Category: Immune System

Excess of activating killer cell immunoglobulin‑like receptors and lack of HLA-Bw4 ligands: a two‑edged weapon in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is an inflammatory disease of unknown aetiology. Researchers have proposed infectious, neurological and immunological causes of this syndrome. Recently, the xenotropic murine leukemia virus-related virus was detected in 67% of patients with CFS in a US study. This observation is in agreement with one ascertained aspect of the disease: a decreased efficiency in NK cell lytic activity in CFS patients. Here, we analyzed the genomic polymorphism of killer cell immunoglobulin-like receptors (KIRs) and their HLA class I cognate ligands in patients with certified CFS. An excess of KIR3DS1 was found in CFS patients with respect to controls, as well as an increased frequency of the genotype missing KIR2DS5. Forty-four CFS patients and 50 controls also underwent genomic typing for the HLA-ligands. In the patients, a great proportion of KIR3DL1 and KIR3DS1 receptors were found to be missing their HLA-Bw4Ile80 binding motif. We hypothesize that an excess of KIR3DS1, combined with an excess of ligand-free KIR3DL1 and KIR3DS1 receptors, may hamper the clearance of a pathogen via NK cells, thus favouring the chronicity of the infection.

Source: Pasi A, Bozzini S, Carlo-Stella N, Martinetti M, Bombardieri S, De Silvestri A, Salvaneschi L, Cuccia M. Excess of activating killer cell immunoglobulin‑like receptors and lack of HLA-Bw4 ligands: a two‑edged weapon in chronic fatigue syndrome. Mol Med Rep. 2011 May-Jun;4(3):535-40. doi: 10.3892/mmr.2011.447. Epub 2011 Mar 4. https://www.ncbi.nlm.nih.gov/pubmed/21468604

Heterologous immunity: immunopathology, autoimmunity and protection during viral infections

There is a strong association between infection-related cell-mediated immunity and autoimmune diseases such as diabetes, multiple sclerosis (MS), rheumatoid arthritis (RA) and lupus erythematosis (SLE)1. Infections have also been associated with unusual immunopathologies of unknown origin, such as Wegner granulomatosis, sarcoidosis, colitis, panniculitis, bronchiolitis obliterans and even chronic fatigue syndrome. Despite exhaustive efforts, a definitive link between one particular pathogen and any of one these pathologies has never been found. More often several pathogens have become associated with each of these conditions. For instance multiple sclerosis has been associated with Epstein Barr virus (EBV), measles virus, HHV-6, varicella-zoster virus, and Picornaviruses2-6. Panniculitis in the form of erythema nodosum and bronchiolitis obliterans have both been associated with unusual cell-mediated immune responses that occur following non-specified viral or intracellular bacterial infections 7-9. Erythema nodosum, which has also been associated with Crohn’s disease8, is a very painful condition, where nodules of inflamed subcutaneous fat often on the shins and forearms persist for months. There is no known therapy. Bronchiolitis obliterans is a lethal condition in humans where the bronchioles become occluded with immune cells and fibrinous material, with no known cause or treatment9.

Chronic fatigue syndrome (CFS) is another unusual multisystem disease which is thought to be associated with immune dysregulation. Over the past two decades millions of patients world wide have suffered from a clinical syndrome of disabling fatigue, myalgias, palpitations and cognitive dysfunction that lasts longer than 6 months. In 50% of cases it develops after a mild viral illness. Cases may appear sporadically or in clusters10,11. Many attempts have been made to define the syndrome on the basis of an etiologic agent. These agents have included Epstein-Barr virus10, Brucella12, Candida albicans13, Borrelia burgdorferi, and human herpesvirus-614,15. More recently it has been associated with enteroviruses and xenoretroviruses 16-18. The general conclusion has been that it is unlikely that the syndrome is caused by a single etiologic agent. The mechanisms mediating CFS are poorly understood, and there are few well designed studies examining its cause. The symptoms of CFS are similar to those experienced during viral infections such as infectious mononucleosis or influenza or in the setting of therapy with cytokines such as interferon or interleukin-2. It has been speculated that some or all the symptoms are reflective of an altered immune response to some pathogen with over production of one or more cytokines. An alternative hypothesis suggests that a number of infectious agents are involved and result in a regulatory imbalance of cytokines and the patient with CFS is unable to reestablish the appropriate balance of cytokines. These theories have been supported by reports of immune deficiency seen associated with CFS19.

 

Source: Selin LK, Wlodarczyk MF, Kraft AR, Nie S, Kenney LL, Puzone R, Celada F. Heterologous immunity: immunopathology, autoimmunity and protection during viral infections. Autoimmunity. 2011 Jun;44(4):328-47. doi: 10.3109/08916934.2011.523277. Epub 2011 Jan 20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3633594/ (Full article)

 

A panel of biomarkers accurately identifies CFS/ME patients and contributes to the understanding of the pathophysiology of the disorder

Abstract: 

Background: CFS/ME is a debilitating illness for which no specific biomarkers have been identified, although several immune abnormalities including neuroinflammation have been described. The goal of this study was to assemble a panel of immune and inflammatory markers, with the ability to accurately identify CFS/ME cases.

Objectives: From observations made in clinical practice, four markers were selected (immune and inflammatory). These markers were initially investigated to establish differences between CFS/ME cases and controls. We then evaluated their potential usefulness as a diagnostic biomarker by establishing their specificity and sensitivity.

Methods: Venous blood was collected from 70 male and 70 female CFS/ME patients (mean age 43 and 44 years, respectively – Fukuda case definition was used) as well as 70 male and 70 female healthy controls (mean age 43.5 and 44.5 years, respectively).

Serum Interleukin 8 (IL-8), soluble CD14 (sCD14, a surrogate marker for bacterial LPS), and prostaglandin E2 (PGE2) were measured for all subjects as were absolute CD3- / CD57+ lymphocytes counts (CD57+ lymph), according to accepted clinical laboratory techniques.

We then established median values for all analysed parameters; independent sample t-test, Mann-Whitney test and ROC curve analysis were used to investigate difference linked to gender and age.

Results: ROC Statistics (area under the ROC curve) revealed a significant difference between CFS/ME cases and controls (p <0.001) for the four parameters separately, both in the male and female cohorts. Sensitivity was 74.3 – 80 % (females) and 52.1 – 85.9 % (males). Specificity was 57.1 – 98.1 (females) and 65.7 – 88.6 (males).

Logistic regression analysis for the combination of parameters in our panel (IL-8, sCD14, PGE2 and CD57+ lymph) correctly predicted in 89.36 % of male CFS/ME cases and in 97.14 % of female CFS/ME cases.

Conclusions: This panel differentiates CFS/ME cases from controls with high sensitivity and specificity and therefore represents a potential tool in selecting CFS/ME subjects for clinical studies. Each of these four biological markers relate strongly to the disorder.

PGE2 activates dendritic cells and suppresses their ability to attract T cells. It also suppresses the function of macrophages and neutrophils as well as Th1, CTL-, NK-cell mediated type 1 immunity (e.g. CD3- / CD57+ lymphocytes). PGE2 additionally promotes Th2, Th17 and Tregs and also modulates chemokine production (e.g. IL-8).

When taken together, these data suggest that lipopolysaccharide (LPS), likely from gut bacteria, plays an important role in the pathophysiology of CFS/ME.

This screening panel represents an initial step toward identifying biomarkers to broadly diagnose subjects with CFS/ME.

Subsequent markers will be required to subcategorize CFS/ME subjects in order to tailor therapeutic solutions.

 

Source: Kenny L. De Meirleir1,2, Tatjana Mijatovic3, Eugene Bosmans3, Nossa Van den Vonder2, Vincent Lombardi1. A panel of biomarkers accurately identifies CFS/ME patients and contributes to the understanding of the pathophysiology of the disorder. Abstract from IACFS/ME Conference 2016 Program.

1. Nevada Center for Biomedical Research at University
of Nevada, Reno, USA
2. Himmunitas vzw, Brussels, Belgium
3. RED Laboratories NV, Zellik, Belgium

 

Biomarkers in chronic fatigue syndrome: evaluation of natural killer cell function and dipeptidyl peptidase IV/CD26

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS) studies from our laboratory and others described decreased natural killer cell cytotoxicity (NKCC) and elevated proportion of lymphocytes expressing the activation marker, dipeptidyl peptidase IV (DPPIV) also known as CD26. However, neither these assays nor other laboratory tests are widely accepted for the diagnosis or prognosis of CFS. This study sought to determine if NKCC or DPPIV/CD26 have diagnostic accuracy for CFS.

METHODS/RESULTS: Subjects included female and male CFS cases and healthy controls. NK cell function was measured with a bioassay, using K562 cells and (51)Cr release. Lymphocyte associated DPPIV/CD26 was assayed by qualitative and quantitative flow cytometry. Serum DPPIV/CD26 was measured by ELISA. Analysis by receiver operating characteristic (ROC) curve assessed biomarker potential. Cytotoxic function of NK cells for 176 CFS subjects was significantly lower than in the 230 controls. According to ROC analysis, NKCC was a good predictor of CFS status. There was no significant difference in NK cell counts between cases and controls. Percent CD2+ lymphocytes (T cells and NK cells) positive for DPPIV/C26 was elevated in CFS cases, but there was a decrease in the number of molecules (rMol) of DPPIV/C26 expressed on T cells and NK cells and a decrease in the soluble form of the enzyme in serum. Analyses by ROC curves indicated that all three measurements of DPPIV/CD26 demonstrated potential as biomarkers for CFS. None of the DPPIV/C26 assays were significantly correlated with NKCC.

CONCLUSIONS: By ROC analysis, NKCC and three methods of measuring DPPIV/C26 examined in this study had potential as biomarkers for CFS. Of these, NKCC, %CD2+CD26+ lymphocytes and rMol CD26/CD2+ lymphocyte, required flow cytometry, fresh blood and access to a high complexity laboratory. Soluble DPPIV/C26 in serum is done with a standard ELISA assay, or with other soluble factors in a multiplex type of ELISA. Dipeptidyl peptidase IV on lymphocytes or in serum was not predictive of NKCC suggesting that these should be considered as non-redundant biomarkers. Abnormalities in DPPIV/CD26 and in NK cell function have particular relevance to the possible role of infection in the initiation and/or the persistence of CFS.

 

Source: Fletcher MA, Zeng XR, Maher K, Levis S, Hurwitz B, Antoni M, Broderick G, Klimas NG. Biomarkers in chronic fatigue syndrome: evaluation of natural killer cell function and dipeptidyl peptidase IV/CD26. PLoS One. 2010 May 25;5(5):e10817. doi: 10.1371/journal.pone.0010817. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2876037/ (Full article)

 

A Comparison of Immune Functionality in Viral versus Non-Viral CFS Subtypes

Abstract:

Participants with CFS were grouped into viral and non-viral onset fatigue categories and assessed for differential immunological marker expression. Peripheral Blood Mononuclear Cells were assessed for differential phenotypic expression of surface adherence glycoproteins on circulating lymphocytes. The flow cytometric analysis employed fluorescent monoclonal antibody labeling.

The viral in comparison to the non-viral group demonstrated significant elevations in several Th1 type subsets including: the percentage and number of CD4+ cells, the percentage and number of CD2+CD26+ cells, the percentage and number of CD2+CD4+CD26+ cells, the percentage and number of CD4+ CD26+ cells, and the percentage of Th2 naïve cells (CD4+ CD45RA+CD62L+).

Of the remaining significant findings, the non viral group demonstrated significant elevations in comparison to the viral group for the following Th1 type subsets: the percentage of CD8+ cells, the percentage of T-cytotoxic suppressor cells (CD3+8+), and the percentage and number of Th1 memory cells (CD8+CD45RA-CD62L-).

The viral group demonstrated a pattern of activation that differed from that of the group with a non-viral etiology, as evidenced by an elevated and out of range percentage and number of CD4+ cells, the percentage of CD2+CD26+, and the percentage of Th2 naïve cells (CD4+CD45RA+CD62L+). Both groups demonstrated reduced and out of range Natural Killer Cell Cytotoxicity and percentage of B-1 cells (CD5+CD19).

In addition, both groups demonstrated an elevated and out of range percentage of CD2+CD8+CD26+, percentage of the Th1 memory subset (CD4+CD45RA-CD62L-), the percentage of Th1 memory and naïve cells (CD8+CD45RA-CD62L-, CD8+CD45RA+CD62L-), the percentage and number of Th2 memory cells (CD4+CD45RA-CD62L+), and the percentage of Th2 memory and naïve cells (CD8+CD45RA-CD62L+, CD8+CD45RA+CD62L+).

These findings imply that the homeostatic mechanism responsible for the regulation of the Th1 (cell mediated) and Th2 (humoral) immune responses is disturbed in CFS. The implications of these findings are discussed.

 

Source: Porter N, Lerch A, Jason LA, Sorenson M, Fletcher MA, Herrington J. A Comparison of Immune Functionality in Viral versus Non-Viral CFS Subtypes. J Behav Neurosci Res. 2010 Jun 1;8(2):1-8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3951052/ (Full article)

 

A formal analysis of cytokine networks in chronic fatigue syndrome

Abstract:

Chronic Fatigue Syndrome (CFS) is a complex illness affecting 4 million Americans for which no characteristic lesion has been identified. Instead of searching for a deficiency in any single marker, we propose that CFS is associated with a profound imbalance in the regulation of immune function forcing a departure from standard pre-programmed responses.

To identify these imbalances we apply network analysis to the co-expression of 16 cytokines in CFS subjects and healthy controls. Concentrations of IL-1a, 1b, 2, 4, 5, 6, 8, 10, 12, 13, 15, 17 and 23, IFN-γ, lymphotoxin-α (LT-α) and TNF-α were measured in the plasma of 40 female CFS and 59 case-matched controls. Cytokine co-expression networks were constructed from the pair-wise mutual information (MI) patterns found within each subject group.

These networks differed in topology significantly more than expected by chance with the CFS network being more hub-like in design. Analysis of local modularity isolated statistically distinct cytokine communities recognizable as pre-programmed immune functional components.

These showed highly attenuated Th1 and Th17 immune responses in CFS. High Th2 marker expression but weak interaction patterns pointed to an established Th2 inflammatory milieu. Similarly, altered associations in CFS provided indirect evidence of diminished NK cell responsiveness to IL-12 and LT-α stimulus.

These observations are consistent with several processes active in latent viral infection and would not have been uncovered by assessing marker expression alone. Furthermore this analysis identifies key sub-networks such as IL-2:IFN-γ:TNF-α that might be targeted in restoring normal immune function.

Copyright © 2010 Elsevier Inc. All rights reserved.

Comment in: Letter to the editor re: “A formal analysis of cytokine networks in chronic fatigue syndrome” by Broderick et al. [Brain Behav Immun. 2010]

 

Source: Broderick G, Fuite J, Kreitz A, Vernon SD, Klimas N, Fletcher MA. A formal analysis of cytokine networks in chronic fatigue syndrome. Brain Behav Immun. 2010 Oct;24(7):1209-17. doi: 10.1016/j.bbi.2010.04.012. Epub 2010 May 4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2939140/ (Full article)

 

Unravelling the nature of postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: the role of elastase, complement C4a and interleukin-1beta

Abstract:

OBJECTIVES: Too vigorous exercise or activity increase frequently triggers postexertional malaise in people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a primary characteristic evident in up to 95% of people with ME/CFS. The present study aimed at examining whether two different types of exercise results in changes in health status, circulating elastase activity, interleukin (IL)-1beta and complement C4a levels.

DESIGN: Comparative experimental design.

SETTING: University.

SUBJECTS: Twenty-two women with ME/CFS and 22 healthy sedentary controls.

INTERVENTIONS: participants were subjected to a submaximal exercise (day 8) and a self-paced, physiologically limited exercise (day 16). Each bout of exercise was preceded and followed by blood sampling, actigraphy and assessment of their health status.

RESULTS: Both submaximal exercise and self-paced, physiologically limited exercise resulted in postexertional malaise in people with ME/CFS. However, neither exercise bout altered elastase activity, IL-1beta or complement C4a split product levels in people with ME/CFS or healthy sedentary control subjects (P > 0.05). Postexercise complement C4a level was identified as a clinically important biomarker for postexertional malaise in people with ME/CFS.

CONCLUSIONS: Submaximal exercise as well as self-paced, physiologically limited exercise triggers postexertional malaise in people with ME/CFS, but neither types of exercise alter acute circulating levels of IL-1beta, complement C4a split product or elastase activity. Further studying of immune alterations in relation to postexertional malaise in people with ME/CFS using multiple measurement points postexercise is required.

 

Source: Nijs J, Van Oosterwijck J, Meeus M, Lambrecht L, Metzger K, Frémont M, Paul L. Unravelling the nature of postexertional malaise in myalgic encephalomyelitis/chronic fatigue syndrome: the role of elastase, complement C4a and interleukin-1beta. J Intern Med. 2010 Apr;267(4):418-35. doi: 10.1111/j.1365-2796.2009.02178.x. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.2009.02178.x/full (Full article)

 

Severity of symptom flare after moderate exercise is linked to cytokine activity in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) patients often report symptom flare (SF) for >24 h after moderate exercise (post-ex). We hypothesized that SF is linked to increases in circulating cytokines and CD40 Ligand (CD40L). In 19 CFS patients and 17 controls, mental and physical fatigue and pain symptom ratings were obtained together with serum for 11 cytokines and CD40L before and at 0.5, 8, 24, and 48 h post-ex.

Before exercise, CFS had lower CD40L (p<.05) but similar cytokines versus controls. In subgroups based on SF at 48 h, high SF patients (n=11) increased in IL-1beta, IL-12, IL-6, IL-8, IL-10, and IL-13 (p<.05) 8 h post-ex. Low SF patients (n=8) showed post-ex decreases in IL-10, IL-13, and CD40L, and controls decreased in IL-10, CD40L, and TNFalpha (p<.05). Thus, in CFS, cytokine activity may vary directly with SF, which may explain prior inconsistent findings.

 

Source: White AT, Light AR, Hughen RW, Bateman L, Martins TB, Hill HR, Light KC. Severity of symptom flare after moderate exercise is linked to cytokine activity in chronic fatigue syndrome. Psychophysiology. 2010 Jul 1;47(4):615-24. doi: 10.1111/j.1469-8986.2010.00978.x. Epub 2010 Mar 4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4378647/ (Full article)

 

Cytokines across the night in chronic fatigue syndrome with and without fibromyalgia

Abstract:

The symptoms of chronic fatigue syndrome (CFS) are consistent with cytokine dysregulation. This has led to the hypothesis of immune dysregulation as the cause of this illness. To further test this hypothesis, we did repeated blood sampling for cytokines while patients and matched healthy controls slept in the sleep lab.

Because no one method for assaying cytokines is acknowledged to be better than another, we assayed for protein in serum, message in peripheral blood lymphocytes (PBLs), and function in resting and stimulated PBLs.

We found no evidence of proinflammatory cytokine upregulation. Instead, in line with some of our earlier studies, we did find some evidence to support a role for an increase in interleukin-10, an anti-inflammatory cytokine. Although the changes were small, they may contribute to the common complaint in CFS patients of disrupted sleep.

 

Source: Nakamura T, Schwander SK, Donnelly R, Ortega F, Togo F, Broderick G, Yamamoto Y, Cherniack NS, Rapoport D, Natelson BH. Cytokines across the night in chronic fatigue syndrome with and without fibromyalgia. Clin Vaccine Immunol. 2010 Apr;17(4):582-7. doi: 10.1128/CVI.00379-09. Epub 2010 Feb 24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2849324/ (Full article)

 

Immune and hemorheological changes in chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS) is a multifactorial disorder that affects various physiological systems including immune and neurological systems. The immune system has been substantially examined in CFS with equivocal results, however, little is known about the role of neutrophils and natural killer (NK) phenotypes in the pathomechanism of this disorder. Additionally the role of erythrocyte rheological characteristics in CFS has not been fully expounded. The objective of this present study was to determine deficiencies in lymphocyte function and erythrocyte rheology in CFS patients.

METHODS: Flow cytometric measurements were performed for neutrophil function, lymphocyte numbers, NK phenotypes (CD56(dim)CD16(+) and CD56(bright)CD16(-)) and NK cytotoxic activity. Erythrocyte aggregation, deformability and fibrinogen levels were also assessed.

RESULTS: CFS patients (n = 10) had significant decreases in neutrophil respiratory burst, NK cytotoxic activity and CD56(bright)CD16(-) NK phenotypes in comparison to healthy controls (n = 10). However, hemorheological characteristic, aggregation, deformability, fibrinogen, lymphocyte numbers and CD56(dim)CD16(+) NK cells were similar between the two groups.

CONCLUSION: These results indicate immune dysfunction as potential contributors to the mechanism of CFS, as indicated by decreases in neutrophil respiratory burst, NK cell activity and NK phenotypes. Thus, immune cell function and phenotypes may be important diagnostic markers for CFS. The absence of rheological changes may indicate no abnormalities in erythrocytes of CFS patients.

 

Source: Brenu EW, Staines DR, Baskurt OK, Ashton KJ, Ramos SB, Christy RM, Marshall-Gradisnik SM. Immune and hemorheological changes in chronic fatigue syndrome. J Transl Med. 2010 Jan 11;8:1. doi: 10.1186/1479-5876-8-1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829521/ (Full article)