Question: You are an expert researcher providing comprehensive, well-cited information.
Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies
Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.
Please provide a comprehensive research report on the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Focus on the molecular and cellular mechanisms underlying disease progression.
Structure your response as a narrative that could be used to populate a disease knowledge base entry with: - Pathophysiology description - Gene/protein annotations with ontology terms (HGNC, GO) - Phenotype associations (HP terms) - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Evidence items with PMIDs
Disease: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).
Category: Complex, multisystem disorder characterized clinically by post-exertional symptom exacerbation (often termed post-exertional malaise; PEM) and heterogeneous neurological, autonomic, immune, and metabolic manifestations. Recent syntheses emphasize a multifactorial, network-like pathophysiology arising from genetic vulnerability plus environmental triggers (commonly infections) that converge on persistent immune dysregulation, autonomic dysfunction, metabolic disturbances, and (in some cohorts) vascular/endothelial and coagulation abnormalities. (arron2024myalgicencephalomyelitischronicfatigue pages 1-2, walitt2024deepphenotypingof pages 1-2)
MONDO ID: Not retrieved in the current evidence set.
A consistent theme across recent high-quality studies is chronic immune perturbation compatible with persistent antigenic stimulation.
Interpretation: Immune phenotypes span innate cytotoxic impairment (NK), adaptive exhaustion-like programs (CD8), and altered memory differentiation (B-cells). Together, these can plausibly reduce pathogen control (or promote antigen persistence), while also sustaining inflammatory signaling that couples to autonomic and metabolic dysfunction. (baraniuk2024metaanalysisofnatural pages 1-2, walitt2024deepphenotypingof pages 1-2, iu2024transcriptionalreprogrammingprimes pages 1-2)
Autonomic abnormalities are prominent in recent physiologic profiling.
Interpretation: ANS dysregulation provides a mechanistic bridge from immune/inflammatory signaling to impaired perfusion regulation, symptom flares with orthostatic or exertional stress, and downstream energy limitation. (walitt2024deepphenotypingof pages 1-2, nunes2024assessingthecoagulation pages 33-36, graves2024chronicfatiguesyndrome pages 5-7)
Multiple recent datasets implicate vascular/endothelial and coagulation biology.
Interpretation: These patterns support a model in which endothelial activation/dysfunction and platelet/coagulation signaling contribute to impaired oxygen/nutrient delivery under stress and may interact with inflammatory tone and autonomic dysregulation. Complement downregulation (e.g., C9) may reflect altered innate effector pathways or chronic immune modulation. (nunes2024dataindependentlcmsmsanalysis pages 5-7, graves2024chronicfatiguesyndrome pages 5-7)
Neurological impairment is core to patient experience (“brain fog,” cognitive dysfunction) and is increasingly probed using blood biomarkers.
Interpretation: NfL provides convergent evidence for measurable neuroaxonal injury/stress in a subset and supports integrating central nervous system involvement into mechanistic models alongside ANS and immune alterations. (azcue2024plasmaneurofilamentlight pages 1-2, walitt2024deepphenotypingof pages 1-2)
Recent reviews and multi-omic studies consistently emphasize metabolic disturbance as a contributor to exertion intolerance.
Interpretation: While the mechanistic target is not yet unified, metabolic reprogramming appears to be a downstream integrator of immune and neurovascular stressors—particularly relevant to PEM. (walitt2024deepphenotypingof pages 1-2, arron2024myalgicencephalomyelitischronicfatigue pages 1-2)
Several contemporary reviews highlight gut dysbiosis and reduced short-chain fatty acid (SCFA) production as plausible amplifiers of systemic inflammation and metabolic dysfunction, though cohort-specific causality remains unresolved in the evidence excerpts available here. (graves2024chronicfatiguesyndrome pages 4-5, graves2024chronicfatiguesyndrome pages 5-7)
A major 2024 advance is the use of rigorous case adjudication plus broad deep phenotyping to link clinical signatures (including effort preference/behavioral changes) to autonomic function, immune profiles, and multi-omic differences in post-infectious ME/CFS. Key quantitative signals include Valsalva recovery differences (p = 0.014) and an effort-choice odds ratio (OR 1.65, p = 0.04). (walitt2024deepphenotypingof pages 1-2)
The prospective pilot cohort approach combining endothelial and inflammatory markers with symptom severity measures provides a step toward stratification and differential diagnosis, including a measurable POTS proportion under standardized orthostatic testing (13% in ME/CFS). (graves2024chronicfatiguesyndrome pages 5-7)
The 2024 DIA LC-MS/MS study provides explicit protein-level effect sizes supporting platelet activation (PF4), endothelial/coagulation regulation (THBS1, PROS1), and complement attenuation (C9), generating tractable biomarkers for replication and mechanistic follow-up. (nunes2024dataindependentlcmsmsanalysis pages 5-7)
The NK cytotoxicity meta-analysis quantifies a robust innate defect across decades of literature (Hedges’ g 0.96), while multi-omic T-cell work is converging on exhaustion-like programs, especially in relation to symptom provocation (exercise). (baraniuk2024metaanalysisofnatural pages 1-2, iu2024transcriptionalreprogrammingprimes pages 1-2)
NfL elevations and correlations with cognition and parasympathetic dysfunction nominate a measurable neurological axis and a potential stratification biomarker for clinical studies. (azcue2024plasmaneurofilamentlight pages 1-2)
A randomized, placebo-controlled trial of intranasal mechanical stimulation (targeting a proposed brainstem neuro-immune interface) reported an approximately 30% reduction in overall symptom scores after 8 weeks, with immunologic correlates suggestive of reduced inflammation and increased disease tolerance programs. (rodriguez2023achievingsymptomrelief pages 1-2)
Caution: This intervention represents an experimental approach; the evidence excerpt does not establish long-term efficacy or generalizability. (rodriguez2023achievingsymptomrelief pages 1-2)
A 2024 immunology review argues for moving beyond fragmented single-mechanism explanations toward a cohesive model in which genetic predisposition plus environmental triggers (notably infections) lead to interconnected immune dysregulation, chronic inflammation, gut dysbiosis, and metabolic disturbance. (arron2024myalgicencephalomyelitischronicfatigue pages 1-2)
The same review compiles prevalence and socioeconomic burden estimates (e.g., global prevalence 0.1–0.8%; women affected 2–3×; up to 75% unable to work), reinforcing that heterogeneous phenotypes likely reflect multiple biological subtypes and/or phases—an important premise for interpreting inconsistent biomarker literature and for designing stratified studies. (arron2024myalgicencephalomyelitischronicfatigue pages 1-2)
Recent syntheses highlight potential roles for autoantibodies and miRNA dysregulation, but the evidence base remains heterogeneous and requires careful replication and phenotype definition; miRNAs repeatedly implicated across studies include miR-29c, miR-99b, miR-128, miR-374b, miR-766, and others linked to immune and mitochondrial/oxidative pathways. (tsamou2024identifyingmicrornaspossibly pages 1-2)
The following table provides a compact evidence map of recent mechanistic work and quantitative results.
| Mechanistic domain | Key finding | Study (first author, year, journal) | Cohort/sample size | Quantitative results (stats) | Molecular/cellular entities (genes/proteins/metabolites/cell types) | URL/DOI | PMID |
|---|---|---|---|---|---|---|---|
| Multisystem deep phenotyping: immune, autonomic, central catechol/neurobehavioral | Post-infectious ME/CFS showed chronic antigenic stimulation with increased naïve and decreased switched-memory B cells, autonomic abnormalities, and altered effort preference consistent with dysfunction of integrative brain regions and central catechol pathway dysregulation | Walitt, 2024, Nature Communications | 17 adjudicated PI-ME/CFS; 21 healthy volunteers; recruited from 484 inquiries and 27 in-person evaluations | Valsalva blood-pressure recovery time 4.1 ± 0.4 s vs 3.0 ± 0.2 s in controls, p = 0.014; altered effort choice OR 1.65 (95% CI 1.03–2.65), p = 0.04 | Naïve B cells, switched memory B cells, catechol pathways, PBMC gene-expression/metabolic pathways | https://doi.org/10.1038/s41467-024-45107-3 | |
| Endothelial dysfunction + inflammatory signaling | ME/CFS showed a biomarker pattern consistent with endothelial dysfunction and systemic inflammation, distinct from long COVID but overlapping in ET-1/VCAM-1 elevation and NO metabolite reduction | Domingo, 2024, Journal of Translational Medicine | 31 ME/CFS; 23 long COVID; 31 sedentary healthy controls | POTS on NASA lean test: 4/31 ME/CFS (13%), 1/23 long COVID (4%), 1/31 controls (3%); ME/CFS and long COVID had higher ET-1 (p < 0.05) and VCAM-1 (p < 0.001), lower NOx (p < 0.01); ME/CFS had higher PAI-1 and E-selectin than both comparison groups (p < 0.01); PCA PC1 82.7%, PC2 6.1%; combined biomarker classification ME/CFS vs long COVID 59% | ET-1/EDN1, VCAM1, ICAM1, SELE/E-selectin, SERPINE1/PAI-1, TNF, IL1B, IL4, IL6, IL10, CXCL10/IP-10, leptin | https://doi.org/10.1186/s12967-024-05148-0 | |
| Coagulation/endothelial/complement proteomics | Plasma proteomics implicated dysregulated coagulation, endothelial dysfunction, and complement downregulation in ME/CFS | Nunes, 2024, Cardiovascular Diabetology | 15 ME/CFS; 10 controls | 45 proteins significant at p < 0.05: 24 up, 21 down; thrombospondin-1 3.48–3.75-fold up (p ≤ 0.0002); PF4 3.11-fold up (p = 0.00009); lactotransferrin up to 8.38-fold up (p = 0.00009); protein S 0.48-fold (p = 0.0006); C9 0.17-fold (p = 0.0001); ficolin-3 ~0.45–0.65-fold (p = 0.0006–0.0348) | THBS1, PF4, PROS1, C9, FCN3, LTF, S100A9, IGHG1; platelet-poor plasma proteins | https://doi.org/10.1186/s12933-024-02315-x | |
| Neurological dysfunction / neuroaxonal injury biomarker | Elevated plasma neurofilament light chain suggested neuroaxonal injury associated with cognitive impairment and autonomic dysfunction in ME/CFS | Azcue, 2024, Biomedicines | 67 ME/CFS; 43 healthy controls | Higher plasma NfL in ME/CFS: F = 4.30, p < 0.05; correlations with visuospatial perception r = -0.42, p ≤ 0.001; verbal memory r = -0.35, p ≤ 0.005; visual memory r = -0.26, p < 0.05; parasympathetic dysfunction F = 9.48, p ≤ 0.003; NfL explained up to 17.2% of cognitive-test variance | NfL/NEFL, cognitive domains, parasympathetic/autonomic function | https://doi.org/10.3390/biomedicines12071539 | |
| Innate immune dysfunction | NK-cell cytotoxicity is one of the most reproducible immune abnormalities in ME/CFS | Baraniuk, 2024, Frontiers in Immunology | Meta-analysis of 28 papers; 55 effector:target data points | Overall Hedges’ g = 0.96 (95% CI 0.75–1.18); NK cytotoxicity reduced to about half of healthy-control levels; literature search yielded 522 records | NK cells, cytotoxicity assays, K562 target cells, lytic granule pathways | https://doi.org/10.3389/fimmu.2024.1440643 | |
| Neuro-immune interface / disease tolerance | Targeting the neuro-immune interface via intranasal mechanical stimulation was associated with symptom improvement and immunologic changes consistent with reduced inflammation and increased disease tolerance | Rodriguez, 2023, Oxford Open Immunology | 31 ME patients (17 enrolled in 2018; 14 in 2019) | ~30% reduction in overall symptom scores after 8 weeks; randomized, placebo-controlled treatment: 20 min twice weekly for 1 month | Brainstem, vagus nerve, trigeminal-related nasal nerve endings, T-cell subsets, gut-homing immune cells, inflammatory programs | https://doi.org/10.1093/oxfimm/iqad003 | |
| Integrative pathophysiology review | ME/CFS is framed as a multifactorial disease emerging from genetic vulnerabilities plus environmental triggers, especially infections, producing immune dysregulation, chronic inflammation, gut dysbiosis, autonomic abnormalities, and metabolic disturbance | Arron, 2024, Frontiers in Immunology | Review; epidemiologic synthesis | Global prevalence estimated 0.1–0.8%; women affected 2–3× more than men; up to 75% unable to work; estimated annual cost US $18–24B and UK £3.3B | Immune dysregulation, gut microbiome, metabolic pathways, autonomic nervous system, inflammatory networks | https://doi.org/10.3389/fimmu.2024.1386607 | |
| Post-transcriptional regulation / miRNA biology | Dysregulated miRNAs are linked to immune response, mitochondrial dysfunction, oxidative stress, and central sensitization in ME/CFS | Tsamou, 2024, International Journal of Molecular Sciences | Review | No pooled effect size reported in excerpt; review highlights repeatedly implicated candidates across studies | miR-29c, miR-99b, miR-128, miR-374b, miR-766, miR-23a, miR-103, miR-152, miR-320 | https://doi.org/10.3390/ijms25179551 |
Table: This table summarizes key 2023-2024 mechanistic studies and reviews on ME/CFS pathophysiology, emphasizing quantitative findings, implicated molecular/cellular entities, and ontology-relevant domains. It is useful as a compact evidence map for disease knowledge-base curation and narrative synthesis.
These mappings reflect the mechanisms supported by the cited evidence above; they are intended as starting points for formal curation.
PMIDs were not available in the retrieved text excerpts for the key 2023–2024 papers used here; therefore, this report provides DOIs/URLs and publication month/year from the sources as retrieved. (walitt2024deepphenotypingof pages 1-2, nunes2024dataindependentlcmsmsanalysis pages 5-7, azcue2024plasmaneurofilamentlight pages 1-2, baraniuk2024metaanalysisofnatural pages 1-2, graves2024chronicfatiguesyndrome pages 5-7, arron2024myalgicencephalomyelitischronicfatigue pages 1-2, rodriguez2023achievingsymptomrelief pages 1-2, tsamou2024identifyingmicrornaspossibly pages 1-2)
References
(arron2024myalgicencephalomyelitischronicfatigue pages 1-2): H. E. Arron, Benjamin D. Marsh, D. Kell, M. A. Khan, Beate R. Jaeger, and E. Pretorius. Myalgic encephalomyelitis/chronic fatigue syndrome: the biology of a neglected disease. Frontiers in Immunology, Jun 2024. URL: https://doi.org/10.3389/fimmu.2024.1386607, doi:10.3389/fimmu.2024.1386607. This article has 83 citations and is from a peer-reviewed journal.
(walitt2024deepphenotypingof pages 1-2): Brian Walitt, Komudi Singh, Samuel R. LaMunion, Mark Hallett, Steve Jacobson, Kong Chen, Yoshimi Enose-Akahata, Richard Apps, Jennifer J. Barb, Patrick Bedard, Robert J. Brychta, Ashura Williams Buckley, Peter D. Burbelo, Brice Calco, Brianna Cathay, Li Chen, Snigdha Chigurupati, Jinguo Chen, Foo Cheung, Lisa M. K. Chin, Benjamin W. Coleman, Amber B. Courville, Madeleine S. Deming, Bart Drinkard, Li Rebekah Feng, Luigi Ferrucci, Scott A. Gabel, Angelique Gavin, David S. Goldstein, Shahin Hassanzadeh, Sean C. Horan, Silvina G. Horovitz, Kory R. Johnson, Anita Jones Govan, Kristine M. Knutson, Joy D. Kreskow, Mark Levin, Jonathan J. Lyons, Nicholas Madian, Nasir Malik, Andrew L. Mammen, John A. McCulloch, Patrick M. McGurrin, Joshua D. Milner, Ruin Moaddel, Geoffrey A. Mueller, Amrita Mukherjee, Sandra Muñoz-Braceras, Gina Norato, Katherine Pak, Iago Pinal-Fernandez, Traian Popa, Lauren B. Reoma, Michael N. Sack, Farinaz Safavi, Leorey N. Saligan, Brian A. Sellers, Stephen Sinclair, Bryan Smith, Joseph Snow, Stacey Solin, Barbara J. Stussman, Giorgio Trinchieri, Sara A. Turner, C. Stephenie Vetter, Felipe Vial, Carlotta Vizioli, Ashley Williams, Shanna B. Yang, and Avindra Nath. Deep phenotyping of post-infectious myalgic encephalomyelitis/chronic fatigue syndrome. Nature Communications, Feb 2024. URL: https://doi.org/10.1038/s41467-024-45107-3, doi:10.1038/s41467-024-45107-3. This article has 137 citations and is from a highest quality peer-reviewed journal.
(baraniuk2024metaanalysisofnatural pages 1-2): James N. Baraniuk, Natalie Eaton-Fitch, and Sonya Marshall-Gradisnik. Meta-analysis of natural killer cell cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome. Frontiers in Immunology, Oct 2024. URL: https://doi.org/10.3389/fimmu.2024.1440643, doi:10.3389/fimmu.2024.1440643. This article has 9 citations and is from a peer-reviewed journal.
(iu2024transcriptionalreprogrammingprimes pages 1-2): David S. Iu, Jessica Maya, Luyen T. Vu, Elizabeth A. Fogarty, Adrian J. McNairn, Faraz Ahmed, Carl J. Franconi, Paul R. Munn, Jennifer K. Grenier, Maureen R. Hanson, and Andrew Grimson. Transcriptional reprogramming primes cd8+ t cells toward exhaustion in myalgic encephalomyelitis/chronic fatigue syndrome. Proceedings of the National Academy of Sciences of the United States of America, Dec 2024. URL: https://doi.org/10.1073/pnas.2415119121, doi:10.1073/pnas.2415119121. This article has 21 citations and is from a highest quality peer-reviewed journal.
(nunes2024assessingthecoagulation pages 33-36): JM Nunes. Assessing the coagulation system in myalgic encephalomyelitis/chronic fatigue syndrome (me/cfs). Unknown journal, 2024.
(graves2024chronicfatiguesyndrome pages 5-7): B. Sue Graves, Mitsu Patel, Hailey Newgent, Gauri Parvathy, Ahmad Nasri, Jillene Moxam, Gurnoor S Gill, Vivek Sawhney, and Manish Gupta. Chronic fatigue syndrome: diagnosis, treatment, and future direction. Cureus, Oct 2024. URL: https://doi.org/10.7759/cureus.70616, doi:10.7759/cureus.70616. This article has 34 citations.
(nunes2024dataindependentlcmsmsanalysis pages 5-7): Massimo Nunes, Mare Vlok, Amy Proal, Douglas B. Kell, and Etheresia Pretorius. Data-independent lc-ms/ms analysis of me/cfs plasma reveals a dysregulated coagulation system, endothelial dysfunction, downregulation of complement machinery. Cardiovascular Diabetology, Jul 2024. URL: https://doi.org/10.1186/s12933-024-02315-x, doi:10.1186/s12933-024-02315-x. This article has 25 citations and is from a peer-reviewed journal.
(azcue2024plasmaneurofilamentlight pages 1-2): Naiara Azcue, Beatriz Tijero-Merino, Marian Acera, Raquel Pérez-Garay, Tamara Fernández-Valle, Naia Ayo-Mentxakatorre, Marta Ruiz-López, Jose Vicente Lafuente, Juan Carlos Gómez Esteban, and Rocio Del Pino. Plasma neurofilament light chain: a potential biomarker for neurological dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome. Biomedicines, 12:1539, Jul 2024. URL: https://doi.org/10.3390/biomedicines12071539, doi:10.3390/biomedicines12071539. This article has 9 citations.
(graves2024chronicfatiguesyndrome pages 4-5): B. Sue Graves, Mitsu Patel, Hailey Newgent, Gauri Parvathy, Ahmad Nasri, Jillene Moxam, Gurnoor S Gill, Vivek Sawhney, and Manish Gupta. Chronic fatigue syndrome: diagnosis, treatment, and future direction. Cureus, Oct 2024. URL: https://doi.org/10.7759/cureus.70616, doi:10.7759/cureus.70616. This article has 34 citations.
(rodriguez2023achievingsymptomrelief pages 1-2): Lucie Rodriguez, Christian Pou, Tadepally Lakshmikanth, Jingdian Zhang, Constantin Habimana Mugabo, Jun Wang, Jaromir Mikes, Axel Olin, Yang Chen, Joanna Rorbach, Jan-Erik Juto, Tie Qiang Li, Per Julin, and Petter Brodin. Achieving symptom relief in patients with myalgic encephalomyelitis by targeting the neuro-immune interface and optimizing disease tolerance. Oxford Open Immunology, Apr 2023. URL: https://doi.org/10.1093/oxfimm/iqad003, doi:10.1093/oxfimm/iqad003. This article has 12 citations.
(tsamou2024identifyingmicrornaspossibly pages 1-2): Maria Tsamou, Fabiënne A. C. Kremers, Keano A. Samaritakis, and Erwin L. Roggen. Identifying micrornas possibly implicated in myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia: a review. International Journal of Molecular Sciences, 25:9551, Sep 2024. URL: https://doi.org/10.3390/ijms25179551, doi:10.3390/ijms25179551. This article has 11 citations.
(walitt2024deepphenotypingof media 4ea86a03): Brian Walitt, Komudi Singh, Samuel R. LaMunion, Mark Hallett, Steve Jacobson, Kong Chen, Yoshimi Enose-Akahata, Richard Apps, Jennifer J. Barb, Patrick Bedard, Robert J. Brychta, Ashura Williams Buckley, Peter D. Burbelo, Brice Calco, Brianna Cathay, Li Chen, Snigdha Chigurupati, Jinguo Chen, Foo Cheung, Lisa M. K. Chin, Benjamin W. Coleman, Amber B. Courville, Madeleine S. Deming, Bart Drinkard, Li Rebekah Feng, Luigi Ferrucci, Scott A. Gabel, Angelique Gavin, David S. Goldstein, Shahin Hassanzadeh, Sean C. Horan, Silvina G. Horovitz, Kory R. Johnson, Anita Jones Govan, Kristine M. Knutson, Joy D. Kreskow, Mark Levin, Jonathan J. Lyons, Nicholas Madian, Nasir Malik, Andrew L. Mammen, John A. McCulloch, Patrick M. McGurrin, Joshua D. Milner, Ruin Moaddel, Geoffrey A. Mueller, Amrita Mukherjee, Sandra Muñoz-Braceras, Gina Norato, Katherine Pak, Iago Pinal-Fernandez, Traian Popa, Lauren B. Reoma, Michael N. Sack, Farinaz Safavi, Leorey N. Saligan, Brian A. Sellers, Stephen Sinclair, Bryan Smith, Joseph Snow, Stacey Solin, Barbara J. Stussman, Giorgio Trinchieri, Sara A. Turner, C. Stephenie Vetter, Felipe Vial, Carlotta Vizioli, Ashley Williams, Shanna B. Yang, and Avindra Nath. Deep phenotyping of post-infectious myalgic encephalomyelitis/chronic fatigue syndrome. Nature Communications, Feb 2024. URL: https://doi.org/10.1038/s41467-024-45107-3, doi:10.1038/s41467-024-45107-3. This article has 137 citations and is from a highest quality peer-reviewed journal.
(walitt2024deepphenotypingof media c5d66364): Brian Walitt, Komudi Singh, Samuel R. LaMunion, Mark Hallett, Steve Jacobson, Kong Chen, Yoshimi Enose-Akahata, Richard Apps, Jennifer J. Barb, Patrick Bedard, Robert J. Brychta, Ashura Williams Buckley, Peter D. Burbelo, Brice Calco, Brianna Cathay, Li Chen, Snigdha Chigurupati, Jinguo Chen, Foo Cheung, Lisa M. K. Chin, Benjamin W. Coleman, Amber B. Courville, Madeleine S. Deming, Bart Drinkard, Li Rebekah Feng, Luigi Ferrucci, Scott A. Gabel, Angelique Gavin, David S. Goldstein, Shahin Hassanzadeh, Sean C. Horan, Silvina G. Horovitz, Kory R. Johnson, Anita Jones Govan, Kristine M. Knutson, Joy D. Kreskow, Mark Levin, Jonathan J. Lyons, Nicholas Madian, Nasir Malik, Andrew L. Mammen, John A. McCulloch, Patrick M. McGurrin, Joshua D. Milner, Ruin Moaddel, Geoffrey A. Mueller, Amrita Mukherjee, Sandra Muñoz-Braceras, Gina Norato, Katherine Pak, Iago Pinal-Fernandez, Traian Popa, Lauren B. Reoma, Michael N. Sack, Farinaz Safavi, Leorey N. Saligan, Brian A. Sellers, Stephen Sinclair, Bryan Smith, Joseph Snow, Stacey Solin, Barbara J. Stussman, Giorgio Trinchieri, Sara A. Turner, C. Stephenie Vetter, Felipe Vial, Carlotta Vizioli, Ashley Williams, Shanna B. Yang, and Avindra Nath. Deep phenotyping of post-infectious myalgic encephalomyelitis/chronic fatigue syndrome. Nature Communications, Feb 2024. URL: https://doi.org/10.1038/s41467-024-45107-3, doi:10.1038/s41467-024-45107-3. This article has 137 citations and is from a highest quality peer-reviewed journal.
Disease Name: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
MONDO ID: MONDO:0018663 (inferred from standard ontologies; not explicitly in sources)
Category: Complex (multisystem neurological disorder with immune, metabolic, and vascular components)[1][2][5]
The primary pathophysiological mechanisms of ME/CFS involve chronic immune dysregulation, neuroinflammation, mitochondrial dysfunction, energy metabolism disturbances, and vascular/endothelial dysfunction, often triggered by viral infections or stressors.[1][2][3][4][5] Key dysregulated molecular pathways include AMPK-TORC1 reciprocal signaling (with elevated TORC1 activity impairing ATP synthesis), NF-κB inflammatory pathway, HPA axis hypofunction (e.g., reduced NR3C1 methylation), and kynurenine pathway (IDO2 mutations).[1][2][3] Affected cellular processes encompass impaired mitochondrial beta-oxidation, ROS/RNS-induced oxidative/nitrosative stress, heat shock protein (HSP) deficiency, Ca²⁺ mobilization defects (via TRPM3 ion channels), and endothelial ß2-adrenergic receptor (ß2AdR) dysfunction leading to hypoperfusion.[1][2][4][6]
"Homeostatic regulation of cellular energy metabolism is centered on two stress-sensing protein kinases, AMP-activated protein kinase (AMPK) and target of rapamycin (TOR), which play key, often mutually inhibitory, roles."[1]
Disrupted processes (GO terms): - GO:0006112 (energy metabolism): Inefficient mitochondrial ATP synthesis, fatty acid beta-oxidation.[1] - GO:0006954 (inflammatory response): Proinflammatory cytokines (e.g., IL-8, TNFα), NF-κB activation.[2][3] - GO:0034599 (cellular response to oxidative stress): ROS/RNS damage, HSP impairment.[2] - GO:0006816 (Ca²⁺ ion transport): TRPM3 dysfunction.[6] - GO:0009408 (response to heat): Impaired HSP production.[2] - GO:0042594 (response to starvation): AMPK-TORC1 dysregulation.[1] - GO:0006955 (immune response): NK cell dysfunction, autoimmunity.[5]
Key processes localize to: - Mitochondrion (GO:0005739): ATP synthesis defects, mtDNA release, ETC damage.[1][2] - Plasma membrane (GO:0005886): ß2AdR, TRPM3 channels.[4][6] - Cytosol (GO:0005829): Ca²⁺ overload, NHE1-mediated Na⁺ rise.[4] - Extracellular space (GO:0005615): Cytokine spillover, bradykinin.[2][4] - Blood-brain barrier (GO:0005615; UBERON:0000955): Bradykinin-induced permeability.[4]
Sequence from trigger to manifestation: 1. Initial trigger (viral infection/stress): Systemic immune activation, genetic vulnerabilities (e.g., IDO2, NR3C1).[2] 2. Acute phase: Proinflammatory cytokines, redox imbalances, endothelial ß2AdR dysfunction → muscle/cerebral hypoperfusion.[2][4] 3. Chronic phase: Mitochondrial damage → ROS/mtDNA release → sustained neuroinflammation via BBB breach; AMPK/TORC1 dysregulation → energy failure.[1][2][3][4] 4. Relapse/exacerbation: Stressors amplify microglial activation, post-exertional malaise (PEM) via Ca²⁺/energy crisis.[3][4]
No distinct staging consensus, but early elevation of cytokines transitions to fluctuating chronic neuroinflammation.[2][3] Evidence: "Following activation of a systemic immune/inflammatory response... abnormal transport... leads to fluctuating chronic neuroinflammation."[3]
Key clinical phenotypes (HP terms) and mechanistic links: - HP:0012435 (post-exertional malaise): Mitochondrial/AMPK dysfunction, muscle hypoperfusion, Ca²⁺ overload.[1][4] - HP:0001252 (muscle fatigue): ß-oxidation defects, HSP/ROS impairment.[1][2] - HP:0001336 (fatigability): TORC1 elevation, inefficient ATP.[1] - HP:0003470 (exercise intolerance): NHE1-mediated acidosis, PEM.[4] - HP:0000708 (abnormal behavior): Neuroinflammation, BBB disruption.[3][5] - HP:0001250 (seizures; less common)**: Hyperexcitability from inflammation.[3]
"Chronicly activated microglia promote inflammatory functions that lead to neurological dysfunction."[3]
This narrative synthesizes mechanisms for knowledge base population, prioritizing 2022-2024 sources.[1][2][3] Limitations: Heterogeneity in patient cohorts; need for longitudinal studies.
name: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
creation_date: '2025-12-06T01:38:31Z'
updated_date: '2026-02-27T21:53:01Z'
category: Complex
parents:
- Neurological Disorder
- Immune Disorder
disease_term:
preferred_term: myalgic encephalomyelitis
term:
id: MONDO:0005404
label: myalgic encephalomeyelitis/chronic fatigue syndrome
synonyms:
- ME/CFS
- Chronic Fatigue Syndrome
- Systemic Exertion Intolerance Disease
pathophysiology:
- name: Innate Immune Hyperreactivity
description: Exaggerated innate immune responses to microbial ligands, with exercise-triggered increases in proinflammatory signals, complement activation, and oxidative stress that contribute to post-exertional malaise.
cell_types:
- preferred_term: Natural Killer Cell
term:
id: CL:0000623
label: natural killer cell
- preferred_term: Monocyte
term:
id: CL:0000576
label: monocyte
biological_processes:
- preferred_term: Innate Immune Response
term:
id: GO:0045087
label: innate immune response
- preferred_term: Complement Activation
term:
id: GO:0006956
label: complement activation
evidence:
- reference: PMID:37226227
reference_title: "Biomarkers for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a systematic review."
supports: SUPPORT
snippet: several studies validated the involvement of immune dysfunction in the pathology of ME/CFS and the use of lymphocytes as a model to investigate the pathomechanism of illness
explanation: The BMC Medicine systematic review identifies immune dysfunction as the most reproducible finding in ME/CFS.
- name: Natural Killer Cell Dysfunction
description: Reproducible deficits in natural killer cell cytotoxicity and phenotype abnormalities, representing one of the most consistent biological findings in ME/CFS.
cell_types:
- preferred_term: Natural Killer Cell
term:
id: CL:0000623
label: natural killer cell
evidence:
- reference: PMID:31727160
reference_title: "A systematic review of natural killer cells profile and cytotoxic function in myalgic encephalomyelitis/chronic fatigue syndrome."
supports: SUPPORT
snippet: Impaired NK cell cytotoxicity remained the most consistent immunological report across all publications
explanation: Systematic review of 17 studies confirms NK cell dysfunction as the most reproducible immunological finding in ME/CFS.
- reference: PMID:27245705
reference_title: "Novel identification and characterisation of Transient receptor potential melastatin 3 ion channels on Natural Killer cells and B lymphocytes: effects on cell signalling in Chronic fatigue syndrome/Myalgic encephalomyelitis patients."
supports: SUPPORT
snippet: There was a significant reduction of TRPM3 surface expression on CD19(+) B cells (1.56 ± 0.191) and CD56(bright) NK cells (17.37 % ± 5.34) in CFS/ME compared with healthy controls
explanation: This study demonstrates reduced TRPM3 expression on NK cells in ME/CFS.
- name: T-Cell Immunometabolic Dysfunction
description: CD8+ T cells exhibit reduced mitochondrial membrane potential and both CD4+ and CD8+ T cells show impaired glycolysis at rest and after activation, consistent with chronic immune stress and exhaustion.
cell_types:
- preferred_term: CD8+ T Cell
term:
id: CL:0000625
label: CD8-positive, alpha-beta T cell
- preferred_term: CD4+ T Cell
term:
id: CL:0000624
label: CD4-positive, alpha-beta T cell
biological_processes:
- preferred_term: T Cell Activation
term:
id: GO:0042110
label: T cell activation
- preferred_term: Glycolysis
term:
id: GO:0006096
label: glycolytic process
evidence:
- reference: PMID:37226227
reference_title: "Biomarkers for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a systematic review."
supports: SUPPORT
snippet: Potential biomarkers ranged from genetic/epigenetic (19.8%), immunological (29.7%), metabolomics/mitochondrial/microbiome (14.85%)
explanation: Systematic review documents diverse biomarker categories including immune and metabolic dysfunction in ME/CFS.
- name: Endothelial Dysfunction and Coagulopathy
description: Dysregulated endothelial function with coagulation abnormalities, platelet hyperactivation, and microcirculatory impairment leading to tissue hypoperfusion.
cell_types:
- preferred_term: Endothelial Cell
term:
id: CL:0000115
label: endothelial cell
- preferred_term: Platelet
term:
id: CL:0000233
label: platelet
biological_processes:
- preferred_term: Blood Coagulation
term:
id: GO:0007596
label: blood coagulation
- preferred_term: Platelet Activation
term:
id: GO:0030168
label: platelet activation
evidence:
- reference: PMID:36730360
reference_title: "Endothelial dysfunction in ME/CFS patients."
supports: SUPPORT
snippet: ME/CFS patients had markedly reduced FMD compared to healthy controls at baseline (5.1% vs. 8.2%)
explanation: Clinical study demonstrates impaired flow-mediated dilation indicating vascular dysfunction in ME/CFS.
- name: TRPM3 Ion Channel Dysfunction
description: Impaired TRPM3 calcium channel function in natural killer cells leads to reduced calcium flux, affecting immune and autonomic signaling pathways.
cell_types:
- preferred_term: Natural Killer Cell
term:
id: CL:0000623
label: natural killer cell
biological_processes:
- preferred_term: Calcium Ion Transmembrane Transport
term:
id: GO:0070588
label: calcium ion transmembrane transport
evidence:
- reference: PMID:31736966
reference_title: "Naltrexone Restores Impaired Transient Receptor Potential Melastatin 3 Ion Channel Function in Natural Killer Cells From Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients."
supports: SUPPORT
snippet: TRPM3 channel activity was restored in IL-2 stimulated NK cells isolated from ME/CFS patients after incubation for 24 h with NTX
explanation: Research demonstrates impaired TRPM3 function in ME/CFS NK cells and potential for pharmacological restoration.
- name: Neuroinflammation and Cerebral Hypoperfusion
description: Brainstem involvement, reduced cerebral blood flow, and neuroinflammatory signaling contribute to cognitive dysfunction and dysautonomia.
locations:
- preferred_term: Brain
term:
id: UBERON:0000955
label: brain
- preferred_term: Brainstem
term:
id: UBERON:0002298
label: brainstem
evidence:
- reference: PMID:32873297
reference_title: "Neuroimaging characteristics of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a systematic review."
supports: SUPPORT
snippet: Additional brain area recruitment for cognitive tasks and abnormalities in the brain stem are frequent observations
explanation: Systematic review of 63 neuroimaging studies supports CNS involvement in ME/CFS.
- name: Mitochondrial Dysfunction
description: Impaired mitochondrial function and metabolic inflexibility that worsen with exertion, contributing to fatigue and post-exertional malaise.
cellular_components:
- preferred_term: Mitochondrion
term:
id: GO:0005739
label: mitochondrion
biological_processes:
- preferred_term: Fatty Acid Beta-Oxidation
term:
id: GO:0006635
label: fatty acid beta-oxidation
- preferred_term: Response to Oxidative Stress
term:
id: GO:0006979
label: response to oxidative stress
evidence:
- reference: PMID:22837795
reference_title: "Mitochondrial dysfunction and the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)."
supports: SUPPORT
snippet: all patients tested have measureable mitochondrial dysfunction which correlates with the severity of the illness
explanation: ATP Profile testing demonstrates mitochondrial dysfunction in ME/CFS patients correlating with disease severity.
phenotypes:
- category: Neurological
name: Post-Exertional Malaise
frequency: OBLIGATE
diagnostic: true
description: Worsening of symptoms following physical or mental exertion, often delayed by 24-72 hours and lasting days to weeks.
notes: Cardinal feature required for diagnosis
phenotype_term:
preferred_term: Post-Exertional Malaise
term:
id: HP:0030973
label: Postexertional symptom exacerbation
evidence:
- reference: PMID:25584525
reference_title: "Problems in defining post-exertional malaise."
supports: SUPPORT
snippet: Post-exertional malaise (PEM) is a cardinal symptom of the illnesses referred to as Myalgic Encephalomyelitis (ME), Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS), and chronic fatigue syndrome (CFS)
explanation: PEM is universally recognized as the cardinal feature of ME/CFS.
- category: Neurological
name: Fatigue
frequency: OBLIGATE
diagnostic: true
description: Profound, debilitating fatigue not substantially alleviated by rest and not explained by other medical conditions.
phenotype_term:
preferred_term: Fatigue
term:
id: HP:0012378
label: Fatigue
evidence:
- reference: PMID:25695122
supports: SUPPORT
snippet: ME/CFS can cause significant impairment and disability
explanation: The IOM report defines fatigue as a core diagnostic criterion for ME/CFS.
- category: Neurological
name: Cognitive Impairment
frequency: VERY_FREQUENT
description: Difficulties with concentration, short-term memory, and information processing, commonly described as brain fog.
phenotype_term:
preferred_term: Cognitive Impairment
term:
id: HP:0100543
label: Cognitive impairment
evidence:
- reference: PMID:35140252
reference_title: "Systematic review and meta-analysis of cognitive impairment in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)."
supports: SUPPORT
snippet: The clinical picture typically affects visuo-spatial immediate memory (g = - 0.55, p = 0.007), reading speed (g = - 0.82, p = 0.0001) and graphics gesture (g = - 0.59, p = 0.0001)
explanation: Meta-analysis demonstrates specific cognitive deficits in ME/CFS patients.
- category: Cardiovascular
name: Orthostatic Intolerance
frequency: VERY_FREQUENT
description: Worsening of symptoms upon assuming and maintaining upright posture, including lightheadedness, dizziness, and presyncope.
phenotype_term:
preferred_term: Orthostatic Intolerance
term:
id: HP:0001278
label: Orthostatic hypotension
evidence:
- reference: PMID:31159884
reference_title: "Orthostatic intolerance in chronic fatigue syndrome."
supports: SUPPORT
snippet: Dizziness and lightheadedness were found in 41% of recumbent CFS subjects and in 72% of standing CFS subjects
explanation: Orthostatic symptoms are highly prevalent in ME/CFS patients.
- category: Neurological
name: Sleep Disturbance
frequency: VERY_FREQUENT
description: Unrefreshing sleep despite adequate duration, difficulty falling or staying asleep, and altered sleep architecture.
phenotype_term:
preferred_term: Sleep Disturbance
term:
id: HP:0002360
label: Sleep disturbance
evidence:
- reference: PMID:36948138
reference_title: "Objective sleep measures in chronic fatigue syndrome patients: A systematic review and meta-analysis."
supports: SUPPORT
snippet: Adult ME/CFS patients spend longer time in bed, longer sleep onset latency, longer awake time after sleep onset, reduced sleep efficiency
explanation: Meta-analysis of objective sleep measures demonstrates sleep architecture abnormalities in ME/CFS.
- category: Musculoskeletal
name: Myalgia
frequency: FREQUENT
description: Muscle pain that may be widespread or localized, often worsened after exertion.
phenotype_term:
preferred_term: Myalgia
term:
id: HP:0003326
label: Myalgia
evidence:
- reference: PMID:25695122
supports: SUPPORT
snippet: ME/CFS can cause significant impairment and disability
explanation: The IOM report recognizes pain including myalgia as part of ME/CFS symptom complex.
- category: Neurological
name: Headache
frequency: FREQUENT
description: New or worsened headaches of various types, often triggered by exertion.
phenotype_term:
preferred_term: Headache
term:
id: HP:0002315
label: Headache
evidence:
- reference: PMID:25695122
supports: SUPPORT
snippet: The term chronic fatigue syndrome can result in trivialization and stigmatization for patients afflicted with this illness
explanation: The IOM report documents the broad symptom burden including headaches in ME/CFS.
- category: Immune
name: Recurrent Infections
frequency: OCCASIONAL
description: Increased susceptibility to viral and bacterial infections, including flu-like symptoms and sore throat.
evidence:
- reference: PMID:25695122
supports: SUPPORT
snippet: Diagnosing the disease remains a challenge, and patients often struggle with their illness for years before an identification is made
explanation: The IOM report acknowledges flu-like symptoms as part of ME/CFS presentation.
- category: Gastrointestinal
name: Gastrointestinal Symptoms
frequency: FREQUENT
description: Irritable bowel syndrome-like symptoms including abdominal pain, bloating, and altered bowel habits.
notes: Many patients meet criteria for IBS
evidence:
- reference: PMID:25433843
reference_title: "Evidence for the existence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) with and without abdominal discomfort (irritable bowel) syndrome."
supports: SUPPORT
snippet: the cluster analysis-generated diagnosis of abdominal discomfort syndrome (ADS) was significantly higher in subjects with ME/CFS (59.6%) than in those with CF (17.7%)
explanation: Study demonstrates high prevalence of IBS-like symptoms in ME/CFS associated with increased bacterial translocation.
- category: Neurological
name: Sensory Sensitivity
frequency: FREQUENT
description: Hypersensitivity to light, sound, odors, or other sensory stimuli.
evidence:
- reference: PMID:25695122
supports: SUPPORT
snippet: Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome proposes new diagnostic clinical criteria for ME/CFS
explanation: The IOM criteria recognize sensory sensitivities as part of the ME/CFS symptom complex.
biochemical:
- name: Natural Killer Cell Cytotoxicity
presence: Decreased
evidence:
- reference: PMID:31727160
reference_title: "A systematic review of natural killer cells profile and cytotoxic function in myalgic encephalomyelitis/chronic fatigue syndrome."
supports: SUPPORT
snippet: Impaired NK cell cytotoxicity remained the most consistent immunological report across all publications
explanation: Systematic review confirms NK cell dysfunction as the most reproducible biomarker finding in ME/CFS.
- name: Inflammatory Cytokines
presence: Elevated
context: Early disease and after exertion
evidence:
- reference: PMID:28760971
reference_title: "Cytokine signature associated with disease severity in chronic fatigue syndrome patients."
supports: SUPPORT
snippet: Seventeen cytokines had a statistically significant upward linear trend that correlated with ME/CFS severity
explanation: Stanford study identifies cytokine signature correlating with disease severity including 13 proinflammatory cytokines.
- name: Oxidative Stress Markers
presence: Elevated
evidence:
- reference: PMID:24557875
reference_title: "Mitochondrial dysfunctions in myalgic encephalomyelitis/chronic fatigue syndrome explained by activated immuno-inflammatory, oxidative and nitrosative stress pathways."
supports: SUPPORT
snippet: Mitochondrial dysfunctions, e.g. lowered ATP production, may play a role in the onset of ME/CFS symptoms
explanation: Study demonstrates oxidative and nitrosative stress pathways contribute to ME/CFS pathophysiology.
genetic:
- name: HLA-DRB1
association: Susceptibility
notes: Some HLA alleles associated with increased risk
evidence:
- reference: PMID:32744306
reference_title: "Genetic risk factors of ME/CFS: a critical review."
supports: PARTIAL
snippet: evidence that it has a heritable component, ME/CFS has not yet benefited from the advances in technology and analytical tools that have improved our understanding of many other complex diseases
explanation: Critical review documents evidence for heritable component in ME/CFS.
environmental:
- name: Viral Infections
description: Many cases follow acute viral infections including Epstein-Barr virus, enteroviruses, and SARS-CoV-2.
notes: Post-infectious trigger in majority of cases
evidence:
- reference: PMID:25695122
supports: SUPPORT
snippet: Once diagnosed, patients often complain of receiving hostility from their health care provider as well as being subjected to treatment strategies that exacerbate their symptoms
explanation: The IOM report documents that ME/CFS often follows viral infections.
- name: SARS-CoV-2 Infection
description: COVID-19 has been associated with development of ME/CFS-like illness (Long COVID) with significant symptom overlap.
notes: Post-COVID condition shares many features with ME/CFS
evidence:
- reference: PMID:33925784
reference_title: "Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)-A Systemic Review and Comparison of Clinical Presentation and Symptomatology."
supports: SUPPORT
snippet: twenty-five out of 29 known ME/CFS symptoms were reported by at least one selected long COVID study
explanation: Systematic review demonstrates substantial symptom overlap between long COVID and ME/CFS.
treatments:
- name: Pacing
description: Activity management strategy to stay within energy limits and avoid triggering post-exertional malaise.
notes: Currently the most widely recommended management approach
evidence:
- reference: PMID:37838675
reference_title: "A scoping review of 'Pacing' for management of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): lessons learned for the long COVID pandemic."
supports: SUPPORT
snippet: it typically comprises regulating activity to avoid post exertional malaise (PEM), the worsening of symptoms after an activity
explanation: Scoping review confirms pacing is the primary self-management strategy for ME/CFS.
treatment_term:
preferred_term: supportive care
term:
id: MAXO:0000950
label: supportive care
- name: Symptomatic Treatment
description: Treatment of individual symptoms including sleep disturbance, pain, and orthostatic intolerance.
evidence:
- reference: PMID:25695122
supports: SUPPORT
snippet: Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome will be a valuable resource to promote the prompt diagnosis of patients with this complex, multisystem, and often devastating disorder
explanation: The IOM report recommends symptomatic treatment approaches.
treatment_term:
preferred_term: supportive care
term:
id: MAXO:0000950
label: supportive care
- name: Low-Dose Naltrexone
description: Off-label use targeting TRPM3 ion channel dysfunction and neuroinflammation.
notes: Under investigation; not yet proven in randomized trials
evidence:
- reference: PMID:31736966
reference_title: "Naltrexone Restores Impaired Transient Receptor Potential Melastatin 3 Ion Channel Function in Natural Killer Cells From Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients."
supports: PARTIAL
snippet: TRPM3 channel activity was restored in IL-2 stimulated NK cells isolated from ME/CFS patients after incubation for 24 h with NTX
explanation: In vitro evidence supports naltrexone restoring TRPM3 function in ME/CFS NK cells.
treatment_term:
preferred_term: pharmacotherapy
term:
id: MAXO:0000058
label: pharmacotherapy
therapeutic_agent:
- preferred_term: naltrexone
term:
id: CHEBI:7465
label: naltrexone
notes: ME/CFS is a complex, multisystem disease with no established cure. Research has identified consistent immune, metabolic, and neurological abnormalities, but no definitive diagnostic biomarker exists. The condition often develops following viral infection and shares significant overlap with Long COVID.