Immune cell proteomes of Long COVID patients have functional changes similar to those in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Of those infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ~ 10% develop the chronic post-viral debilitating condition, Long COVID (LC). Although LC is a heterogeneous condition, about half of cases have a typical post-viral fatigue condition with onset and symptoms that are very similar to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). A key question is whether these conditions are closely related.

ME/CFS is a post-stressor fatigue condition that arises from multiple triggers. To investigate the pathophysiology of LC, a pilot study of patients and healthy controls has used quantitative proteomics to discover changes in peripheral blood mononuclear cell (PBMC) proteins. A principal component analysis separated all Long COVID patients from healthy controls.

Analysis of 3131 proteins identified 162 proteins differentially regulated, of which 37 were related to immune functions, and 21 to mitochondrial functions. Markov cluster analysis identified clusters involved in immune system processes, and two aspects of gene expression-spliceosome and transcription. These results were compared with an earlier dataset of 346 differentially regulated proteins in PBMC’s from ME/CFS patients analysed by the same methodology.

There were overlapping protein clusters and enriched molecular pathways particularly in immune functions, suggesting the two conditions have similar immune pathophysiology as a prominent feature, and mitochondrial functions involved in energy production were affected in both conditions.

Source: Katie Peppercorn, Christina D. Edgar, Torsten Kleffmann, Warren. P Tate. Immune cell proteomes of Long COVID patients have functional changes similar to those in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Research Square preprint https://doi.org/10.21203/rs.3.rs-3335919/v1 https://www.researchsquare.com/article/rs-3335919/v1 (Full text) https://www.nature.com/articles/s41598-023-49402-9 (Final 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)

Healthcare system barriers impacting the care of Canadians with myalgic encephalomyelitis: a scoping review

Abstract:

Background: Myalgic encephalomyelitis (ME, also known as chronic fatigue syndrome or ME/CFS) is a debilitating, complex, multi-system illness. Developing a comprehensive understanding of the multiple and interconnected barriers to optimal care will help advance strategies and care models to improve quality of life for people living with ME in Canada.

Objectives: To: (1) identify and systematically map the available evidence; (2) investigate the design and conduct of research; (3) identify and categorize key characteristics; and (4) identify and analyze knowledge gaps related to healthcare system barriers for people living with ME in Canada.

Methods: The protocol was preregistered in July 2022. Peer-reviewed and grey literature was searched, and patient partners retrieved additional records. Eligible records were Canadian, included people with ME/CFS and included data or synthesis relevant to healthcare system barriers.

Results: In total, 1821 records were identified, 406 were reviewed in full, and 21 were included. Healthcare system barriers arose from an underlying lack of consensus and research on ME and ME care; the impact of long-standing stigma, disbelief, and sexism; inadequate or inconsistent healthcare provider education and training on ME; and the heterogeneity of care coordinated by family physicians.

Conclusions: People living with ME in Canada face significant barriers to care, though this has received relatively limited attention. This synthesis, which points to several areas for future research, can be used as a starting point for researchers, healthcare providers and decision-makers who are new to the area or encountering ME more frequently due to the COVID-19 pandemic.

Source: Said Hussein, Lauren Eiriksson, Maureen MacQuarrie, Scot Merriam, Maria Dalton, Eleanor Stein, Rosie Twomey. Healthcare system barriers impacting the care of Canadians with myalgic encephalomyelitis: a scoping review. medRxiv [Preprint] https://www.medrxiv.org/content/10.1101/2023.09.20.23295809v1.full-text (Full text)

Prevalence of Fibromyalgia and Chronic Fatigue Syndrome among Individuals with Irritable Bowel Syndrome: An Analysis of United States National Inpatient Sample Database

Abstract:

Background and Aim: Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder associated with other somatic disorders. We studied the prevalence and predictors of fibromyalgia and chronic fatigue syndrome (CFS) in IBS patients.
Methods: We used the National Inpatient Sample and included hospitalization of individuals with IBS, using ICD-10 codes, from 2016–2019. The prevalence and predictors of fibromyalgia and CFS in IBS patients were studied. Univariate and multivariate patient- and hospital-level regression models were used to calculate the adjusted odds of fibromyalgia and CFS in the IBS patient population.
Results: Of 1,256,325 patients with an ICD-10 code of IBS included in the study, 10.73% (134,890) also had ICD-10 codes for fibromyalgia and 0.42% (5220) for CFS. The prevalence of fibromyalgia and CFS was significantly higher in IBS patients (adjusted odds ratio (AOR) 5.33, 95% confidence interval (CI) 5.24–5.41, p < 0.001, and AOR 5.40, 95% CI 5.04–5.78, p < 0.001, respectively) compared to the general adult population without IBS. IBS-diarrhea, IBS-constipation, and IBS-mixed types were independently associated with increased odds of fibromyalgia and CFS. Increasing age (AOR 1.02, 95% CI 1.01–1.04, p 0.003; AOR 1.02, 95% CI 1.01–1.03, p 0.001), female gender (AOR 11.2, 95% CI 11.1–11.4, p < 0.001; AOR 1.86, 95% CI 1.78–1.93, p < 0.001) and white race (AOR 2.04, 95% CI 1.95–2.12, p < 0.001; AOR 1.69, 95% CI 1.34–2.13, p < 0.001) were independent predictors of increased odds of fibromyalgia and CFS, respectively.
Conclusions: It appears that IBS is associated with an increased prevalence of somatic disorders such as fibromyalgia and CFS.
Source: Tarar ZI, Farooq U, Nawaz A, Gandhi M, Ghouri YA, Bhatt A, Cash BD. Prevalence of Fibromyalgia and Chronic Fatigue Syndrome among Individuals with Irritable Bowel Syndrome: An Analysis of United States National Inpatient Sample Database. Biomedicines. 2023; 11(10):2594. https://doi.org/10.3390/biomedicines11102594 https://www.mdpi.com/2227-9059/11/10/2594 (Full text)

Bayesian Statistics Improves Biological Interpretability of Metabolomics Data from Human Cohorts

Abstract:

Univariate analyses of metabolomics data currently follow a frequentist approach, using p-values to reject a null hypothesis. We here propose the use of Bayesian statistics to quantify evidence supporting different hypotheses and discriminate between the null hypothesis versus the lack of statistical power.

We used metabolomics data from three independent human cohorts that studied the plasma signatures of subjects with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The data are publicly available, covering 84-197 subjects in each study with 562-888 identified metabolites of which 777 were common between the two studies and 93 were compounds reported in all three studies. We show how Bayesian statistics incorporates results from one study as “prior information” into the next study, thereby improving the overall assessment of the likelihood of finding specific differences between plasma metabolite levels.

Using classic statistics and Benjamini-Hochberg FDR-corrections, Study 1 detected 18 metabolic differences and Study 2 detected no differences. Using Bayesian statistics on the same data, we found a high likelihood that 97 compounds were altered in concentration in Study 2, after using the results of Study 1 as the prior distributions. These findings included lower levels of peroxisome-produced ether-lipids, higher levels of long-chain unsaturated triacylglycerides, and the presence of exposome compounds that are explained by the difference in diet and medication between healthy subjects and ME/CFS patients.

Although Study 3 reported only 92 compounds in common with the other two studies, these major differences were confirmed. We also found that prostaglandin F2alpha, a lipid mediator of physiological relevance, was reduced in ME/CFS patients across all three studies. The use of Bayesian statistics led to biological conclusions from metabolomic data that were not found through frequentist approaches. We propose that Bayesian statistics is highly useful for studies with similar research designs if similar metabolomic assays are used.

Source: Brydges C, Che X, Lipkin WI, Fiehn O. Bayesian Statistics Improves Biological Interpretability of Metabolomics Data from Human Cohorts. Metabolites. 2023 Aug 31;13(9):984. doi: 10.3390/metabo13090984. PMID: 37755264; PMCID: PMC10535181. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10535181/ (Full text)

Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome – State of the art: Report of the 2nd international meeting at the Charité fatigue center

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a devastating disease affecting millions of people worldwide. Due to the 2019 pandemic of coronavirus disease (COVID-19), we are facing a significant increase of ME/CFS prevalence. On May 11th to 12th, 2023, the second international ME/CFS conference of the Charité Fatigue Center was held in Berlin, Germany, focusing on pathomechanisms, diagnosis, and treatment.

During the two-day conference, more than 100 researchers from various research fields met on-site and over 700 attendees participated online to discuss the state of the art and novel findings in this field. Key topics from the conference included: the role of the immune system, dysfunction of endothelial and autonomic nervous system, and viral reactivation. Furthermore, there were presentations on innovative diagnostic measures and assessments for this complex disease, cutting-edge treatment approaches, and clinical studies.

Despite the increased public attention due to the COVID-19 pandemic, the subsequent rise of Long COVID-19 cases, and the rise of funding opportunities to unravel the pathomechanisms underlying ME/CFS, this severe disease remains highly underresearched. Future adequately funded research efforts are needed to further explore the disease etiology and to identify diagnostic markers and targeted therapies.

Source: Steiner S, Fehrer A, Hoheisel F, Schoening S, Aschenbrenner A, Babel N, Bellmann-Strobl J, Finke C, Fluge Ø, Froehlich L, Goebel A, Grande B, Haas JP, Hohberger B, Jason LA, Komaroff AL, Lacerda E, Liebl M, Maier A, Mella O, Nacul L, Paul F, Prusty BK, Puta C, Riemekasten G, Ries W, Rowe PC, Sawitzki B, Shoenfeld Y, Schultze JL, Seifert M, Sepúlveda N, Sotzny F, Stein E, Stingl M, Ufer F, Veauthier C, Westermeier F, Wirth K, Wolfarth B, Zalewski P, Behrends U, Scheibenbogen C. Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome – State of the art: Report of the 2nd international meeting at the Charité fatigue center. Autoimmun Rev. 2023 Sep 22:103452. doi: 10.1016/j.autrev.2023.103452. Epub ahead of print. PMID: 37742748. https://www.sciencedirect.com/science/article/abs/pii/S1568997223001866

Long-term health outcomes of Q-fever fatigue syndrome patients

Summary:

This study determined long-term health outcomes (≥10 years) of Q-fever fatigue syndrome (QFS). Longterm health complaints, health-related quality of life (HRQL), health status, energy level, fatigue, post exertional malaise, anxiety and depression were assessed. Outcomes and determinants were studied for the total sample and compared among age subgroups: young (<40y), middle-aged (≥40-<65y), and older
(≥65y) patients.

368 QFS patients were included. Participants reported a median number of 12.0 long-term health complaints. Their HRQL (median EQ-5D-5L index: 0.63) and health status (median EQ VAS: 50.0) were low, their level of fatigue was high, and many experienced post-exertional malaise complaints (98.9%). Young and middle-aged patients reported worse health outcomes compared to older patients, with both groups reporting a significantly worse health status, higher fatigue levels and anxiety, and more post-exertional malaise complaints; and middle-aged patients having a lower HRQL and a higher risk of depression.

Multivariate regression analyses confirmed that older age is associated with better outcomes, except for the number of health complaints. QFS has thus a considerable impact on patients’ health more than 10 years after infection. Young and middle-aged patients experience more long-term health consequences compared to older patients. Tailored healthcare is recommended to provide optimal care for each QFS patient.

Source: Spronk, I., Brus, I., Groot, A., Tieleman, P., Olde Loohuis, A., Haagsma, J., & Polinder, S. (2023). Long-term health outcomes of Q-fever fatigue syndrome patients. Epidemiology & Infection, 1-35. doi:10.1017/S0950268823001401 https://www.cambridge.org/core/journals/epidemiology-and-infection/article/longterm-health-outcomes-of-qfever-fatigue-syndrome-patients/99B3D80E172A66619C216506E020BB02 (Full text available as PDF file)

Bone marrow alterations in COVID-19 infection: The root of hematological problems

Abstract:

Introduction: The 2019 coronavirus disease (COVID-19) is a respiratory infection caused by the SARS-CoV-2 virus with a significant impact on the hematopoietic system and homeostasis. The effect of the virus on blood cells indicates the involvement of the bone marrow (BM) as the place of production and maturation of these cells by the virus and it reminds the necessity of investigating the effect of the virus on the bone marrow.

Method: To investigate the effects of COVID-19 infection in BM, we reviewed literature from the Google Scholar search engine and PubMed database up to 2022 using the terms “COVID-19; SARS-CoV-2; Bone marrow; Thrombocytopenia; HemophagocytosisPancytopenia and Thrombocytopenia.

Results: Infection with the SARS-CoV-2 virus is accompanied by alterations such as single-line cytopenia, pancytopenia, hemophagocytosis, and BM necrosis. The presence of factors such as cytokine release syndrome, the direct effect of the virus on cells through different receptors, and the side effects of current treatments such as corticosteroids are some of the important mechanisms in the occurrence of these alterations.

Conclusion: To our knowledge, this review is the first study to comprehensively investigate BM alterations caused by SAR-CoV-2 virus infection. The available findings show that the significant impact of this viral infection on blood cells and the clinical consequences resulting from them are deeper than previously thought and it may be rooted in the changes that the virus causes in the BM of patients.

Source: Zeylabi F, Nameh Goshay Fard N, Parsi A, Pezeshki SMS. Bone marrow alterations in COVID-19 infection: The root of hematological problems. Curr Res Transl Med. 2023 Jul 25;71(3):103407. doi: 10.1016/j.retram.2023.103407. Epub ahead of print. PMID: 37544028. https://www.sciencedirect.com/science/article/abs/pii/S2452318623000314 (Full text)

Association Between Chronic Fatigue Syndrome/Myalgic Encephalomyelitis and Cardiovascular Disease

Abstract:

Background: Chronic Fatigue Syndrome or Myalgic Encephalomyelitis (CFS/ME) is a medical condition characterized by severe and prolonged fatigue that is not relieved by rest or attributed to any underlying medical or psychological condition. Individuals with CFS/ME are considered to have an increased risk of a wide range of comorbid conditions, including cardiovascular disease (CVD). The association between CFS/ME and CVD is not fully understood.

Objective: To determine the prevalence of CFS/ME in a sample population and examine its association with CVD.

Methods: Data was analyzed from the 2021 National Health Interview Survey (NHIS). Information on sociodemographic factors, CVD risk factors, and history of CFS/ME and CVD were collected. Multivariate logistic regression model was used to determine the association between CFS/ME and CVD, adjusting for traditional CVD risk factors (age, sex, race, hypertension, diabetes, dyslipidemia, smoking, and body mass index (BMI).

Results: Median age of participants was 53 years, and majority of participants were female (53.9%). Prevalence of CFS/ME was 1.4%. A history of CFS/ME was significantly associated with CVD (aOR: 3.13, 95%CI: 2.37, 4.15, p-value: <0.001) after adjusting for traditional CVD risk factors.

Conclusion: A history of CFS/ME was independently associated with CVD after adjusting for traditional CVD risk factors. Patients with CFS/ME need close evaluation for CVD. Further studies are needed to better understand the relationship between CFS/ME and CVD.

Source: Mawulorm KI Denu, Ritika Revoori, Cherita Eghan, Fredrick Larbi Kwapong, Andrew Hillman, Cornelius A Normeshie, Kofi Poku Berko, Emily L. Aidoo. Association Between Chronic Fatigue Syndrome/Myalgic Encephalomyelitis and Cardiovascular Disease. BMC Archives of Publis Health. https://doi.org/10.21203/rs.3.rs-3332913/v1 (Full text)

Long COVID: Clinical Findings, Pathology, and Endothelial Molecular Mechanisms

Abstract:

Persistence of COVID-19 symptoms may follow SARS-CoV-2 infection. The incidence of long COVID increases with the severity of acute disease, but even mild disease can be associated with sequelae. The symptoms vary widely with fatigue, shortness of breath, and cognitive dysfunction being the most common. Abnormalities of multiple organs have been documented and histopathology has revealed widespread microthrombi. Elevated levels of complement are present in acute COVID-19 patients and may persist at lower levels in long COVID. Evidence supports complement activation with endotheliopathy associated disease as the molecular mechanism causing both acute and long COVID.

Section snippets

Prevalence and Definition: A review and meta-analysis of published results of long COVID studies suggest a global prevalence of the post COVID-19 condition of approximately 43% with a wide range of 9-81%.1 Using a population-representative survey epidemiologists have estimated the prevalence of long COVID in the United States to be 7.3%.2 In an effort to standardize the definition of long COVID the World Health Organization (WHO) established a Clinical Case Definition Working Group on the Post-COVID-19 Condition.3

Symptoms: The symptoms of long COVID are similar to those observed in patients following chronic critical illness and hospitalization in intensive care units.4 In the United Kingdom a retrospective matched cohort study was undertaken to determine symptoms beyond 12 weeks in non-hospitalized SARS-CoV-2 infected patients compared with uninfected patients.5 A cohort of 486,149 non-hospitalized adults with confirmed SARS-CoV-2 infection was compared to 1,944,580 propensity score-matched adults with no record

Evaluation and Testing: The previously referenced study of COVID patients 6 months after discharge from hospital in Wuhan, China enrolled patients in radiographic, pulmonary function, and blood testing.7 High resolution computerized tomography (HRCT) was performed on 390 patients and was abnormal in 52% not requiring supplemental oxygen and 54% of patients requiring supplemental oxygen. Lung diffusion impairment was noted in 22% of patients not requiring oxygen and up to 56% of patients requiring supplemental oxygen

Pathology and Histopathology: Autopsy data has contributed considerable information to our understanding of SARS-CoV-2 infection. A review of the histopathological findings in coronavirus disease 2019 reported diffuse alveolar damage (DAD), multiple organ microvasculitis, and lymphocytic infiltration with changes in immune organs and emphasized the observance of microthrombosis in numerous studies.18 An autopsy study from New York Presbyterian Hospital revealed macroscopic and/or microscopic thrombi in 84% patients.19

Complement, von Willebrand factor, and Endotheliopathy: A prospective study in the Netherlands was conducted to examine the role of complement as a component of the innate immune response to SARS-CoV-2 infection.29 Investigators found that complement factors C3a, C3c, and the terminal complement complex or membrane attack complex (MAC) were increased in COVID-19 patients compared to healthy controls. Furthermore, these complement factors were more increased in patients who were admitted to intensive care units, died, or experienced thromboembolic

Discussion: Long COVID or post acute sequelae of COVID-19 (PASC) is a frequent occurrence in patients recovering from acute SARS-CoV-2 infection. Estimates of the incidence vary widely with the more recent estimates trending below 10% in the United States. Changes in definition, increasing population immunity, treatment with antivirals and monoclonal antibodies, and newer variants may all play a role in the downward trend. The symptoms of long COVID are numerous and reflect the multi-organ nature of both…

Conclusion: The pathology and histopathology of COVID-19 patients has demonstrated the presence of widespread multi-organ microthrombi as a central feature of SARS-CoV-2 infection. Elevated levels of complement factors and von Willebrand factor have been found in COVID-19 patients and the degree of increases are directly related to the severity of disease and persistent high levels correlate with long COVID symptoms.39 Persisting symptoms following acute COVID-19 occur more often and are more debilitating

Source: Hawley HB. Long COVID: Clinical Findings, Pathology, and Endothelial Molecular Mechanisms. Am J Med. 2023 Sep 11:S0002-9343(23)00539-9. doi: 10.1016/j.amjmed.2023.08.008. Epub ahead of print. PMID: 37704072. https://www.sciencedirect.com/science/article/abs/pii/S0002934323005399