Chronic fatigue syndrome and the immune system: Where are we now?

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterised by multiple symptoms including fatigue, headaches and cognitive impairment, which have a significantly adverse effect on the normal functioning and well-being of the individual. These symptoms are often triggered or worsened following physical or mental exertion. ME/CFS has long been thought of as having a significant immunological component, but reports describing changes in immune function are often inconsistent between study groups.

Although the wide range of physical, neurocognitive and autonomic symptoms reported have seriously hampered attempts to understand pathophysiological pathways, investment in biomedical research in ME/CFS is finally increasing with a number of novel and promising investigations being published. The onset of ME/CFS may often be linked to (viral) infections which would be consistent with a variety of alterations in natural killer (NK) cell function as described by a number of different groups. Consistency in cytokine data has been lacking so far, although recently more sophisticated approaches have led to more robust data from large patient cohorts.

New hope has also been given to sufferers with the possibility that therapies that deplete B cells can result in clinical improvement. To understand the pathogenic mechanism in this complex condition, it is important to consider repeated analysis in different cohorts. In this review, we will discuss the potential of different components of the immune system to be involved in the pathogenesis of ME/CFS.

Copyright © 2017 Elsevier Masson SAS. All rights reserved

 

Source: Mensah FKF, Bansal AS, Ford B, Cambridge G. Chronic fatigue syndrome and the immune system: Where are we now? Neurophysiol Clin. 2017 Apr 11. pii: S0987-7053(17)30006-0. doi: 10.1016/j.neucli.2017.02.002. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28410877

 

Immune network analysis of cerebrospinal fluid in myalgic encephalomyelitis/chronic fatigue syndrome with atypical and classical presentations

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a persistent and debilitating disorder marked by cognitive and sensory dysfunction and unexplained physical fatigue. Classically, cases present after a prodrome consistent with infection; however, some cases are atypical and have a different presentation and comorbidities that pose challenges for differential diagnosis. We analyzed cerebrospinal fluid (CSF) from 32 cases with classical ME/CFS and 27 cases with atypical ME/CFS using a 51-plex cytokine assay. Atypical subjects differed in cytokine profiles from classical subjects.

In logistic regression models incorporating immune molecules that were identified as potential predictor variables through feature selection, we found strong associations between the atypical ME/CFS phenotype and lower CSF levels of the inflammatory mediators, interleukin 17A and CXCL9. Network analysis revealed an absence of inverse inter-cytokine relationships in CSF from atypical patients, and more sparse positive intercorrelations, than classical subjects. Interleukin 1 receptor antagonist appeared to be a negative regulator in classical ME/CFS, with patterns suggestive of disturbances in interleukin 1 signaling and autoimmunity-type patterns of immune activation.

Immune signatures in the central nervous system of ME/CFS patients with atypical features may be distinct from those with more typical clinical presentations.

 

Source: Hornig M, Gottschalk CG, Eddy ML, Che X, Ukaigwe JE, Peterson DL, Lipkin WI. Immune network analysis of cerebrospinal fluid in myalgic encephalomyelitis/chronic fatigue syndrome with atypical and classical presentations. Transl Psychiatry. 2017 Apr 4;7(4):e1080. doi: 10.1038/tp.2017.44. https://www.ncbi.nlm.nih.gov/pubmed/28375204

 

Scientists Discover Biological Evidence of “Atypical” Chronic Fatigue Syndrome

Press Release: NEW YORK, April 4, 2017. Scientists at the Center for Infection and Immunity (CII) at Columbia University’s Mailman School of Public Health are the first to report immune signatures differentiating two subgroups of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): “classical” and “atypical.” This complex, debilitating disease is characterized by symptoms ranging from extreme fatigue after exertion to difficulty concentrating, headaches, and muscle pain.

The study appears in the Nature Publishing Group journal, Translational Psychiatry.

Typically, symptoms of ME/CFS begin suddenly following a flu-like infection, but a subset of cases classified by the investigators as “atypical” follows a different disease course, either from triggers preceding symptoms by months or years, or accompanied by the later development of additional serious illnesses.

Continue reading “Scientists Discover Biological Evidence of “Atypical” Chronic Fatigue Syndrome”

Further clues in the fight against chronic fatigue syndrome

New findings regarding the pathology of Chronic Fatigue Syndrome (CFS) are bringing Griffith University researchers closer to identifying the cause of this disabling illness.

This is the news from a team at the National Centre for Neuroimmunology and Emerging Diseases at the Menzies Health Institute Queensland.

Professors Marshall-Gradisnik and Don Staines and their research team have identified significant impairments in cellular function of people with CFS.

CFS — sometimes known as ME (myalgic encephalomyelitis) — is a complex illness characterized 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.

“While the patho-mechanism of CFS/ME is unknown, these recent findings by NCNED researchers provide further evidence for the pathology of this illness,” says Professor Sonya Marshall-Gradisnik, who speaks as we approach International CFS Awareness Day on Thursday May 12.

Published in the Journal of Translational Medicine, the results report significant differences in intracellular signalling of cells with CFS patients.

“In this group, we see that dysfunctional signalling may contribute to impaired cell activity. These findings are consistent with our previous findings and align with the presentation of symptoms in patients,” says Professor Staines.

The current research findings build upon recent discoveries including novel identification of key genetic changes in cells of the immune system.

The NCNED — internationally recognised for research into CFS/ME — will present a seminar on current research findings on this disease on International CFS/ME Awareness Day, Thursday May 12 at Griffith University, Gold Coast Campus, commencing 1pm, location G17, Lecture theatre 3.

Griffith University will also be illuminating the Griffith Health Centre in blue to further help raise awareness for CFS/ME.

Journal Reference: Teilah Kathryn Huth, Donald Staines, Sonya Marshall-Gradisnik. ERK1/2, MEK1/2 and p38 downstream signalling molecules impaired in CD56dimCD16 and CD56brightCD16dim/− natural killer cells in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis patients. Journal of Translational Medicine, 2016; 14 (1) DOI: 10.1186/s12967-016-0859-z

 

Source: Griffith University. “Further clues in the fight against chronic fatigue syndrome.” ScienceDaily. ScienceDaily, 10 May 2016. https://www.sciencedaily.com/releases/2016/05/160510093906.htm

 

Giardia-specific cellular immune responses in post-giardiasis chronic fatigue syndrome

Abstract:

BACKGROUND: The role of pathogen specific cellular immune responses against the eliciting pathogen in development of post-infectious chronic fatigue syndrome (PI-CFS) is not known and such studies are difficult to perform. The aim of this study was to evaluate specific anti-Giardia cellular immunity in cases that developed CFS after Giardia infection compared to cases that recovered well. Patients reporting chronic fatigue in a questionnaire study three years after a Giardia outbreak were clinically evaluated five years after the outbreak and grouped according to Fukuda criteria for CFS and idiopathic chronic fatigue. Giardia specific immune responses were evaluated in 39 of these patients by proliferation assay, T cell activation and cytokine release analysis. 20 Giardia exposed non-fatigued individuals and 10 healthy unexposed individuals were recruited as controls.

RESULTS: Patients were clinically classified into CFS (n = 15), idiopathic chronic fatigue (n = 5), fatigue from other causes (n = 9) and recovered from fatigue (n = 10). There were statistically significant antigen specific differences between these Giardia exposed groups and unexposed controls. However, we did not find differences between the Giardia exposed fatigue classification groups with regard to CD4 T cell activation, proliferation or cytokine levels in 6 days cultured PBMCs. Interestingly, sCD40L was increased in patients with PI-CFS and other persons with fatigue after Giardia infection compared to the non-fatigued group, and correlated well with fatigue levels at the time of sampling.

CONCLUSION: Our data show antigen specific cellular immune responses in the groups previously exposed to Giardia and increased sCD40L in fatigued patients.

 

Source: Hanevik K, Kristoffersen E, Mørch K, Rye KP, Sørnes S, Svärd S, Bruserud Ø, Langeland N. Giardia-specific cellular immune responses in post-giardiasis chronic fatigue syndrome. BMC Immunol. 2017 Jan 28;18(1):5. doi: 10.1186/s12865-017-0190-3.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5279576/ (Full article)

 

Poor sleep quality is associated with greater circulating pro-inflammatory cytokines and severity and frequency of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) symptoms in women

Abstract:

OBJECTIVE: Poor sleep quality has been linked to inflammatory processes and worse disease outcomes in the context of many chronic illnesses, but less is known in conditions such as chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). This study examines the relationships between sleep quality, pro-inflammatory cytokines, and CFS/ME symptoms.

METHODS: Sixty women diagnosed with CFS/ME were assessed using the Pittsburgh Sleep Quality Index (PSQI), Fatigue Symptom Inventory (FSI) and Center for Disease Control and Prevention (CDC)-based CFS/ME symptom questionnaires. Circulating plasma pro-inflammatory cytokine levels were measured by ELISA. Multiple regression analyses examined associations between sleep, cytokines and symptoms, controlling for age, education, and body mass index.

RESULTS: Poor sleep quality (PSQI global score) was associated with greater pro-inflammatory cytokine levels: interleukin-1β (IL-1β) (β=0.258, p=0.043), IL-6 (β=0.281, p=0.033), and tumor necrosis factor-alpha (TNF-α) (β=0.263, p=0.044). Worse sleep quality related to greater fatigue severity (β=0.395, p=0.003) and fatigue-related interference with daily activities (β=0.464, p<0.001), and more severe and frequent CDC-defined core CFS/ME symptoms (β=0.499, p<0.001, and β=0.556, p<0.001, respectively).

CONCLUSIONS: Results underscore the importance of managing sleep-related difficulties in this patient population. Further research is needed to identify the etiology of sleep disruptions in CFS/ME and mechanistic factors linking sleep quality to symptom severity and inflammatory processes.

Copyright © 2016 Elsevier B.V. All rights reserved.

 

Source: Milrad SF, Hall DL, Jutagir DR, Lattie EG, Ironson GH, Wohlgemuth W, Nunez MV, Garcia L, Czaja SJ, Perdomo DM, Fletcher MA, Klimas N, Antoni MH. Poor sleep quality is associated with greater circulating pro-inflammatory cytokines and severity and frequency of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) symptoms in women. J Neuroimmunol. 2017 Feb 15;303:43-50. doi: 10.1016/j.jneuroim.2016.12.008. Epub 2016 Dec 14. https://www.ncbi.nlm.nih.gov/pubmed/28038892

 

Humoral Immunity Profiling of Subjects with Myalgic Encephalomyelitis Using a Random Peptide Microarray Differentiates Cases from Controls with High Specificity and Sensitivity

Abstract:

Myalgic encephalomyelitis (ME) is a complex, heterogeneous illness of unknown etiology. The search for biomarkers that can delineate cases from controls is one of the most active areas of ME research; however, little progress has been made in achieving this goal. In contrast to identifying biomarkers that are directly involved in the pathological process, an immunosignature identifies antibodies raised to proteins expressed during, and potentially involved in, the pathological process. Although these proteins might be unknown, it is possible to detect antibodies that react to these proteins using random peptide arrays.

In the present study, we probe a custom 125,000 random 12-mer peptide microarray with sera from 21 ME cases and 21 controls from the USA and Europe and used these data to develop a diagnostic signature. We further used these peptide sequences to potentially uncover the naturally occurring candidate antigens to which these antibodies may specifically react with in vivo.

Our analysis revealed a subset of 25 peptides that distinguished cases and controls with high specificity and sensitivity. Additionally, Basic Local Alignment Search Tool (BLAST) searches suggest that these peptides primarily represent human self-antigens and endogenous retroviral sequences and, to a minor extent, viral and bacterial pathogens.

 

Source: Singh S, Stafford P, Schlauch KA, Tillett RR, Gollery M, Johnston SA, Khaiboullina SF, De Meirleir KL, Rawat S, Mijatovic T, Subramanian K, Palotás A, Lombardi VC. Humoral Immunity Profiling of Subjects with Myalgic Encephalomyelitis Using a Random Peptide Microarray Differentiates Cases from Controls with High Specificity and Sensitivity. Mol Neurobiol. 2016 Dec 15. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27981498

 

Impaired calcium mobilization in natural killer cells from chronic fatigue syndrome/myalgic encephalomyelitis patients is associated with transient receptor potential melastatin 3 ion channels

Abstract:

Transient receptor potential melastatin subfamily 3 (TRPM3) ion channels play a role in calcium (Ca2+ ) cell signalling. Reduced TRPM3 protein expression has been identified in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) patients. However, the significance of TRPM3 and association with intracellular Ca2+ mobilization has yet to be determined.

Fifteen CFS/ME patients (mean age 48·82 ± 9·83 years) and 25 healthy controls (mean age 39·2 ± 12·12 years) were examined. Isolated natural killer (NK) cells were labelled with fluorescent antibodies to determine TRPM3, CD107a and CD69 receptors on CD56dim CD16+ NK cells and CD56bright CD16dim/- NK cells. Ca2+ flux and NK cytotoxicity activity was measured under various stimulants, including pregnenolone sulphate (PregS), thapsigargin (TG), 2-aminoethoxydiphenyl borate (2APB) and ionomycin.

Unstimulated CD56bright CD16dim/- NK cells showed significantly reduced TRPM3 receptors in CFS/ME compared with healthy controls (HC). Ca2+ flux showed no significant difference between groups. Moreover, PregS-stimulated CD56bright CD16dim/- NK cells showed a significant increase in Ca2+ flux in CFS/ME patients compared with HC. By comparison, unstimulated CD56dim CD16+ NK cells showed no significant difference in both Ca2+ flux and TRPM3 expression. PregS-stimulated CD56dim CD16+ NK cells increased TRPM3 expression significantly in CFS/ME, but this was not associated with a significant increase in Ca2+ flux.

Furthermore, TG-stimulated CD56dim CD16+ NK cells increased K562 cell lysis prior to PregS stimulation in CFS/ME patients compared with HC. Differential expression of TRPM3 and Ca2+ flux between NK cell subtypes may provide evidence for their role in the pathomechanism involving NK cell cytotoxicity activity in CFS/ME.

© 2016 The Authors. Clinical & Experimental Immunology published by John Wiley & Sons Ltd on behalf of British Society for Immunology.

 

Source: Nguyen T, Johnston S, Clarke L, Smith P, Staines D, Marshall-Gradisnik S. Impaired calcium mobilization in natural killer cells from chronic fatigue syndrome/myalgic encephalomyelitis patients is associated with transient receptor potential melastatin 3 ion channels. Clin Exp Immunol. 2017 Feb;187(2):284-293. doi: 10.1111/cei.12882. Epub 2016 Nov 23. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5217865/ (Full article)

 

Dysregulation of Protein Kinase Gene Expression in NK Cells from Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients

Abstract:

BACKGROUND: The etiology and pathomechanism of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) are unknown. However, natural killer (NK) cell dysfunction, in particular reduced NK cytotoxic activity, is a consistent finding in CFS/ME patients. Previous research has reported significant changes in intracellular mitogen-activated protein kinase pathways from isolated NK cells. The purpose of this present investigation was to examine whether protein kinase genes have a role in abnormal NK cell intracellular signaling in CFS/ME.

METHOD: Messenger RNA (mRNA) expression of 528 protein kinase genes in isolated NK cells was analyzed (nCounter GX Human Kinase Kit v2 (XT); NanoString Technologies) from moderate (n = 11; age, 54.9 ± 10.3 years) and severe (n = 12; age, 47.5 ± 8.0 years) CFS/ME patients (classified by the 2011 International Consensus Criteria) and nonfatigued controls (n = 11; age, 50.0 ± 12.3 years).

RESULTS: The expression of 92 protein kinase genes was significantly different in the severe CFS/ME group compared with nonfatigued controls. Among these, 37 genes were significantly upregulated and 55 genes were significantly downregulated in severe CFS/ME patients compared with nonfatigued controls.

CONCLUSIONS: In severe CFS/ME patients, dysfunction in protein kinase genes may contribute to impairments in NK cell intracellular signaling and effector function. Similar changes in protein kinase genes may be present in other cells, potentially contributing to the pathomechanism of this illness.

 

Source: Chacko A, Staines DR, Johnston SC, Marshall-Gradisnik SM. Dysregulation of Protein Kinase Gene Expression in NK Cells from Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients. Gene Regul Syst Bio. 2016 Aug 28;10:85-93. doi: 10.4137/GRSB.S40036. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5003121/ (Full article)

 

Serum BAFF and APRIL Levels, T-Lymphocyte Subsets, and Immunoglobulins after B-Cell Depletion Using the Monoclonal Anti-CD20 Antibody Rituximab in Myalgic Encephalopathy/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalopathy/Chronic Fatigue Syndrome (ME/CFS) is a disease of unknown etiology. We have previously suggested clinical benefit from B-cell depletion using the monoclonal anti-CD20 antibody rituximab in a randomized and placebo-controlled study. Prolonged responses were then demonstrated in an open-label phase-II study with maintenance rituximab treatment.

Using blood samples from patients in the previous two clinical trials, we investigated quantitative changes in T-lymphocyte subsets, in immunoglobulins, and in serum levels of two B-cell regulating cytokines during follow-up. B-lymphocyte activating factor of the tumor necrosis family (BAFF) in baseline serum samples was elevated in 70 ME/CFS patients as compared to 56 healthy controls (p = 0.011). There were no significant differences in baseline serum BAFF levels between patients with mild, moderate, or severe ME/CFS, or between responders and non-responders to rituximab.

A proliferation-inducing ligand (APRIL) serum levels were not significantly different in ME/CFS patients compared to healthy controls at baseline, and no changes in serum levels were seen during follow-up. Immunophenotyping of peripheral blood T-lymphocyte subsets and T-cell activation markers at multiple time points during follow-up showed no significant differences over time, between rituximab and placebo groups, or between responders and non-responders to rituximab.

Baseline serum IgG levels were significantly lower in patients with subsequent response after rituximab therapy compared to non-responders (p = 0.03). In the maintenance study, slight but significant reductions in mean serum immunoglobulin levels were observed at 24 months compared to baseline; IgG 10.6-9.5 g/L, IgA 1.8-1.5 g/L, and IgM 0.97-0.70 g/L.

Although no functional assays were performed, the lack of significant associations of T- and NK-cell subset numbers with B-cell depletion, as well as the lack of associations to clinical responses, suggest that B-cell regulatory effects on T-cell or NK-cell subsets are not the main mechanisms for the observed improvements in ME/CFS symptoms observed in the two previous trials. The modest increase in serum BAFF levels at baseline may indicate an activated B-lymphocyte system in a subgroup of ME/CFS patients.

 

Source: Lunde S, Kristoffersen EK, Sapkota D, Risa K, Dahl O, Bruland O, Mella O, Fluge Ø. Serum BAFF and APRIL Levels, T-Lymphocyte Subsets, and Immunoglobulins after B-Cell Depletion Using the Monoclonal Anti-CD20 Antibody Rituximab in Myalgic Encephalopathy/Chronic Fatigue Syndrome. PLoS One. 2016 Aug 18;11(8):e0161226. doi: 10.1371/journal.pone.0161226. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4990178/ (Full article)