Hypothalamus volumes in adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): impact of self-reported fatigue and illness duration.

Adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex illness of unknown aetiology. Emerging theories suggest ME/CFS may reflect a progressive, aberrant state of homeostasis caused by disturbances within the hypothalamus, yet few studies have investigated this using magnetic resonance imaging in adolescents with ME/CFS. We conducted a volumetric analysis to investigate whether whole and regional hypothalamus volumes in adolescents with ME/CFS differed compared to healthy controls, and whether these volumes were associated with fatigue severity and illness duration. 48 adolescents (25 ME/CFS, 23 controls) were recruited. Lateralised whole and regional hypothalamus volumes, including the anterior-superior, superior tubular, posterior, anterior-inferior and inferior tubular subregions, were calculated from T1-weighted images. When controlling for age, sex and intracranial volume, Bayesian linear regression models revealed no evidence for differences in hypothalamus volumes between groups. However, in the ME/CFS group, a weak linear relationship between increased right anterior-superior volumes and fatigue severity was identified, which was absent in controls. In addition, Bayesian quantile regression revealed a likely-positive association between illness duration and right superior tubular volumes in the ME/CFS group. While these findings suggest overall comparability in regional and whole hypothalamus volumes between adolescents with ME/CFS and controls, preliminary evidence was identified to suggest greater fatigue severity and longer illness duration were associated with greater right anterior-superior and superior-tubular volumes, respectively. These regions contain the anterior and superior divisions of the paraventricular nucleus, involved in the neuroendocrine response to stress, suggesting involvement in ME/CFS pathophysiology. However, replication in a larger, longitudinal cohort is required.

Elevated ATG13 in serum of patients with ME/CFS stimulates oxidative stress response in microglial cells via activation of receptor for advanced glycation end products (RAGE).

Myalgic Encephalomyelitis, also known as Chronic Fatigue Syndrome (ME/CFS), is a multisystem illness characterized by extreme muscle fatigue associated with pain, neurocognitive impairment, and chronic inflammation. Despite intense investigation, the molecular mechanism of this disease is still unknown. Here we demonstrate that autophagy-related protein ATG13 is strongly upregulated in the serum of ME/CFS patients, indicative of impairment in the metabolic events of autophagy. A Thioflavin T-based protein aggregation assay, array screening for autophagy-related factors, densitometric analyses, and confirmation with ELISA revealed that the level of ATG13 was strongly elevated in serum samples of ME/CFS patients compared to age-matched controls. Moreover, our microglia-based oxidative stress response experiments indicated that serum samples of ME/CFS patients evoke the production of reactive oxygen species (ROS) and nitric oxide in human HMC3 microglial cells, whereas neutralization of ATG13 strongly diminishes the production of ROS and NO, suggesting that ATG13 plays a role in the observed stress response in microglial cells. Finally, an in vitro ligand binding assay provided evidence that ATG13 employs the Receptor for Advanced Glycation End-products (RAGE) to stimulate ROS in microglial cells. Collectively, our results suggest that an impairment of autophagy following the release of ATG13 into serum could be a pathological signal in ME/CFS.

Limbic Perfusion Is Reduced in Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is an illness characterized by a diverse range of debilitating symptoms including autonomic, immunologic, and cognitive dysfunction. Although neurological and cognitive aberrations have been consistently reported, relatively little is known regarding the regional cerebral blood flow (rCBF) in ME/CFS. In this study, we studied a cohort of 31 ME/CSF patients (average age: 42.8 ± 13.5 years) and 48 healthy controls (average age: 42.9 ± 12.0 years) using the pseudo-continuous arterial spin labeling (PCASL) technique on a whole-body clinical 3T MRI scanner. Besides routine clinical MRI, the protocol included a session of over 8 min-long rCBF measurement. The differences in the rCBF between the ME/CSF patients and healthy controls were statistically assessed with voxel-wise and AAL ROI-based two-sample t-tests. Linear regression analysis was also performed on the rCBF data by using the symptom severity score as the main regressor. In comparison with the healthy controls, the patient group showed significant hypoperfusion (uncorrected voxel wise p ≤ 0.001, FWE p ≤ 0.01) in several brain regions of the limbic system, including the anterior cingulate cortex, putamen, pallidum, and anterior ventral insular area. For the ME/CFS patients, the overall symptom severity score at rest was significantly associated with a reduced rCBF in the anterior cingulate cortex. The results of this study show that brain blood flow abnormalities in the limbic system may contribute to ME/CFS pathogenesis.

"Chronic fatigue, quality of life and long-term side-effects of chemotherapy in patients treated for non-epithelial ovarian cancer: national case-control protocol study of the GINECO-Vivrovaire rare tumors INCa French network for rare malignant ovarian tumors".

BACKGROUND: Germ cell tumors and sex cord stromal tumors are rare cancers of the ovary. They mainly affect young women and are associated with a high survival rate. The standard treatment mainly involves conservative surgery combined with chemotherapy [bleomycin, etoposide and cisplatin (BEP)] depending on the stage and the prognostic factors, as for testicular cancers. As reported in testicular cancer survivors, chemotherapy may induce sequelae impacting quality of life, which has not yet been evaluated in survivors of germ cell tumors and sex cord stromal tumors. The GINECO-VIVROVAIRE-Rare tumor study is a two-step investigation aiming to assess i) chronic fatigue and quality of life and ii) long-term side-effects of chemotherapy with a focus on cardiovascular and pulmonary disorders. METHODS: Using self-reported questionnaires, chronic fatigue and quality of life are compared between 134 ovarian cancer survivors (cancer-free ≥2 years after treatment) treated with surgery and chemotherapy and 2 control groups (67 ovarian cancer survivors treated with surgery alone and 67 age-matched healthy women). Medical data are collected from patient records. In the second step evaluating the long-term side-effects of chemotherapy, a subgroup of 90 patients treated with chemotherapy and 45 controls undergo the following work-up: cardiovascular evaluation (clinical examination, non-invasive cardiovascular tests to explore heart disease, blood tests), pulmonary function testing, audiogram, metabolic and hormonal blood tests. Costs of sequelae will be also assessed. Patients are selected from the registry of the INCa French Network for Rare Malignant Ovarian Tumors, and healthy women by the 'Seintinelles' connected network (collaborative research platform). DISCUSSION: This study will provide important data on the potential long-term physical side-effects of chemotherapy in survivors of Germ Cell Tumors (GCT) and Sex Cord Stromal Tumors (SCST), especially cardiovascular and pulmonary disorders, and neurotoxicity. The identification of long-term side-effects can contribute to adjusting the treatment of ovarian GCT or SCST patients and to managing follow-up with adapted recommendations regarding practices and chemotherapy regimens, in order to reduce toxicity while maintaining efficacy. Based on the results, intervention strategies could be proposed to improve the management of these patients during their treatment and in the long term. TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov : 03418844 , on 1 February 2018. This trial was registered on 25 October 2017 under the unique European identification number (ID-RCB): 2017-A03028-45. Recruitment Status: Recruiting. PROTOCOL VERSION: Version n° 4.2 dated from Feb 19, 2021. TRIAL SPONSOR: Centre François Baclesse, 3 avenue du Général Harris, F-14076 Caen cedex 05, France.

RADIATION DAMAGE OF THE NERVOUS SYSTEM AND ENDOCANABINOIDS. / RADIATsIINE URAZhENNIa NERVOVOÏ SYSTEMY I ENDOKANABINOÏDY.

The review analyzes the change of the existing paradigm of high radioresistance of the nervous system according tothe results of the study of neuropsychiatric disorders in in the aftermath of the Chornobyl accident in both earlyand remote post-accident period. The participation of the endocannabinoid system in ensuring homeostasis andpathology formation, potential possibilities of using cannabis drugs, agonists and antagonists of endocannabinoidreceptors for the treatment of early and long-term effects of radiation are considered.

Deep phenotyping of myalgic encephalomyelitis/chronic fatigue syndrome in Japanese population.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex and debilitating disease with no molecular diagnostics and no treatment options. To identify potential markers of this illness, we profiled 48 patients and 52 controls for standard laboratory tests, plasma metabolomics, blood immuno-phenotyping and transcriptomics, and fecal microbiome analysis. Here, we identified a set of 26 potential molecular markers that distinguished ME/CFS patients from healthy controls. Monocyte number, microbiome abundance, and lipoprotein profiles appeared to be the most informative markers. When we correlated these molecular changes to sleep and cognitive measurements of fatigue, we found that lipoprotein and microbiome profiles most closely correlated with sleep disruption while a different set of markers correlated with a cognitive parameter. Sleep, lipoprotein, and microbiome changes occur early during the course of illness suggesting that these markers can be examined in a larger cohort for potential biomarker application. Our study points to a cluster of sleep-related molecular changes as a prominent feature of ME/CFS in our Japanese cohort.

Substrate utilisation of cultured skeletal muscle cells in patients with CFS.

Chronic fatigue syndrome (CFS) patients often suffer from severe muscle pain and an inability to exercise due to muscle fatigue. It has previously been shown that CFS skeletal muscle cells have lower levels of ATP and have AMP-activated protein kinase dysfunction. This study outlines experiments looking at the utilisation of different substrates by skeletal muscle cells from CFS patients (n = 9) and healthy controls (n = 11) using extracellular flux analysis. Results show that CFS skeletal muscle cells are unable to utilise glucose to the same extent as healthy control cells. CFS skeletal muscle cells were shown to oxidise galactose and fatty acids normally, indicating that the bioenergetic dysfunction lies upstream of the TCA cycle. The dysfunction in glucose oxidation is similar to what has previously been shown in blood cells from CFS patients. The consistency of cellular bioenergetic dysfunction in different cell types supports the hypothesis that CFS is a systemic disease. The retention of bioenergetic defects in cultured cells indicates that there is a genetic or epigenetic component to the disease. This is the first study to use cells derived from skeletal muscle biopsies in CFS patients and healthy controls to look at cellular bioenergetic function in whole cells.

Environmental, Neuro-immune, and Neuro-oxidative Stress Interactions in Chronic Fatigue Syndrome.

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS) is a complex, multisystem disease that is characterized by long-term fatigue, exhaustion, disabilities, pain, neurocognitive impairments, gastrointestinal symptoms, and post-exertional malaise, as well as lowered occupational, educational, and social functions. The clinical and biomarker diagnosis of this disorder is hampered by the lack of validated diagnostic criteria and laboratory tests with adequate figures of merit, although there are now many disease biomarkers indicating the pathophysiology of CFS. Here, we review multiple factors, such as immunological and environmental factors, which are associated with CFS and evaluate current concepts on the involvement of immune and environmental factors in the pathophysiology of CFS. The most frequently reported immune dysregulations in CFS are modifications in immunoglobulin contents, changes in B and T cell phenotypes and cytokine profiles, and decreased cytotoxicity of natural killer cells. Some of these immune aberrations display a moderate diagnostic performance to externally validate the clinical diagnosis of CFS, including the expression of activation markers and protein kinase R (PKR) activity. Associated with the immune aberrations are activated nitro-oxidative pathways, which may explain the key symptoms of CFS. This review shows that viral and bacterial infections, as well as nutritional deficiencies, may further aggravate the immune-oxidative pathophysiology of CFS. Targeted treatments with antioxidants and lipid replacement treatments may have some clinical efficacy in CFS. We conclude that complex interactions between immune and nitro-oxidative pathways, infectious agents, environmental factors, and nutritional deficiencies play a role in the pathophysiology of CFS.

Genetic risk factors of ME/CFS: a critical review.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multisystem illness that lacks effective therapy and a biomedical understanding of its causes. Despite a prevalence of ∼0.2-0.4% and its high public health burden, and evidence that it has a heritable component, ME/CFS has not yet benefited from the advances in technology and analytical tools that have improved our understanding of many other complex diseases. Here we critically review existing evidence that genetic factors alter ME/CFS risk before concluding that most ME/CFS candidate gene associations are not replicated by the larger CFS cohort within the UK Biobank. Multiple genome-wide association studies of this cohort also have not yielded consistently significant associations. Ahead of upcoming larger genome-wide association studies, we discuss how these could generate new lines of enquiry into the DNA variants, genes and cell types that are causally involved in ME/CFS disease.

Plasma proteomic profiling suggests an association between antigen driven clonal B cell expansion and ME/CFS.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is an unexplained chronic, debilitating illness characterized by fatigue, sleep disturbances, cognitive dysfunction, orthostatic intolerance and gastrointestinal problems. Using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), we analyzed the plasma proteomes of 39 ME/CFS patients and 41 healthy controls. Logistic regression models, with both linear and quadratic terms of the protein levels as independent variables, revealed a significant association between ME/CFS and the immunoglobulin heavy variable (IGHV) region 3-23/30. Stratifying the ME/CFS group based on self-reported irritable bowel syndrome (sr-IBS) status revealed a significant quadratic effect of immunoglobulin lambda constant region 7 on its association with ME/CFS with sr-IBS whilst IGHV3-23/30 and immunoglobulin kappa variable region 3-11 were significantly associated with ME/CFS without sr-IBS. In addition, we were able to predict ME/CFS status with a high degree of accuracy (AUC = 0.774-0.838) using a panel of proteins selected by 3 different machine learning algorithms: Lasso, Random Forests, and XGBoost. These algorithms also identified proteomic profiles that predicted the status of ME/CFS patients with sr-IBS (AUC = 0.806-0.846) and ME/CFS without sr-IBS (AUC = 0.754-0.780). Our findings are consistent with a significant association of ME/CFS with immune dysregulation and highlight the potential use of the plasma proteome as a source of biomarkers for disease.

A Unifying Hypothesis of the Pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Recognitions from the finding of autoantibodies against ß2-adrenergic receptors.

Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (CFS/ME) is a complex and severely disabling disease with a prevalence of 0.3% and no approved treatment and therefore a very high medical need. Following an infectious onset patients suffer from severe central and muscle fatigue, chronic pain, cognitive impairment, and immune and autonomic dysfunction. Although the etiology of CFS/ME is not solved yet, there is numerous evidence for an autoantibody mediated dysregulation of the immune and autonomic nervous system. We found elevated ß2 adrenergic receptor (ß2AdR) and M3 acetylcholine receptor antibodies in a subset of CFS/ME patients. As both ß2AdR and M3 acetylcholine receptor are important vasodilators, we would expect their functional disturbance to result in vasoconstriction and hypoxemia. An impaired circulation and oxygen supply could result in many symptoms of ME/CFS. There are consistent reports of vascular dysfunction in ME/CFS. Muscular and cerebral hypoperfusion has been shown in ME/CFS in various studies and correlated with fatigue. Metabolic changes in ME/CFS are also in line with a concept of hypoxia and ischemia. Here we try to develop a unifying working concept for the complex pathomechanism of ME/CFS based on the presence of dysfunctional autoantibodies against ß2AdR and M3 acetylcholine receptor and extrapolate it to the pathophysiology of ME/CFS without an autoimmune pathogenesis.

Myalgic encephalomyelitis/chronic fatigue syndrome patients exhibit altered T cell metabolism and cytokine associations.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease with no known cause or mechanism. There is an increasing appreciation for the role of immune and metabolic dysfunction in the disease. ME/CFS has historically presented in outbreaks, often has a flu-like onset, and results in inflammatory symptoms. Patients suffer from severe fatigue and postexertional malaise. There is little known about the metabolism of specific immune cells in patients with ME/CFS. To investigate immune metabolism in ME/CFS, we isolated CD4+ and CD8+ T cells from 53 patients with ME/CFS and 45 healthy controls. We analyzed glycolysis and mitochondrial respiration in resting and activated T cells, along with markers related to cellular metabolism and plasma cytokines. We found that ME/CFS CD8+ T cells had reduced mitochondrial membrane potential compared with those from healthy controls. Both CD4+ and CD8+ T cells from patients with ME/CFS had reduced glycolysis at rest, whereas CD8+ T cells also had reduced glycolysis following activation. Patients with ME/CFS had significant correlations between measures of T cell metabolism and plasma cytokine abundance that differed from correlations seen in healthy control subjects. Our data indicate that patients have impaired T cell metabolism consistent with ongoing immune alterations in ME/CFS that may illuminate the mechanism behind this disease.

Naltrexone Restores Impaired Transient Receptor Potential Melastatin 3 Ion Channel Function in Natural Killer Cells From Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a seriously long-term and debilitating illness of unknown cause hallmarked by chronic pain and fatigue, memory and concentration impairment, and inflammation. ME/CFS hypothesis involves impaired Transient receptor potential melastatin 3 (TRPM3) ion channel function, affecting calcium signaling and Natural killer (NK) cell functions. Currently, substances called opioids, agonists of mu (µ)-opioid receptors (µOR), are the strongest painkillers clinically available for people suffering from strong or long-lasting pain characteristic of ME/CFS. µOR have been reported to specifically inhibit TRPM3 and to be expressed in immune cells where they play an immunomodulatory and immunosuppressive role. Naltrexone hydrochloride (NTX) acts as an antagonist to the µOR thus negating the inhibitory function of this opioid receptor on TRPM3. Therefore, understanding the mechanism of action for NTX in regulating and modulating TRPM3 channel function in NK cells will provide important information for the development of effective therapeutic interventions for ME/CFS. Whole-cell patch-clamp technique was used to measure TRPM3 activity in Interleukin-2 (IL-2) stimulated and NTX-treated NK cells for 24 h on eight ME/CFS patients and 8 age- and sex-matched healthy controls, after modulation with a TRPM3-agonist, pregnenolone sulfate (PregS), NTX and a TRPM3-antagonist, ononetin. We confirmed impaired TRPM3 function in ME/CFS patients through electrophysiological investigations in IL-2 stimulated NK cells after modulation with PregS and ononetin. Importantly, TRPM3 channel activity was restored in IL-2 stimulated NK cells isolated from ME/CFS patients after incubation for 24 h with NTX. Moreover, we demonstrated that NTX does not act as an agonist by directly coupling on the TRPM3 ion channel gating. The opioid antagonist NTX has the potential to negate the inhibitory function of opioid receptors on TRPM3 in NK cells from ME/CFS patients, resulting in calcium signals remodeling, which will in turn affect cell functions, supporting the hypothesis that NTX may have potential for use as a treatment for ME/CFS. Our results demonstrate, for the first time, and based on novel patch clamp electrophysiology, potential pharmaco-therapeutic interventions in ME/CFS.

Myalgic encephalomyelitis/chronic fatigue syndrome: From pathophysiological insights to novel therapeutic opportunities.

Myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS) is a common and disabling condition with a paucity of effective and evidence-based therapies, reflecting a major unmet need. Cognitive behavioural therapy and graded exercise are of modest benefit for only some ME/CFS patients, and many sufferers report aggravation of symptoms of fatigue with exercise. The presence of a multiplicity of pathophysiological abnormalities in at least the subgroup of people with ME/CFS diagnosed with the current international consensus "Fukuda" criteria, points to numerous potential therapeutic targets. Such abnormalities include extensive data showing that at least a subgroup has a pro-inflammatory state, increased oxidative and nitrosative stress, disruption of gut mucosal barriers and mitochondrial dysfunction together with dysregulated bioenergetics. In this paper, these pathways are summarised, and data regarding promising therapeutic options that target these pathways are highlighted; they include coenzyme Q10, melatonin, curcumin, molecular hydrogen and N-acetylcysteine. These data are promising yet preliminary, suggesting hopeful avenues to address this major unmet burden of illness.

Biotransformation profiles from a cohort of chronic fatigue women in response to a hepatic detoxification challenge.

Chronic fatigue, in its various manifestations, frequently co-occur with pain, sleep disturbances and depression and is a non-communicable condition which is rapidly becoming endemic worldwide. However, it is handicapped by a lack of objective definitions and diagnostic measures. This has prompted the World Health Organization to develop an international instrument whose intended purpose is to improve quality of life (QOL), with energy and fatigue as one domain of focus. To complement this objective, the interface between detoxification, the exposome, and xenobiotic-sensing by nuclear receptors that mediate induction of biotransformation-linked genes, is stimulating renewed attention to a rational development of strategies to identify the metabolic profiles in complex multifactorial conditions like fatigue. Here we present results from a seven-year study of a cohort of 576 female patients suffering from low to high levels of chronic fatigue, in which phase I and phase II biotransformation was assessed. The biotransformation profiles used were based on hepatic detoxification challenge tests through oral caffeine, acetaminophen and acetylsalicylic acid ingestion coupled with oxidative stress analyses. The interventions indicated normal phase I but increased phase II glucuronidation and glycination conjugation. Complementarity was indicated between a fatigue scale, medical symptoms and associated energy-related parameters by application of Chi-square Automatic Interaction Detector (CHAID) analysis. The presented study provides a cluster of data from which we propose that multidisciplinary inputs from the combination of a fatigue scale, medical symptoms and biotransformation profiles provide the rationale for the development of a comprehensive laboratory instrument for improved diagnostics and personalized interventions in patients with chronic fatigue with a view to improving their QOL.

Impairments in cognitive performance in chronic fatigue syndrome are common, not related to co-morbid depression but do associate with autonomic dysfunction.

OBJECTIVES: To explore cognitive performance in chronic fatigue syndrome (CFS) examining two cohorts. To establish findings associated with CFS and those related to co-morbid depression or autonomic dysfunction. METHODS: Identification and recruitment of participants was identical in both phases, all CFS patients fulfilled Fukuda criteria. In Phase 1 (n = 48) we explored cognitive function in a heterogeneous cohort of CFS patients, investigating links with depressive symptoms (HADS). In phase 2 (n = 51 CFS & n = 20 controls) participants with co-morbid major depression were excluded (SCID). Furthermore, we investigated relationships between cognitive performance and heart rate variability (HRV). RESULTS: Cognitive performance in unselected CFS patients is in average range on most measures. However, 0-23% of the CFS sample fell below the 5th percentile. Negative correlations occurred between depressive symptoms (HAD-S) with Digit-Symbol-Coding (r = -.507, p = .006) and TMT-A (r = -.382, p = .049). In CFS without depression, impairments of cognitive performance remained with significant differences in indices of psychomotor speed (TMT-A: p = 0.027; digit-symbol substitution: p = 0.004; digit-symbol copy: p = 0.007; scanning: p = .034) Stroop test suggested differences due to processing speed rather than inhibition. Both cohorts confirmed relationships between cognitive performance and HRV (digit-symbol copy (r = .330, p = .018), digit-symbol substitution (r = .313, p = .025), colour-naming trials Stroop task (r = .279, p = .050). CONCLUSION: Cognitive difficulties in CFS may not be as broad as suggested and may be restricted to slowing in basic processing speed. While depressive symptoms can be associated with impairments, co-morbidity with major depression is not itself responsible for reductions in cognitive performance. Impaired autonomic control of heart-rate associates with reductions in basic processing speed.

Systemic exertion intolerance disease/chronic fatigue syndrome is common in sleep centre patients with hypersomnolence: A retrospective pilot study.

Symptoms of the central disorders of hypersomnolence extend beyond excessive daytime sleepiness to include non-restorative sleep, fatigue and cognitive dysfunction. They share much in common with myalgic encephalomyelitis/chronic fatigue syndrome, recently renamed systemic exertion intolerance disease, whose additional features include post-exertional malaise and orthostatic intolerance. We sought to determine the frequency and correlates of systemic exertion intolerance disease in a hypersomnolent population. One-hundred and eighty-seven hypersomnolent patients completed questionnaires regarding sleepiness and fatigue; questionnaires and clinical records were used to assess for systemic exertion intolerance disease. Sleep studies, hypocretin and cataplexy were additionally used to assign diagnoses of hypersomnolence disorders or sleep apnea. Included diagnoses were idiopathic hypersomnia (n = 63), narcolepsy type 2 (n = 25), persistent sleepiness after obstructive sleep apnea treatment (n = 25), short habitual sleep duration (n = 41), and sleepiness with normal sleep study (n = 33). Twenty-one percent met systemic exertion intolerance disease criteria, and the frequency of systemic exertion intolerance disease was not different across sleep diagnoses (p = .37). Patients with systemic exertion intolerance disease were no different from those without this diagnosis by gender, age, Epworth Sleepiness Scale, depressive symptoms, or sleep study parameters. The whole cohort reported substantial fatigue on questionnaires, but the systemic exertion intolerance disease group exhibited more profound fatigue and was less likely to respond to traditional wake-promoting agents (88.6% versus 67.7%, p = .01). Systemic exertion intolerance disease appears to be a common co-morbidity in patients with hypersomnolence, which is not specific to hypersomnolence subtype but may portend a poorer prognosis for treatment response.

Persistent fatigue induced by interferon-alpha: a novel, inflammation-based, proxy model of chronic fatigue syndrome.

The role of immune or infective triggers in the pathogenesis of Chronic Fatigue Syndrome (CFS) is not yet fully understood. Barriers to obtaining immune measures at baseline (i.e., before the trigger) in CFS and post-infective fatigue model cohorts have prevented the study of pre-existing immune dysfunction and subsequent immune changes in response to the trigger. This study presents interferon-alpha (IFN-α)-induced persistent fatigue as a model of CFS. IFN-α, which is used in the treatment of chronic Hepatitis C Virus (HCV) infection, induces a persistent fatigue in some individuals, which does not abate post-treatment, that is, once there is no longer immune activation. This model allows for the assessment of patients before and during exposure to the immune trigger, and afterwards when the original trigger is no longer present. Fifty-five patients undergoing IFN-α treatment for chronic HCV were assessed at baseline, during the 6-12 months of IFN-α treatment, and at six-months post-treatment. Measures of fatigue, cytokines and kynurenine pathway metabolites were obtained. Fifty-four CFS patients and 57 healthy volunteers completed the same measures at a one-off assessment, which were compared with post-treatment follow-up measures from the HCV patients. Eighteen patients undergoing IFN-α treatment (33%) were subsequently defined as having 'persistent fatigue' (the proposed model for CFS), if their levels of fatigue were higher six-months post-treatment than at baseline; the other 67% were considered 'resolved fatigue'. Patients who went on to develop persistent fatigue experienced a greater increase in fatigue symptoms over the first four weeks of IFN-α, compared with patients who did not (Δ Treatment Week (TW)-0 vs. TW4; PF: 7.1 ± 1.5 vs. RF: 4.0 ± 0.8, p = 0.046). Moreover, there was a trend towards increased baseline interleukin (IL)-6, and significantly higher baseline IL-10 levels, as well as higher levels of these cytokines in response to IFN-α treatment, alongside concurrent increases in fatigue. Levels increased to more than double those of the other patients by Treatment Week (TW)4 (p = 0.011 for IL-6 and p = 0.001 for IL-10). There was no evidence of an association between persistent fatigue and peripheral inflammation six-months post-treatment, nor did we observe peripheral inflammation in the CFS cohort. While there were changes in kynurenine metabolites in response to IFN-α, there was no association with persistent fatigue. CFS patients had lower levels of the ratio of kynurenine to tryptophan and 3-hydroxykynurenine than controls. Future studies are needed to elucidate the mechanisms behind the initial exaggerated response of the immune system in those who go on to experience persistent fatigue even if the immune trigger is no longer present, and the change from acute to chronic fatigue in the absence of continued peripheral immune activation.

Why do some ME/CFS patients benefit from treatment with sodium dichloroacetate, but others do not?

Myalgic Encephalopathy/Chronic Fatigue Syndrome (ME/CFS) is an enigmatic disease the pathogenesis of which remains elusive. Pragmatic proof-of-principle of the hypothetical mechanisms causing the clinical symptoms has been delivered, but it is hard to explain why some patients do respond favourably to treatment with sodium dichloroacetate (DCA), which enhances the activity of the mitochondrial enzyme pyruvate dehydrogenase, but other patients experience no benefit from this substance. In a prospective trial including 35 ME/CFS patients, logistic regression analysis with stepwise elimination has identified 6 pre-treatment characteristics allowing for the differentiation between responders (n = 13) and non-reponders (n = 22) with high accuracy (P < 0.0001; area under the ROC-curve = 0.92). A formula was derived generating the probability of belonging to the group of responders. This finding may assist in selecting ME/CFS patients suitable for treatment with DCA, but requires further studies as to the predictive capacity of the derived formula.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-Metabolic Disease or Disturbed Homeostasis due to Focal Inflammation in the Hypothalamus?

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease characterized by debilitating fatigue, lasting for at least 6 months, with associated malaise, headaches, sleep disturbance, and cognitive impairment, which severely impacts quality of life. A significant percentage of ME/CFS patients remain undiagnosed, mainly due to the complexity of the disease and the lack of reliable objective biomarkers. ME/CFS patients display decreased metabolism and the severity of symptoms appears to be directly correlated to the degree of metabolic reduction that may be unique to each individual patient. However, the precise pathogenesis is still unknown, preventing the development of effective treatments. The ME/CFS phenotype has been associated with abnormalities in energy metabolism, which are apparently due to mitochondrial dysfunction in the absence of mitochondrial diseases, resulting in reduced oxidative metabolism. Such mitochondria may be further contributing to the ME/CFS symptomatology by extracellular secretion of mitochondrial DNA, which could act as an innate pathogen and create an autoinflammatory state in the hypothalamus. We propose that stimulation of hypothalamic mast cells by environmental, neuroimmune, pathogenic and stress triggers activates microglia, leading to focal inflammation in the brain and disturbed homeostasis. This process could be targeted for the development of novel effective treatments.