Category: Biomarker

Altered endothelial dysfunction-related miRs in plasma from ME/CFS patients

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease characterized by unexplained debilitating fatigue. Although the etiology is unknown, evidence supports immunological abnormalities, such as persistent inflammation and immune-cell activation, in a subset of patients. Since the interplay between inflammation and vascular alterations is well-established in other diseases, endothelial dysfunction has emerged as another player in ME/CFS pathogenesis.

Endothelial nitric oxide synthase (eNOS) generates nitric oxide (NO) that maintains endothelial homeostasis. eNOS is activated by silent information regulator 1 (Sirt1), an anti-inflammatory protein. Despite its relevance, no study has addressed the Sirt1/eNOS axis in ME/CFS. The interest in circulating microRNAs (miRs) as potential biomarkers in ME/CFS has increased in recent years. Accordingly, we analyze a set of miRs reported to modulate the Sirt1/eNOS axis using plasma from ME/CFS patients.

Our results show that miR-21, miR-34a, miR-92a, miR-126, and miR-200c are jointly increased in ME/CFS patients compared to healthy controls. A similar finding was obtained when analyzing public miR data on peripheral blood mononuclear cells. Bioinformatics analysis shows that endothelial function-related signaling pathways are associated with these miRs, including oxidative stress and oxygen regulation. Interestingly, histone deacetylase 1, a protein responsible for epigenetic regulations, represented the most relevant node within the network.

In conclusion, our study provides a basis to find endothelial dysfunction-related biomarkers and explore novel targets in ME/CFS.

Source: Blauensteiner J, Bertinat R, León LE, Riederer M, Sepúlveda N, Westermeier F. Altered endothelial dysfunction-related miRs in plasma from ME/CFS patients. Sci Rep. 2021 May 19;11(1):10604. doi: 10.1038/s41598-021-89834-9. PMID: 34011981. https://pubmed.ncbi.nlm.nih.gov/34011981/

Insights into Metabolite Diagnostic Biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a persistent and unexplained pathological state characterized by exertional and severely debilitating fatigue, with/without infectious or neuropsychiatric symptoms, and with a minimum duration of 6 consecutive months. Its pathogenesis is not fully understood. There are no firmly established diagnostic biomarkers or treatment, due to incomplete understanding of the etiology of ME/CFS and diagnostic uncertainty. Establishing a biomarker for the objective diagnosis is urgently needed to treat a lot of patients. Recently, research on ME/CFS using metabolome analysis methods has been increasing. Here, we overview recent findings concerning the metabolic features in patients with ME/CFS and the animal models which contribute to the development of diagnostic biomarkers for ME/CFS and its treatment. In addition, we discuss future perspectives of studies on ME/CFS.

Source: Yamano E, Watanabe Y, Kataoka Y. Insights into Metabolite Diagnostic Biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Int J Mol Sci. 2021 Mar 26;22(7):3423. doi: 10.3390/ijms22073423. PMID: 33810365. https://pubmed.ncbi.nlm.nih.gov/33810365/

Recursive ensemble feature selection provides a robust mRNA expression signature for myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic disorder characterized by disabling fatigue. Several studies have sought to identify diagnostic biomarkers, with varying results. Here, we innovate this process by combining both mRNA expression and DNA methylation data. We performed recursive ensemble feature selection (REFS) on publicly available mRNA expression data in peripheral blood mononuclear cells (PBMCs) of 93 ME/CFS patients and 25 healthy controls, and found a signature of 23 genes capable of distinguishing cases and controls.

REFS highly outperformed other methods, with an AUC of 0.92. We validated the results on a different platform (AUC of 0.95) and in DNA methylation data obtained from four public studies on ME/CFS (99 patients and 50 controls), identifying 48 gene-associated CpGs that predicted disease status as well (AUC of 0.97). Finally, ten of the 23 genes could be interpreted in the context of the derailed immune system of ME/CFS.

Source: Metselaar, P.I., Mendoza-Maldonado, L., Li Yim, A.Y.F. et al. Recursive ensemble feature selection provides a robust mRNA expression signature for myalgic encephalomyelitis/chronic fatigue syndrome. Sci Rep 11, 4541 (2021). https://doi.org/10.1038/s41598-021-83660-9 https://www.nature.com/articles/s41598-021-83660-9 (Full text)

Are Circulating FGF21 and NT-proBNP promising novel biomarkers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, disabling, and complex multisystem illness of unknown etiology. The protein FGF21 regulates glucose homeostasis and lipid metabolism, and the protein NT-proBNP is strongly associated with an elevated cardiovascular risk; however, little is known about their role in ME/CFS patients. To address this gap, we explored the association between FGF21 and NT-proBNP and oxidative stress and inflammatory markers in ME/CFS.

Twenty-one ME/CFS patients and 20 matched healthy controls were included in the study. Participants filled out validated self-reported questionnaires on their current health status covering demographic and clinical characteristics. Plasma showed significantly decreased total antioxidant capacity and increased lipoperoxides levels (p = 0.009 and p = 0.021, respectively) in ME/CFS. These ME/CFS patients also had significantly increased levels of inflammatory cytokines (IL-1β, IL-6, IL-10, TNF-α, and C-reactive protein (p < 0.05 for all) but not for IL-8 (p = 0.833) in ME/CFS, indicating low-grade systemic inflammation status. Circulating FGF21 and NT-proBNP levels were significantly higher (p < 0.0001 and p = 0.005, respectively) in ME/CFS patients than in healthy controls.

Significantly positive correlations were found between NT-proBNP levels and IL-1β and IL-6 (p = 0.04 and p = 0.01) in ME/CFS patients but not between FGF21 and these cytokines. In contrast, no significant correlations were found for either FGF21 or NT-proBNP in controls. These findings lead to the hypothesis that elevated FGF21 and NT-proBNP levels and the association between NT-proBNP and inflammation may be promising novel diagnostic and therapeutic targets in ME/CFS.

Source: Domingo JC, Cordobilla B, Ferrer R, Giralt M, Alegre-Martin J, Castro-Marrero J. Are Circulating FGF21 and NT-proBNP promising novel biomarkers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome? Antioxid Redox Signal. 2020 Dec 22. doi: 10.1089/ars.2020.8230. Epub ahead of print. PMID: 33353469. https://pubmed.ncbi.nlm.nih.gov/33353469/

Impact of Long-Term Cryopreservation on Blood Immune Cell Markers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Implications for Biomarker Discovery

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex neuroimmune disorder characterized by numerous symptoms of unknown etiology. The ME/CFS immune markers reported so far have failed to generate a clinical consensus, perhaps partly due to the limitations of biospecimen biobanking. To address this issue, we performed a comparative analysis of the impact of long-term biobanking on previously identified immune markers and also explored additional potential immune markers linked to infection in ME/CFS.

A correlation analysis of marker cryostability across immune cell subsets based on flow cytometry immunophenotyping of fresh blood and frozen PBMC samples collected from individuals with ME/CFS (n = 18) and matched healthy controls (n = 18) was performed. The functionality of biobanked samples was assessed on the basis of cytokine production assay after stimulation of frozen PBMCs. T cell markers defining Treg subsets and the expression of surface glycoprotein CD56 in T cells and the frequency of the effector CD8 T cells, together with CD57 expression in NK cells, appeared unaltered by biobanking. By contrast, NK cell markers CD25 and CD69 were notably increased, and NKp46 expression markedly reduced, by long-term cryopreservation and thawing. Further exploration of Treg and NK cell subsets failed to identify significant differences between ME/CFS patients and healthy controls in terms of biobanked PBMCs.

Our findings show that some of the previously identified immune markers in T and NK cell subsets become unstable after cell biobanking, thus limiting their use in further immunophenotyping studies for ME/CFS. These data are potentially relevant for future multisite intervention studies and cooperative projects for biomarker discovery using ME/CFS biobanked samples. Further studies are needed to develop novel tools for the assessment of biomarker stability in cryopreserved immune cells from people with ME/CFS.

Source: Gómez-Mora E, Carrillo J, Urrea V, Rigau J, Alegre J, Cabrera C, Oltra E, Castro-Marrero J, Blanco J. Impact of Long-Term Cryopreservation on Blood Immune Cell Markers in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Implications for Biomarker Discovery. Front Immunol. 2020 Nov 17;11:582330. doi: 10.3389/fimmu.2020.582330. PMID: 33329554; PMCID: PMC7732598. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7732598/  (Full text)

Deep phenotyping of myalgic encephalomyelitis/chronic fatigue syndrome in Japanese population

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex and debilitating disease with no molecular diagnostics and no treatment options. To identify potential markers of this illness, we profiled 48 patients and 52 controls for standard laboratory tests, plasma metabolomics, blood immuno-phenotyping and transcriptomics, and fecal microbiome analysis. Here, we identified a set of 26 potential molecular markers that distinguished ME/CFS patients from healthy controls. Monocyte number, microbiome abundance, and lipoprotein profiles appeared to be the most informative markers.

When we correlated these molecular changes to sleep and cognitive measurements of fatigue, we found that lipoprotein and microbiome profiles most closely correlated with sleep disruption while a different set of markers correlated with a cognitive parameter. Sleep, lipoprotein, and microbiome changes occur early during the course of illness suggesting that these markers can be examined in a larger cohort for potential biomarker application. Our study points to a cluster of sleep-related molecular changes as a prominent feature of ME/CFS in our Japanese cohort.

Source: Kitami T, Fukuda S, Kato T, Yamaguti K, Nakatomi Y, Yamano E, Kataoka Y, Mizuno K, Tsuboi Y, Kogo Y, Suzuki H, Itoh M, Morioka MS, Kawaji H, Koseki H, Kikuchi J, Hayashizaki Y, Ohno H, Kuratsune H, Watanabe Y. Deep phenotyping of myalgic encephalomyelitis/chronic fatigue syndrome in Japanese population. Sci Rep. 2020 Nov 16;10(1):19933. doi: 10.1038/s41598-020-77105-y. PMID: 33199820; PMCID: PMC7669873.  https://www.nature.com/articles/s41598-020-77105-y (Full text)

Plasma proteomic profiling suggests an association between antigen driven clonal B cell expansion and ME/CFS

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is an unexplained chronic, debilitating illness characterized by fatigue, sleep disturbances, cognitive dysfunction, orthostatic intolerance and gastrointestinal problems.

Using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), we analyzed the plasma proteomes of 39 ME/CFS patients and 41 healthy controls. Logistic regression models, with both linear and quadratic terms of the protein levels as independent variables, revealed a significant association between ME/CFS and the immunoglobulin heavy variable (IGHV) region 3-23/30.

Stratifying the ME/CFS group based on self-reported irritable bowel syndrome (sr-IBS) status revealed a significant quadratic effect of immunoglobulin lambda constant region 7 on its association with ME/CFS with sr-IBS whilst IGHV3-23/30 and immunoglobulin kappa variable region 3-11 were significantly associated with ME/CFS without sr-IBS.

In addition, we were able to predict ME/CFS status with a high degree of accuracy (AUC = 0.774-0.838) using a panel of proteins selected by 3 different machine learning algorithms: Lasso, Random Forests, and XGBoost. These algorithms also identified proteomic profiles that predicted the status of ME/CFS patients with sr-IBS (AUC = 0.806-0.846) and ME/CFS without sr-IBS (AUC = 0.754-0.780).

Our findings are consistent with a significant association of ME/CFS with immune dysregulation and highlight the potential use of the plasma proteome as a source of biomarkers for disease.

Source: Milivojevic M, Che X, Bateman L, et al. Plasma proteomic profiling suggests an association between antigen driven clonal B cell expansion and ME/CFS. PLoS One. 2020;15(7):e0236148. Published 2020 Jul 21. doi:10.1371/journal.pone.0236148 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236148 (Full text)

Altered Structural Brain Networks Related to Adrenergic/Muscarinic Receptor Autoantibodies in Chronic Fatigue Syndrome

Abstract:

Background and purpose: Recent studies suggest that the autoantibodies against adrenergic/muscarinic receptors might be one of the causes and potential markers of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The purpose of this study was to investigate the structural network changes related to autoantibody titers against adrenergic/muscarinic receptors in ME/CFS by performing a single-subject gray matter similarity-based structural network analysis.

Methods: We prospectively examined 89 consecutive right-handed ME/CFS patients who underwent both brain MRI including 3D T1-wighted images and a blood analysis of autoantibodies titers against β1 adrenergic receptor (β1 AdR-Ab), β2 AdR-Ab, M3 acetylcholine receptor (M3 AchR-Ab), and M4 AchR-Ab. Single-subject gray matter similarity-based structural networks were extracted from segmented gray matter images for each patient. We calculated local network properties (betweenness centrality, clustering coefficient, and characteristic path length) and global network properties (normalized path length λ, normalized clustering coefficient γ, and small-world network value δ). We investigated the correlations between the autoantibody titers and regional gray matter/white matter volumes, the local network properties, and the global network properties.

Results: Betweenness centrality showed a significant positive correlation with β1-AdR-Ab in the right dorsolateral prefrontal cortex. The characteristic path length showed a significant negative correlation with β2-AdR-Ab in the right precentral gyrus. There were no significant correlations between the antibody titers and the regional gray matter/white matter volumes, and the global network properties.

Conclusions: Our findings suggest that β1 AdR-Ab and β2 AdR-Ab are potential markers of ME/CFS.

Source: Fujii H, Sato W, Kimura Y, et al. Altered Structural Brain Networks Related to Adrenergic/Muscarinic Receptor Autoantibodies in Chronic Fatigue Syndrome [published online ahead of print, 2020 Jul 1]. J Neuroimaging. 2020;10.1111/jon.12751. doi:10.1111/jon.12751 https://pubmed.ncbi.nlm.nih.gov/32609410/

Inclusion of Family Members Without ME/CFS in Research Studies Promotes Discovery of Biomarkers Specific for ME/CFS

Abstract:

Background: The search for a biomarker specific for ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome) has been long, arduous and, to date, unsuccessful. Researchers need to consider their expenditures on each new candidate biomarker. In a previous study of antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer lymphocytes, we found lower ADCC for ME/CFS patients vs. unrelated donors but ruled against low ADCC as a biomarker because of similar ADCC for patients vs. their family members without ME/CFS.

Objective: We applied inclusion of family members without ME/CFS, from families with multiple CFS patients, as a second non-ME/CFS control group in order to re-examine inflammation in ME/CFS.

Method: Total and CD16A-positive ‘non-classical’ anti-inflammatory monocytes were monitored.

Results: Non-classical monocytes were elevated for patients vs. unrelated healthy donors but these differences were insignificant between patients vs. unaffected family members.

Conclusions: Inclusion of family members ruled against biomarker considerations for the monocytes characterized. These pilot findings for the non-classical monocytes are novel in the field of ME/CFS. We recommend that occupational therapists advocate and explain to family members without ME/CFS the need for the family members’ participation as a second set of controls in pilot studies to rapidly eliminate false biomarkers, optimize patient participation, and save researchers’ labor.

Source: Tokunaga K, Sung AP, Tang JJ, et al. Inclusion of family members without ME/CFS in research studies promotes discovery of biomarkers specific for ME/CFS [published online ahead of print, 2020 Jun 16]. Work. 2020;10.3233/WOR-203177. doi:10.3233/WOR-203177 https://pubmed.ncbi.nlm.nih.gov/32568152/

Properties of Measurements Obtained During Cardiopulmonary Exercise Testing in Individuals With Myalgic encephalomyelitis/chronic Fatigue Syndrome

Abstract:

Background: Diminished cardiopulmonary exercise test (CPET) performance indicates the physiological basis for reduced capacity for activities of daily living and work. Thus, it may be a biomarker for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Objective: To determine statistical properties of cardiac, pulmonary, and metabolic measurements obtained during CPET in people with ME/CFS.

Methods: Fifty-one females with ME/CFS and 10 sedentary females with similar age and body mass received cardiac, pulmonary, and metabolic measurements during 2 CPETs separated by 24 hours. Two-way analysis of variance and effect size calculations (Cohen’s d) were used to assess the magnitude and statistical significance of differences in measurements between groups. Reliability of CPET measurements was estimated using intraclass correlation coefficients (formula 2,1; ICC2,1). Responsiveness of CPET measurements was assessed using minimum detectable change outside the 95% confidence interval (MDC95) and coefficients of variation (CoV).

Results: CPET measurements demonstrated moderate to high reliability for individuals with ME/CFS. Comparing subjects with ME/CFS and control subjects yielded moderate to large effect sizes on all CPET measurements. MDC95 for all individuals with ME/CFS generally exceeded control subjects and CoVs for CPET measurements were comparable between groups.

Conclusions: CPET measurements demonstrate adequate responsiveness and reproducibility for research and clinical applications.

Source: Davenport TE, Stevens SR, Stevens MAJ, Snell CR, Van Ness JM. Properties of measurements obtained during cardiopulmonary exercise testing in individuals with myalgic encephalomyelitis/chronic fatigue syndrome [published online ahead of print, 2020 Jun 16]. Work. 2020;10.3233/WOR-203170. doi:10.3233/WOR-203170