Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms

Developing a Blood Cell-Based Diagnostic Test for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Using Peripheral Blood Mononuclear Cells

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by debilitating fatigue that profoundly impacts patients' lives. Diagnosis of ME/CFS remains challenging, with most patients relying on self-report, questionnaires, and subjective measures to receive a diagnosis, and many never receiving a clear diagnosis at all. In this study, a single-cell Raman platform and artificial intelligence are utilized to analyze blood cells from 98 human subjects, including 61 ME/CFS patients of varying disease severity and 37 healthy and disease controls. These results demonstrate that Raman profiles of blood cells can distinguish between healthy individuals, disease controls, and ME/CFS patients with high accuracy (91%), and can further differentiate between mild, moderate, and severe ME/CFS patients (84%). Additionally, specific Raman peaks that correlate with ME/CFS phenotypes and have the potential to provide insights into biological changes and support the development of new therapeutics are identified. This study presents a promising approach for aiding in the diagnosis and management of ME/CFS and can be extended to other unexplained chronic diseases such as long COVID and post-treatment Lyme disease syndrome, which share many of the same symptoms as ME/CFS.

The Crosstalk between Gut Microbiota and Nervous System: A Bidirectional Interaction between Microorganisms and Metabolome

Several studies have shown that the gut microbiota influences behavior and, in turn, changes in the immune system associated with symptoms of depression or anxiety disorder may be mirrored by corresponding changes in the gut microbiota. Although the composition/function of the intestinal microbiota appears to affect the central nervous system (CNS) activities through multiple mechanisms, accurate epidemiological evidence that clearly explains the connection between the CNS pathology and the intestinal dysbiosis is not yet available. The enteric nervous system (ENS) is a separate branch of the autonomic nervous system (ANS) and the largest part of the peripheral nervous system (PNS). It is composed of a vast and complex network of neurons which communicate via several neuromodulators and neurotransmitters, like those found in the CNS. Interestingly, despite its tight connections to both the PNS and ANS, the ENS is also capable of some independent activities. This concept, together with the suggested role played by intestinal microorganisms and the metabolome in the onset and progression of CNS neurological (neurodegenerative, autoimmune) and psychopathological (depression, anxiety disorders, autism) diseases, explains the large number of investigations exploring the functional role and the physiopathological implications of the gut microbiota/brain axis.

Factors Influencing the Prognosis of Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a long-term debilitating multisystem condition with poor prognosis. Studies that examined predictors of ME/CFS outcomes yielded contradictory results. We aimed to explore epidemiological and clinical prognostic factors of ME/CFS using operationalized criteria for recovery/improvement. Adult ME/CFS patients who attended the Internal Medicine Department of Angers University Hospital, Angers, France between October 2011 and December 2019, and were followed up until December 2020, were included retrospectively. Their medical records were reviewed for data collection. Patients were classified into two groups according to the presence or absence of recovery/improvement (R/I) and compared for epidemiological characteristics, fatigue features, post-exertional malaise severity, clinical manifestations, and comorbidities. The subgroups of recovered and significantly improved patients were then compared. 168 patients were included. Recovery and improvement rates were 8.3% and 4.8%, respectively. Older age at disease onset was associated with R/I (OR 1.06 [95% CI 1.007-1.110] (p = 0.028)), while diagnostic delay was inversely associated with R/I (OR 0.98 [95% CI 0.964-0.996] (p = 0.036)). The study findings confirmed the poor prognosis of ME/CFS and the deleterious effect of diagnostic delay on disease progression. Interestingly, being older at disease onset was associated with better outcomes, which offers hope to patients for recovery/improvement even at an advanced age.

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

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.

Warning Signals of Post-Exertional Malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Retrospective Analysis of 197 Patients

Post-exertional malaise (PEM), the key feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), is characterized by baseline symptom exacerbation after exposure to a stressor, and some patients can experience new or non-typical symptoms. We hypothesized that new or non-typical symptoms occurring long enough before onset of baseline symptom exacerbation could be warning signals predicting PEM. Adult ME/CFS patients who attended the internal medicine department of Angers University Hospital (France) between October 2011 and December 2019 were included in a retrospective medical records review. Patients who experienced one or more new or non-typical symptoms before baseline symptom exacerbation were compared with the rest of the study population for PEM features, epidemiological characteristics, fatigue features, and comorbidities. New or non-typical symptoms preceded baseline symptom exacerbation in 27/197 (13.7%) patients, and the most frequent ones were mood disorders (37%). When compared to the rest of the study population, only PEM intensity was significantly lower in these patients (p = 0.004), even after adjustment for sex and age at disease onset (p = 0.007). New or non-typical symptoms preceding baseline symptom exacerbation in some ME/CFS patients could be warning signals for PEM. Their identification could help preventing PEM occurrences or reducing their intensity leading to improving disease prognosis.

The evidence base for physiotherapy in myalgic encephalomyelitis/chronic fatigue syndrome when considering post-exertional malaise: a systematic review and narrative synthesis

BACKGROUND

Due to the inconsistent use of diagnostic criteria in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), it is unsure whether physiotherapeutic management regarded effective in ME/CFS is appropriate for patients diagnosed with criteria that consider post-exertional malaise (PEM) as a hallmark feature.

PURPOSE

To appraise current evidence of the effects of physiotherapy on symptoms and functioning in ME/CFS patients in view of the significance of PEM in the applied diagnostic criteria for inclusion.

METHODS

A systematic review of randomized controlled trials published over the last two decades was conducted. Studies evaluating physiotherapeutic interventions for adult ME/CFS patients were included. The diagnostic criteria sets were classified into three groups according to the extent to which the importance of PEM was emphasized: chronic fatigue (CF; PEM not mentioned as a criterion), CFS (PEM included as an optional or minor criterion) or ME (PEM is a required symptom). The main results of included studies were synthesized in relation to the classification of the applied diagnostic criteria. In addition, special attention was given to the tolerability of the interventions.

RESULTS

Eighteen RCTs were included in the systematic review: three RCTs with CF patients, 14 RCTs with CFS patients and one RCT covering ME patients with PEM. Intervention effects, if any, seemed to disappear with more narrow case definitions, increasing objectivity of the outcome measures and longer follow-up.

CONCLUSION

Currently, there is no scientific evidence when it comes to effective physiotherapy for ME patients. Applying treatment that seems effective for CF or CFS patients may have adverse consequences for ME patients and should be avoided.

Selenium-associated DNA methylation modifications in placenta and neurobehavioral development of newborns: An epigenome-wide study of two U.S. birth cohorts

BACKGROUND/AIM

Selenium (Se) levels in pregnancy have been linked to neurobehavioral development of the offspring. DNA methylation is a potential mechanism underlying the impacts of environmental exposures on fetal development; however, very few studies have been done elucidating the role of DNA methylation linking prenatal Se and child neurobehavior. We aimed to investigate the associations between placental Se concentration and epigenome-wide DNA methylation in two U.S. cohorts, and to assess the association between Se-related DNA methylation modifications and newborns' neurobehavior.

METHODS

We measured placental Se concentrations in 343 newborns enrolled in the New Hampshire Birth Cohort Study and in 141 newborns in the Rhode Island Child Health Study. Genome-wide placental DNA methylation was measured by HumanMethylation450 BeadChip, and newborn neurobehavioral development was assessed by the NICU Network Neurobehavioral Scales (NNNS). We meta-analyzed the associations between placental Se concentration and DNA methylation in each cohort, adjusting for covariates. We also fit multiple linear regression and ordinal logistic regression for methylation and newborn NNNS summary scores.

RESULTS

We identified five Se-related differentially methylated CpG sites. Among them was cg09674502 (GFI1), where selenium concentration was positively associated with methylation (β-coefficient = 1.11, FDR-adjusted p-value = 0.045), and where we observed that a one percent methylation level increase was associated with a 15% reduced odds of higher muscle tone in the arms, legs and trunk of newborns, (OR [95% Confidence Interval, CI] = 0.85 [0.77, 0.95]). We also observed for each interquartile range (IQR) increase in selenium concentration in the placenta, there was 1.76 times greater odds of higher hypotonicity (OR [95% CI] = 1.76 [1.12, 2.82]).

CONCLUSIONS

Placental selenium concentration was inversely associated with muscle tone of newborns, and hypermethylation of GFI1 could be a potential mechanism underlying this association.

Chronic Systemic Symptoms in Head and Neck Cancer Patients

The systemic effects and manifestations of disease and treatment have been of interest for millennium. Until recently, basic and clinical research is just now reaching a watershed. Systemic symptoms usually do not occur in isolation but rather in clusters; however, much of the cutting-edge research pertaining to the etiology, mechanism, manifestations, and moderators of systemic symptoms in humans has been directed at individual symptoms, thus creating silos of knowledge. Breaching these silos and bridging the knowledge from disparate arenas of investigation to build a comprehensive depiction of acute and chronic systemic symptoms has been a challenge. In addition, much of the recent work in systemic symptoms has been conducted in the setting of nonmalignant disease. The degree to which the findings from other chronic disease processes can be translated into the oncologic realm is unknown. This article will explore inflammation as a major contributing factor to systemic symptoms and sickness behavior, discuss the most common manifestations in cancer survivors, and, where available, discuss specific data pertaining to head and neck cancer survivors.

Myalgic Encephalomyelitis or What? The International Consensus Criteria

Myalgic encephalomyelitis (ME) is a neuromuscular disease with two distinctive types of symptoms (muscle fatigability or prolonged muscle weakness after minor exertion and symptoms related to neurological disturbance, especially of sensory, cognitive, and autonomic functions) and variable involvement of other bodily systems. Chronic fatigue syndrome (CFS), introduced in 1988 and re-specified in 1994, is defined as (unexplained) chronic fatigue accompanied by at least four out of eight listed (ill-defined) symptoms. Although ME and CFS are two distinct clinical entities (with partial overlap), CFS overshadowed ME for decades. In 2011, a panel of experts recommended abandoning the label CFS and its definition and proposed a new definition of ME: the International Consensus Criteria for ME (ME-ICC). In addition to post-exertional neuroimmune exhaustion (PENE), a mandatory feature, a patient must experience at least three symptoms related to neurological impairments; at least three symptoms related to immune, gastro-intestinal, and genitourinary impairments; and at least one symptom related to energy production or transportation impairments to meet the diagnosis of ME-ICC. A comparison between the original definition of ME and the ME-ICC shows that there are some crucial differences between ME and ME-ICC. Muscle fatigability, or long-lasting post-exertional muscle weakness, is the hallmark feature of ME, while this symptom is facultative for the diagnosis under the ME-ICC. PENE, an abstract notion that is very different from post-exertional muscle weakness, is the hallmark feature of the ME-ICC but is not required for the diagnosis of ME. The diagnosis of ME requires only two type of symptoms (post-exertional muscle weakness and neurological dysfunction), but a patient has to experience at least eight symptoms to meet the diagnosis according to the ME-ICC. Autonomic, sensory, and cognitive dysfunction, mandatory for the diagnosis of ME, are not compulsory to meet the ME-ICC subcriteria for 'neurological impairments'. In conclusion, the diagnostic criteria for ME and of the ME-ICC define two different patient groups. Thus, the definitions of ME and ME-ICC are not interchangeable.

Hand Grip Strength as a Clinical Biomarker for ME/CFS and Disease Severity

Background: The diagnosis of myalgic encephalomyelitis (ME/CFS) in research and clinical practice has largely relied on clinical history, which can be subjective in nature. Clinical signs are often subtle, overlap with other conditions, and are not formally included as part of diagnostic workup. The characterization of clinical signs and biomarkers is needed for better diagnosis and classification of patients and to monitor treatment response. Hand grip strength (HGS) has been used as an objective measure of muscle strength and fatigue, which is a primary symptom of ME/CFS. We assessed the potential usefulness of HGS as a diagnostic marker in ME/CFS. Methods: We compared HGS measurements from participants in the UK ME/CFS Biobank, with groups consisting of people with ME/CFS of differing severity (n = 272), healthy (n = 136), multiple sclerosis (n = 76) controls, and others with chronic fatigue not meeting the diagnosis of ME/CFS (n = 37). We correlated the maximum and minimum of, and differences between, 3 repeated HGS measurements with parameters of disease severity, including fatigue and pain analog scales, and physical and mental component summaries from the SF-36v2TM questionnaire across recruitment groups. Results: HGS indicators were associated with having ME/CFS, with magnitudes of association stronger in severely affected than in mild/moderately affected patients. Compared with healthy controls, being severely affected was associated with a reduction in minimum HGS of 15.3 kg (95%CI 19.3-11.3; p < 0.001), while being mild/moderately affected was associated with a 10.5 kg (95%CI 13.2-7.8; p < 0.001) reduction. The association persisted after adjusting for age, sex and body mass index. ME/CFS cases also showed lower values of maximum HGS and significant drops in values from the first to second and third trials, compared to other study groups. There were significant correlations between HGS indicators and clinical parameters of disease severity, including fatigue analog scale (Spearman's Rho = -0.40, p < 0.001), pain analog scale (Rho = -0.38, p < 0.001), and physical component summary (Rho = 0.42, p < 0.001). Discussion: HGS is markedly reduced in ME/CFS, particularly in patients with more severe disease, and may indicate muscle and fatigue related symptoms. HGS is a potential diagnostic tool in ME/CFS, and could also be used to enhance patient phenotyping and as an outcome measure following interventions.

Dutch Health Council Advisory Report on Myalgic Encephalomyelitis and Chronic Fatigue Syndrome: Taking the Wrong Turn

Recently, the Dutch Health Council published their advisory report on Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) which is meant to determine the medical policy with regard to ME in the Netherlands. The Health Council briefly discusses several diagnostic criteria and proposes to use new diagnostic criteria for "ME/CFS" in research and clinical practice in the future. The advisory report then summarizes organic abnormalities observed in the last decades and concludes that "ME/CFS" is a "serious, chronic, multisystem disease". According to the Health Council there are no curative treatments for "ME/CFS", due to lack of knowledge, but specific medication could bring symptomatic relief. The Health Council recommends conducting more research, to (re)educate medical professionals about "ME/CFS", to appoint three academic expertise centres, which will install a care network for patients, and to fairly judge the limitations (disability) of patients when they apply for a disability income, medical aid and care. The advisory report was welcomed by many patients, because it puts an end to the dominance of the (bio)psychosocial explanatory model and seems to offer a perspective of improving the situation of patients. However, the starting point of the advisory report, a new definition of "ME/CFS", will have serious (long-lasting) consequences for patients and researchers.

Does the microbiome and virome contribute to myalgic encephalomyelitis/chronic fatigue syndrome?

Myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) (ME/CFS) is a disabling and debilitating disease of unknown aetiology. It is a heterogeneous disease characterized by various inflammatory, immune, viral, neurological and endocrine symptoms. Several microbiome studies have described alterations in the bacterial component of the microbiome (dysbiosis) consistent with a possible role in disease development. However, in focusing on the bacterial components of the microbiome, these studies have neglected the viral constituent known as the virome. Viruses, particularly those infecting bacteria (bacteriophages), have the potential to alter the function and structure of the microbiome via gene transfer and host lysis. Viral-induced microbiome changes can directly and indirectly influence host health and disease. The contribution of viruses towards disease pathogenesis is therefore an important area for research in ME/CFS. Recent advancements in sequencing technology and bioinformatics now allow more comprehensive and inclusive investigations of human microbiomes. However, as the number of microbiome studies increases, the need for greater consistency in study design and analysis also increases. Comparisons between different ME/CFS microbiome studies are difficult because of differences in patient selection and diagnosis criteria, sample processing, genome sequencing and downstream bioinformatics analysis. It is therefore important that microbiome studies adopt robust, reproducible and consistent study design to enable more reliable and valid comparisons and conclusions to be made between studies. This article provides a comprehensive review of the current evidence supporting microbiome alterations in ME/CFS patients. Additionally, the pitfalls and challenges associated with microbiome studies are discussed.

Infection Elicited Autoimmunity and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: An Explanatory Model

Myalgic encephalomyelitis (ME) often also called chronic fatigue syndrome (ME/CFS) is a common, debilitating, disease of unknown origin. Although a subject of controversy and a considerable scientific literature, we think that a solid understanding of ME/CFS pathogenesis is emerging. In this study, we compiled recent findings and placed them in the context of the clinical picture and natural history of the disease. A pattern emerged, giving rise to an explanatory model. ME/CFS often starts after or during an infection. A logical explanation is that the infection initiates an autoreactive process, which affects several functions, including brain and energy metabolism. According to our model for ME/CFS pathogenesis, patients with a genetic predisposition and dysbiosis experience a gradual development of B cell clones prone to autoreactivity. Under normal circumstances these B cell offsprings would have led to tolerance. Subsequent exogenous microbial exposition (triggering) can lead to comorbidities such as fibromyalgia, thyroid disorder, and orthostatic hypotension. A decisive infectious trigger may then lead to immunization against autoantigens involved in aerobic energy production and/or hormone receptors and ion channel proteins, producing postexertional malaise and ME/CFS, affecting both muscle and brain. In principle, cloning and sequencing of immunoglobulin variable domains could reveal the evolution of pathogenic clones. Although evidence consistent with the model accumulated in recent years, there are several missing links in it. Hopefully, the hypothesis generates testable propositions that can augment the understanding of the pathogenesis of ME/CFS.

Effects of Chronic Diurnal Disruption and Acute Inflammatory Challenge on Mice with Latent Murine Gammaherpesvirus Infection

People who engage in shift work (SW) have increased risk of developing illnesses, including infectious diseases and various inflammatory conditions. We hypothesized that exposure to repeated cycles of diurnal disruption, mimicking SW, influences viral clearance, latent viral load, or viral reactivation from latency in mice infected with murine gammaherpesvirus (MuGHV). To test this idea, we inoculated BALB/cByJ and C.129S7(B6)-Ifng tm1Ts/J (IFNgKO) mice with MuGHV and housed them under either a stable light:dark (LD) cycle or one mimicking SW. Compared with BALB/cByJ mice, IFNgKO mice generally had higher levels of lytic virus during the 6-wk period after inoculation. In addition, more IFNgKO mice were positive for replicating virus than were BALB/cByJ mice. Exposure to SW did not alter these measures consistently. After the virus had entered the latent phase of infection, mice received either LPS or pyrogen-free saline intraperitoneally. Mice exposed to SW and then injected with LPS during latent infection had greater viral loads and more replicating virus in the lung at 7 d after injection than did either mice that received pyrogen-free saline or those exposed to LD and then treated with LPS. Some cytokine and chemokine concentrations were changed in lung collected 1 d after but not at 7 d after LPS administration. These findings suggest that exposure to repeated chronic diurnal disruption and an acute inflammatory challenge during latent MuGHV infection, in the context of impaired host immune competence, contribute to enhanced viral reactivity and an increased viral load that might trigger 'sickness behavior' symptoms of infectious disease and perhaps contribute to chronic fatigue syndrome.

Replacing Myalgic Encephalomyelitis and Chronic Fatigue Syndrome with Systemic Exercise Intolerance Disease Is Not the Way forward

Myalgic encephalomyelitis (ME), described in the medical literature since 1938, is characterized by distinctive muscular symptoms, neurological symptoms, and signs of circulatory impairment. The only mandatory feature of chronic fatigue syndrome (CFS), introduced in 1988 and redefined in 1994, is chronic fatigue, which should be accompanied by at least four or more out of eight "additional" symptoms. The use of the abstract, polythetic criteria of CFS, which define a heterogeneous patient population, and self-report has hampered both scientific progress and accurate diagnosis. To resolve the "diagnostic impasse" the Institute of Medicine proposes that a new clinical entity, systemic exercise intolerance disease (SEID), should replace the clinical entities ME and CFS. However, adopting SEID and its defining symptoms, does not resolve methodological and diagnostic issues. Firstly, a new diagnostic entity cannot replace two distinct, partially overlapping, clinical entities such as ME and CFS. Secondly, due to the nature of the diagnostic criteria, the employment of self-report, and the lack of criteria to exclude patients with other conditions, the SEID criteria seem to select an even more heterogeneous patient population, causing additional diagnostic confusion. This article discusses methodological and diagnostic issues related to SEID and proposes a methodological solution for the current "diagnostic impasse".