Patient-Reported Treatment Outcomes in ME/CFS and Long COVID

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Long COVID are persistent multi-system illnesses affecting many patients. With no known effective FDA-approved treatments for either condition, patient-reported outcomes of treatments are invaluable for guiding management strategies in patient care and generating new avenues for research. Here, we present the results of an ME/CFS and Long COVID treatment survey with responses from 3,925 patients.

We assessed the experiences of these patients with more than 150 treatments, as well as their demographics, symptoms, and comorbidities. Patients with each condition who participated in the study shared similar symptom profiles, including all the core symptoms of ME/CFS, e.g., 89.7% of ME/CFS and 79.4% of Long COVID reported post-exertional malaise (PEM). Treatments with the greatest perceived benefits were identified, which had varied effects on different core symptoms.

In addition, treatment responses were significantly correlated (R² = 0.68) between the two patient groups. Patient subgroups with distinct profiles of symptoms and comorbidities showed varied responses to treatments, e.g., a POTS-dominant cluster benefiting from autonomic modulators and a cognitive-dysfunction cluster from CNS stimulants.

This study underscores the symptomatic and therapeutic similarities between ME/CFS and Long COVID and highlights the commonalities and nuanced complexities of infection-associated chronic diseases and related conditions. Insights from patient-reported experiences, in the absence of approved treatments, provide urgently needed real-world evidence for targeted therapies in patient care and for developing future clinical trials.

Source: Martha EckeyPeng LiBraxton MorrisonRonald W DavisWenzhong Xiao. Patient-Reported Treatment Outcomes in ME/CFS and Long COVID.

Transcriptional reprogramming primes CD8+ T cells toward exhaustion in Myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME) is a severe, debilitating disease, with substantial evidence pointing to immune dysregulation as a key contributor to pathophysiology. To characterize the gene regulatory state underlying T cell dysregulation in ME, we performed multiomic analysis across T cell subsets by integrating single-cell RNA-seq, RNA-seq, and ATAC-seq and further analyzed CD8+ T cell subpopulations following symptom provocation.

Specific subsets of CD8+ T cells, as well as certain innate T cells, displayed the most pronounced dysregulation in ME. We observed upregulation of key transcription factors associated with T cell exhaustion in CD8+ T cell effector memory subsets, as well as an altered chromatin landscape and metabolic reprogramming consistent with an exhausted immune cell state. To validate these observations, we analyzed expression of exhaustion markers using flow cytometry, detecting a higher frequency of exhaustion-associated factors.

Together, these data identify T cell exhaustion as a component of ME, a finding which may provide a basis for future therapies, such as checkpoint blockade, metabolic interventions, or drugs that target chronic viral infections.

Source: Iu DS, Maya J, Vu LT, Fogarty EA, McNairn AJ, Ahmed F, Franconi CJ, Munn PR, Grenier JK, Hanson MR, Grimson A. Transcriptional reprogramming primes CD8+ T cells toward exhaustion in Myalgic encephalomyelitis/chronic fatigue syndrome. Proc Natl Acad Sci U S A. 2024 Dec 10;121(50):e2415119121. doi: 10.1073/pnas.2415119121. Epub 2024 Dec 2. PMID: 39621903. https://www.pnas.org/doi/10.1073/pnas.2415119121 (Full text)

Central and peripheral kynurenine pathway metabolites in COVID-19: Implications for neurological and immunological responses

Abstract:

Long-term symptoms such as pain, fatigue, and cognitive impairments are commonly observed in individuals affected by coronavirus disease 2019 (COVID-19). Metabolites of the kynurenine pathway have been proposed to account for cognitive impairment in COVID-19 patients.

Here, cerebrospinal fluid (CSF) and plasma levels of kynurenine pathway metabolites in 53 COVID-19 patients and 12 non-inflammatory neurological disease controls in Sweden were measured with an ultra-performance liquid chromatography-tandem mass spectrometry system (UPLC-MS/MS) and correlated with immunological markers and neurological markers. Single cell transcriptomic data from a previous study of 130 COVID-19 patients was used to investigate the expression of key genes in the kynurenine pathway.

The present study reveals that the neuroactive kynurenine pathway metabolites quinolinic acid (QUIN) and kynurenic acid (KYNA) are increased in CSF in patients with acute COVID-19. In addition, CSF levels of kynurenine, ratio of kynurenine/tryptophan (rKT) and QUIN correlate with neurodegenerative markers.

Furthermore, tryptophan is significantly decreased in plasma but not in the CSF. In addition, the kynurenine pathway is strongly activated in the plasma and correlates with the peripheral immunological marker neopterin. Single-cell transcriptomics revealed upregulated gene expressions of the rate-limiting enzyme indoleamine 2,3- dioxygenase1 (IDO1) in CD14+ and CD16+ monocytes that correlated with type II-interferon response exclusively in COVID-19 patients.

In summary, our study confirms significant activation of the peripheral kynurenine pathway in patients with acute COVID-19 and, notably, this is the first study to identify elevated levels of kynurenine metabolites in the central nervous system associated with the disease. Our findings suggest that peripheral inflammation, potentially linked to overexpression of IDO1 in monocytes, activates the kynurenine pathway. Increased plasma kynurenine, crossing the blood-brain barrier, serves as a source for elevated brain KYNA and neurotoxic QUIN.

We conclude that blocking peripheral-to-central kynurenine transport could be a promising strategy to protect against neurotoxic effects of QUIN in COVID-19 patients.

Source: Li X, Edén A, Malwade S, Cunningham JL, Bergquist J, Weidenfors JA, Sellgren CM, Engberg G, Piehl F, Gisslen M, Kumlien E, Virhammar J, Orhan F, Rostami E, Schwieler L, Erhardt S. Central and peripheral kynurenine pathway metabolites in COVID-19: Implications for neurological and immunological responses. Brain Behav Immun. 2024 Nov 28:S0889-1591(24)00720-7. doi: 10.1016/j.bbi.2024.11.031. Epub ahead of print. PMID: 39615604. https://www.sciencedirect.com/science/article/abs/pii/S0889159124007207

Upregulation of olfactory receptors and neuronal-associated genes highlights complex immune and neuronal dysregulation in Long COVID patients

Abstract:

A substantial portion of patients infected with SARS-CoV-2 experience prolonged complications, known as Long COVID (LC). A subset of these patients exhibits the most debilitating symptoms, similar to those defined in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). We performed bulk RNA sequencing (RNAseq) on the whole blood of LC with ME/CFS, at least 12 months post-onset of the acute disease, and compared them with controls.

We found that LC patients had a distinct transcriptional profile compared to controls. Key findings include the upregulation of genes involved in immune dysregulation and neuronal development, such as Fezf2, BRINP2, HOXC12, MEIS2, ZFHX3, and RELN. These genes are linked to neuroinflammatory responses, cognitive impairments, and hematopoietic disturbances, suggesting ongoing neurological and immune disturbances in LC patients. RELN, encoding the Reelin protein, was notably elevated in LC patients, potentially serving as a biomarker for LC pathogenesis due to its role in inflammation and neuronal function.

Immune cell analysis showed altered profiles in LC patients, with increased activated memory CD4 + T cells and neutrophils, and decreased regulatory T cells and NK cells, reflecting immune dysregulation. Changes in cytokine and chemokine expression further underscore the chronic inflammatory state in LC patients. Notably, a unique upregulation of olfactory receptors (ORs) suggest alternative roles for ORs in non-olfactory tissues. Pathway analysis revealed upregulation in ribosomal RNA processing, amino acid metabolism, protein synthesis, cell proliferation, DNA repair, and mitochondrial pathways, indicating heightened metabolic and immune demands. Conversely, downregulated pathways, such as VEGF signaling and TP53 activity, point to impaired tissue repair and cellular stress responses.

Overall, our study underscores the complex interplay between immune and neuronal dysfunction in LC patients, providing insights into potential diagnostic biomarkers and therapeutic targets. Future research is needed to fully understand the roles and interactions of these genes in LC pathophysiology.

Source: Shahbaz S, Rezaeifar M, Syed H, Redmond D, Terveart JWC, Osman M, Elahi S. Upregulation of olfactory receptors and neuronal-associated genes highlights complex immune and neuronal dysregulation in Long COVID patients. Brain Behav Immun. 2024 Nov 28:S0889-1591(24)00721-9. doi: 10.1016/j.bbi.2024.11.032. Epub ahead of print. PMID: 39615603. https://www.sciencedirect.com/science/article/pii/S0889159124007219 (Full text)

Persistence of spike protein at the skull-meninges-brain axis may contribute to the neurological sequelae of COVID-19

Abstract:

SARS-CoV-2 infection is associated with long-lasting neurological symptoms, although the underlying mechanisms remain unclear. Using optical clearing and imaging, we observed the accumulation of SARS-CoV-2 spike protein in the skull-meninges-brain axis of human COVID-19 patients, persisting long after viral clearance. Further, biomarkers of neurodegeneration were elevated in the cerebrospinal fluid from long COVID patients, and proteomic analysis of human skull, meninges, and brain samples revealed dysregulated inflammatory pathways and neurodegeneration-associated changes.

Similar distribution patterns of the spike protein were observed in SARS-CoV-2-infected mice. Injection of spike protein alone was sufficient to induce neuroinflammation, proteome changes in the skull-meninges-brain axis, anxiety-like behavior, and exacerbated outcomes in mouse models of stroke and traumatic brain injury. Vaccination reduced but did not eliminate spike protein accumulation after infection in mice. Our findings suggest persistent spike protein at the brain borders may contribute to lasting neurological sequelae of COVID-19.

Source: Rong Z, Mai H, Ebert G, Kapoor S, Puelles VG, Czogalla J, Hu S, Su J, Prtvar D, Singh I, Schädler J, Delbridge C, Steinke H, Frenzel H, Schmidt K, Braun C, Bruch G, Ruf V, Ali M, Sühs KW, Nemati M, Hopfner F, Ulukaya S, Jeridi D, Mistretta D, Caliskan ÖS, Wettengel JM, Cherif F, Kolabas ZI, Molbay M, Horvath I, Zhao S, Krahmer N, Yildirim AÖ, Ussar S, Herms J, Huber TB, Tahirovic S, Schwarzmaier SM, Plesnila N, Höglinger G, Ondruschka B, Bechmann I, Protzer U, Elsner M, Bhatia HS, Hellal F, Ertürk A. Persistence of spike protein at the skull-meninges-brain axis may contribute to the neurological sequelae of COVID-19. Cell Host Microbe. 2024 Nov 26:S1931-3128(24)00438-4. doi: 10.1016/j.chom.2024.11.007. Epub ahead of print. PMID: 39615487. https://www.sciencedirect.com/science/article/pii/S1931312824004384 (Full text)

RESTORE ME: a RCT of oxaloacetate for improving fatigue in patients with myalgic encephalomyelitis/chronic fatigue syndrome

Background: The energy metabolite oxaloacetate is significantly lower in the blood plasma of ME/CFS subjects. A previous open-label trial with oxaloacetate supplementation demonstrated a significant reduction in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)-related fatigue.

Methods: In this follow-up trial, 82 ME/CFS subjects were enrolled in a 3-month randomized, double-blinded, controlled study, receiving either 2,000 mg of oxaloacetate or control per day. The primary endpoints were safety and reduction in fatigue from baseline. Secondary and exploratory endpoints included functional capacity and general health status.

Results: Anhydrous enol-oxaloacetate (oxaloacetate) was well tolerated at the tested doses. Oxaloacetate significantly reduced fatigue by more than 25% from baseline, while the control group showed a non-significant reduction of approximately 10%. Intergroup analysis showed a significant decrease in fatigue levels in the oxaloacetate group (p = 0.0039) with no notable change in the control group. A greater proportion of subjects in the oxaloacetate group achieved a reduction in fatigue greater than 25% compared to the control group (p < 0.05). Additionally, 40.5% of the oxaloacetate group were classified as “enhanced responders,” with an average fatigue reduction of 63%. Both physical and mental fatigue improved with oxaloacetate supplementation.

Conclusion: Oxaloacetate is well tolerated and effectively helps reduce fatigue in ME/CFS patients.

Clinical trial registration: https://clinicaltrials.gov/study/NCT05273372.

Source: Alan B. Cash, Suzanne D. Vernon, Candace Rond, Saeed Abbaszadeh, Jen Bell, Brayden Yellman, Lucinda Bateman, David Kaufman. RESTORE ME: a RCT of oxaloacetate for improving fatigue in patients with myalgic encephalomyelitis/chronic fatigue syndrome. Front. Neurol., 26 November 2024. Sec. Experimental Therapeutics. Volume 15 – 2024 | https://doi.org/10.3389/fneur.2024.1483876 https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2024.1483876/full (Full text)

Plasma taurine level is linked to symptom burden and clinical outcomes in post-COVID condition

Abstract:

Background: A subset of individuals (10-20%) experience post-COVID condition (PCC) subsequent to initial SARS-CoV-2 infection, which lacks effective treatment. PCC carries a substantial global burden associated with negative economic and health impacts. This study aims to evaluate the association between plasma taurine levels with self-reported symptoms and adverse clinical outcomes in patients with PCC.

Methods and findings: We analyzed the plasma proteome and metabolome of 117 individuals during their acute COVID-19 hospitalization and at the convalescence phase six-month post infection. Findings were compared with 28 age and sex-matched healthy controls. Plasma taurine levels were negatively associated with PCC symptoms and correlated with markers of inflammation, tryptophan metabolism, and gut dysbiosis. Stratifying patients based on the trajectories of plasma taurine levels during six-month follow-up revealed a significant association with adverse clinical events. Increase in taurine levels during the transition to convalescence were associated with a reduction in adverse events independent of comorbidities and acute COVID-19 severity. In a multivariate analysis, increased plasma taurine level between acute and convalescence phase was associated with marked protection from adverse clinical events with a hazard ratio of 0.13 (95% CI: 0.05-0.35; p<0.001).

Conclusions: Taurine emerges as a promising predictive biomarker and potential therapeutic target in PCC. Taurine supplementation has already demonstrated clinical benefits in various diseases and warrants exploration in large-scale clinical trials for alleviating PCC.

Source: Khoramjoo M, Wang K, Srinivasan K, Gheblawi M, Mandal R, Rousseau S, Wishart D, Prasad V, Richer L, Cheung AM, Oudit GY. Plasma taurine level is linked to symptom burden and clinical outcomes in post-COVID condition. PLoS One. 2024 Jun 5;19(6):e0304522. doi: 10.1371/journal.pone.0304522. PMID: 38837993; PMCID: PMC11152273. https://pmc.ncbi.nlm.nih.gov/articles/PMC11152273/ (Full text)

Discriminating Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and comorbid conditions using metabolomics in UK Biobank

Abstract:

Background: Diagnosing complex illnesses like Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is complicated due to the diverse symptomology and presence of comorbid conditions. ME/CFS patients often present with multiple health issues, therefore, incorporating comorbidities into research can provide a more accurate understanding of the condition’s symptomatology and severity, to better reflect real-life patient experiences.

Methods: We performed association studies and machine learning on 1194 ME/CFS individuals with blood plasma nuclear magnetic resonance (NMR) metabolomics profiles, and seven exclusive comorbid cohorts: hypertension (n = 13,559), depression (n = 2522), asthma (n = 6406), irritable bowel syndrome (n = 859), hay fever (n = 3025), hypothyroidism (n = 1226), migraine (n = 1551) and a non-diseased control group (n = 53,009).

Results: We present a lipoprotein perspective on ME/CFS pathophysiology, highlighting gender-specific differences and identifying overlapping associations with comorbid conditions, specifically surface lipids, and ketone bodies from 168 significant individual biomarker associations. Additionally, we searched for, trained, and optimised a machine learning algorithm, resulting in a predictive model using 19 baseline characteristics and nine NMR biomarkers which could identify ME/CFS with an AUC of 0.83 and recall of 0.70. A multi-variable score was subsequently derived from the same 28 features, which exhibited ~2.5 times greater association than the top individual biomarker.

Conclusions: This study provides an end-to-end analytical workflow that explores the potential clinical utility that association scores may have for ME/CFS and other difficult to diagnose conditions.

Source: Huang K, G C de Sá A, Thomas N, Phair RD, Gooley PR, Ascher DB, Armstrong CW. Discriminating Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and comorbid conditions using metabolomics in UK Biobank. Commun Med (Lond). 2024 Nov 26;4(1):248. doi: 10.1038/s43856-024-00669-7. PMID: 39592839; PMCID: PMC11599898.  https://pmc.ncbi.nlm.nih.gov/articles/PMC11599898/ (Full text)

The effects of 3-month supplementation with synbiotic on patient-reported outcomes, exercise tolerance, and brain and muscle metabolism in adult patients with post-COVID-19 chronic fatigue syndrome (STOP-FATIGUE): a randomized Placebo-controlled clinical trial

Abstract:

Purpose: Considering the observed gastrointestinal issues linked to post-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), beneficially modulating the gut microbiota could offer a safe, cost-effective nutritional strategy. This trial aimed to evaluate the effects of medium-term synbiotic supplementation on patient-reported outcomes, exercise tolerance, and tissue metabolism in patients with post-COVID-19 ME/CFS.

Methods: Between September 2022 and December 2023, we investigated the impact of 3-month supplementation with a synbiotic mixture including L. rhamnosus DSM 32550, Humiome® L. plantarum DSM 34532, B. lactis DSM 32269, B. longum DSM 32946, fructooligosaccharides and zinc, on predetermined primary and secondary outcome measures in twenty six post-COVID-19 ME/CFS patients utilizing a parallel-group, randomized, placebo-controlled, double-blind design.

Results: Both the synbiotic and placebo intake resulted in a significant reduction in general fatigue after 3 months compared to the baseline values (P ≤ 0.05). This was accompanied by a significant interaction effect (time vs. treatment) for post-exercise malaise (P = 0.02), with synbiotic superior to placebo to attenuate post-exercise malaise. The synbiotic also demonstrated a significant advantage over placebo in increasing choline levels at the thalamus (P = 0.02), and creatine levels at left frontal white matter (P = 0.05) and left frontal grey matter (P = 0.04).

Conclusion: Taking the synbiotic mixture for three months improves tissue metabolism and mitigates clinical features of post-COVID-19 fatigue syndrome. The presented data show promise in addressing the widespread issue of ME/CFS following the COVID-19 pandemic; however, further validation is needed before endorsing the synbiotics within this clinical context. The study is registered at ClinicalTrials.gov (NCT06013072).

Source: Ranisavljev M, Stajer V, Todorovic N, Ostojic J, Cvejic JH, Steinert RE, Ostojic SM. The effects of 3-month supplementation with synbiotic on patient-reported outcomes, exercise tolerance, and brain and muscle metabolism in adult patients with post-COVID-19 chronic fatigue syndrome (STOP-FATIGUE): a randomized Placebo-controlled clinical trial. Eur J Nutr. 2024 Nov 26;64(1):28. doi: 10.1007/s00394-024-03546-0. PMID: 39592468. https://pubmed.ncbi.nlm.nih.gov/39592468/

Depressive and anxiety symptoms in current, previous, and no history of ME/CFS: NHIS 2022 analysis

Abstract:

Purpose: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is associated with anxiety and depressive symptoms. Psychological symptoms are predisposing factors for, as well as symptoms of, ME/CFS. Recovery from ME/CFS is poorly understood and heterogenous, and it is unclear how psychological symptoms may change with recovery. The aim of this study was to examine the associations of depressive and anxious symptoms among individuals with current, previous, and no history of ME/CFS.

Methods: National Health Interview Survey 2022 data were analyzed to assess ME/CFS status, as well as anxiety and depression burden. Adults (unweighted N = 27,651) in the United States reported sociodemographic and health behavior characteristics, with 453 adults reporting current ME/CFS, while 119 reported previous ME/CFS. Sample weights and variance estimation variables were implemented. Multivariable linear regression models were used to analyze the associations between ME/CFS status and anxiety and depression severity after adjusting for sociodemographic and health behavior variables.

Results: Participants were on average 48.1 years of age, and most identified as female (51.3%), white (76.6%), and not Hispanic or Latine (82.8%). Current and previous ME/CFS were associated with anxiety and depressive symptoms compared to individuals with no history of ME/CFS. Clinically significant levels of anxiety and depressive symptoms were substantial for individuals with current (37.6%; 49.0%) and previous (26.5%; 33.4%) ME/CFS compared to individuals with no history of ME/CFS (6.1%; 6.7%).

Conclusion: ME/CFS, regardless of current presence, was related to significantly greater anxiety and depressive symptom burden.

Source: Sirotiak Z, Adamowicz JL, Thomas EBK. Depressive and anxiety symptoms in current, previous, and no history of ME/CFS: NHIS 2022 analysis. Qual Life Res. 2024 Nov 23. doi: 10.1007/s11136-024-03854-2. Epub ahead of print. PMID: 39579271. https://link.springer.com/article/10.1007/s11136-024-03854-2 (Full text)