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)

What Long COVID investigators can learn from four decades of ME/CFS research

Abstract:

Four decades of research in the field of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) have yielded lessons that may be instructive for those devising criteria to better comprehend Post-Acute Sequelae of SARS CoV-2 Infection (PASC) and Long COVID.

For instance, substantial effort has been devoted to defining classification systems, operationalizing methods, and developing instruments with adequate reliability and validity in the ME/CFS field.

The current article provides guidelines for developing a case definition for Long COVID and discusses the significance of psychometric issues and criterion variance, including how to specify symptoms, develop thresholds, subtypes, and exclusionary conditions. ME/CFS research could enhance our knowledge of Long COVID pathophysiology, early diagnosis, prognosis, and the identification of effective treatments.

Source: Leonard A. Jason, Benjamin H. Natelson, Hector Bonilla, Zaki A. Sherif, Suzanne D. Vernon, Monica Verduzco Gutierrez, Lisa O’Brien, Emily Taylor. What Long COVID investigators can learn from four decades of ME/CFS research. Brain Behavior and Immunity Integrative, Volume 4, 2023, 100022. https://www.sciencedirect.com/science/article/pii/S2949834123000211 (Full text)

Epstein-Barr virus-acquired immunodeficiency in myalgic encephalomyelitis-Is it present in long COVID?

Abstract:

Both myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) and long COVID (LC) are characterized by similar immunological alterations, persistence of chronic viral infection, autoimmunity, chronic inflammatory state, viral reactivation, hypocortisolism, and microclot formation. They also present with similar symptoms such as asthenia, exercise intolerance, sleep disorders, cognitive dysfunction, and neurological and gastrointestinal complaints. In addition, both pathologies present Epstein-Barr virus (EBV) reactivation, indicating the possibility of this virus being the link between both pathologies.

Therefore, we propose that latency and recurrent EBV reactivation could generate an acquired immunodeficiency syndrome in three steps: first, an acquired EBV immunodeficiency develops in individuals with “weak” EBV HLA-II haplotypes, which prevents the control of latency I cells. Second, ectopic lymphoid structures with EBV latency form in different tissues (including the CNS), promoting inflammatory responses and further impairment of cell-mediated immunity.

Finally, immune exhaustion occurs due to chronic exposure to viral antigens, with consolidation of the disease. In the case of LC, prior to the first step, there is the possibility of previous SARS-CoV-2 infection in individuals with “weak” HLA-II haplotypes against this virus and/or EBV.

Source: Ruiz-Pablos M, Paiva B, Zabaleta A. Epstein-Barr virus-acquired immunodeficiency in myalgic encephalomyelitis-Is it present in long COVID? J Transl Med. 2023 Sep 17;21(1):633. doi: 10.1186/s12967-023-04515-7. PMID: 37718435. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-04515-7 (Full text)

The Potential Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Post-COVID-19 Condition: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog

Abstract:

Post-COVID-19 condition (commonly known as Long COVID) is a heterogeneous clinical condition in which Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and brain fog stand out among the different clinical symptoms and syndromes. Cerebral metabolic alterations and neuroendocrine disorders seem to constitute an important part of the pathophysiology of Post-COVID-19 condition (PCC).

Given the substantial lack of specific drugs and effective therapeutic strategies, hypothalamic phospholipid liposomes, which have been on the market for several years as adjuvant therapy for cerebral metabolic alterations resulting from neuroendocrine disorders, might represent a potential option in an overall therapeutic strategy that aims to control PCC-associated symptoms and syndromes. Their pharmacological mechanisms and clinical effects strongly support their potential effectiveness in PCC. Our initial clinical experience seems to corroborate this rationale. Further controlled clinical research is warranted in order to verify this hypothesis.

Source: Menichetti F. The Potential Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Post-COVID-19 Condition: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog. J Clin Med. 2023 Aug 23;12(17):5478. doi: 10.3390/jcm12175478. PMID: 37685544; PMCID: PMC10488182. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10488182/ (Full text)

A Scoping Review of ‘Pacing’ for Management of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Lessons Learned for the Long COVID Pandemic

Abstract:

Background Controversy over treatment for people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a barrier to appropriate treatment. Energy management or pacing is a prominent coping strategy for people with ME/CFS that involves regulating activity to avoid post exertional malaise (PEM), the worsening of symptoms after an activity. Until now, characteristics of pacing, and the effects on patients’ symptoms had not been systematically reviewed. This is problematic as the most common approach to pacing, pacing prescription, and the pooled efficacy of pacing was unknown. Collating evidence may help advise those suffering with similar symptoms, including long COVID, as practitioners would be better informed on methodological approaches to adopt, pacing implementation, and expected outcomes.

Objectives In this scoping review of the literature, we aggregated type of, and outcomes of, pacing in people with ME/CFS.

Eligibility criteria Original investigations concerning pacing were considered in participants with ME/CFS.

Sources of evidence Six electronic databases (PubMed, Scholar, ScienceDirect, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials [CENTRAL]) were searched; and websites MEPedia, Action for ME, and ME Action were also searched for grey literature.

Methods A scoping review was conducted. Review selection and characterisation was performed by two independent reviewers using pretested forms.

Results Authors reviewed 177 titles and abstracts, resulting in included 17 studies: three randomised control trials (RCTs); one uncontrolled trial; one interventional case series; one retrospective observational study; two prospective observational studies; four cross-sectional observational studies; and five cross-sectional analytical studies. Studies included variable designs, durations, and outcome measures. In terms of pacing administration, studies used educational sessions and diaries for activity monitoring. Eleven studies reported benefits of pacing, four studies reported no effect, and two studies reported a detrimental effect in comparison to the control group.

Conclusions Highly variable study designs and outcome measures, allied to poor to fair methodological quality resulted in heterogenous findings and highlights the requirement for more research examining pacing. Looking to the long COVID pandemic, future studies should be RCTs utilising objectively quantified digitised pacing, over a longer duration of examination, using the core outcome set for patient reported outcome measures.

Source: Nilihan E.M. Sanal-Hayes, Marie Mclaughlin, Lawrence D. Hayes, Jacqueline L. Mair, Jane Ormerod, David Carless, Natalie Hilliard, Rachel Meach, Joanne Ingram, Nicholas F. Sculthorpe. A Scoping Review of ‘Pacing’ for Management of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Lessons Learned for the Long COVID Pandemic. medRxiv 2023.08.10.23293935; doi: https://doi.org/10.1101/2023.08.10.23293935 https://www.medrxiv.org/content/10.1101/2023.08.10.23293935v1.full-text (Full text)

The importance of estimating prevalence of ME/CFS in future epidemiological studies of long COVID

Abstract:

The resolution of the COVID-19 pandemic is giving rise to another public health challenge due to the explosion of long COVID (LC) cases. In many cases, LC results in persistent fatigue, post-exertional malaise (PEM), and other debilitating symptoms that resemble the clinical manifestation of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). The similarity of these two diseases suggests that future epidemiological studies of LC could take the opportunity to also estimate the prevalence of ME/CFS at a minimal cost.

With this opportunity in mind, we revisited the most consensual case definitions of ME/CFS for research purposes. We then compared the symptoms assessed at the participants’ enrollment in the UK ME/CFS Biobank with those documented in three systematic reviews encompassing hundreds of LC epidemiological studies. We found that published epidemiological studies of LC did not consistently assess or report the prevalence of PEM, which is a compulsory symptom for ME/CFS diagnosis. However, these studies assessed many neuro-cognitive, immunologic, and autonomic symptoms.

In this scenario, we recommend that the estimation of ME/CFS prevalence in the context of LC epidemiology is easily achievable by deploying tested and validated diagnosis tools used in ME/CFS. The knowledge of ME/CFS prevalence within the LC population is of cardinal importance to optimal allocation of resources and better design of healthcare interventions to manage and treat patients with this devastating disease.

Source: Anna D. Grabowska, Francisco Westermeier, Luís Nacul, Eliana Lacerda, Nuno Sepúlveda. The importance of estimating prevalence of ME/CFS in future epidemiological studies of long COVID. DOI:10.13140/RG.2.2.20997.52967 https://www.researchgate.net/publication/373043778_The_importance_of_estimating_prevalence_of_MECFS_in_future_epidemiological_studies_of_long_COVID (Full text)

Chronic inflammation, neuroglial dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

Highlights:

  • Plasmalogens (Pls) are lipids containing a vinyl-ether bond in their glycerol backbone.
  • Pls have antioxidant properties and are important for curved membrane assemblies.
  • Post-COVID-19 symptoms are highly prevalent and share several features with ME/CFS.
  • Pls depletion is a shared biological hallmark of ME/CFS and acute COVID-19 syndrome.
  • Pls replacement is a promising tool against neuroinflammation in these two conditions.

Abstract:

After five waves of coronavirus disease 2019 (COVID-19) outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties (“brain fog”), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions.

Of great interest, recent evidence revealed a significant reduction of plasmalogen contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms.

Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

Source: Adriano Maia Chaves-Filho, Olivia Braniff, Angelina Angelova, Yuru Deng, Marie-Ève Tremblay. Chronic inflammation, neuroglial dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome. Brain Research Bulletin, Volume 201, September 2023, 110702. https://www.sciencedirect.com/science/article/pii/S0361923023001272 (Full text)

Long COVID, POTS, CFS and MTHFR: Linked by Biochemistry and Nutrition

Abstract:

The recent pandemic has energized research spotlighting chronic fatigue disorders. The similarities between Long COVID (LC) and Chronic Fatigue Syndrome (CFS), often accompanied by postural orthostatic tachycardia syndrome (POTS) are striking.

Furthermore, the majority afflicted with LC and CFS may be those with methylenetetrahydrofolate reductase (MTHFR) polymorphisms, present in the majority of Americans and characterized by hypomethylation. Elevated homocysteine (Hcy) and depressed B9 and B12 may be links. Speculation about an association between these laboratory analytes and MTHFR abnormalities has been previously reported (Regland et al., 2015).

The absence of a blood-brain barrier (BBB) in CNS circumventricular organs (CVOs) that control autonomic and neuroendocrine functions, problematic in LC, CFS, POTS, and MTHFR, is provocative. Diffusion of CNS Hcy is associated with brain fog, cognitive impairment, and dementia. This provides a distinct link between MTHFR variants and the fog of LC, CFS, and POTS.

Small intestine bacterial overgrowth (SIBO), present in about 17% of Americans, is linked to POTS, mast cell activation syndrome (MCAS), and Ehlers Danlos syndrome (EDS). All exhibit histamine intolerance and female predominance. This may be due to hypomethylation and/or intestinal diamine oxidase (DAO) deficiency.

Metabolism of monoamines and histamine requires methylation. Specific CNS nuclei in CVOs may also provide insight to the POTS paradox. The similar gut microbiomes of LC/CFS (and vitamin D deficiency) may via CVOs trigger an imbalance in glutamate/GABA neurotransmission that translates to neuroendocrine and baroreflex dysfunction. Homozygosity for the MTHFR 677T allele can facilitate hypermethylation via an alternative “rescue” riboflavin pathway triggered by significant Hcy increase.

Hypermethylation predominates in Long Covid. The primary problem in these syndromes is compromised mitochondrial function due to oxidative stress induced by an antioxidant shortfall.

Victims are also frequently deficient in 25(OH)D3 (the storage form of vitamin D), magnesium, and B vitamins, consumed by the persistent chronic inflammatory state. Estrogen increases histamine, norepinephrine, and bradykinin (BKN), which may in part explain the brain fog and its predilection for females.

Source: Patrick W Chambers. Long COVID, POTS, CFS and MTHFR: Linked by Biochemistry and Nutrition. Journal of Orthomolecular Medicine. 38. https://www.researchgate.net/publication/373073968_Long_Covid_POTS_CFS_and_MTHFR_Linked_by_Biochemistry_and_Nutrition#fullTextFileContent (Full text)

Long-term symptom severity and clinical biomarkers in post-COVID-19/chronic fatigue syndrome: results from a prospective observational cohort

Summary:

Background: Post-COVID-19 syndrome (PCS) is characterised by a wide range of symptoms, primarily fatigue and exertion intolerance. While disease courses in the early months post-infection have been well-described, the long-term health consequences for patients with PCS with disabling fatigue remain unclear.

Methods: In this prospective observational cohort study, we evaluated symptom severity and various biomarkers, including hand grip strength (HGS), cardiovascular function, and laboratory parameters, in 106 patients with PCS with moderate to severe fatigue and exertion intolerance at three time points after infection (3–8, 9–16, and 17–20 months). The study was conducted at the Charité’s Fatigue Centre and the Charité’s outpatient clinic for neuroimmunology at Berlin, Germany from July 16, 2020, to February 18, 2022. A subset of patients (PCS-ME/CFS) met the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome according to the Canadian Consensus Criteria (CCC). The aim was to determine differences in the disease course between the two patient groups (i.e., PCS vs PCS-ME/CFS) and identify correlating biomarkers.

Findings: Patients with PCS-ME/CFS reported persistently high severity of most symptoms up to 20 months after infection, while patients with PCS showed overall health improvement. Although fatigue and post-exertional malaise (PEM), hallmarks of post-infectious fatigue syndromes, were still evident in both groups, they remained more pronounced in PCS-ME/CFS. Inflammatory biomarkers decreased in both groups, but not antinuclear antibodies. Lower HGS at onset correlated with symptom persistence, particularly in patients with PCS-ME/CFS.

Interpretation: Our findings suggest that PCS can persist beyond 20 months post-infection and encompass the full scope of post-infectious ME/CFS as defined by the CCC. Sub-classifying patients with PCS based on the CCC can assist in the management and monitoring of patients with PCS-ME/CFS due to their persistently higher symptom severity.

Source: Franziska Legler, Lil Meyer-Arndt, Lukas Mödl, Claudia Kedor, Helma Freitag, Elisa Stein, Uta Hoppmann, Rebekka Rust, Kirsten Wittke, Nadja Siebert, Janina Behrens, Andreas Thiel, Frank Konietschke, Friedemann Paul, Carmen Scheibenbogen, Judith Bellmann-Strobl,
Long-term symptom severity and clinical biomarkers in post-COVID-19/chronic fatigue syndrome: results from a prospective observational cohort, eClinicalMedicine, Volume 63, 2023, 102146, ISSN 2589-5370, https://doi.org/10.1016/j.eclinm.2023.102146. https://www.sciencedirect.com/science/article/pii/S2589537023003231 (Full text)

Longterm course of neuropsychological symptoms and ME/CFS after SARS-CoV-2-infection: a prospective registry study

Abstract:

A significant proportion of patients after SARS-CoV-2 infection suffer from long-lasting symptoms. Although many different symptoms are described, the majority of patients complains about neuropsychological symptoms. Additionally, a subgroup of patients fulfills diagnostic criteria for ME/CFS. We analyzed a registry of all patients presenting in the out-patients clinic at a German university center. For patients with more than one visit, changes in reported symptoms from first to second visit were analyzed.

A total of 1022 patients were included in the study, 411 of them had more than one visit. 95.5% of the patients reported a polysymptomatic disease. At the first visit 31.3% of the patients fulfilled ME/CFS criteria after a median time of 255 days post infection and and at the second visit after a median of 402 days, 19.4% still suffered from ME/CFS. Self-reported fatigue (83.7-72.7%) and concentration impairment (66.2-57.9%) decreased from first to second visit contrasting non-significant changes in the structured screening.

A significant proportion of SARS-CoV-2 survivors presenting with ongoing symptoms present with ME/CFS. Although the proportion of subjective reported symptoms and their severity reduce over time, a significant proportion of patients suffer from long-lasting symptoms necessitating new therapeutic concepts.

Source: Reuken PA, Besteher B, Finke K, Fischer A, Holl A, Katzer K, Lehmann-Pohl K, Lemhöfer C, Nowka M, Puta C, Walter M, Weißenborn C, Stallmach A. Longterm course of neuropsychological symptoms and ME/CFS after SARS-CoV-2-infection: a prospective registry study. Eur Arch Psychiatry Clin Neurosci. 2023 Aug 16. doi: 10.1007/s00406-023-01661-3. Epub ahead of print. PMID: 37587244. https://link.springer.com/article/10.1007/s00406-023-01661-3 (Full text)