Association of circulating biomarkers with illness severity measures differentiates myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID-19 condition: a prospective cohort study

Abstract:

Background: Accumulating evidence suggests that autonomic dysfunction and persistent systemic inflammation are common clinical features in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID. However, there is limited knowledge regarding their potential association with circulating biomarkers and illness severity status.

Methods: This prospective, cross-sectional, case-control cohort study aimed to distinguish between the two patient populations by using self-reported outcome measures and circulating biomarkers to assess endothelial function and systemic inflammation. Thirty-one individuals with ME/CFS, 23 individuals with long COVID, and 31 matched healthy subjects were included. Regression analysis was used to examine associations between self-reported outcome measures and circulating biomarkers in study participants. Classification across groups was based on principal component and discriminant analyses.

Results: Four ME/CFS patients (13%), 1 with long COVID (4%), and 1 healthy control (3%) presented postural orthostatic tachycardia syndrome (POTS) with the 10-min NASA lean test. Compared with healthy controls, ME/CFS and long COVID subjects showed higher levels of ET-1 (p < 0.05) and VCAM-1 (p < 0.001), and lower levels of nitrites (NOx assessed as NO2 + NO3) (p < 0.01). ME/CFS patients also showed higher levels of serpin E1 (PAI-1) and E-selectin than did both long COVID and control subjects (p < 0.01 in all cases). Long COVID patients had lower TSP-1 levels than did ME/CFS patients and healthy controls (p < 0.001). As for inflammation biomarkers, both long COVID and ME/CFS subjects had higher levels of TNF-α than did healthy controls (p < 0.01 in both comparisons). Compared with controls, ME/CFS patients had higher levels of IL-1β (p < 0.001), IL-4 (p < 0.001), IL-6 (p < 0.01), IL-10 (p < 0.001), IP-10 (p < 0.05), and leptin (p < 0.001). Principal component analysis supported differentiation between groups based on self-reported outcome measures and endothelial and inflammatory biomarkers.

Conclusions: Our findings revealed that combining biomarkers of endothelial dysfunction and inflammation with outcome measures differentiate ME/CFS and Long COVID using robust discriminant analysis of principal components. Further research is needed to provide a more comprehensive characterization of these underlying pathomechanisms, which could be promising targets for therapeutic and preventive strategies in these conditions.

Source: Joan Carles Domingo, Federica Battistini, Begoña Cordobilla et al. Association of circulating biomarkers with illness severity measures differentiates myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID-19 condition: a prospective cohort study, 16 December 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3736031/v1] https://www.researchsquare.com/article/rs-3736031/v1 (Full text)

Post-acute COVID-19 complications in UK doctors: results of a cross-sectional survey

Abstract:

Background: As a consequence of their occupation, doctors and other healthcare workers were at higher risk of contracting coronavirus disease 2019 (COVID-19), and more likely to experience severe disease compared to the general population. However, systematic information on post-acute COVID complications in doctors is very limited.

Aims: This study aimed to determine the symptoms, perceived determinants, health and occupational impact, and consequent needs relating to post-acute COVID complications in UK doctors.

Methods: An online cross-sectional survey was distributed to UK doctors self-identifying as having Long COVID or other post-acute COVID complications.

Results: Of 795 responses, 603 fulfilled the inclusion criteria of being a UK-based medical doctor experiencing one or more post-acute COVID complications. Twenty-eight per cent reported a lack of adequate Respiratory Protective Equipment at the time of contracting COVID-19. Eighteen per cent of eligible respondents reported that they had been unable to return to work since acquiring COVID.

Conclusions: Post-acute COVID (Long COVID) in UK doctors is a substantial burden for respondents to our questionnaire. The results indicated that insufficient respiratory protection could have contributed to occupational disease, with COVID-19 being contracted in the workplace, and resultant post-COVID complications. Although it may be too late to address the perceived determinants of inadequate protection for those already suffering with Long COVID, more investment is needed in rehabilitation and support of those afflicted.

Source: D Bland, R Evans, A Binesmael, S Wood, S P Qureshi, K Fearnley, A Small, W D Strain, R Agius, Post-acute COVID-19 complications in UK doctors: results of a cross-sectional survey, Occupational Medicine, 2023;, kqad120, https://doi.org/10.1093/occmed/kqad120 https://academic.oup.com/occmed/advance-article-abstract/doi/10.1093/occmed/kqad120/7468904?redirectedFrom=fulltext

Effectiveness of Antiviral Therapy on Long COVID: A Systematic Review and Meta-Analysis

Abstract:

Antiviral treatment reduces the severity and mortality of SARS-CoV-2 infection; however, its effectiveness against long COVID-19 is unclear. This study aimed to evaluate the effectiveness of antiviral drugs in preventing long COVID and related hospitalizations/deaths. Scientific and medical databases were searched from 1 January 2020 to 30 June 2023. We included observational cohort studies comparing individuals receiving early antiviral therapy for COVID-19 and those receiving supportive treatment.
A fixed-effects model was used to merge the effects reported in two or more studies. The risk of post-acute sequelae of COVID-19 (PASC) was combined as an odds ratio (OR). Six studies were selected, including a total of 3,352,235 participants. The occurrence of PASC was 27.5% lower in patients who received antiviral drugs during the early stages of SARS-CoV-2 infection (OR = 0.725; 95% confidence interval [CI] = 0.409–0.747) than in the supportive treatment group. Moreover, the risk of PASC-associated hospitalization and mortality was 29.7% lower in patients receiving early antiviral therapy than in the supportive treatment group (OR = 0.721; 95% CI = 0.697–0.794).
Early antiviral therapy was associated with a reduced risk of PASC and related hospitalization or death. Thus, early antiviral therapy is recommended for at-risk individuals.
Source: Choi YJ, Seo YB, Seo J-W, Lee J, Nham E, Seong H, Yoon JG, Noh JY, Cheong HJ, Kim WJ, et al. Effectiveness of Antiviral Therapy on Long COVID: A Systematic Review and Meta-Analysis. Journal of Clinical Medicine. 2023; 12(23):7375. https://doi.org/10.3390/jcm12237375 https://www.mdpi.com/2077-0383/12/23/7375 (Full text)

Predictive Factors and ACE-2 Gene Polymorphisms in Susceptibility to Long COVID-19 Syndrome

Abstract:

Long COVID-19 syndrome is present in 5–10% of patients infected with SARS-CoV-2, and there is still little information on the predisposing factors that lead to its development. The purpose of the study was to evaluate the predictive factors in early symptoms, clinical features and the role of Angiotensin-Converting Enzyme-2 (ACE-2) c.513-1451G>A (rs2106806) and c.15643279T>C (rs6629110) polymorphisms in the susceptibility to developing Long COVID-19 syndrome subsequent to COVID-19 infection.
A total of 29 patients who suffered COVID-19 were recruited in a descriptive longitudinal study of two groups: Long COVID-19 (n = 16) and non-Long COVID-19 (n = 13). Early symptoms and clinical features during COVID-19 were classified by a medical service. ACE-2 polymorphisms were genotyped by using a Single Nucleotide Primer Extension (SNPE). Of the early symptoms, fatigue, myalgia and headache showed a high risk of increasing Long COVID-19 susceptibility. Clinical features such as emergency care, SARS-CoV-2 reinfection, previous diseases, respiratory disease and brain fog also had a high risk of increasing Long COVID-19 susceptibility.
The A allele in the rs2106806 variant was associated with an odds ratio (OR) of 4.214 (95% CI 2.521–8.853; p < 0.001), and the T allele in the rs6629110 variant was associated with an OR of 3.754 (95% CI 1.785–6.105; p = 0.002) of increasing Long COVID-19 susceptibility. This study shows the risk of ACE-2 polymorphisms, different early symptoms and clinical features during SARS-CoV-2 infection in susceptibility to Long COVID-19.
Source: Varillas-Delgado D, Jimenez-Antona C, Lizcano-Alvarez A, Cano-de-la-Cuerda R, Molero-Sanchez A, Laguarta-Val S. Predictive Factors and ACE-2 Gene Polymorphisms in Susceptibility to Long COVID-19 Syndrome. International Journal of Molecular Sciences. 2023; 24(23):16717. https://doi.org/10.3390/ijms242316717 https://www.mdpi.com/1422-0067/24/23/16717 (Full text)

Assessing symptoms of long/post COVID and chronic fatigue syndrome using the DePaul symptom questionnaire-2: a validation in a German-speaking population

Abstract:

Objective: A subset of Covid-19 survivors will develop persisting health sequelae (i.e. Long Covid/LC or Post Covid/PC) similar to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). In the absence of a reliable biomarker to diagnose LC/PC and ME/CFS, their classification based on symptoms becomes indispensable. Hence, we translated and validated the DePaul Symptom Questionnaire−2 (DSQ-2), to offer a screening tool for the German-speaking population.

Methods: A sample of healthy adults, and adults with ME/CFS and LC/PC (N = 502) completed a reduced-item version of the DSQ-2 and SF-36 questionnaire online. We performed an exploratory factor analysis, assessed construct validity, diagnostic accuracy and compared the symptom profiles of individuals with ME/CFS versus LC/PC versus healthy adults.

Results: Exploratory factor analysis revealed a 10-factor solution with excellent internal consistencies. The sensitivity of the DSQ-2 was excellent. The specificity was moderate with moderate inter-rater reliability. Construct validity of the DSQ-2 was supported by strong negative correlations with physical health subscales of the SF-36. A visual comparison of the symptom profiles of individuals with ME/CFS versus LC/PC revealed a comparable pattern.

Conclusion: Despite lower symptom severity, individuals with LC/PC reported significantly stronger limitations in general health and physical functioning and were more likely to meet ME/CFS diagnostic criteria with ongoing sickness duration, suggesting that ME/CFS can be considered a long-term sequela of LC/PC. This study offers a translated and validated version of the reduced-item DSQ-2 that can guide medical evaluation and aid physicians in identifying a ME/CFS-like subtype of LC/PC.

Source: Nina BuntićLeonard A. JasonJochen SchneiderMarc Schlesser & André Schulz (2023) Assessing symptoms of long/post COVID and chronic fatigue syndrome using the DePaul symptom questionnaire-2: a validation in a German-speaking population, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2023.2295419 https://www.tandfonline.com/doi/full/10.1080/21641846.2023.2295419 (Full text)

Urine Metabolite Analysis to Identify Pathomechanisms of Long COVID: A Pilot Study

Abstract:

Background: Around 10% of people who had COVID-9 infection suffer from persistent symptoms such as fatigue, dyspnoea, chest pain, arthralgia/myalgia, sleep disturbances, cognitive dysfunction and impairment of mental health. Different underlying pathomechanisms appear to be involved, in particular inflammation, alterations in amino acid metabolism, autonomic dysfunction and gut dysbiosis.

Aim: As routine tests are often inconspicuous in patients with Long COVID (LC), similarly to patients suffering from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), accessible biomarkers indicating dysregulation of specific pathways are urgently needed to identify underlying pathomechanisms and enable personalized medicine treatment. Within this pilot study we aimed to proof traceability of altered metabolism by urine analysis.

Patients and methods: Urine metabolome analyses were performed to investigate the metabolic signature of patients with LC (n = 25; 20 women, 5 men) in comparison to healthy controls (Ctrl, n = 8; 7 women, 1 man) and individuals with ME/CFS (n = 8; 2 women, 6 men). Concentrations of neurotransmitter precursors tryptophan, phenylalanine and their downstream metabolites, as well as their association with symptoms (fatigue, anxiety and depression) in the patients were examined.

Results and conclusion: Phenylalanine levels were significantly lower in both the LC and ME/CFS patient groups when compared to the Ctrl group. In many LC patients, the concentrations of downstream metabolites of tryptophan and tyrosine, such as serotonin, dopamine and catecholamines, deviated from the reference ranges. Several symptoms (sleep disturbance, pain or autonomic dysfunction) were associated with certain metabolites. Patients experiencing fatigue had lower levels of kynurenine, phenylalanine and a reduced kynurenine to tryptophan ratio (Kyn/Trp). Lower concentrations of gamma-aminobutyric acid (GABA) and higher activity of kynurenine 3-monooxygenase (KMO) were observed in patients with anxiety.

Conclusively, our results suggest that amino acid metabolism and neurotransmitter synthesis is disturbed in patients with LC and ME/CFS. The identified metabolites and their associated dysregulations could serve as potential biomarkers for elucidating underlying pathomechanisms thus enabling personalized treatment strategies for these patient populations.

Source: Taenzer M, Löffler-Ragg J, Schroll A, Monfort-Lanzas P, Engl S, Weiss G, Brigo N, Kurz K. Urine Metabolite Analysis to Identify Pathomechanisms of Long COVID: A Pilot Study. Int J Tryptophan Res. 2023 Dec 22;16:11786469231220781. doi: 10.1177/11786469231220781. PMID: 38144169; PMCID: PMC10748708. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10748708/ (Full text)

Clinical features of Japanese patients with gastrointestinal long-COVID symptoms

Introduction:

Although the development of new therapeutic approaches and vaccines has decreased coronavirus disease 2019 (COVID-19)-associated mortality, prolonged systemic symptoms after COVID-19, termed long-COVID, have been a major concern, considering their potential impact on health-related quality of life (QOL). Gastrointestinal (GI) symptoms, including diarrhea and abdominal pain, have been reported in patients with long-COVID even months after the initial COVID-19 symptoms have resolved.

Although emerging evidence suggests that GI symptoms in long-COVID are affected by the dysregulation of the immune system or ongoing inflammation and damage to the GI tract caused by the initial COVID-19 infection, the clinical features of patients with GI long-COVID symptoms remain elusive. Our study aimed to clarify these features.

Source: Kazuma Yagi, Takanori Asakura, Hideki Terai, Keiko Ohgino, Katsunori Masaki, Ho Namkoong, Shotaro Chubachi, Jun Miyata, Ichiro Kawada, Nobuhiro Kodama, Satoshi Sakamoto, Akira Umeda, Takashi Ishiguro, Makoto Ishii, Koichi Fukunaga. JGH Open. First published: 06 December 2023 https://doi.org/10.1002/jgh3.13006 https://onlinelibrary.wiley.com/doi/full/10.1002/jgh3.13006 (Full text)

Mechanisms of long COVID: An updated review

Abstract:

The coronavirus disease 2019 (COVID-19) pandemic has been ongoing for more than 3 years, with an enormous impact on global health and economies. In some patients, symptoms and signs may remain after recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which cannot be explained by an alternate diagnosis; this condition has been defined as long COVID.

Long COVID may exist in patients with both mild and severe disease and is prevalent after infection with different SARS-CoV-2 variants. The most common symptoms include fatigue, dyspnea, and other symptoms involving multiple organs. Vaccination results in lower rates of long COVID. To date, the mechanisms of long COVID remain unclear. In this narrative review, we summarized the clinical presentations and current evidence regarding the pathogenesis of long COVID.

Source: Yan Liu, Xiaoying Gu, Haibo Li, Hui Zhang, Jiuyang Xu. Mechanisms of long COVID: An updated review. Chinese Medical Journal Pulmonary and Critical Care Medicine, Volume 1, Issue 4, December 2023, Pages 231-240. https://www.sciencedirect.com/science/article/pii/S2772558823000580 (Full text)

Investigating the Human Intestinal DNA Virome and Predicting Disease-Associated Virus-Host Interactions in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Understanding how the human virome, and which of its constituents, contributes to health or disease states is reliant on obtaining comprehensive virome profiles. By combining DNA viromes from isolated virus-like particles (VLPs) and whole metagenomes from the same faecal sample of a small cohort of healthy individuals and patients with severe myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), we have obtained a more inclusive profile of the human intestinal DNA virome.

Key features are the identification of a core virome comprising tailed phages of the class Caudoviricetes, and a greater diversity of DNA viruses including extracellular phages and integrated prophages. Using an in silico approach, we predicted interactions between members of the Anaerotruncus genus and unique viruses present in ME/CFS microbiomes. This study therefore provides a framework and rationale for studies of larger cohorts of patients to further investigate disease-associated interactions between the intestinal virome and the bacteriome.

Source: Hsieh SY, Savva GM, Telatin A, Tiwari SK, Tariq MA, Newberry F, Seton KA, Booth C, Bansal AS, Wileman T, Adriaenssens EM, Carding SR. Investigating the Human Intestinal DNA Virome and Predicting Disease-Associated Virus-Host Interactions in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Int J Mol Sci. 2023 Dec 8;24(24):17267. doi: 10.3390/ijms242417267. PMID: 38139096. https://www.mdpi.com/1422-0067/24/24/17267 (Full text)

Large scale phenotyping of long COVID inflammation reveals mechanistic subtypes of disease after COVID-19 hospitalisation

Abstract:

One in ten SARS-CoV-2 infections result in prolonged symptoms termed long COVID, yet disease phenotypes and mechanisms are poorly understood. We studied the blood proteome of 719 previously hospitalised adults with long COVID grouped by symptoms. Elevated markers of myeloid inflammation and complement activation were associated with long COVID; elevated IL1R2, MATN2 and COLEC12 were associated with cardiorespiratory symptoms, fatigue, and anxiety/depression, while MATN2 and DPP10 were elevated in gastrointestinal (GI) symptoms, and C1QA in cognitive impairment.
Proteins suggestive of neurodegeneration were elevated in cognitive impairment, whilst SCG3 (indicative of brain-gut axis disturbance) was specific to GI symptoms. Nasal inflammation was apparent after COVID-19 but did not associate with symptoms. Although SARS-CoV-2 specific IgG was elevated with some long COVID symptoms, virus was not detected from sputum. Thus, systemic inflammation is evident in long COVID and could be targeted in therapeutic trials tailored to pathophysiological differences between symptom groups.

Source: Peter Openshaw, Felicity Liew, Claudia Efstathiou et al. Large scale phenotyping of long COVID inflammation reveals mechanistic subtypes of disease after COVID-19 hospitalisation, 04 December 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3427282/v1] https://www.researchsquare.com/article/rs-3427282/v1 (Full text)