Tag: biomarker

Dysregulation of the Kynurenine Pathway, Cytokine Expression Pattern, and Proteomics Profile Link to Symptomology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Dysregulation of the kynurenine pathway (KP) is believed to play a significant role in neurodegenerative and cognitive disorders. While some evidence links the KP to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), further studies are needed to clarify the overall picture of how inflammation-driven KP disturbances may contribute to symptomology in ME/CFS.

Here, we report that plasma levels of most bioactive KP metabolites differed significantly between ME/CFS patients and healthy controls in a manner consistent with their known contribution to symptomology in other neurological disorders. Importantly, we found that enhanced production of the first KP metabolite, kynurenine (KYN), correlated with symptom severity, highlighting the relationship between inflammation, KP dysregulation, and ME/CFS symptomology.

Other significant changes in the KP included lower levels of the downstream KP metabolites 3-HK, 3-HAA, QUIN, and PIC that could negatively impact cellular energetics. We also rationalized KP dysregulation to changes in the expression of inflammatory cytokines and, for the first time, assessed levels of the iron (Fe)-regulating hormone hepcidin that is also inflammation-responsive. Levels of hepcidin in ME/CFS decreased nearly by half, which might reflect systemic low Fe levels or possibly ongoing hypoxia.

We next performed a proteomics screen to survey for other significant differences in protein expression in ME/CFS. Interestingly, out of the seven most significantly modulated proteins in ME/CFS patient plasma, 5 proteins have roles in maintaining gut health, which considering the new appreciation of how gut microbiome and health modulates systemic KP could highlight a new explanation of symptomology in ME/CFS patients and potential new prognostic biomarker/s and/or treatment avenues.

Source: Kavyani B, Ahn SB, Missailidis D, Annesley SJ, Fisher PR, Schloeffel R, Guillemin GJ, Lovejoy DB, Heng B. Dysregulation of the Kynurenine Pathway, Cytokine Expression Pattern, and Proteomics Profile Link to Symptomology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Mol Neurobiol. 2023 Nov 28. doi: 10.1007/s12035-023-03784-z. Epub ahead of print. PMID: 38015302. https://pubmed.ncbi.nlm.nih.gov/38015302/

Investigation into the Plasma Proteome Signature in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Background: ME/CFS is a complex disease with unclear etiology. Current diagnostic criteria lack objective laboratory measures.

Aims: This study aimed to investigate the plasma proteomic profile of ME/CFS patients and determine any differentially expressed proteins compared to controls.

Methods: Plasma samples obtained from 19 ME/CFS patients and 9 controls underwent analysis (Somalogic, Inc, CO). The ME/CFS patients met the National Academy of Medicine criteria for the disease. Samples were collected from a mixed venous compartment. Statistical analysis and a Mixed Graphical Model were used to identify candidate biomarker.

Results: Among ~7000 proteins detected, ~400 were differentially expressed between patients and controls (False Discovery Rate<0.05 and Absolute Fold Change ≥1.5). Selectin E (SELE), ATP Synthase Subunit F6 (ATP5PF), and Transcobalamin 2 (TCN2) were identified as top candidates. A classifier of these proteins in pulmonary artery blood of patients were distinguishable from controls (AUC =0.99).

Conclusion: The study highlighted potential biomarkers for ME/CFS, the top candidates of which are involved in inflammation, cellular energy metabolism, and Vitamin B12 transport. The plasma proteomic signature identifies ME/CFS from normals and suggests that the disease’s pathophysiology is driven by abnormalities of aerobic metabolism, vascular dysregulation, and Vitamin B12 metabolism.

Source: Johanna Squires, Sarra Al-Zayer, Peng Li, Wenzhong Xiao, David Systrom. Investigation into the Plasma Proteome Signature in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). European Respiratory Journal Sep 2023, 62 (suppl 67) PA2960; DOI: 10.1183/13993003.congress-2023.PA2960 https://erj.ersjournals.com/content/62/suppl_67/PA2960.abstract

Bioimpedance spectroscopy characterization of Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) peripheral blood mononuclear cells

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a disabling and chronic disease, importantly related to the current COVID-19 pandemic. Currently, there are no specific laboratory tests to directly diagnose ME/CFS. In this work, the use of impedance spectroscopy is studied as a potential technique for the diagnosis of ME/CFS. A specific device for the electrical characterization of peripheral blood mononuclear cells was designed and implemented.

Impedance spectroscopy measurements in the range from 1 Hz to 500 MHz were carried out after the osmotic stress of the samples with sodium chloride solution at 1M concentration. The evolution in time after the osmotic stress at two specific frequencies (1.36 kHz and 154 kHz) was analyzed.

The device showed its sensitivity to the presence of cells and the evolution of the osmotic processes. Higher values of impedance (around 15% for both the real and imaginary part) were measured at 1.36 kHz in ME/CFS patients compared to control samples. No significant difference was found between patient samples and control samples at 154 kHz. Results help to further understand the diagnosis of ME/CFS patients and the relation of their blood samples with bioimpedance measurements.

Source: Sara Martinez Rodriguez, Alberto Olmo Fernandez, Daniel Martin Fernandez, Isabel Martin-Garrido. Bioimpedance spectroscopy characterization of Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS) peripheral blood mononuclear cells. Biomedical Letters, Volume 9, Issue 2: 121-128. http://thesciencepublishers.com/biomed_lett/v9i2abstract6.html (Full text available as PDF file)

A Systematic Analysis of the Effectiveness of Mitochondrial-Based Therapies for the Management of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Background: This study aimed to compile and analyze an assortment of research findings concerning potential therapeutic strategies for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). The understanding of the multifaceted nature of ME/CFS and the need for varied and personalized therapeutic approaches were central to this investigation.

Methods: A comprehensive review and analysis of various studies conducted on ME/CFS was undertaken. These studies covered a wide array of interventions, including pharmacological treatments, nutritional supplements, dietary changes, physical therapies, and lifestyle modifications. The analysis pertained to the effectiveness of these interventions, potential physiological and biochemical markers, and the response of ME/CFS patients to different treatment strategies.

Results: The 22 selected papers investigated demonstrated varied responses to the multitude of interventions. While some interventions showed significant improvement in fatigue and biochemical parameters, others found no significant differences between the treated and control groups. Potential physiological and biochemical markers for ME/CFS, such as impaired T cell metabolism, reduced flow-mediated dilation, and decreased work rate at the ventilatory threshold, were highlighted.

Conclusion: The findings underscored the complexity of ME/CFS and the need for personalized treatment strategies. Despite mixed results and several limitations, these studies collectively contributed to understanding ME/CFS’s complex pathophysiology and treatment, laying the groundwork for future research towards more effective therapeutic strategies for this debilitating disease.

Source: Keferstein, L.G. A Systematic Analysis of the Effectiveness of Mitochondrial-Based Therapies for the Management of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Preprints 2023, 2023100637. https://doi.org/10.20944/preprints202310.0637.v1 https://www.preprints.org/manuscript/202310.0637/v1 (Full text available as PDF)

THU581 Possible Markers For Myalgic Encephalomyelitis / Chronic Fatigue Syndrome Developed In Long Covid: Utility Of Serum Ferritin And Insulin-like Growth Factor-I

Abstract:

Almost three years have passed since coronavirus disease 2019 (COVID-19) pandemic broke out, and along with the number of acute COVID-19 patients, the number of patients suffering from chronic prolonged symptoms after COVID-19, long COVID, or post COVID-19 condition, has also increased.

We established an outpatient clinic specialized for COVID-19 after care (CAC) in Okayama University Hospital in Japan in February 2021. Our recent study has revealed that the most common symptom is “fatigue”, a part of which potentially may develop into myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). However, the pathogenesis and specific prognosticator have yet to be elucidated. The aim of this study was to elucidate the clinical characteristics of patients who developed ME/CFS after COVID-19.

This retrospective observational study investigated the patients who visited our CAC outpatient clinic between February 2021 and March 2022. Of the 234 patients, 139 (59.4%) had fatigue symptoms, of whom 50 (21.4%) met the criteria for ME/CFS (ME/CFS group), while other 89 did not (non-ME/CFS group); 95 patients had no fatigue complaints (no-fatigue group). Although the patients’ backgrounds were not significantly different among the three groups, the ME/CFS group presented the highest scores on the self-rating symptom scales, including the Fatigue Assessment Scale (FAS), EuroQol, and Self-Rating Depression Scale (SDS).

Of note, serum ferritin levels, which were correlated to FAS and SDS scores, were significantly higher in the ME/CFS group (193.0 μg/mL; interquartile range (IQR), 58.8-353.8) than those of non-ME/CFS (98.2 μg/mL; 40.4-251.5) and no-fatigue (86.7 μg/mL; 37.5-209.0) groups, and this trend was prominent in the female patients. Endocrine workup further showed that the ME/CFS group had higher thyrotropin levels but lower growth hormone levels in the serum, and that insulin-like growth factor (IGF)-I levels were inversely correlated with ferritin levels (R = -0.328, p < 0.05).

Collectively, we revealed that serum ferritin levels could be a possible predictor for developing ME/CFS related to long COVID, especially in female patients. Earlier studies have suggested that hyperferritinemia is a clinical feature in the patients of long COVID, in which hepcidin-like effects could also be involved. Our present study also uncovered a relationship between hyperferrinemia and endocrine disorders among patients developing ME/CFS after COVID-19, although further investigations are necessary to understand the characteristics of ferritin metabolism.

Presentation: Thursday, June 15, 2023

Source: Yukichika Yamamoto, Yuki Otsuka, Kazuki Tokumasu, Naruhiko Sunada, Yasuhiro Nakano, Hiroyuki Honda, Yasue Sakurada, Toru Hasegawa, Hideharu Hagiya, Fumio Otsuka, THU581 Possible Markers For Myalgic Encephalomyelitis / Chronic Fatigue Syndrome Developed In Long Covid: Utility Of Serum Ferritin And Insulin-like Growth Factor-I, Journal of the Endocrine Society, Volume 7, Issue Supplement_1, October-November 2023, bvad114.1370, https://doi.org/10.1210/jendso/bvad114.1370 (Full text available as PDF file)

Unsupervised cluster analysis reveals distinct subtypes of ME/CFS patients based on peak oxygen consumption and SF-36 scores

Abstract:

Purpose: Myalgic encephalomyelitis, commonly referred to as chronic fatigue syndrome (ME/CFS), is a severe, disabling chronic disease and an objective assessment of prognosis is crucial to evaluate the efficacy of future drugs. Attempts are ongoing to find a biomarker to objectively assess the health status of (ME/CFS), patients. This study therefore aims to demonstrate that oxygen consumption is a biomarker of ME/CFS provides a method to classify patients diagnosed with ME/CFS based on their responses to the Short Form-36 (SF-36) questionnaire, which can predict oxygen consumption using cardiopulmonary exercise testing (CPET).

Methods: Two datasets were used in the study. The first contained SF-36 responses from 2,347 validated records of ME/CFS diagnosed participants, and an unsupervised machine learning model was developed to cluster the data. The second dataset was used as a validation set and included the cardiopulmonary exercise test (CPET) results of 239 participants diagnosed with ME/CFS. Participants from this dataset were grouped by peak oxygen consumption according to Weber’s classification. The SF-36 questionnaire was correctly completed by only 92 patients, who were clustered using the machine learning model. Two categorical variables were then entered into a contingency table: the cluster with values {0,1} and Weber classification {A, B, C, D} were assigned. Finally, the Chi-square test of independence was used to assess the statistical significance of the relationship between the two parameters.

Findings: The results indicate that the Weber classification is directly linked to the score on the SF-36 questionnaire. Furthermore, the 36-response matrix in the machine learning model was shown to give more reliable results than the subscale matrix (p – value < 0.05) for classifying patients with ME/CFS.

Implications: Low oxygen consumption on CPET can be considered a biomarker in patients with ME/CFS. Our analysis showed a close relationship between the cluster based on their SF-36 questionnaire score and the Weber classification, which was based on peak oxygen consumption during CPET. The dataset for the training model comprised raw responses from the SF-36 questionnaire, which is proven to better preserve the original information, thus improving the quality of the model.

Source: Lacasa M, Launois P, Prados F, Alegre J, Casas-Roma J. Unsupervised cluster analysis reveals distinct subtypes of ME/CFS patients based on peak oxygen consumption and SF-36 scores. Clin Ther. 2023 Oct 4:S0149-2918(23)00352-1. doi: 10.1016/j.clinthera.2023.09.007. Epub ahead of print. PMID: 37802746. https://www.clinicaltherapeutics.com/article/S0149-2918(23)00352-1/fulltext (Full text)

Long read sequencing characterises a novel structural variant, revealing underactive AKR1C1 with overactive AKR1C2 as a possible cause of unexplained severe fatigue

Abstract

Background: Causative genetic variants cannot yet be found for many disorders with a clear heritable component, including chronic fatigue disorders like myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). These conditions may involve genes in difficult-to-align genomic regions that are refractory to short read approaches. Structural variants in these regions can be particularly hard to detect or define with short reads, yet may account for a significant number of cases. Long read sequencing can overcome these difficulties but so far little data is available regarding the specific analytical challenges inherent in such regions, which need to be taken into account to ensure that variants are correctly identified.

Research into chronic fatigue disorders faces the additional challenge that the heterogeneous patient population likely encompasses multiple aetiologies with overlapping symptoms, rather than a single disease entity, such that each individual abnormality may lack statistical significance within a larger sample. Better delineation of patient subgroups is needed to target research and treatment.

Methods: We use nanopore sequencing in a case of unexplained severe fatigue to identify and fully characterise a large inversion in a highly homologous region spanning the AKR1C gene locus, which was indicated but could not be resolved by short-read sequencing. We then use GC-MS/MS serum steroid analysis to investigate the functional consequences.

Results: Several commonly used bioinformatics tools are confounded by the homology but a combined approach including visual inspection allows the variant to be accurately resolved. The DNA inversion appears to increase the expression of AKR1C2 while limiting AKR1C1 activity, resulting in a relative increase of inhibitory neurosteroids and impaired progesterone metabolism.

Conclusions: This study provides an example of how long read sequencing can improve diagnostic yield in research and clinical care, and highlights some of the analytical challenges presented by regions containing tandem arrays of genes. It also proposes a novel gene associated with a specific disease aetiology that may be an underlying cause of complex chronic fatigue and possibly other conditions too. It reveals biomarkers that could be assessed in a larger cohort, potentially identifying a subset of patients who might respond to treatments suggested by the aetiology.

Source: Julia Oakley, Martin Hill, Adam Giess, Mélanie Tanguy, Greg Elgar. Long read sequencing characterises a novel structural variant, revealing underactive AKR1C1 with overactive AKR1C2 as a possible cause of unexplained severe fatigue. ResearchSquare [Preprint] https://www.researchsquare.com/article/rs-3218228/v2 (Full text)

Investigating the potential role of circulatory extracellular vesicles in myalgic encephalomyelitis/ chronic fatigue syndrome

Abstract:

ME/CFS is a debilitating disease thought to affect millions of individuals. Still, the etiology of ME/CFS is unknown, and there are no standard treatments or established biomarkers. The current symptom-based diagnosis is extensive, and the use of different diagnostic criteria contributes to heterogeneity among patients and may problematize the comparison of findings. Thus, the discovery of a biomarker for ME/CFS is urgent and would benefit both patients and the ME/CFS research field.

Extracellular vesicles (EVs) are membrane limited vesicles secreted by all cells to the extracellular environment and can be collected through biofluids. EVs serve many functions, including transferring functional proteins, lipids, and nucleic acids between cells, thus mediating cell-to-cell communication. EV secretion and cargo may reflect disease state and EVs thus pose great potential as source of minimally invasive biomarkers.

The primary aim of this project was to study EVs in plasma from ME/CFS patients and assess the potential of EVs as source of biomarkers for the disease.

Using size exclusion chromatography, EVs were enriched from plasma from ME/CFS patients (n = 20) and healthy controls (n=20). Success of EV isolation was determined in representative patient- and control EV pools (n=5) using western blotting and transmission electron microscopy. Western blot experiments for detection of EV markers CD9, CD63 and TSG101, and albumin, were optimized and confirmed enrichment of EVs and presence of non-EV eluates in the isolated samples.

EV enrichment was further validated through observation of intact EVs on transmission electron micrographs, however few CD63-positive EVs were observed. Through analysis of nanoparticle tracking analysis data, the isolated EV population primarily consisted of small EVs (< 200 nm). Within this EV population, meanand mode EV size was similar between cohorts, but the EV concentration was significantly elevated in samples from patients compared to controls (p = 0.006). However, statistical tests may have been influenced by high variation within the ME/CFS cohort.

Early-stage analysis of tandem mass spectrometry data identified 663 EV associated proteins. The majority of detected proteins overlapped with registered EV proteins, but only few differences could be observed between patient- and control derived samples. However, differential expression was not analyzed.

A biomarker for ME/CFS could not be suggested at this stage of the study, however increased EV concentration suggests abnormality in EV secretion in patients which strengthens their potential as source of biomarkers and further motivates EV research in ME/CFS and related diseases.

Source: Elena Støvring Yran. Investigating the potential role of circulatory extracellular vesicles in myalgic encephalomyelitis/ chronic fatigue syndrome. Master Thesis [University of Oslo] https://www.duo.uio.no/bitstream/handle/10852/103812/1/Masterthesis_ElenaYran_May15th2023.pdf  (Full text)

Dysregulation of extracellular vesicle protein cargo in female ME/CFS cases and sedentary controls in response to maximal exercise

Abstract:

In healthy individuals, physical exercise improves cardiovascular health and muscle stre ngth, alleviates fatigue, and reduces risk of chronic diseases. Although exercise is suggested as a lifestyle intervention to manage various chronic illnesses, it negatively affects people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), who suffer from exercise intolerance. We hypothesized that altered extracellular vesicle (EV) signaling in ME/CFS patients after an exercise challenge may contribute to their prolonged and exacerbated negative response to exertion (post-exertional malaise).

EVs were isolated by size exclusion chromatography from the plasma of 18 female ME/CFS patients and 17 age- and BMI-matched female sedentary controls at three time points: before, 15 minutes, and 24 hours after a maximal cardiopulmonary exercise test. EVs were characterized using nanoparticle tracking analysis and their protein cargo was quantified using Tandem Mass Tag-based (TMT) proteomics.

The results show that exercise affects the EV proteome in ME/CFS patients differently than in healthy individuals and that changes in EV proteins after exercise are strongly correlated with symptom severity in ME/CFS. Differentially abundant proteins in ME/CFS patients vs. controls were involved in many pathways and systems, including coagulation processes, muscle contraction (both smooth and skeletal muscle), cytoskeletal proteins, the immune system, and brain signaling.

Source: Ludovic Giloteaux, Katherine A. Glass, Arnaud Germain, Sheng Zhang, Maureen R. Hanson. Dysregulation of extracellular vesicle protein cargo in female ME/CFS cases and sedentary controls in response to maximal exercise. bioRxiv 2023.08.28.555033; doi: https://doi.org/10.1101/2023.08.28.555033 https://www.biorxiv.org/content/10.1101/2023.08.28.555033v1.full (Full text)

Increased gut permeability and bacterial translocation are associated with fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome: implications for disease-related biomarker discovery

Abstract:

Background: There is growing evidence of the significance of gastrointestinal complaints in the impairment of the intestinal mucosal barrier function and inflammation in fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome. However, data on intestinal permeability and gut barrier dysfunction in FM and ME/CFS are still limited with conflicting results. This study aimed to assess circulating biomarkers potentially related to intestinal barrier dysfunction and bacterial translocation and their association with self-reported symptoms in these conditions.

Methods: A pilot multicentre, cross-sectional cohort study with consecutive enrolment of 22 patients with FM, 30 with ME/CFS, and 26 matched healthy controls. Plasma levels of anti-beta-lactoglobulin antibodies (IgG anti-beta-LGB), zonulin-1 (ZO-1), LPS, sCD14, and IL-1β) were assayed using ELISA. Demographic and clinical characteristics of the participants were recorded using validated self-reported outcome measures. The diagnostic accuracy of each biomarker was assessed using the ROC curve analysis.

Results: FM patients had significantly higher levels of anti-β-LGB, ZO-1, LPS, and sCD14 than healthy controls (all P < 0.0001). In ME/CFS patients, levels of anti-β-LGB, ZO-1, LPS, and sCD14 were significantly higher than controls, but lower than in FM (all P < 0.01), while there was no significant difference in IL-1β level. In the FM and ME/CFS cohorts, both anti-β-LGB and ZO-1 correlated significantly with LPS and sCD14 (P < 0.001 for both). In the FM group, both anti-beta-LGB and ZO-1 were correlated significantly with physical and mental health components on the SF-36 scale (P < 0.05); whereas IL-1beta negatively correlated with the COMPASS-31 score (P < 0.05). In the ME/CFS cohort, ZO-1 was positively correlated with the COMPASS-31 score (P < 0.05). The ROC curve analysis indicated a strong ability of anti-β-LGB, ZO-1, LPS, and sCD14 to predictively distinguish between FM and ME/CFS from healthy controls (P < 0.0001).

Conclusions: Biomarkers of intestinal barrier function and inflammation were associated with autonomic dysfunction assessed by COMPASS-31 scores in FM and ME/CFS respectively. Anti-β-LGB antibodies, ZO-1, LPS, and sCD14 may be putative predictors of intestinal barrier dysfunction in these cohorts. Further studies are needed to assess whether these findings are causal and can therefore be applied in clinical practice.

Source: Franz Martin, Manuel Blanco Suárez2 Paola Zambrano, Óscar Cáceres Calle, Miriam Almirall, Jose Alegre-Martín, Beatriz Lobo, Ana María Gonzalez-Castro, Javier Santos, Joan Carles Domingo, Joanna Jurek, Jesús Castro-Marrero. Increased gut permeability and bacterial translocation are associated with fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome: implications for disease-related biomarker discovery. Front. Immunol., Sec. Mucosal Immunity, Volume 14 – 2023 | doi: 10.3389/fimmu.2023.1253121 https://www.frontiersin.org/articles/10.3389/fimmu.2023.1253121/abstract