Data-independent LC-MS/MS analysis of ME/CFS plasma reveals a dysregulated coagulation system, endothelial dysfunction, downregulation of complement machinery

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic condition that is characterized by unresolved fatigue, post-exertion symptom exacerbation (PESE), cognitive dysfunction, orthostatic intolerance, and other symptoms. ME/CFS lacks established clinical biomarkers and requires further elucidation of disease mechanisms.

A growing number of studies demonstrate signs of hematological and cardiovascular pathology in ME/CFS cohorts, including hyperactivated platelets, endothelial dysfunction, vascular dysregulation, and anomalous clotting processes. To build on these findings, and to identify potential biomarkers that can be related to pathophysiology, we measured differences in protein expression in platelet-poor plasma (PPP) samples from 15 ME/CFS study participants and 10 controls not previously infected with SARS-CoV-2, using DIA LC-MS/MS.

We identified 24 proteins that are significantly increased in the ME/CFS group compared to the controls, and 21 proteins that are significantly downregulated. Proteins related to clotting processes – thrombospondin-1 (important in platelet activation), platelet factor 4, and protein S – were differentially expressed in the ME/CFS group, suggestive of a dysregulated coagulation system and abnormal endothelial function. Complement machinery was also significantly downregulated, including C9 which forms part of the membrane attack complex. Additionally, we identified a significant upregulation of lactotransferrin, protein S100-A9, and an immunoglobulin variant.

The findings from this experiment further implicate the coagulation and immune system in ME/CFS, and bring to attention the pathology of or imposed on the endothelium. This study highlights potential systems and proteins that require further research with regards to their contribution to the pathogenesis of ME/CFS, symptom manifestation, and biomarker potential, and also gives insight into the hematological and cardiovascular risk for ME/CFS individuals affected by diabetes mellitus.

Source: Nunes, M., Vlok, M., Proal, A. et al. Data-independent LC-MS/MS analysis of ME/CFS plasma reveals a dysregulated coagulation system, endothelial dysfunction, downregulation of complement machinery. Cardiovasc Diabetol 23, 254 (2024). https://doi.org/10.1186/s12933-024-02315-x https://cardiab.biomedcentral.com/articles/10.1186/s12933-024-02315-x (Full text)

Neuroinflammation in post-acute sequelae of COVID-19 (PASC) as assessed by [11C]PBR28 PET correlates with vascular disease measures

Abstract:

The COVID-19 pandemic caused by SARS-CoV-2 has triggered a consequential public health crisis of post-acute sequelae of COVID-19 (PASC), sometimes referred to as long COVID. The mechanisms of the heterogeneous persistent symptoms and signs that comprise PASC are under investigation, and several studies have pointed to the central nervous and vascular systems as being potential sites of dysfunction.

In the current study, we recruited individuals with PASC with diverse symptoms, and examined the relationship between neuroinflammation and circulating markers of vascular dysfunction. We used [11C]PBR28 PET neuroimaging, a marker of neuroinflammation, to compare 12 PASC individuals versus 43 normative healthy controls.

We found significantly increased neuroinflammation in PASC versus controls across a wide swath of brain regions including midcingulate and anterior cingulate cortex, corpus callosum, thalamus, basal ganglia, and at the boundaries of ventricles. We also collected and analyzed peripheral blood plasma from the PASC individuals and found significant positive correlations between neuroinflammation and several circulating analytes related to vascular dysfunction.

These results suggest that an interaction between neuroinflammation and vascular health may contribute to common symptoms of PASC.

Source: Michael B VanElzakkerHannah F BuesLudovica BrusaferriMinhae KimDeena SaadiEva-Maria RataiDarin D DoughertyMarco L Loggia. Neuroinflammation in post-acute sequelae of COVID-19 (PASC) as assessed by [11C]PBR28 PET correlates with vascular disease measures. https://www.biorxiv.org/content/10.1101/2023.10.19.563117v1 (Full text available as PDF file)

A Molecular Biomarker-Based Triage Approach for Targeted Treatment of Post-COVID-19 Syndrome Patients with Persistent Neurological or Neuropsychiatric Symptoms

Abstract:

Approximately 30% of COVID-19 cases may experience chronic symptoms, known as post-COVID-19 syndrome (PCS). Common PCS symptoms can include fatigue, cognitive impairment, and persistent physical, neurological, and neuropsychiatric complaints.

To improve healthcare and management of the current and future pandemics, we highlight the need for establishing interdisciplinary post-viral outpatient clinics comprised of specialists in fields such as psychiatry, psychotherapy, neurology, cardiology, pneumology, and immunology. In this way, PCS patients with a high health burden can receive modern diagnostics and targeted therapeutic recommendations. A key objective is to distinguish the “sick recovered” from the “healthy recovered.”

Our hypothesis is that there is a PCS subgroup with autoimmune-mediated systemic and brain-vascular dysregulation, which may lead to circulatory disorders, fatigue, cognitive impairment, depression, and anxiety. This can be clarified using a combination of specific antibody diagnostics and precise clinical, psychological, and apparative testing.

Source: Guest PC, Neyazi A, Braun-Dullaeus RC, Müller P, Schreiber J, Haghikia A, Vasilevska V, Steiner J. A Molecular Biomarker-Based Triage Approach for Targeted Treatment of Post-COVID-19 Syndrome Patients with Persistent Neurological or Neuropsychiatric Symptoms. Adv Exp Med Biol. 2023;1412:97-115. doi: 10.1007/978-3-031-28012-2_5. PMID: 37378763. https://pubmed.ncbi.nlm.nih.gov/37378763/

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Comorbidities: Linked by Vascular Pathomechanisms and Vasoactive Mediators?

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is often associated with various other syndromes or conditions including mast cell activation (MCA), dysmenorrhea and endometriosis, postural tachycardia (POTS) and small fiber neuropathy (SFN). The causes of these syndromes and the reason for their frequent association are not yet fully understood.

We previously published a comprehensive hypothesis of the ME/CFS pathophysiology that explains the majority of symptoms, findings and chronicity of the disease. We wondered whether some of the identified key pathomechanisms in ME/CFS are also operative in MCA, endometriosis and dysmenorrhea, POTS, decreased cerebral blood flow and SFN, and possibly may provide clues on their causes and frequent co-occurrence.

Our analysis indeed provides strong arguments in favor of this assumption, and we conclude that the main pathomechanisms responsible for this association are excessive generation and spillover into the systemic circulation of inflammatory and vasoactive tissue mediators, dysfunctional β2AdR, and the mutual triggering of symptomatology and disease initiation. Overall, vascular dysfunction appears to be a strong common denominator in these linkages.

Source: Wirth KJ, Löhn M. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Comorbidities: Linked by Vascular Pathomechanisms and Vasoactive Mediators? Medicina. 2023; 59(5):978. https://doi.org/10.3390/medicina59050978  https://www.mdpi.com/1648-9144/59/5/978 (Full text)