow in Long-Haul COVID-19 Patients: Similarities with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Medicina. 2022; 58(1):28. https://doi.org/10.3390/medicina58010028  (Full text)

Patient perceptions of infectious illnesses preceding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Objectives: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is often reported to be caused by an infectious agent. However, it is unclear whether one infectious agent might be the cause or whether there might be many different infectious agents. The objective of this study was to identify self-reported infectious illnesses associated with the onset of ME/CFS.

Methods: The present study involved data from multiple sites in several countries. 1773 individuals diagnosed with either ME, CFS or ME/CFS provided qualitative data concerning infectious triggers which were coded and classified for analysis.

Results: 60.3% of patients report a variety of infectious illnesses some time before onset of ME/CFS. The most frequently reported infectious illness was Mononucleosis, which occurred in 30% of infections. However, over 100 other infectious illnesses were mentioned.

Discussion: The findings suggest that many infectious agents might be associated with the onset of ME/CFS.

Source: Jason LA, Yoo S, Bhatia S. Patient perceptions of infectious illnesses preceding Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Chronic Illn. 2021 Sep 20:17423953211043106. doi: 10.1177/17423953211043106. Epub ahead of print. PMID: 34541918. https://pubmed.ncbi.nlm.nih.gov/34541918/

Exploring Symptom Fluctuations and Triggers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Novel Patient-Centred N-of-1 Observational Designs: A Protocol for a Feasibility and Acceptability Study

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic condition of unknown aetiology associated with a range of disabling symptoms, including post-exertional malaise, chronic fatigue, musculoskeletal pain, orthostatic intolerance, unrefreshing sleep, and cognitive dysfunction. ME/CFS is a heterogeneous disorder, with significant variation in symptom type and severity between individuals, as well as within individuals over time. The diversity of ME/CFS symptom presentation makes management challenging; treatments supported by data from randomised controlled trials may not work for all individuals due to the variability in experienced symptoms. Studies using quantitative N-of-1 observational designs involve repeated outcome measurements in an individual over time and can generate rigorous individual-specific conclusions about symptom patterns and triggers in individuals with ME/CFS. This study aims to explore the feasibility and acceptability of using novel patient-centred N-of-1 observational designs to explore symptom fluctuations and triggers in ME/CFS at the individual level.

Methods and analysis: Individuals with a medical diagnosis of ME/CFS will be recruited through ME/CFS patient organisations to participate in a series of patient-centred N-of-1 observational studies. Using a wrist-worn electronic diary, participants will complete ecological momentary assessments of fatigue, stress, mood, and cognitive demand, three times per day for a period of 6-12 weeks. Personally relevant symptoms and triggers will also be incorporated into the questionnaire design. Physical activity will be objectively measured via an integrated accelerometer. Feasibility and acceptability outcomes will be assessed including the percentage of diary entries completed, as well as recruitment and retention rate, feasibility of analysing and interpreting the data collected, and participant views about participation elicited via a post-study semi-structured interview.

Discussion: This study will assess the feasibility and acceptability of patient-centred N-of-1 observational studies to assess diseases with complex presentations such as ME/CFS, as well as provide individual-level evidence about fluctuations and triggers of ME/CFS symptoms that may aid self-management.

Trial registration: Australian and New Zealand Clinical Trials Registry: ACTRN12618001898246. Registered on 22 November 2018.

Source: McDonald S, Tan SX, Banu S, van Driel M, McGree JM, Mitchell G, Nikles J. Exploring Symptom Fluctuations and Triggers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Novel Patient-Centred N-of-1 Observational Designs: A Protocol for a Feasibility and Acceptability Study. Patient. 2021 Aug 9. doi: 10.1007/s40271-021-00540-0. Epub ahead of print. PMID: 34368926.  https://pubmed.ncbi.nlm.nih.gov/34368926/

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome as a Hyper-Regulated Immune System Driven by an Interplay Between Regulatory T Cells and Chronic Human Herpesvirus Infections

Abstract:

Autoimmunity and chronic viral infections are recurrent clinical observations in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a complex disease with an unknown cause. Given these observations, the regulatory CD4+ T cells (Tregs) show promise to be good candidates for the underlying pathology due to their capacity to suppress the immune responses against both self and microbial antigens. Here, we discussed the overlooked role of these cells in the chronicity of Human Herpes Virus 6 (HHV6), Herpes Simplex 1 (HSV1), and Epstein-Barr virus (EBV), as often reported as triggers of ME/CFS.

Using simulations of the cross-regulation model for the dynamics of Tregs, we illustrated that mild infections might lead to a chronically activated immune responses under control of Tregs if the responding clone has a high autoimmune potential. Such infections promote persistent inflammation and possibly fatigue. We then hypothesized that ME/CFS is a condition characterized by a predominance of this type of infections under control of Tregs. In contrast, healthy individuals are hypothesized to trigger immune responses of a virus-specific clone with a low autoimmune potential.

According to this hypothesis, simple model simulations of the CD4+ T-cell repertoire could reproduce the increased density and percentages of Tregs observed in patients suffering from the disease, when compared to healthy controls. A deeper analysis of Tregs in the pathogenesis of ME/CFS will help to assess the validity of this hypothesis.

Copyright © 2019 Sepúlveda, Carneiro, Lacerda and Nacul.

Source: Sepúlveda N, Carneiro J, Lacerda E, Nacul L. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome as a Hyper-Regulated Immune System Driven by an Interplay Between Regulatory T Cells and Chronic Human Herpesvirus Infections. Front Immunol. 2019 Nov 21;10:2684. doi: 10.3389/fimmu.2019.02684. eCollection 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6883905/ (Full article)