Investigation into the Plasma Proteome Signature in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Abstract:

Background: ME/CFS is a complex disease with unclear etiology. Current diagnostic criteria lack objective laboratory measures.

Aims: This study aimed to investigate the plasma proteomic profile of ME/CFS patients and determine any differentially expressed proteins compared to controls.

Methods: Plasma samples obtained from 19 ME/CFS patients and 9 controls underwent analysis (Somalogic, Inc, CO). The ME/CFS patients met the National Academy of Medicine criteria for the disease. Samples were collected from a mixed venous compartment. Statistical analysis and a Mixed Graphical Model were used to identify candidate biomarker.

Results: Among ~7000 proteins detected, ~400 were differentially expressed between patients and controls (False Discovery Rate<0.05 and Absolute Fold Change ≥1.5). Selectin E (SELE), ATP Synthase Subunit F6 (ATP5PF), and Transcobalamin 2 (TCN2) were identified as top candidates. A classifier of these proteins in pulmonary artery blood of patients were distinguishable from controls (AUC =0.99).

Conclusion: The study highlighted potential biomarkers for ME/CFS, the top candidates of which are involved in inflammation, cellular energy metabolism, and Vitamin B12 transport. The plasma proteomic signature identifies ME/CFS from normals and suggests that the disease’s pathophysiology is driven by abnormalities of aerobic metabolism, vascular dysregulation, and Vitamin B12 metabolism.

Source: Johanna SquiresSarra Al-ZayerPeng LiWenzhong XiaoDavid Systrom. Investigation into the Plasma Proteome Signature in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). https://erj.ersjournals.com/content/62/suppl_67/PA2960.abstract

Successful treatment of myalgic encephalomyelitis/chronic fatigue syndrome using hydrogen gas: four case reports

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained fatigue and malaise that persist for more than 6 months with neuropsychiatric symptoms, including slight fever, headache, weakness, impaired thinking, and depression.[1,2] The onset and severity of these symptoms vary and reduce the quality of life as well as social, occupational, and personal activities of those affected, with some becoming bedridden.[1,2] The number of ME/CFS patients in the United States is estimated to be between 836,000 and 2.5 million.[3]

Although it currently remains unclear whether there are objective and biological abnormalities in ME/CFS, recent neuroimaging, blood marker analyses, and energy metabolism and mitochondrial studies detected these abnormalities in ME/CFS patients.[4] ME/CFS may be caused by the activation of the immune system, both within and outside the brain, which induces the release of inflammatory cytokines. ME/CFS is presumed to cause abnormalities in the central and autonomic nervous systems, systemic energy metabolism, and immune system and also involve oxidative and nitrosative stress.[4,5,6] Dysfunctions in systemic energy metabolism may be related to abnormalities in the structure and function of mitochondria.[7,8,9,10]

Molecular hydrogen (H2) is a gaseous molecule that selectively scavenges reactive oxygen and nitrogen species with strong oxidizing power, namely, hydroxyl radicals (·OH) and peroxynitrite, respectively.[11,12] H2 easily crosses the blood-brain barrier and biological membranes, reaches mitochondria, and protects cells from ·OH-induced cell damage.[11,12] A recent literature review revealed that H2 attenuated acute or chronic fatigue in animals and healthy subjects.[13] We also reported that the anti-fatigue effects of H2 involved the protection of mitochondria, which may also ameliorate the pathogenesis of ME/CFS.[13] Therefore, we conducted this case study to test this hypothesis by examining the efficacy of H2 gas inhalation in four patients with ME/CFS.

Source: Hirano, Shin-ichi*; Ichikawa, Yusuke; Sato, Bunpei; Takefuji, Yoshiyasu; Satoh, Fumitake. Successful treatment of myalgic encephalomyelitis/chronic fatigue syndrome using hydrogen gas: four case reports. Medical Gas Research 14(2):p 84-86, June 2024. | DOI: 10.4103/2045-9912.385441 https://journals.lww.com/mgar/fulltext/2024/14020/successful_treatment_of_myalgic.7.aspx (Full text)

Exercise capacity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) treated with long-term pyridostigmine

Abstract:

Background: The pathophysiology underlying exertional intolerance in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) remains poorly understood. Previously, a single-dose of 60 mg pyridostigmine, a reversible acetylcholinesterase inhibitor, was found to acutely improve aerobic capacity (Joseph, P. et al. Chest 2022; 162:1116–26).

Aims: To build upon these prior findings, this study aimed to evaluate the long-term effect (>1 month) of pyridostigmine treatment on exercise intolerance in ME/CFS.

Methods: Between 2017-2022, patients who met the National Academy of Medicine criteria for ME/CFS, and had a minimum of two clinical, constant load, submaximal exercise tests (Shape Medical System, MN) were evaluated. Patients who began pyridostigmine after their baseline test were considered the treatment group. Measurements were taken at baseline (T0) and most recent follow-up (T1).

Results: At the follow-up evaluation (690 ± 547 days), the treatment group (n=37, dose range: 24-360mg/d) demonstrated a significant increase in oxygen uptake efficiency slope (OUES) (T0: 1.82 ± 0.56, T1: 1.98 ± 0.53; p=0.044) and pulmonary vascular capacitance (PVCAP) (T0: 486.19 ± 169.89 ml*mmHg, T1: 540.03 ± 170.59 ml*mmHg; p=0.040). These differences were not observed in the control group (n=16) OUES (T0: 1.62 ± 0.40, T1: 1.77 ± 0.47; p=0.268) and PVCAP (T0: 446.94 ± 144.80 ml*mmHg, T1: 465.81 ± 124.34 ml*mmHg; p=0.590).

Conclusion: Long-term treatment with pyridostigmine improved aerobic capacity in ME/CFS as demonstrated by an increase in OUES, mediated by improvements in central hemodynamics (PVCAP).

Source: Johanna SquiresSarra Al-ZayerDavid Systrom. Exercise capacity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) treated with long-term pyridostigmine.

Incidence and persistence of post-COVID condition in children – a matched cohort study in Germany

Abstract:

Introduction: Long-term health effects of COVID-19 have been investigated by several large cohort studies. As most of these studies have been conducted in adults, data on the incidence and persistence of post-COVID-19 condition (PCC) among children and adolescents are still limited.
Methods: Using routine healthcare data from statutory health insurance in Germany, children and adolescents with laboratory-confirmed COVID-19 in 2020 were matched to controls (neither documented nor clinically suspected COVID-19) and followed for incident health conditions until 2021-09-30. To study PCC in children we considered selected health outcomes including malaise/fatigue (R53), dyspnea (R06.0), and cognitive dysfunction (F06.7, U51, R41), developmental delay (F80-89), adjustment disorder (F43), chronic fatigue syndrome (CFS; G93.3), and altered smell/anosmia (R43). The incidence of PCC was determined based on the lack of related diagnoses in the 12 months preceding the index quarter. For each outcome incidence rate ratios (IRR) were estimated using Poisson regression.
Results: At 3-month-follow-up, about 40% more individuals with COVID-19 suffered from at least one of the specified health conditions compared to controls. IRR were highest for smell/anosmia and CFS. IRR were generally higher among adolescents (≥12 years) than among younger children. Only a minority of PCC diagnoses persisted for 12 months within the COVID cohort. Diagnoses were more frequently persistent in the younger age group after one year.
Conclusions: Despite that long-term consequences of COVID-19 are less common and usually less severe in children, a considerable share of those diagnosed with PCC still suffered from specific symptoms 12 months after acute infection. Considering the high number of infected persons our findings suggest a relevant PCC related burden for health care even among children and adolescents.
Key messages:

• In routine healthcare data adolescents showed stronger associations between COVID-19 and post COVID-19 related ICD-10 diagnoses than children < 12 years of age.

• Serious ICD-10 diagnoses persisted for a longer time in younger children than adolescents.

Source: F Ehm, D Wende, F Loser, A Vivirito, S Menzer, M Batram, T Buschmann, G Sarganas, C Scheidt-Nave, J Schmitt, Incidence and persistence of post-COVID condition in children – a matched cohort study in Germany, European Journal of Public Health, Volume 33, Issue Supplement_2, October 2023, ckad160.095, https://doi.org/10.1093/eurpub/ckad160.095 https://academic.oup.com/eurpub/article/33/Supplement_2/ckad160.095/7327923 (Full text available as PDF file)

The long-term health outcomes, pathophysiological mechanisms and multidisciplinary management of long COVID

Abstract:

There have been hundreds of millions of cases of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the growing population of recovered patients, it is crucial to understand the long-term consequences of the disease and management strategies.

Although COVID-19 was initially considered an acute respiratory illness, recent evidence suggests that manifestations including but not limited to those of the cardiovascular, respiratory, neuropsychiatric, gastrointestinal, reproductive, and musculoskeletal systems may persist long after the acute phase. These persistent manifestations, also referred to as long COVID, could impact all patients with COVID-19 across the full spectrum of illness severity.

Herein, we comprehensively review the current literature on long COVID, highlighting its epidemiological understanding, the impact of vaccinations, organ-specific sequelae, pathophysiological mechanisms, and multidisciplinary management strategies. In addition, the impact of psychological and psychosomatic factors is also underscored.

Despite these crucial findings on long COVID, the current diagnostic and therapeutic strategies based on previous experience and pilot studies remain inadequate, and well-designed clinical trials should be prioritized to validate existing hypotheses. Thus, we propose the primary challenges concerning biological knowledge gaps and efficient remedies as well as discuss the corresponding recommendations.

Source: Li, J., Zhou, Y., Ma, J. et al. The long-term health outcomes, pathophysiological mechanisms and multidisciplinary management of long COVID. Sig Transduct Target Ther 8, 416 (2023). https://doi.org/10.1038/s41392-023-01640-z https://www.nature.com/articles/s41392-023-01640-z (Full text)

Long-term Prognosis at 1.5 years after Infection with Wild-type strain of SARS-CoV-2 and Alpha, Delta, as well as Omicron Variants

Highlights:

  • Trajectory of long COVID in SARS-CoV-2 wild-type, Alpha, Delta, and Omicron
  • Similar patterns of symptoms and severity of long COVID across all four variants
  • No clinically significant decline in median severity up to 1.5 years after infection
  • More than 50% of long COVID patients failed to improve using any outcome measure
  • Patients infected with Omicron may experience severe non-improving long COVID

Abstract:

Objectives: Knowledge is limited on how changing SARS-CoV-2 variants may translate into different characteristics and affect prognosis of patients with long COVID, especially following Omicron variants. We compared long-term prognosis of patients in a Danish Post COVID Clinic infected with wild-type strain, Alpha, Delta, or Omicron variants as well as the pre-Omicron compared to the Omicron period.

Methods: At enrollment a Post COVID symptom Questionnaire (PCQ), and standard health scores, were registered, and repeated four times until 1.5 years after infection. PCQ was the primary outcome to assess severity of long COVID, and delta PCQ to assess failure to improve.

Results: A total of 806 patients were enrolled. Patients infected with Omicron and Delta variants presented with more severe long COVID (median PCQ 43 in Delta vs 38 in wild-type, P=0.003) and health scores (EQ5D-index was 0.70 in Omicron vs 0.76 in wild-type, P=0.009 and 0.78 pre-Omicron, P=0.006). At 1.5 year after infection patients had no clinically meaningful decline in severity of long COVID, and 57% (245/429) of patients failed to improve 1.5 years after infection, with no differences between variants.

Conclusions: More than half of patients referred to a Post COVID Clinic failed to improve in long COVID severity 1.5 years after infection regardless of variants of SARS-CoV-2.

Source: Jane Agergaard , Jesper Damsgaard Gunst , Berit Schiøttz-Christensen , Lars Østergaard , Christian Wejse , Long-term Prognosis at 1.5 years after Infection with Wild-type strain of SARS-CoV-2 and Alpha, Delta, as well as Omicron Variants, International Journal of Infectious Diseases (2023), doi: https://doi.org/10.1016/j.ijid.2023.10.022 https://www.ijidonline.com/article/S1201-9712(23)00760-9/fulltext (Full text)

Long-COVID is Associated with Impaired Red Blood Cell Function

Abstract:

COVID-19 disease, caused by the severe acute respiratory syndrome virus 2 (SARS-CoV-2), induces a broad spectrum of clinical symptoms ranging from asymptomatic cases to fatal outcomes. About 10-35% of all COVID-19 patients, even those with mild COVID-19 symptoms, continue to show symptoms, i. e., fatigue, shortness of breath, cough, and cognitive dysfunction, after initial recovery.

Previously, we and others identified red blood cell precursors as a direct target of SARS-CoV-2 and suggested that SARS-CoV-2 induces dysregulation in hemoglobin- and iron-metabolism contributing to the severe systemic course of COVID-19. Here, we put particular emphasis on differences in parameters of clinical blood gas analysis and hematological parameters of more than 20 healthy and Long-COVID patients, respectively.

Long-COVID patients showed impaired oxygen binding to hemoglobin with concomitant increase in carbon monoxide binding. Hand in hand with decreased plasma iron concentration and transferrin saturation, mean corpuscular hemoglobin was elevated in Long-COVID patients compared to healthy donors suggesting a potential compensatory mechanism. Although blood pH was within the physiological range in both groups, base excess- and bicarbonate values were significantly lower in Long-COVID patients.

Furthermore, Long-COVID patients displayed reduced lymphocyte levels. The clinical relevance of these findings, e. g., as a cause of chronic immunodeficiency, remains to be investigated in future studies.

In conclusion, our data suggest impaired erythrocyte functionality in Long-COVID patients, leading to diminished oxygen supply. This in turn could be an explanation for the CFS, dyspnea and anemia. Further investigations are necessary to identify the underlying pathomechanisms.

Source: Kronstein-Wiedemann R, Tausche K, Kolditz M, Teichert M, Thiel J, Koschel D, Tonn T, Künzel SR. Long-COVID is Associated with Impaired Red Blood Cell Function. Horm Metab Res. 2023 Oct 27. doi: 10.1055/a-2186-8108. Epub ahead of print. PMID: 37890507. https://pubmed.ncbi.nlm.nih.gov/37890507/

Relevance of complement immunity with brain fog in patients with long COVID

Abstract:

Introduction: This study aimed to elucidate the prevalence and clinical characteristics of patients with long COVID (coronavirus disease 2019), especially focusing on 50% hemolytic complement activity (CH50).

Methods: This retrospective observational study focused on patients who visited Okayama University Hospital (Japan) for the treatment of long COVID between February 2021 and March 2023. CH50 levels were measured using liposome immunometric assay (Autokit CH50 Assay, FUJIFILM Wako Pure Chemical Corporation, Japan); high CH50 was defined as ≥59 U/mL. Univariate analyses assessed differences in the clinical background, long COVID symptoms, inflammatory markers, and clinical scores of patients with normal and high CH50. Logistic regression model investigated the association between high CH50 levels and these factors.

Results: Of 659 patients who visited our hospital, 478 patients were included. Of these, 284 (59.4%) patients had high CH50 levels. Poor concentration was significantly more frequent in the high CH50 group (7.2% vs. 13.7%), whereas no differences were observed in other subjective symptoms (fatigue, headache, insomnia, dyspnea, tiredness, and brain fog). Multivariate analysis was performed on factors that could be associated with poor concentration, suggesting a significant relationship to high CH50 levels (adjusted odds ratio [aOR], 2.70; 95% confidence interval [CI], 1.33–5.49). Also, high CH50 was significantly associated with brain fog (aOR, 1.66; 95% CI, 1.04–2.66).

Conclusions: High CH50 levels were frequently reported in individuals with long COVID, indicating a relationship with brain fog. Future in-depth research should examine the pathological role and causal link between complement immunity and the development of long COVID.

Source: Hagiya H, Tokumasu K, Otsuka Y, Sunada N, Nakano Y, Honda H, Furukawa M, Otsuka F. Relevance of complement immunity with brain fog in patients with long COVID. J Infect Chemother. 2023 Oct 20:S1341-321X(23)00261-1. doi: 10.1016/j.jiac.2023.10.016. Epub ahead of print. PMID: 37866620. https://www.sciencedirect.com/science/article/abs/pii/S1341321X23002611

Altered functional brain connectivity, efficiency, and information flow associated with brain fog after mild to moderate COVID-19 infection

Abstract:

COVID-19 is associated with increased risk for cognitive decline but very little is known regarding the neural mechanisms of this risk. We enrolled 49 adults (55% female, mean age = 30.7 +/- 8.7), 25 with and 24 without a history of COVID-19 infection. We administered standardized tests of cognitive function and acquired brain connectivity data using MRI.

The COVID-19 group demonstrated significantly lower cognitive function (W = 475, p < 0.001, effect size r = 0.58) and lower functional connectivity in multiple brain regions (mean t = 3.47 +/- 0.36, p = 0.03, corrected, effect size d = 0.92 to 1.5). Hypo-connectivity of these regions was inversely correlated with subjective cognitive function and directly correlated with fatigue (p < 0.05, corrected). These regions demonstrated significantly reduced local efficiency (p < 0.026, corrected) and altered effective connectivity (p < 0.001, corrected).

COVID-19 may have a widespread effect on the functional connectome characterized by lower functional connectivity and altered patterns of information processing efficiency and effective information flow. This may serve as an adaptation to the pathology of SARS-CoV-2 wherein the brain can continue functioning at near expected objective levels, but patients experience lowered efficiency as brain fog.

Source: Shelli R. Kesler, Oscar Y. Franco Rocha, Alexa De La Torre Schutz et al. Altered functional brain connectivity, efficiency, and information flow associated with brain fog after mild to moderate COVID-19 infection, 20 October 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3466991/v1] https://www.researchsquare.com/article/rs-3466991/v1 (Full text)

Clinical and pulmonary function analysis in long-COVID revealed that long-term pulmonary dysfunction is associated with vascular inflammation pathways and metabolic syndrome

Abstract:

Introduction: Long-term pulmonary dysfunction (L-TPD) is one of the most critical manifestations of long-COVID. This lung affection has been associated with disease severity during the acute phase and the presence of previous comorbidities, however, the clinical manifestations, the concomitant consequences and the molecular pathways supporting this clinical condition remain unknown. The aim of this study was to identify and characterize L-TPD in patients with long-COVID and elucidate the main pathways and long-term consequences attributed to this condition by analyzing clinical parameters and functional tests supported by machine learning and serum proteome profiling.

Methods: Patients with L-TPD were classified according to the results of their computer-tomography (CT) scan and diffusing capacity of the lungs for carbon monoxide adjusted for hemoglobin (DLCOc) tests at 4 and 12-months post-infection.

Results: Regarding the acute phase, our data showed that L-TPD was favored in elderly patients with hypertension or insulin resistance, supported by pathways associated with vascular inflammation and chemotaxis of phagocytes, according to computer proteomics. Then, at 4-months post-infection, clinical and functional tests revealed that L-TPD patients exhibited a restrictive lung condition, impaired aerobic capacity and reduced muscular strength. At this time point, high circulating levels of platelets and CXCL9, and an inhibited FCgamma-receptor-mediated-phagocytosis due to reduced FcγRIII (CD16) expression in CD14+ monocytes was observed in patients with L-TPD. Finally, 1-year post infection, patients with L-TPD worsened metabolic syndrome and augmented body mass index in comparison with other patient groups.

Discussion: Overall, our data demonstrated that CT scan and DLCOc identified patients with L-TPD after COVID-19. This condition was associated with vascular inflammation and impair phagocytosis of virus-antibody immune complexes by reduced FcγRIII expression. In addition, we conclude that COVID-19 survivors required a personalized follow-up and adequate intervention to reduce long-term sequelae and the appearance of further metabolic diseases.

Source: Sanhueza S, Vidal MA, Hernandez MA, Henriquez-Beltran ME, Cabrera C, Quiroga R, Antilef BE, Aguilar KP, Castillo DA, Llerena FJ, Fraga Figueroa M, Nazal M, Castro E, Lagos P, Moreno A, Lastra JJ, Gajardo J, Garcés P, Riffo B, Buchert J, Sanhueza R, Ormazába V, Saldivia P, Vargas C, Nourdin G, Koch E, Zuñiga FA, Lamperti L, Bustos P, Guzmán-Gutiérrez E, Tapia CA, Ferrada L, Cerda G, Woehlbier U, Riquelme E, Yuseff MI, Muñoz Ramirez BA, Lombardi G, De Gonzalo-Calvo D, Salomon C, Verdugo RA, Quiñones LA, Colombo A, Barría MI, Labarca G, Nova-Lamperti E. Clinical and pulmonary function analysis in long-COVID revealed that long-term pulmonary dysfunction is associated with vascular inflammation pathways and metabolic syndrome. Front Med (Lausanne). 2023 Oct 6;10:1271863. doi: 10.3389/fmed.2023.1271863. PMID: 37869162; PMCID: PMC10590130. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10590130/ (Full text)