Category: Immune System

Transient Receptor Potential Ion Channels in the Etiology and Pathomechanism of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Abstract:

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disabling condition of unknown cause having multi-system manifestations. Our group has investigated the potential role of transient receptor potential (TRP) ion channels in the etiology and pathomechanism of this illness. Store-operated calcium entry (SOCE) signaling is the primary intracellular calcium signaling mechanism in non-excitable cells and is associated with TRP ion channels. While the sub-family (Canonical) TRPC has been traditionally associated with this important cellular mechanism, a member of the TRPM sub-family group (Melastatin), TRPM3, has also been recently identified as participating in SOCE in white matter of the central nervous system. We have identified single nucleotide polymorphisms (SNPs) in TRP genes in natural killer (NK) cells and peripheral blood mononuclear cells (PBMCs) in CFS/ME patients. We also describe biochemical pathway changes and calcium signaling perturbations in blood cells from patients. The ubiquitous distribution of TRP ion channels and specific locations of sub-family group members such as TRPM3 suggest a contribution to systemic pathology in CFS/ME.

Source: D. Staines, S. Du Preez, H. Cabanas, C. Balinas, N. Eaton, R. Passmore, R. Maksoud, J. Redmayne, S. Marshall-Gradisnik. Transient Receptor Potential Ion Channels in the Etiology and Pathomechanism of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. IJCM, Vol.9 No.5, May 2018. DOI: 10.4236/ijcm.2018.95038 

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome – Evidence for an autoimmune disease

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a frequent and severe chronic disease drastically impairing life quality. The underlying pathomechanism is incompletely understood yet but there is convincing evidence that in at least a subset of patients ME/CFS has an autoimmune etiology.

In this review, we will discuss current autoimmune aspects for ME/CFS. Immune dysregulation in ME/CFS has been frequently described including changes in cytokine profiles and immunoglobulin levels, T- and B-cell phenotype and a decrease of natural killer cell cytotoxicity. Moreover, autoantibodies against various antigens including neurotransmitter receptors have been recently identified in ME/CFS individuals by several groups. Consistently, clinical trials from Norway have shown that B-cell depletion with rituximab results in clinical benefits in about half of ME/CFS patients.

Furthermore, recent studies have provided evidence for severe metabolic disturbances presumably mediated by serum autoantibodies in ME/CFS. Therefore, further efforts are required to delineate the role of autoantibodies in the onset and pathomechanisms of ME/CFS in order to better understand and properly treat this disease.

Source: Sotzny F, Blanco J, Capelli E, Castro-Marrero J, Steiner S1, Murovska M, Scheibenbogen C; European Network on ME/CFS (EUROMENE). Myalgic Encephalomyelitis/Chronic Fatigue Syndrome – Evidence for an autoimmune disease. Autoimmun Rev. 2018 Apr 7. pii: S1568-9972(18)30088-0. doi: 10.1016/j.autrev.2018.01.009. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29635081

Drug hoped to treat CFS causes impaired immune function, Griffith study says

Reports that a drug used to treat autoimmune diseases and cancer could also treat Chronic Fatigue Syndrome (CFS) have been refuted by a new Griffith University study.

To be published in BMC Pharmacology and Toxicology, the study by Griffith’s National Centre for Neuroimmunology and Emerging Diseases(NCNED) concluded that the use of Rituximab in CFS patients could incur problems with their immune cells and is not beneficial as a potential treatment.

The Natural Killer (NK) cells have vital functions in fighting viruses, bacteria and tumours.

“We found that these functions were significantly impaired when exposed to Rituximab in CFS patients,” says Scientific Co-Director of NCNED, Professor Sonya Marshall-Gradisnik.

CFS – sometimes known as ME (myalgic encephalomyelitis) – is a complex illness characterised by impaired memory and concentration, metabolic, cardiac, gut and immune dysfunction and debilitating muscle pain and fatigue on exertion (also known as neuroimmune exhaustion).

It is estimated that the prevalence rate of CFS/ME worldwide is between 1 and 2 per cent.

Related to the ion channels

The Gold Coast NCNED team has discovered the illness is related to problems in the ion channels that allow calcium into the body’s cells. Calcium is required by almost every cell in the human body and is vital in helping the immune system destroy a virus or infection.

The team has proven that patients with CFS/ME have lower levels of calcium coming into their cells, that their cells store less calcium and that this is the basis of their illness.

Professor Don Staines, Clinical Co-Director of NCNED, says: “These results are important as NK cells are already known to have impaired function in CFS patients, suggesting certain doses of Rituximab may not be beneficial for the treatment of this condition.”

“Undertaking an initial study has enabled us to secure additional research funding from the national competitive grants process from the Mason Foundation where we can now undertake a larger study using this drug in vitro to validate our novel findings,” says Professor Staines.

First author for these world-first scientific findings was PhD student, Ms Natalie Eaton.  She will be presenting the study at an NCNED-sponsored conference later this year.  The focus of the conference will be promoting greater understanding of pathology and pharmacothereapeutics for CFS, through a Research, Innovation, Discovery, Learning and Education (RIDLE) model.

Source: Press Release: Griffith University, March 27, 2018.

Immunoadsorption to remove ß2 adrenergic receptor antibodies in Chronic Fatigue Syndrome CFS/ME

Abstract:

Introduction: Infection-triggered disease onset, chronic immune activation and autonomic dysregulation in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) point to an autoimmune disease directed against neurotransmitter receptors. We had observed elevated autoantibodies against ß2 adrenergic receptors, and muscarinic 3 and 4 acetylcholine receptors in a subset of patients. Immunoadsorption (IA) was shown to be effective in removing autoantibodies and improve outcome in various autoimmune diseases.

Methods: 10 patients with post-infectious CFS/ME and elevated ß2 autoantibodies were treated with IA with an IgG-binding column for 5 days. We assessed severity of symptoms as outcome parameter by disease specific scores. Antibodies were determined by ELISA and B cell phenotype by flow cytometry.

Results: IgG levels dropped to median 0.73 g/l (normal 7–16 g/l) after the 4th cycle of IA, while IgA and IgM levels remained unchanged. Similarly, elevated ß2 IgG antibodies rapidly decreased during IA in 9 of 10 patients. Also 6 months later ß2 autoantibodies were significantly lower compared to pretreatment. Frequency of memory B cells significantly decreased and frequency of plasma cells increased after the 4th IA cycle. A rapid improvement of symptoms was reported by 7 patients during the IA. 3 of these patients had long lasting moderate to marked improvement for 6–12+ months, 2 patients had short improvement only and 2 patients improved for several months following initial worsening.

Conclusions: IA can remove autoantibodies against ß2 adrenergic receptor and lead to clinical improvement. B cell phenotyping provides evidence for an effect of IA on memory B cell development. Data from our pilot trial warrants further studies in CFS/ME.

Source: Carmen Scheibenbogen, Madlen Loebel, Helma Freitag, Anne Krueger, Sandra Bauer, Michaela Antelmann, Wolfram Doehner, Nadja Scherbakov, Harald Heidecke, Petra Reinke, Hans-Dieter Volk, Patricia Grabowski. Immunoadsorption to remove ß2 adrenergic receptor antibodies in Chronic Fatigue Syndrome CFS/ME. PLOS ONE. Published: March 15, 2018 https://doi.org/10.1371/journal.pone.0193672 (Full article)

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

Abstract:

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.

Source: Jonas Blomberg, Gerhard Gottfries, Amal Elfaitouri, Muhammad Rizwan and Anders Rosén. Infection Elicited Autoimmunity and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: An Explanatory Model. Hypothesis and Theory Article, Front. Immunol., 15 February 2018 | https://doi.org/10.3389/fimmu.2018.00229 (Full article)

Value of Circulating Cytokine Profiling During Submaximal Exercise Testing in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (ME/CFS) is a heterogeneous syndrome in which patients often experience severe fatigue and malaise following exertion. Immune and cardiovascular dysfunction have been postulated to play a role in the pathophysiology. We therefore, examined whether cytokine profiling or cardiovascular testing following exercise would differentiate patients with ME/CFS.

Twenty-four ME/CFS patients were matched to 24 sedentary controls and underwent cardiovascular and circulating immune profiling. Cardiovascular analysis included echocardiography, cardiopulmonary exercise and endothelial function testing. Cytokine and growth factor profiles were analyzed using a 51-plex Luminex bead kit at baseline and 18 hours following exercise. Cardiac structure and exercise capacity were similar between groups.

Sparse partial least square discriminant analyses of cytokine profiles 18 hours post exercise offered the most reliable discrimination between ME/CFS and controls (κ = 0.62(0.34,0.84)). The most discriminatory cytokines post exercise were CD40L, platelet activator inhibitor, interleukin 1-β, interferon-α and CXCL1. In conclusion, cytokine profiling following exercise may help differentiate patients with ME/CFS from sedentary controls.

Source: Kegan J. Moneghetti, Mehdi Skhiri, Kévin Contrepois, Yukari Kobayashi, Holden Maecker, Mark Davis, Michael Snyder, Francois Haddad & Jose G. Montoya. Value of Circulating Cytokine Profiling During Submaximal Exercise Testing in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Scientific Reports volume 8, Article number: 2779 (2018). doi:10.1038/s41598-018-20941-w. Received:02 November 2017. Accepted:26 January 2018. Published online:09 February 2018. https://www.nature.com/articles/s41598-018-20941-w (Full article)

Immunopathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

A recent study on the pathogenesis of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has revealed an elevation of inflammatory and anti-inflammatory cytokines in the sera and cerebrospinal fluids of the patients and presence of autoantibodies in subgroups of ME/CFS patients. Furthermore, investigator-initiated clinical trials have proved the efficacy of anti-CD20 antibody (rituximab), that eliminate B cells, in the treatment of ME/CFS. Based on these findings, we hypothesize that immune abnormalities, such as enhanced autoimmune responses, may play an essential role in the neuroinflammatory pathogenesis of ME/CFS.

Source: Yamamura T, Ono H, Sato W. Immunopathogenesis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Brain Nerve. 2018 Jan;70(1):35-40. doi: 10.11477/mf.1416200947 [Article in Japanese]   https://www.ncbi.nlm.nih.gov/pubmed/29348373

Longitudinal associations of lymphocyte subsets with clinical outcomes in chronic fatigue syndrome

Abstract:

Background: Chronic fatigue syndrome (CFS) is characterized by prolonged fatigue and other physical and neurocognitive symptoms. Some studies suggest that CFS is accompanied by disruptions in the number and function of various lymphocytes. However, it is not clear which lymphocytes might influence CFS symptoms.

Purpose: To determine if patient reported fatigue symptoms and physical functioning scores significantly changed across time with lymphocyte counts as evidence of a relation among chronic fatigue symptoms and the immune response.

Methods: The current longitudinal, naturalistic study assessed the cellular expression of three lymphocyte subtypes – natural killer (NK) cells (CD3 − CD16+ and CD3 − CD56+) and naïve T cells (CD4 + CD45RA+) – to determine whether changes in lymphocytes at 4 time points across 18 months were associated with clinical outcomes, including CFS symptoms, physical functioning, and vitality, among patients with chronic fatigue. Latent growth curve models were used to examine the longitudinal relationship between lymphocytes and clinical outcomes.

Results: Ninety-three patients with Fukuda-based CFS and seven with non-CFS fatigue provided study data. Results indicated that higher proportions of naïve T cells and lower proportions of NK cells were associated with worse physical functioning, whereas higher proportions of NK cells (CD3 − CD16+) and lower proportions of naïve T cells were associated with fewer CFS symptoms.

Conclusion: These findings suggest that lymphocytes are modestly related to clinical outcomes over time.

Source: Melissa L. Mehalick, Karen B. Schmaling, Daniel E. Sabath & Dedra S.Buchwald. Longitudinal associations of lymphocyte subsets with clinical outcomes in chronic fatigue syndrome. Fatigue: Biomedicine, Health & Behavior, Published online: 12 Jan 2018. http://www.tandfonline.com/action/showCitFormats?doi=10.1080%2F21641846.2018.1426371

Transforming growth factor beta (TGF-β) in adolescent chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a prevalent and disabling condition among adolescent. The disease mechanisms are unknown. Previous studies have suggested elevated plasma levels of several cytokines, but a recent meta-analysis of 38 articles found that of 77 different cytokines measured in plasma, transforming growth factor beta (TGF-β) was the only one that was elevated in patients compared to controls in a sufficient number of articles. In the present study we therefore compared the plasma levels of the three TGF-β isoforms in adolescent CFS patients and healthy controls. In addition, the study explored associations between TGF-β levels, neuroendocrine markers, clinical markers and differentially expressed genes within the CFS group.

METHODS: CFS patients aged 12-18 years (n = 120) were recruited nation-wide to a single referral center as part of the NorCAPITAL project (ClinicalTrials ID: NCT01040429). A broad case definition of CFS was applied, requiring 3 months of unexplained, disabling chronic/relapsing fatigue of new onset, whereas no accompanying symptoms were necessary. Healthy controls (n = 68) were recruited from local schools. The three isoforms of TGF-β (TGF-β1, TGF-β2, TGF-β3) were assayed using multiplex technology. Neuroendocrine markers encompassed plasma and urine levels of catecholamines and cortisol, as well as heart rate variability indices. Clinical markers consisted of questionnaire scores for symptoms of post-exertional malaise, inflammation, fatigue, depression and trait anxiety, as well as activity recordings. Whole blood gene expression was assessed by RNA sequencing in a subgroup of patients (n = 29) and controls (n = 18).

RESULTS: Plasma levels of all three isoforms of TGF-β were equal in the CFS patients and the healthy controls. Subgrouping according to the Fukuda and Canada 2003 criteria of CFS did not reveal differential results. Within the CFS group, all isoforms of TGF-β were associated with plasma cortisol, urine norepinephrine and urine epinephrine, and this association pattern was related to fatigue score. Also, TGF-β3 was related to expression of the B cell annotated genes TNFRSF13C and CXCR5.

CONCLUSIONS: Plasma levels of all TGF-β isoforms were not altered in adolescent CFS. However, the TGF-β isoforms were associated with neuroendocrine markers, an association related to fatigue score. Furthermore, TGF-β3 might partly mediate an association between plasma cortisol and B cell gene expression. Trial registration Clinical Trials NCT01040429.

Source: Wyller VB, Nguyen CB, Ludviksen JA, Mollnes TE. Transforming growth factor beta (TGF-β) in adolescent chronic fatigue syndrome. J Transl Med. 2017 Dec 4;15(1):245. doi: 10.1186/s12967-017-1350-1. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-017-1350-1 (Full article)