Assessing the Coagulation System in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)
| dc.contributor.advisor | Pretorius, Resia | en_ZA |
| dc.contributor.author | Nunes, Jean Massimo | en_ZA |
| dc.contributor.other | Stellenbosch University. Faculty of Science. Dept. of Physiological Science. | en_ZA |
| dc.date.accessioned | 2025-04-04T09:13:22Z | |
| dc.date.available | 2025-04-04T09:13:22Z | |
| dc.date.issued | 2024-12 | |
| dc.description | Thesis (PhD)--Stellenbosch University, 2024. | en_ZA |
| dc.description.abstract | Introduction: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating and chronic post-viral disease that is characterized by unresolved fatigue, post-exertional symptom exacerbation (PESE), cognitive dysfunction, orthostatic intolerance, and gastrointestinal disturbances, among other symptoms. ME/CFS shares significant overlap with Long COVID (LC), the post-viral disease associated with SARS-CoV-2 infection, in both disease presentation and etiology. A prominent feature of LC pathology is a dysregulated coagulation system, characterized by anomalous clot formation, hyperactivated platelets, and microclots. In ME/CFS, the coagulation system is understudied, and hence represents a gap in knowledge. Therefore, this study aims to assess whether the clotting pathology present in LC is mirrored in ME/CFS. Methods: To assess the coagulation system in ME/CFS, 29 ME/CFS (22 females, 7 males, mean age of 45.7 ± 14.9) and 30 age- and gender-matched control (21 females, 9 males, mean age of 49.1 ± 11.3) blood samples were analyzed. Viscoelastic analysis of blood samples was conducted using thromboelastography (TEG®). Platelet activity was assessed via fluorescent microscopy and the use of two fluorescent markers specific for platelet activation markers, glycoprotein IIb/IIIa and P-selectin. Thioflavin T (ThT) was used to visualize microclots using fluorescent microscopy. Representative micrographs and ImageJ processing were used to infer, crudely, concentration values of microclots. To validate this assessment, microclot concentrations were measured by a recently established cell-free flow cytometry technique. To identify differentially expressed proteins, 15 randomly selected ME/CFS and 10 control PPP samples were subject to liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. Results: Findings from the TEG® assessment indicate that over half of the ME/CFS WB samples fell out of the standard clinical range, representative of a hypercoagulable profile. This inference is further supported by the analysis of PPP, where the greatest differences were recorded in α-angle (p=0.0006) and maximum rate to thrombus generation (p=0.0001). Roughly half of the ME/CFS cohort demonstrated platelet hyperactivity as determined by spreading, whereas only a quarter of the cohort was positive for significant platelet clumping. Using fluorescent microscopy and ImageJ software, it was inferred that the ME/CFS group contains more than 10x the levels of microclots (0.70 [11.21]) than the controls (0.06 [2.23]) (p<0.0001). Appropriate quantitative analysis with cell-free flow cytometry determined that the ME/CFS group exhibits a microclot burden 5x (27808 [107203]) that of the control group (4898 [20709]) (p<0.0001). Furthermore, ME/CFS PPP sample contain a greater prevalence of large microclots (≤100-400μm2). The proteomics analysis identified 45 differentially expressed proteins. Importantly, proteins related to clotting processes – thrombospondin-1, platelet factor 4, and protein S – were implicated. Complement machinery was also downregulated, whereas lactotransferrin and protein S100-A9 were upregulated. Conclusion: Overall, this study demonstrates that dysregulated clotting processes are an aspect of ME/CFS pathology, and that these abnormalities in coagulation are similar to that observed in LC. These findings provide further overlap between ME/CFS and LC, and has the potential to guide future research and prompt investigations into haematological pathology in ME/CFS. Importantly, 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 cardiovascular risk experienced by ME/CFS individuals. | en_ZA |
| dc.description.version | Doctoral | en_ZA |
| dc.format.extent | 204 pages | en_ZA |
| dc.identifier.uri | https://scholar.sun.ac.za/handle/10019.1/131870 | |
| dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
| dc.rights.holder | Stellenbosch University | en_ZA |
| dc.title | Assessing the Coagulation System in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) | en_ZA |
| dc.type | Thesis | en_ZA |