Category: Biomarker

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and fibromyalgia are indistinguishable by their cerebrospinal fluid proteomes

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and fibromyalgia have overlapping neurologic symptoms particularly disabling fatigue. This has given rise to the question whether they are distinct central nervous system (CNS) entities or is one an extension of the other. To investigate this, we used unbiased quantitative mass spectrometry-based proteomics to examine the most proximal fluid to the brain, cerebrospinal fluid (CSF). This was to ascertain if the proteome profile of one was the same or different from the other.

We examined two separate groups of ME/CFS, one with (n=15) and one without (n=15) fibromyalgia. We quantified a total of 2,083 proteins using immunoaffinity depletion, tandem mass tag isobaric labeling and offline two-dimensional liquid chromatography coupled to tandem mass spectrometry, including 1,789 that were quantified in all the CSF samples. ANOVA analysis did not yield any proteins with an adjusted p-value < 0.05. This supports the notion that ME/CFS and fibromyalgia as currently defined are not distinct entities.

Source: Steven E. Schutzer, Tao Liu, Chia-Feng Tsai, Vladislav A. Petyuk, Athena A. Schepmoes, Yi-Ting Wang, Karl K. Weitz, Jonas Bergquist, Richard D. Smith, Benjamin H Natelson. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and fibromyalgia are indistinguishable by their cerebrospinal fluid proteomes. bioRxiv 2022.09.14.506792; doi: https://doi.org/10.1101/2022.09.14.506792 https://www.biorxiv.org/content/10.1101/2022.09.14.506792v2.full (Full text)

Autoimmune gene expression profiling of fingerstick whole blood in Chronic Fatigue Syndrome

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating condition that can lead to severe impairment of physical, psychological, cognitive, social, and occupational functions. The cause of ME/CFS remains incompletely understood. There is no clinical diagnostic test for ME/CFS. Although many therapies have been used off-label to manage symptoms of ME/CFS, there are limited, if any, specific therapies or cure for ME/CFS. In this study, we investigated the expression of genes specific to key immune functions, and viral infection status in ME/CFS patients with an aim of identifying biomarkers for characterization and/or treatment of the disease.

Methods: In 2021, one-hundred and sixty-six (166) patients diagnosed with ME/CFS and 83 healthy controls in the US participated in this study via a social media-based application (app). The patients and heathy volunteers consented to the study and provided self-collected finger-stick blood and first morning void urine samples from home. RNA from the fingerstick blood was tested using DxTerity’s 51-gene autoimmune RNA expression panel (AIP). In addition, DNA from the same fingerstick blood sample was extracted to detect viral load of 4 known ME/CFS associated viruses (HHV6, HHV7, CMV and EBV) using a real-time PCR method.

Results: Among the 166 ME/CFS participants in the study, approximately half (49%) of the ME/CFS patients reported being house-bound or bedridden due to severe symptoms of the disease. From the AIP testing, ME/CFS patients with severe, bedridden conditions displayed significant increases in gene expression of IKZF2, IKZF3, HSPA8, BACH2, ABCE1 and CD3D, as compared to patients with mild to moderate disease conditions. These six aforementioned genes were further upregulated in the 22 bedridden participants who suffer not only from ME/CFS but also from other autoimmune diseases. These genes are involved in T cell, B cell and autoimmunity functions. Furthermore, IKZF3 (Aiolos) and IKZF2 (Helios), and BACH2 have been implicated in other autoimmune diseases such as systemic lupus erythematosus (SLE) and Rheumatoid Arthritis (RA). Among the 240 participants tested with the viral assays, 9 samples showed positive results (including 1 EBV positive and 8 HHV6 positives).

Conclusions: Our study indicates that gene expression biomarkers may be used in identifying or differentiating subsets of ME/CFS patients having different levels of disease severity. These gene targets may also represent opportunities for new therapeutic modalities for the treatment of ME/CFS. The use of social media engaged patient recruitment and at-home sample collection represents a novel approach for conducting clinical research which saves cost, time and eliminates travel for office visits.

Source: Wang Z, Waldman MF, Basavanhally TJ, Jacobs AR, Lopez G, Perichon RY, Ma JJ, Mackenzie EM, Healy JB, Wang Y, Hersey SA. Autoimmune gene expression profiling of fingerstick whole blood in Chronic Fatigue Syndrome. J Transl Med. 2022 Oct 25;20(1):486. doi: 10.1186/s12967-022-03682-3. PMID: 36284352; PMCID: PMC9592873.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9592873/ (Full study)

Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease that is mainly diagnosed based on its clinical symptoms. Biomarkers that could facilitate the diagnosis of ME/CFS are not yet available; therefore, reliable and clinically useful disease indicators are of high importance. The aim of this work was to analyze the association between ME/CFS clinical course severity, presence of HHV-6A/B infection markers, and plasma levels of autoantibodies against adrenergic and muscarinic acetylcholine receptors.

A total of 134 patients with ME/CFS and 33 healthy controls were analyzed for the presence of HHV-6A/B using PCRs, and antibodies against beta2-adrenergic receptors (β2AdR) and muscarinic acetylcholine receptors (M3 AChR and M4 AChR) using ELISAs. HHV-6A/B U3 genomic sequence in whole-blood DNA was detected in 19/31 patients with severe ME/CFS, in 18/73 moderate ME/CFS cases, and in 7/30 mild ME/CFS cases. Severity-related differences were found among those with a virus load of more than 1,000 copies/106 PBMCs.

Although no disease severity-related differences in anti-β2AdR levels were observed in ME/CFS patients, the median concentration of these antibodies in plasma samples of ME/CFS patients was 1.4 ng/ml, while in healthy controls, it was 0.81 ng/ml, with a statistically significant increased level in those with ME/CFS (p = 0.0103). A significant difference of antibodies against M4 AChR median concentration was found between ME/CFS patients (8.15 ng/ml) and healthy controls (6.45 ng/ml) (p = 0.0250). The levels of anti-M4 plotted against disease severity did not show any difference; however, increased viral load correlates with the increase in anti-M4 level.

ME/CFS patients with high HHV-6 load have a more severe course of the disease, thus confirming that the severity of the disease depends on the viral load—the course of the disease is more severe with a higher viral load. An increase in anti-M4 AchR and anti-β2AdR levels is detected in all ME/CFS patient groups in comparison to the control group not depending on ME/CFS clinical course severity. However, the increase in HHV-6 load correlates with the increase in anti-M4 level, and the increase in anti-M4 level, in turn, is associated with the increase in anti-β2AdR level. Elevated levels of antibodies against β2AdR and M4 receptors in ME/CFS patients support their usage as clinical biomarkers in the diagnostic algorithm of ME/CFS.

Source: Gravelsina S, Vilmane A, Svirskis S, Rasa-Dzelzkaleja S, Nora-Krukle Z, Vecvagare K, Krumina A, Leineman I, Shoenfeld Y and Murovska M (2022) Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome. Front. Immunol. 13:928945. doi: 10.3389/fimmu.2022.928945 https://www.frontiersin.org/articles/10.3389/fimmu.2022.928945/full (Full text)

Post-COVID-19 syndrome: retinal microcirculation as a potential marker for chronic fatigue

Abstract:

Post-COVID-19 syndrome (PCS) summarizes persisting sequelae after infection with the severe-acute-respiratory-syndrome-Coronavirus-2 (SARS-CoV-2). PCS can affect patients of all covid-19 disease severities. As previous studies revealed impaired blood flow as a provoking factor for triggering PCS, it was the aim of the present study to investigate a potential association of self-reported chronic fatigue and retinal microcirculation in patients with PCS, potentially indicating an objective biomarker.

A prospective study was performed, including 201 subjects: 173 patients with PCS and 28 controls. Retinal microcirculation was visualized by OCT-Angiography (OCT-A) and quantified by the Erlangen-Angio-Tool as macula and peripapillary vessel density (VD). Chronic Fatigue (CF) was assessed with the variables ‘Bell score’, age and gender. The VD in the superficial vascular plexus (SVP), intermediate capillary plexus (ICP) and deep capillary plexus (DCP) were analyzed considering the repetitions (12 times). Taking in account of such repetitions a mixed model was performed to detect possible differences in the least square means between different groups of analysis.

An age effect on VD was observed between patients and controls (p<0.0001). Gender analysis yielded that women with PCS showed lower VD levels in SVP compared to male patients (p=0.0015). The PCS patients showed significantly lower VD of ICP as compared to the controls (p=0.0001, [CI: 0.32; 1]). Moreover, considering PCS patients, the mixed model reveals a significant difference between chronic fatigue (CF) and without CF in VD of SVP (p=0.0033, [CI: -4.5; -0.92]). The model included age, gender and the variable ‘Bell score’, representing a subjective marker for CF. Consequently, the retinal microcirculation might be an objective biomarker in subjective-reported chronic fatigue of patients with PCS.

Source: Sarah Schlick, Marianna Lucio, Alexander Bartsch, Adam Skornia, Jakob Hoffmanns, Charlotte Szewczykowski, Thora Schröder, Franziska Raith, Lennart Rogge, Felix Heltmann, Michael Moritz, Lorenz Beitlich, Julia Schottenhamml, Martin Herrmann, Thomas Harrer, Marion Ganslmayer, Friedrich E. Kruse, Robert Lämmer, Christian Mardin, Bettina Hohberger. Post-COVID-19 syndrome: retinal microcirculation as a potential marker for chronic fatigue. medRxiv 2022.09.23.22280264; doi: https://doi.org/10.1101/2022.09.23.22280264 https://www.medrxiv.org/content/10.1101/2022.09.23.22280264v1.full-text (Full text)

Autoimmune Gene Expression Proling of Fingerstick Whole Blood in Chronic Fatigue Syndrome

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating condition that can lead to severe impairment of physical, psychological, cognitive, social, and occupational functions.

The cause of ME/CFS remains incompletely understood. There is no clinical diagnostic test for ME/CFS. Although many therapies have been used off-label to manage symptoms of ME/CFS, there are limited, if any, specific therapies or cure for ME/CFS.

In this study, we investigated the expression of genes specific to key immune functions, and viral infection status in ME/CFS patients with an aim of identifying biomarkers for characterization and/or treatment of the disease.

Methods: In 2021, one-hundred and sixty-six (166) patients diagnosed with ME/CFS and 83 healthy controls in the US participated in this study via a social media-based application (app). The patients and heathy volunteers consented to the study and provided self-collected finger-stick blood and first morning void urine samples from home.

RNA from the fingerstick blood was tested using DxTerity’s 51-gene autoimmune RNA expression panel (AIP). In addition, DNA from the same fingerstick blood sample was extracted to detect viral load of 4 known ME/CFS associated viruses (HHV6, HHV7, CMV and EBV) using a real-time PCR method.

Results: Among the 166 ME/CFS participants in the study, approximately half (49%) of the ME/CFS patients reported being house-bound or bedridden due to severe symptoms of the disease.

From the AIP testing, ME/CFS patients with severe, bedridden conditions displayed significant increases in gene expression of IKZF2, IKZF3, HSPA8, BACH2, ABCE1 and CD3D, as compared to 2 patients with mild to moderate disease conditions.

These six aforementioned genes were further upregulated in the 22 bedridden participants who suffer not only from ME/CFS but also from other autoimmune diseases.

These genes are involved in T cell, B cell and autoimmunity functions. Furthermore, IKZF3 (Aiolos) and IKZF2 (Helios), and BACH2 have been implicated in other autoimmune diseases such as systemic lupus erythematosus (SLE) and Rheumatoid Arthritis (RA).

Among the 240 participants tested with the viral assays, 9 samples showed positive results (including 1 EBV positive and 8 HHV6 positives).

Conclusions: Our study indicates that gene expression biomarkers may be used in identifying or differentiating subsets of ME/CFS patients having different levels of disease severity.

These gene targets may also represent opportunities for new therapeutic modalities for the treatment of ME/CFS. The use of social media engaged patient recruitment and at-home sample collection represents a novel approach for conducting clinical research which saves cost, time and eliminates travel for office visits.

Source: Zheng Wang, Michelle F. Waldman, Tara J. Basavanhally, Aviva R. Jacobs, et al. Autoimmune Gene Expression Proling of Fingerstick Whole Blood in Chronic Fatigue Syndrome. https://doi.org/10.21203/rs.3.rs-1942047/v1  (Full text)

A prospective observational study of post-COVID-19 chronic fatigue syndrome following the first pandemic wave in Germany and biomarkers associated with symptom severity

Abstract:

A subset of patients has long-lasting symptoms after mild to moderate Coronavirus disease 2019 (COVID-19). In a prospective observational cohort study, we analyze clinical and laboratory parameters in 42 post-COVID-19 syndrome patients (29 female/13 male, median age 36.5 years) with persistent moderate to severe fatigue and exertion intolerance six months following COVID-19. Further we evaluate an age- and sex-matched postinfectious non-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome cohort comparatively.

Most post-COVID-19 syndrome patients are moderately to severely impaired in daily live. 19 post-COVID-19 syndrome patients fulfill the 2003 Canadian Consensus Criteria for myalgic encephalomyelitis/chronic fatigue syndrome. Disease severity and symptom burden is similar in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome and non-COVID-19/myalgic encephalomyelitis/chronic fatigue syndrome patients. Hand grip strength is diminished in most patients compared to normal values in healthy.

Association of hand grip strength with hemoglobin, interleukin 8 and C-reactive protein in post-COVID-19 syndrome/non-myalgic encephalomyelitis/chronic fatigue syndrome and with hemoglobin, N-terminal prohormone of brain natriuretic peptide, bilirubin, and ferritin in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome may indicate low level inflammation and hypoperfusion as potential pathomechanisms.

Source: Kedor C, Freitag H, Meyer-Arndt L, Wittke K, Hanitsch LG, Zoller T, Steinbeis F, Haffke M, Rudolf G, Heidecker B, Bobbert T, Spranger J, Volk HD, Skurk C, Konietschke F, Paul F, Behrends U, Bellmann-Strobl J, Scheibenbogen C. A prospective observational study of post-COVID-19 chronic fatigue syndrome following the first pandemic wave in Germany and biomarkers associated with symptom severity. Nat Commun. 2022 Aug 30;13(1):5104. doi: 10.1038/s41467-022-32507-6. PMID: 36042189. https://www.nature.com/articles/s41467-022-32507-6 (Full text)

Diminished Cardiopulmonary Capacity During Post-Exertional Malaise

Abstract:

Reduced functional capacity and post-exertional malaise following physical activity are hallmark symptoms of Chronic Fatigue Syndrome (CFS). That these symptoms are often delayed may explain the equivocal results for clinical cardiopulmonary exercise testing with CFS patients. The reproducibility of VO2 max in healthy subjects is well documented. This may not be the case with CFS due to delayed recovery symptoms.

Purpose: To compare results from repeated exercise tests as indicators of post-exertional malaise in CFS.

Methods: Peak oxygen consumption (VO2 peak), percentage of predicted peak heart rate (HR%), and VO2 at anaerobic threshold (AT), were compared between six CFS patients and six control subjects for two maximal exercise tests separated by 24 hours.

Results: Multivariate analysis showed no significant differences between control and CFS, respectively, for test 1: VO2 peak (28.4 ± 7.2 ml/ kg/min; 26.2 ± 4.9 ml/kg/min), AT (17.5 ± 4.8 ml/kg/min; 15.0 ± 4.9 ml/ kg/min) or HR% (87.0 ± 25.4%; 94.8 ± 8.8%). However, for test 2 the CFS patients achieved significantly lower values for both VO2 peak (28.9 ± 8.0 ml/kg/min; 20.5 ± 1.8 ml/kg/min, p = 0.031) and AT (18.0 ± 5.2 ml/kg/min; 11.0 ± 3.4 ml/kg/min, p = 0.021). HR% was not significantly different (97.6 ± 27.2%; 87.8 ± 9.3%, p = 0.07). A follow-up classification analysis differentiated between CFS patients and controls with an overall accuracy of 92%.

Conclusion: In the absence of a second exercise test, the lack of any significant differences for the first test would appear to suggest no functional impairment in CFS patients. However, the results from the second test indicate the presence of a CFS related post-exertional malaise. It might be concluded then that a single exercise test is insufficient to demonstrate functional impairment in CFS patients. A second test may be necessary to document the atypical recovery response and protracted malaise unique to CFS.

Source: J. Mark Vanness, Christopher R. Snell & Staci R. Stevens (2007) Diminished Cardiopulmonary Capacity During Post-Exertional Malaise, Journal of Chronic Fatigue Syndrome, 14:2, 77-85, DOI: 10.1300/J092v14n02_07

Validity of 2-Day Cardiopulmonary Exercise Testing in Male Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Introduction: Among the main characteristics of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are effort intolerance along with a prolonged recovery from exercise and post-exertional exacerbation of ME/CFS symptoms. The gold standard for measuring the severity of physical activity intolerance is cardiopulmonary exercise testing (CPET). Multiple studies have shown that peak oxygen consumption is reduced in the majority of ME/CFS patients. A consecutive day CPET protocol has shown a difference on day 2 in ME/CFS patients in contrast to sedentary controls. Because of the low number of male ME/CFS patients in the published literature, and because of a possible gender difference in the clinical phenotype, the aim of this study was to examine whether the response to a 2-day CPET protocol in a larger sample of male ME/CFS patients was similar to that observed in females.

Methods: From 77 male patients, 25 male ME/CFS patients fulfilled the criteria of a 2-day CPET protocol for analysis. Measures of oxygen consumption (VO2), heart rate (HR), systolic and diastolic blood pressure, workload (Work), and respiratory exchange ratio (RER) were made at maximal (peak) and ventilatory threshold (VT) intensities. Data were analysed using a paired t-test.

Results: Baseline characteristics of the group were as follows. Mean age was 44 (12) years, mean BMI was 27.1 (4.4) kg/m2. Median disease duration was 10 years (IQR 7 – 13). Heart rate, systolic and diastolic blood pressure at rest and the RER did not differ significantly between CPET 1 and CPET 2. All other CPET parameters at the ventilatory threshold and maximum exercise differed significantly (p-value between <0.005 and <0.0001). All patients experienced a deterioration of performance on CPET2 as measured by the predicted and actual VO2 and workload at peak exercise and ventilatory threshold.

Conclusion: This study confirms that male ME/CFS patients have a reduction in exercise capacity in response to a consecutive day CPET. These results are similar to published results in female ME/CFS populations.

Source:

 

Repeated maximal exercise tests of peak oxygen consumption in people with myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and meta-analysis

Abstract:

Background: Repeated maximal exercise separated by 24 hours may be useful in identifying possible objective markers in people with ME/CFS that are not present in healthy controls.

Aim: We aimed to synthesise studies in which the test-to-retest (24 hours) changes in VO2 and work rate have been compared between people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and controls.

Methods: Seven databases (CINAHL, PubMed, PsycINFO, Web of Knowledge, Embase, Scopus and MEDLINE) were searched. Included studies were observational studies that assessed adults over the age of 18 years with a clinical diagnosis of ME/CFS compared to healthy controls. The methodological quality of included studies was assessed using the Systematic Appraisal of Quality for Observational Research critical appraisal framework. Data from included studies were synthesised using a random effects meta-analysis.

Results: The pooled mean decrease in peak work rate (five studies), measured at retest, was greater in ME/CFS by −8.55 (95% CI −15.38 to –1.72) W. The pooled mean decrease in work rate at anaerobic threshold (four studies) measured at retest was greater in ME/CFS by −21 (95%CI −38 to −4, tau = 9.8) W. The likelihood that a future study in a similar setting would report a difference in work rate at anaerobic threshold which would exceed a minimal clinically important difference (10 W) is 78% (95% CI 40%–91%).

Conclusion: Synthesised data indicate that people with ME/CFS demonstrate a clinically significant test–retest reduction in work rate at the anaerobic threshold when compared to apparently healthy controls.

Source: John Derek Franklin & Michael Graham (2022) Repeated maximal exercise tests of peak oxygen consumption in people with myalgic encephalomyelitis/chronic fatigue syndrome: a systematic review and meta-analysis, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2022.2108628  https://www.tandfonline.com/doi/full/10.1080/21641846.2022.2108628 (Full text)

Distinguishing features of Long COVID identified through immune profiling

Abstract:

SARS-CoV-2 infection can result in the development of a constellation of persistent sequelae following acute disease called post-acute sequelae of COVID-19 (PASC) or Long COVID. Individuals diagnosed with Long COVID frequently report unremitting fatigue, post-exertional malaise, and a variety of cognitive and autonomic dysfunctions; however, the basic biological mechanisms responsible for these debilitating symptoms are unclear. Here, 215 individuals were included in an exploratory, cross-sectional study to perform multi-dimensional immune phenotyping in conjunction with machine learning methods to identify key immunological features distinguishing Long COVID.

Marked differences were noted in specific circulating myeloid and lymphocyte populations relative to matched control groups, as well as evidence of elevated humoral responses directed against SARS-CoV-2 among participants with Long COVID. Further, unexpected increases were observed in antibody responses directed against non-SARS-CoV-2 viral pathogens, particularly Epstein-Barr virus.

Analysis of circulating immune mediators and various hormones also revealed pronounced differences, with levels of cortisol being uniformly lower among participants with Long COVID relative to matched control groups. Integration of immune phenotyping data into unbiased machine learning models identified significant distinguishing features critical in accurate classification of Long COVID, with decreased levels of cortisol being the most significant individual predictor. These findings will help guide additional studies into the pathobiology of Long COVID and may aid in the future development of objective biomarkers for Long COVID.

Source: Jon Klein, Jamie Wood, Jillian Jaycox, Peiwen Lu, Rahul M. Dhodapkar, Jeffrey R. Gehlhausen, Alexandra Tabachnikova, Laura Tabacof, Amyn A. Malik, Kathy Kamath, Kerrie Greene, Valter Silva Monteiro, Mario Pena-Hernandez, Tianyang Mao, Bornali Bhattacharjee, Takehiro Takahashi, Carolina Lucas, Julio Silva, Dayna Mccarthy, Erica Breyman, Jenna Tosto-Mancuso, Yile Dai, Emily Perotti, Koray Akduman, Tiffany Tzeng, Lan Xu, Inci Yildirim, Harlan M. Krumholz, John Shon, Ruslan Medzhitov, Saad B. Omer, David van Dijk, Aaron M. Ring, David Putrino, Akiko Iwasaki. Distinguishing features of Long COVID identified through immune profiling. medRxiv 2022.08.09.22278592; doi: https://doi.org/10.1101/2022.08.09.22278592