Pitfalls in cytokine measurements – Plasma TGF-β1 in chronic fatigue syndrome

Abstract:

BACKGROUND: Serum TGF-β1 concentrations are reported to be elevated in chronic fatigue syndrome (CFS). However, measurement of circulating cytokines is a complex procedure and control of pre-analytical procedures is essential. The objective of the current study was to measure circulating TGF-β1 concentrations in CFS patients compared to healthy controls, taking into account differences in pre-analytical procedures.

METHODS: Two cohorts of female CFS patients were included. In both studies patients were asked to bring a healthy, age-matched control. At baseline, TGF-β1 levels were measured in plasma and additionally P-selectin, a marker of platelet activity, was determined in a subgroup of participants.

RESULTS: 50 patients and 48 controls were included in cohort I, and 90 patients and 29 controls in cohort II. Within the cohorts there were no differences in TGF-β1 concentrations. However, between the cohorts there was a large discrepancy, which appeared to be caused by differences in g-force of the centrifuges used. The lower g-force used in cohort II (1361 g) caused more platelet activation, reflected by higher p-selectin concentrations, compared to cohort I (p < 0.0001), which was confirmed in a second independent experiment. There was a correlation between TGF-β1 and p-selectin concentrations (r 0.79, p < 0.0001).

CONCLUSION: These results demonstrate that control of pre-analytical procedures is an essential aspect when measuring circulating cytokines. No evidence for enhanced TGF-β1 in patients with CFS was found.

Source: Roerink ME, van der Schaaf ME, Hawinkels LJAC, Raijmakers RPH, Knoop H, Joosten LAB, van der Meer JWM. Pitfalls in cytokine measurements – Plasma TGF-β1 in chronic fatigue syndrome. Neth J Med. 2018 Sep;76(7):310-313. https://www.ncbi.nlm.nih.gov/pubmed/30220655

Reduction of Glucocorticoid Receptor Function in Chronic Fatigue Syndrome

Abstract:

Glucocorticoid receptor (GR) function may have aetiopathogenic significance in chronic fatigue syndrome (CFS), via its essential role in mediating inflammatory responses as well as in hypothalamic-pituitary-adrenal axis regulation. GR function can be estimated ex vivo by measuring dexamethasone (dex) modulation of cytokine response to lipopolysaccharide (LPS), and in vivo using the impact of dex on cortisol levels. This study aimed to compare the GR function between CFS (n = 48), primary Sjögren’s syndrome (a disease group control) (n = 27), and sedentary healthy controls (HCs) (n = 20), and to investigate its relationship with clinical measures.

In the GR ex vivo response assay, whole blood was diluted and incubated with LPS (to stimulate cytokine production), with or without 10 or 100 nanomolar concentrations of dex. Cytometric bead array (CBA) and flow cytometry enabled quantification of cytokine levels (TNFα, interleukin- (IL-) 6, and IL-10) in the supernatants. In the in vivo response assay, five plasma samples were taken for determination of total cortisol concentration using ELISA at half-hourly intervals on two consecutive mornings separated by ingestion of 0.5 mg of dex at 11 pm. The association of the data from the in vivo and ex vivo analyses with reported childhood adversity was also examined.

CFS patients had reduced LPS-induced IL-6 and TNFα production compared to both control groups and reduced suppression of TNFα by the higher dose of dex compared to HCs. Cortisol levels, before or after dex, did not differ between CFS and HCs. Cortisol levels were more variable in CFS than HCs. In the combined group (CFS plus HC), cortisol concentrations positively and ex vivo GR function (determined by dex-mediated suppression of IL-10) negatively correlated with childhood adversity score.

The results do not support the hypothesis that GR dysregulation is aetiopathogenic in CFS and suggest that current and future endocrine cross-sectional studies in CFS may be vulnerable to the confounding influence of childhood trauma which is likely increased by comorbid depression.

Source: Lynn M, Maclachlan L, Finkelmeyer A, Clark J, Locke J, Todryk S, Ng WF, Newton JL, Watson S. Reduction of Glucocorticoid Receptor Function in Chronic Fatigue Syndrome. Mediators Inflamm. 2018 Jun 10;2018:3972104. doi: 10.1155/2018/3972104. eCollection 2018. https://www.ncbi.nlm.nih.gov/pubmed/29983634

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)

Cytokine signatures in chronic fatigue syndrome patients: a Case Control Study and the effect of anakinra treatment

Abstract:

BACKGROUND: Cytokine disturbances have been suggested to be associated with the Chronic Fatigue Syndrome/Myalgic encephalomyelitis (CFS/ME) for decades.

METHODS: Fifty female CFS patients were included in a study on the effect of the interleukin-1-receptor antagonist anakinra or placebo during 4 weeks. EDTA plasma was collected from patients before and directly after treatment. At baseline, plasma samples were collected at the same time from 48 healthy, age-matched female neighborhood controls. A panel of 92 inflammatory markers was determined in parallel in 1 μL samples using a ‘proximity extension assay’ (PEA) based immunoassay. Since Transforming growth factor beta (TGF-β) and interleukin-1 receptor antagonist (IL-1Ra) were not included in this platform, these cytokines were measured with ELISA.

RESULTS: In CFS/ME patients, the ‘normalized protein expression’ value of IL-12p40 and CSF-1 was significantly higher (p value 0.0042 and 0.049, respectively). Furthermore, using LASSO regression, a combination of 47 markers yielded a prediction model with a corrected AUC of 0.73. After correction for multiple testing, anakinra had no effect on circulating cytokines. TGF-β did not differ between patients and controls.

CONCLUSIONS: In conclusion, this study demonstrated increased IL-12p40 and CSF-1 concentrations in CFS/ME patients in addition to a set of predictive biomarkers. There was no effect of anakinra on circulating cytokines other than IL-1Ra.

TRIAL REGISTRATION:ClinicalTrials.gov Identifier: NCT02108210 , Registered April 2014.

Source: Roerink ME, Knoop H, Bronkhorst EM, Mouthaan HA, Hawinkels LJAC, Joosten LAB, van der Meer JWM. Cytokine signatures in chronic fatigue syndrome patients: a Case Control Study and the effect of anakinra treatment. J Transl Med. 2017 Dec 29;15(1):267. doi: 10.1186/s12967-017-1371-9. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-017-1371-9 (Full article)

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)

Cytokine signature in chronic fatigue syndrome

Extract:

One of the major findings in the publication by Montoya et al. on cytokine signatures in chronic fatigue syndrome is elevation of circulating TGF-β in patients with chronic fatigue syndrome (CFS). Unfortunately, the materials and methods do not give much information on how the controls were recruited, and how the blood samples …

(This article is behind a paywall. You can address correspondence to jos.vandermeer@radboudumc.nl.)

Source: Megan E. Roerink, Matthew Buckland, Andrew R. Lloyd, and Jos W. M. van der Meer. Cytokine signature in chronic fatigue syndrome. Proc Natl Acad Sci U S A. 2017 Oct 30. pii: 201714011. doi: 10.1073/pnas.1714011114. [Epub ahead of print] http://www.pnas.org/content/early/2017/10/26/1714011114.short?rss=1

Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: Case control study

Abstract:

Chronic fatigue syndrome (CFS) is characterized by fatigue after exertion. A systematic review suggested that transforming growth factor beta (TGF-β) concentrations are often elevated in cases of CFS when compared to healthy controls. This study attempted to replicate this finding, and investigate whether post-exertional symptoms were associated with altered cytokine protein concentrations and their RNA in CFS patients. Twenty-four patients fulfilling Centers for Disease Control criteria for CFS, but with no comorbid psychiatric disorders, were recruited from two CFS clinics in London, UK. Twenty-one healthy, sedentary controls were matched by gender, age, and other variables. Circulating proteins and RNA were measured for TGF-β, TNF, IL-8, IL-6 and IL-1β.

We measured six further cytokine protein concentrations (IL-2, IL-4, IL-5, IL-10, IL-12p70, and IFN-γ). Measures were taken at rest, and before and after both commuting and aerobic exercise. CFS cases had higher TGF-β protein levels compared to controls at rest (median (quartiles) = 43.9 (19.2, 61.8) versus 18.9 (16.1, 30.0) ng/ml) (p = 0.003), and consistently so over a nine-day period. However, this was a spurious finding due to variation between different assay batches.

There were no differences between groups in changes to TGF-β protein concentrations after either commuting or exercise. All other cytokine protein and RNA levels were similar between cases and controls. Post-exertional symptoms and perceived effort were not associated with any increased cytokines. We were unable to replicate previously found elevations in circulating cytokine concentrations, suggesting that elevated circulating cytokines are not important in the pathophysiology of CFS.

This article is protected by copyright. All rights reserved.

© 2017 British Society for Immunology

Source: Clark LV, Buckland M, Murphy G, Taylor N, Vleck V, Mein C, Wozniak E, Smuk M, White PD. Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: Case control study .Clin Exp Immunol. 2017 Aug 5. doi: 10.1111/cei.13023. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28779554

Cytokine signature associated with disease severity in chronic fatigue syndrome patients

Abstract:

Although some signs of inflammation have been reported previously in patients with myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), the data are limited and contradictory. High-throughput methods now allow us to interrogate the human immune system for multiple markers of inflammation at a scale that was not previously possible.

To determine whether a signature of serum cytokines could be associated with ME/CFS and correlated with disease severity and fatigue duration, cytokines of 192 ME/CFS patients and 392 healthy controls were measured using a 51-multiplex array on a Luminex system. Each cytokine’s preprocessed data were regressed on ME/CFS severity plus covariates for age, sex, race, and an assay property of newly discovered importance: nonspecific binding.

On average, TGF-β was elevated (P = 0.0052) and resistin was lower (P = 0.0052) in patients compared with controls. Seventeen cytokines had a statistically significant upward linear trend that correlated with ME/CFS severity: CCL11 (Eotaxin-1), CXCL1 (GROα), CXCL10 (IP-10), IFN-γ, IL-4, IL-5, IL-7, IL-12p70, IL-13, IL-17F, leptin, G-CSF, GM-CSF, LIF, NGF, SCF, and TGF-α. Of the 17 cytokines that correlated with severity, 13 are proinflammatory, likely contributing to many of the symptoms experienced by patients and establishing a strong immune system component of the disease. Only CXCL9 (MIG) inversely correlated with fatigue duration.

Source: Montoya JG, Holmes TH, Anderson JN, Maecker HT, Rosenberg-Hasson Y, Valencia IJ, Chu L, Younger JW, Tato CM, Davis MM. Cytokine signature associated with disease severity in chronic fatigue syndrome patients. Proc Natl Acad Sci U S A. 2017 Jul 31. pii: 201710519. doi: 10.1073/pnas.1710519114. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28760971

Researchers identify biomarkers associated with chronic fatigue syndrome severity

Researchers at the Stanford University School of Medicine have linked chronic fatigue syndrome to variations in 17 immune-system signaling proteins, or cytokines, whose concentrations in the blood correlate with the disease’s severity.

The findings provide evidence that inflammation is a powerful driver of this mysterious condition, whose underpinnings have eluded researchers for 35 years.

You can read the rest of this article herehttp://med.stanford.edu/news/all-news/2017/07/researchers-id-biomarkers-associated-with-chronic-fatigue-syndrome.html

The European ME/CFS Biomarker Landscape project: an initiative of the European network EUROMENE

Abstract:

Myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) is a common and severe disease with a considerable social and economic impact. So far, the etiology is not known, and neither a diagnostic marker nor licensed treatments are available yet. The EUROMENE network of European researchers and clinicians aims to promote cooperation and advance research on ME/CFS. To improve diagnosis and facilitate the analysis of clinical trials surrogate markers are urgently needed. As a first step for developing such biomarkers for clinical use a database of active biomarker research in Europe was established called the ME/CFS EUROMENE Biomarker Landscape project and the results are presented in this review. Further we suggest strategies to improve biomarker development and encourage researchers to take these into consideration for designing and reporting biomarker studies.

Source: Carmen Scheibenbogen, Helma Freitag, Julià Blanco, Enrica Capelli, Eliana Lacerda, Jerome Authier, Mira Meeus, Jesus Castro Marrero, Zaiga Nora-Krukle, Elisa Oltra, Elin Bolle Strand, Evelina Shikova, Slobodan Sekulic and Modra Murovska. The European ME/CFS Biomarker Landscape project: an initiative of the European network EUROMENE. Journal of Translational Medicine201715:162. https://doi.org/10.1186/s12967-017-1263-z https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-017-1263-z (Full article)