Analysis of post COVID-19 condition and its overlap with myalgic encephalomyelitis/chronic fatigue syndrome

Illness presentation and quality of life in myalgic encephalomyelitis/chronic fatigue syndrome and post COVID-19 condition: a pilot Australian cross-sectional study

PURPOSE

Post COVID-19 Condition (PCC), being persistent COVID-19 symptoms, is reminiscent of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)-a chronic multi-systemic illness characterised by neurocognitive, autonomic, endocrinological and immunological disturbances. This novel cross-sectional investigation aims to: (1) compare symptoms among people with ME/CFS (pwME/CFS) and people with PCC (pwPCC) to inform developing PCC diagnostic criteria; and (2) compare health outcomes between patients and people without acute or chronic illness (controls) to highlight the illness burdens of ME/CFS and PCC.

METHODS

Sociodemographic and health outcome data were collected from n = 61 pwME/CFS, n = 31 pwPCC and n = 54 controls via validated, self-administered questionnaires, including the 36-Item Short-Form Health Survey version 2 (SF-36v2) and World Health Organization Disability Assessment Schedule version 2.0 (WHODAS 2.0). PwME/CFS and pwPCC also provided self-reported severity and frequency of symptoms derived from the Canadian and International Consensus Criteria for ME/CFS and the World Health Organization case definition for PCC.

RESULTS

Both illness cohorts similarly experienced key ME/CFS symptoms. Few differences in symptoms were observed, with memory disturbances, muscle weakness, lymphadenopathy and nausea more prevalent, light-headedness more severe, unrefreshed sleep more frequent, and heart palpitations less frequent among pwME/CFS (all p < 0.05). The ME/CFS and PCC participants' SF-36v2 or WHODAS 2.0 scores were comparable (all p > 0.05); however, both cohorts returned significantly lower scores in all SF-36v2 and WHODAS 2.0 domains when compared with controls (all p < 0.001).

CONCLUSION

This Australian-first investigation demonstrates the congruent and debilitating nature of ME/CFS and PCC, thereby emphasising the need for multidisciplinary care to maximise patient health outcomes.

Effect of long COVID-19 syndrome on health-related quality of life: a cross-sectional study

Purpose

This study aimed to assess the association of anxiety, headache, and insomnia on the QoL of patients with long COVID-19.

Methods

We conducted a cross-sectional survey between August 2020 and March 2023. A total of 200 participants were eligible, 53 were excluded and 147 patients with long COVID were included. QoL was evaluated across eight domains using the 36-Item Short Form Health Survey (SF-36). Standardized protocols including the Beck Anxiety Inventory (BAI) (n = 103), Pittsburgh Sleep Quality Index (PSQI) (n = 73), and Migraine Disability Assessment (MIDAS) (n = 67) were also used.

Results

Participants with sleep disorders had significantly lower Vitality (p < 0.001). Participants with anxiety disorders had significantly lower Vitality (p = 0.001), poorer Mental Health (p = 0.008), and more severe Bodily Pain (p = 0.008). Participants with headache had significantly lower Vitality (p = 0.032), poorer Mental Health (p = 0.036), and poorer Physical Functioning (p = 0.016). Participants with both headache and anxiety had significantly lower Vitality (p = 0.005) and Mental Health (p = 0.043) domain scores. Correlation analysis revealed that higher scores for anxiety, sleep disorder, and headache were independently correlated with poorer QoL across various domains. The presence of sleep disorder was associated with a fourfold increase in risk of experiencing diminished Vitality (odds ratio [OR]4.47; 95% CI 1.01-19.69; p = 0.048).

Conclusion

Participants with anxiety, sleep, and headache disorders tended to have a worse QoL. The Vitality and Mental Health domains were the most adversely affected in patients with long COVID. Sleep disorders were associated with a fourfold increase in the risk of poor Vitality.

Investigation into the restoration of TRPM3 ion channel activity in post-COVID-19 condition: a potential pharmacotherapeutic target

Introduction

Recently, we reported that post COVID-19 condition patients also have Transient Receptor Potential Melastatin 3 (TRPM3) ion channel dysfunction, a potential biomarker reported in natural killer (NK) cells from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients. As there is no universal treatment for post COVID-19 condition, knowledge of ME/CFS may provide advances to investigate therapeutic targets. Naltrexone hydrochloride (NTX) has been demonstrated to be beneficial as a pharmacological intervention for ME/CFS patients and experimental investigations have shown NTX restored TRPM3 function in NK cells. This research aimed to: i) validate impaired TRPM3 ion channel function in post COVID-19 condition patients compared with ME/CFS; and ii) investigate NTX effects on TRPM3 ion channel activity in post COVID-19 condition patients.

Methods

Whole-cell patch-clamp was performed to characterize TRPM3 ion channel activity in freshly isolated NK cells of post COVID-19 condition (N = 9; 40.56 ± 11.26 years), ME/CFS (N = 9; 39.33 ± 9.80 years) and healthy controls (HC) (N = 9; 45.22 ± 9.67 years). NTX effects were assessed on post COVID-19 condition (N = 9; 40.56 ± 11.26 years) and HC (N = 7; 45.43 ± 10.50 years) where NK cells were incubated for 24 hours in two protocols: treated with 200 µM NTX, or non-treated; TRPM3 channel function was assessed with patch-clamp protocol.

Results

This investigation confirmed impaired TRPM3 ion channel function in NK cells from post COVID-19 condition and ME/CFS patients. Importantly, PregS-induced TRPM3 currents were significantly restored in NTX-treated NK cells from post COVID-19 condition compared with HC. Furthermore, the sensitivity of NK cells to ononetin was not significantly different between post COVID-19 condition and HC after treatment with NTX.

Discussion

Our findings provide further evidence identifying similarities of TRPM3 ion channel dysfunction between ME/CFS and post COVID-19 condition patients. This study also reports, for the first time, TRPM3 ion channel activity was restored in NK cells isolated from post COVID-19 condition patients after in vitro treatment with NTX. The TRPM3 restoration consequently may re-establish TRPM3-dependent calcium (Ca2+) influx. This investigation proposes NTX as a potential therapeutic intervention and TRPM3 as a treatment biomarker for post COVID-19 condition.

Long-Term Impairment of Working Ability in Subjects under 60 Years of Age Hospitalised for COVID-19 at 2 Years of Follow-Up: A Cross-Sectional Study

Background: Coronavirus disease 2019 (COVID-19) can lead to persistent and debilitating symptoms referred to as Post-Acute sequelae of SARS-CoV-2 infection (PASC) This broad symptomatology lasts for months after the acute infection and impacts physical and mental health and everyday functioning. In the present study, we aimed to evaluate the prevalence and predictors of long-term impairment of working ability in non-elderly people hospitalised for COVID-19. Methods: This cross-sectional study involved 322 subjects hospitalised for COVID-19 from 1 March 2020 to 31 December 2022 in the University Hospital of Bari, Apulia, Italy, enrolled at the time of their hospital discharge and followed-up at a median of 731 days since hospitalization (IQR 466-884). Subjects reporting comparable working ability and those reporting impaired working ability were compared using the Mann-Whitney test (continuous data) and Fisher's test or Chi-Square test (categorical data). Multivariable analysis of impaired working ability was performed using a logistic regression model. Results: Among the 322 subjects who were interviewed, 184 reported comparable working ability (57.1%) and 134 reported impaired working ability (41.6%) compared to the pre-COVID-19 period. Multivariable analysis identified age at hospital admission (OR 1.02, 95% CI 0.99 to 1.04), female sex (OR 1.90, 95% CI 1.18 to 3.08), diabetes (OR 3.73, 95% CI 1.57 to 9.65), receiving oxygen during hospital stay (OR 1.76, 95% CI 1.01 to 3.06), and severe disease (OR 0.51, 95% CI 0.26 to 1.01) as independent predictors of long-term impaired working ability after being hospitalised for COVID-19. Conclusions: Our findings suggest that PASC promotes conditions that could result in decreased working ability and unemployment. These results highlight the significant impact of this syndrome on public health and the global economy, and the need to develop clinical pathways and guidelines for long-term care with specific focus on working impairment.

Precision Phenotyping for Curating Research Cohorts of Patients with Post-Acute Sequelae of COVID-19 (PASC) as a Diagnosis of Exclusion

Scalable identification of patients with the post-acute sequelae of COVID-19 (PASC) is challenging due to a lack of reproducible precision phenotyping algorithms and the suboptimal accuracy, demographic biases, and underestimation of the PASC diagnosis code (ICD-10 U09.9). In a retrospective case-control study, we developed a precision phenotyping algorithm for identifying research cohorts of PASC patients, defined as a diagnosis of exclusion. We used longitudinal electronic health records (EHR) data from over 295 thousand patients from 14 hospitals and 20 community health centers in Massachusetts. The algorithm employs an attention mechanism to exclude sequelae that prior conditions can explain. We performed independent chart reviews to tune and validate our precision phenotyping algorithm. Our PASC phenotyping algorithm improves precision and prevalence estimation and reduces bias in identifying Long COVID patients compared to the U09.9 diagnosis code. Our algorithm identified a PASC research cohort of over 24 thousand patients (compared to about 6 thousand when using the U09.9 diagnosis code), with a 79.9 percent precision (compared to 77.8 percent from the U09.9 diagnosis code). Our estimated prevalence of PASC was 22.8 percent, which is close to the national estimates for the region. We also provide an in-depth analysis outlining the clinical attributes, encompassing identified lingering effects by organ, comorbidity profiles, and temporal differences in the risk of PASC. The PASC phenotyping method presented in this study boasts superior precision, accurately gauges the prevalence of PASC without underestimating it, and exhibits less bias in pinpointing Long COVID patients. The PASC cohort derived from our algorithm will serve as a springboard for delving into Long COVID's genetic, metabolomic, and clinical intricacies, surmounting the constraints of recent PASC cohort studies, which were hampered by their limited size and available outcome data.

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

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 in these conditions.

METHODS

This single-site, prospective, cross-sectional, pilot cohort study aimed to distinguish between the two patient populations by using self-reported outcome measures and circulating biomarkers of endothelial function and systemic inflammation status. Thirty-one individuals with ME/CFS, 23 individuals with long COVID, and 31 matched sedentary healthy controls were included. All study participants underwent non-invasive cardiovascular hemodynamic challenge testing (10 min NASA lean test) for assessment of orthostatic intolerance. Regression analysis was used to examine associations between outcome measures and circulating biomarkers in the 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) using the 10-min NASA lean test. Compared with matched 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 matched control subjects (p < 0.01 in all cases). Long COVID patients had lower TSP-1 levels than did ME/CFS patients and matched sedentary healthy controls (p < 0.001). As for inflammation biomarkers, both long COVID and ME/CFS subjects had higher levels of TNF-α than did matched 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 biomarkers of endothelial function and inflammatory status in the study population.

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.

Severe pediatric COVID-19: a review from the clinical and immunopathophysiological perspectives

BACKGROUND

Coronavirus disease 2019 (COVID-19) tends to have mild presentations in children. However, severe and critical cases do arise in the pediatric population with debilitating systemic impacts and can be fatal at times, meriting further attention from clinicians. Meanwhile, the intricate interactions between the pathogen virulence factors and host defense mechanisms are believed to play indispensable roles in severe COVID-19 pathophysiology but remain incompletely understood.

DATA SOURCES

A comprehensive literature review was conducted for pertinent publications by reviewers independently using the PubMed, Embase, and Wanfang databases. Searched keywords included "COVID-19 in children", "severe pediatric COVID-19", and "critical illness in children with COVID-19".

RESULTS

Risks of developing severe COVID-19 in children escalate with increasing numbers of co-morbidities and an unvaccinated status. Acute respiratory distress stress and necrotizing pneumonia are prominent pulmonary manifestations, while various forms of cardiovascular and neurological involvement may also be seen. Multiple immunological processes are implicated in the host response to COVID-19 including the type I interferon and inflammasome pathways, whose dysregulation in severe and critical diseases translates into adverse clinical manifestations. Multisystem inflammatory syndrome in children (MIS-C), a potentially life-threatening immune-mediated condition chronologically associated with COVID-19 exposure, denotes another scientific and clinical conundrum that exemplifies the complexity of pediatric immunity. Despite the considerable dissimilarities between the pediatric and adult immune systems, clinical trials dedicated to children are lacking and current management recommendations are largely adapted from adult guidelines.

CONCLUSIONS

Severe pediatric COVID-19 can affect multiple organ systems. The dysregulated immune pathways in severe COVID-19 shape the disease course, epitomize the vast functional diversity of the pediatric immune system and highlight the immunophenotypical differences between children and adults. Consequently, further research may be warranted to adequately address them in pediatric-specific clinical practice guidelines.

Mast cells in the autonomic nervous system and potential role in disorders with dysautonomia and neuroinflammation

Mast cells (MC) are ubiquitous in the body, and they are critical for not only in allergic diseases but also in immunity and inflammation, including having potential involvement in the pathophysiology of dysautonomias and neuroinflammatory disorders. MC are located perivascularly close to nerve endings and sites such as the carotid bodies, heart, hypothalamus, the pineal gland, and the adrenal gland that would allow them not only to regulate but also to be affected by the autonomic nervous system (ANS). MC are stimulated not only by allergens but also many other triggers including some from the ANS that can affect MC release of neurosensitizing, proinflammatory, and vasoactive mediators. Hence, MC may be able to regulate homeostatic functions that seem to be dysfunctional in many conditions, such as postural orthostatic tachycardia syndrome, autism spectrum disorder, myalgic encephalomyelitis/chronic fatigue syndrome, and Long-COVID syndrome. The evidence indicates that there is a possible association between these conditions and diseases associated with MC activation. There is no effective treatment for any form of these conditions other than minimizing symptoms. Given the many ways MC could be activated and the numerous mediators released, it would be important to develop ways to inhibit stimulation of MC and the release of ANS-relevant mediators.

Efficacy and safety of bamlanivimab in patients with COVID-19: A systematic review and meta-analysis

BACKGROUND

Monoclonal antibodies (mAbs) have shown clinical benefits against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several studies have reported the use of bamlanivimab as a promising treatment option for COVID-19.

AIM

To synthesize the latest evidence for the efficacy and safety of bamlanivimab alone in the treatment of adult patients with COVID-19.

METHODS

A literature search was conducted in PubMed, Cochrane Library, Web of Science, medRxiv, and Google Scholar using "SARS-CoV-2", "COVID-19", "LY-CoV555", and "Bamlanivimab" keywords up to January 25, 2023. The quality of included studies was assessed using the Cochrane bias tools. The Comprehensive Meta-Analysis software version 3.0 was used to analyze the data.

RESULTS

A total of 30 studies involving 47368 patients were included. A significant difference was observed between the bamlanivimab and standard of care/placebo groups in terms of mortality rate [risk ratio (RR) = 50, 95% confidence interval (CI): 0.36-0.70], hospitalization rate (RR = 0.51; 95%CI: 0.39-0.68), and emergency department (ED) visits (RR = 0.69; 95%CI: 0.47-0.99); while the two groups exhibited no significant difference in terms of intensive care unit (ICU) admission (P > 0.05). Compared to other mAbs, bamlanivimab was associated with a higher rate of hospitalization (RR = 1.44; 95%CI: 1.07-1.94). However, no significant difference was detected between the bamlanivimab and other mAbs groups in terms of mortality rate, ICU admission, and ED (P > 0.05). The incidence of any adverse events was similar between the bamlanivimab and control groups (P > 0.05).

CONCLUSION

Although the results suggest the efficacy and safety of bamlanivimab in COVID-19 patients, further research is required to confirm the efficacy of this drug for the current circulating SARS-CoV-2 variants.

Co-Morbidity Clusters in Post-COVID-19 Syndrome

Background: Post-COVID-19 syndrome, characterized by persistent symptoms emerging more than 12 weeks after acute infection, displays diverse manifestations. This study aimed to analyze co-existing organ dysfunctions in post-COVID-19 patients and explore their potential association with the acute COVID-19 episode and functional impairment. Methods: Data from 238 patients attending post-COVID-19 outpatient care between 1 March 2021 and 1 March 2022, after previous hospitalization for acute COVID-19, were retrospectively analyzed with 80 having comprehensive mapping of organ involvement. Results: The average time between acute episode and post-COVID-19 care was 149 days. Spirometry indicated significant abnormalities in lung function. Predominant symptoms included respiratory (75%), fatigue (73%), neurological (62.5%), and ear-nose-throat issues (51.25%). Multiorgan dysfunctions were observed in 87.5% of patients, contributing to an 18.33% reduction in health quality compared to pre-acute COVID-19 levels. Subgroup analysis identified four distinct post-COVID-19 syndrome subgroups, highlighting the coexistence of respiratory and neurological disorders as potential indicators and drivers of further organ involvement. Our results reveal that most patients with post-COVID-19 syndrome suffer from multiorgan disorders. Conclusions: The presence of coexisting respiratory and neurological symptoms suggests the involvement of other organ systems as well. The complexity of multiorgan involvement requires further studies to provide insights into the different symptom clusters and identify potential targets for personalized preventive and therapeutic interventions to improve patient outcome.

A synbiotic preparation (SIM01) for post-acute COVID-19 syndrome in Hong Kong (RECOVERY): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Post-acute COVID-19 syndrome (PACS) affects over 65 million individuals worldwide but treatment options are scarce. We aimed to assess a synbiotic preparation (SIM01) for the alleviation of PACS symptoms.

METHODS

In this randomised, double-blind, placebo-controlled trial at a tertiary referral centre in Hong Kong, patients with PACS according to the US Centers for Disease Control and Prevention criteria were randomly assigned (1:1) by random permuted blocks to receive SIM01 (10 billion colony-forming units in sachets twice daily) or placebo orally for 6 months. Inclusion criterion was the presence of at least one of 14 PACS symptoms for 4 weeks or more after confirmed SARS-CoV-2 infection, including fatigue, memory loss, difficulty in concentration, insomnia, mood disturbance, hair loss, shortness of breath, coughing, inability to exercise, chest pain, muscle pain, joint pain, gastrointestinal upset, or general unwellness. Individuals were excluded if they were immunocompromised, were pregnant or breastfeeding, were unable to receive oral fluids, or if they had received gastrointestinal surgery in the 30 days before randomisation. Participants, care providers, and investigators were masked to group assignment. The primary outcome was alleviation of PACS symptoms by 6 months, assessed by an interviewer-administered 14-item questionnaire in the intention-to-treat population. Forward stepwise multivariable logistical regression was performed to identify predictors of symptom alleviation. The trial is registered with ClinicalTrials.gov, NCT04950803.

FINDINGS

Between June 25, 2021, and Aug 12, 2022, 463 patients were randomly assigned to receive SIM01 (n=232) or placebo (n=231). At 6 months, significantly higher proportions of the SIM01 group had alleviation of fatigue (OR 2·273, 95% CI 1·520-3·397, p=0·0001), memory loss (1·967, 1·271-3·044, p=0·0024), difficulty in concentration (2·644, 1·687-4·143, p<0·0001), gastrointestinal upset (1·995, 1·304-3·051, p=0·0014), and general unwellness (2·360, 1·428-3·900, p=0·0008) compared with the placebo group. Adverse event rates were similar between groups during treatment (SIM01 22 [10%] of 232 vs placebo 25 [11%] of 231; p=0·63). Treatment with SIM01, infection with omicron variants, vaccination before COVID-19, and mild acute COVID-19, were predictors of symptom alleviation (p<0·0036).

INTERPRETATION

Treatment with SIM01 alleviates multiple symptoms of PACS. Our findings have implications on the management of PACS through gut microbiome modulation. Further studies are warranted to explore the beneficial effects of SIM01 in other chronic or post-infection conditions.

FUNDING

Health and Medical Research Fund of Hong Kong, Hui Hoy and Chow Sin Lan Charity Fund, and InnoHK of the HKSAR Government.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Improved Functioning and Activity According to the International Classification of Functioning and Disability after Multidisciplinary Telerehabilitation for Post-COVID-19 Condition-A Randomized Control Study

This study investigates the outcomes and feasibility concerning the functioning and activity of multidisciplinary group telerehabilitation for a post-COVID-19 condition. Recruitment for the group rehabilitation was announced three times during 2021 and 2022 through the COVID-19 patient organization in Sweden. The key inclusion criteria were remaining symptoms and functional impairments beyond 12 weeks after SARS-CoV-2 infection; medical assessment and treatment regarding comorbidities or new postinfection symptoms; the ability to use the Internet. Participants were randomized into a rehabilitation group or onto a waiting list using an Internet program. Multiple outcomes included self-scored questionnaires and physical tests before and after eight weeks, and at six months follow-up. Here, we present the self-scored outcomes on the International Classification of Functioning and Disability questionnaire (ICF, 22 body functions and 16 activity/participation categories) and breathing scales. Of the 164 participants who registered for the study, 67 (mean age 43, 78% women) participated in an eight-week group rehabilitation compared to 42 who served as waiting list controls (mean age 47, 88% women). At six months follow-up, 60 participants from the rehabilitation group and 21 from the waiting list completed the data. The results indicate that a larger number of ICF body functions and activity/participation categories had improved in the rehabilitation group after eight weeks and six months. Overall credibility, as assessed by the Credibility Expectancy Questionnaire, was high, and the attrition rate in rehabilitation was low. The results indicate beneficial outcomes for multidisciplinary telerehabilitation in people suffering from a post-COVID-19 condition. Therefore, rehabilitation interventions should be further developed and implemented in clinical practice.

Health equity, care access and quality in headache - part 1

Current definitions of migraine that are based mainly on clinical characteristics do not account for other patient's features such as those related to an impaired quality of life, due to loss of social life and productivity, and the differences related to the geographical distribution of the disease and cultural misconceptions which tend to underestimate migraine as a psychosocial rather than neurobiological disorder.Global differences definition, care access, and health equity for headache disorders, especially migraine are reported in this paper from a collaborative group of the editorial board members of the Journal of Headache and Pain. Other components that affect patients with migraine, in addition to the impact promoted by the migraine symptoms such as stigma and social determinants, are also reported.

Lymphocyte and neutrophil count combined with intestinal bacteria abundance predict the severity of COVID-19

IMPORTANCE

The 2019 coronavirus disease (COVID-19) patients had a unique profile of gut bacteria. In this study, we characterized the intestinal bacteria in our COVID-19 cohorts and found that there was an increased incidence of severe cases in COVID-19 patients with decreased lymphocytes and increased neutrophils. Levels of lymphocytes and neutrophils and abundances of intestinal bacteria correlated with the severity of COVID-19.

Characterising respiratory infections among hospitalised children during the COVID-19 pandemic in southeastern China: a cross-sectional study of pathogens and clinical association

OBJECTIVE

Children with acute respiratory tract infections (ARTIs) pose significantly burden on healthcare facilities due to high hospitalisation rates and mortality. However, limited epidemiological and clinical characteristics data on ARTIs in southeastern China during the COVID-19 pandemic exists.

DESIGN

Cross-sectional.

SETTING

Tertiary hospital associated with the First Affiliated Hospital, Fujian Medical University, China.

PARTICIPANTS

1007 hospitalised children diagnosed with ARTIs, aged 30 days to 15 years, were enrolled in this study from 1 January 2020 to 31 December 2021.

OUTCOME MEASURE

The primary outcomes are the rate of pathogen infections in children with ARTIs. Secondary outcomes are the description of risk factors associated with ARTIs in children.

RESULTS

Of the 1007 enrolled children, 28.2%, 42.2%, 21.8% and 7.7% were diagnosed with upper respiratory tract infection, bronchopneumonia, bronchitis and pneumonia, respectively. Mycoplasma pneumoniae (MP) was the most prevalent pathogen (31.9%), followed by influenza B virus (IFVB; 29.1%) and influenza A virus (IFVA; 19.1%). The study found that children under 1 year old (older than 30 days: ORIFVB=12.50; ORMP=8.53), children aged 1-3 years (ORMP=1.62), the winter season (ORIFVA=1.36), the time from symptoms onset to hospitalisation (ORMP=1.10) and increased precipitation (ORLP=1.01) were high-risk factors for ARTIs.

CONCLUSION

This investigation offers significant insights into the prevalence and distribution of common pathogens among children experiencing ARTIs in the context of the COVID-19 pandemic. The discernment of high-risk factors linked to these pathogens enhances our understanding of the epidemiological characteristics of ARTIs in children.

Post-COVID exercise intolerance is associated with capillary alterations and immune dysregulations in skeletal muscles

The SARS-CoV-2 pandemic not only resulted in millions of acute infections worldwide, but also in many cases of post-infectious syndromes, colloquially referred to as "long COVID". Due to the heterogeneous nature of symptoms and scarcity of available tissue samples, little is known about the underlying mechanisms. We present an in-depth analysis of skeletal muscle biopsies obtained from eleven patients suffering from enduring fatigue and post-exertional malaise after an infection with SARS-CoV-2. Compared to two independent historical control cohorts, patients with post-COVID exertion intolerance had fewer capillaries, thicker capillary basement membranes and increased numbers of CD169+ macrophages. SARS-CoV-2 RNA could not be detected in the muscle tissues. In addition, complement system related proteins were more abundant in the serum of patients with PCS, matching observations on the transcriptomic level in the muscle tissue. We hypothesize that the initial viral infection may have caused immune-mediated structural changes of the microvasculature, potentially explaining the exercise-dependent fatigue and muscle pain.

Markers of oxidative stress during post-COVID-19 fatigue: a hypothesis-generating, exploratory pilot study on hospital employees

Introduction

Post-COVID-19 fatigue is common after recovery from COVID-19. Excess formation of reactive oxygen species (ROS) leading to oxidative stress-related mitochondrial dysfunction is referred to as a cause of these chronic fatigue-like symptoms. The present observational pilot study aimed to investigate a possible relationship between the course of ROS formation, subsequent oxidative stress, and post-COVID-19 fatigue.

Method

A total of 21 post-COVID-19 employees of the General Hospital Nuremberg suffering from fatigue-like symptoms were studied during their first consultation (T1: on average 3 months after recovery from COVID-19), which comprised an educational talk on post-COVID-19 symptomatology and individualized outpatient strategies to resume normal activity, and 8 weeks thereafter (T2). Fatigue severity was quantified using the Chalder Fatigue Scale together with a health survey (Patient Health Questionnaire) and self-report on wellbeing (12-Item Short-Form Health Survey). We measured whole blood superoxide anion (O 2 • - ) production rate (electron spin resonance, as a surrogate for ROS production) and oxidative stress-induced DNA strand breaks (single cell gel electrophoresis: "tail moment" in the "comet assay").

Results

Data are presented as mean ± SD or median (interquartile range) depending on the data distribution. Differences between T1 and T2 were tested using a paired Wilcoxon rank sign or t-test. Fatigue intensity decreased from 24 ± 5 at T1 to 18 ± 8 at T2 (p < 0.05), which coincided with reduced O 2 • - formation (from 239 ± 55 to 195 ± 59 nmol/s; p < 0.05) and attenuated DNA damage [tail moment from 0.67 (0.36-1.28) to 0.32 (0.23-0.71); p = 0.05].

Discussion

Our pilot study shows that post-COVID-19 fatigue coincides with (i) enhanced O 2 • - formation and oxidative stress, which are (ii) reduced with attenuation of fatigue symptoms.

Attention deficits and depressive symptoms improve differentially after rehabilitation of post-COVID condition - A prospective cohort study

BACKGROUND

Depressive and cognitive symptoms like fatigue, loss of energy or sleep disorders characterise the post-COVID condition. Post-COVID psychosomatic rehabilitation should focus on both symptom groups. The current prospective cohort study addresses the change in these symptoms in the context of a psychosomatic rehabilitation.

METHOD

N = 80 patients with post-COVID symptoms underwent psychological testing on admission and discharge: PHQ-9 questionnaire for depression, TAP - test battery for the attention test with the sub-tests working memory, sustained attention, divided attention and alertness. Sample characteristics, including health-related and work-related parameters, the general symptom load and the course of symptoms during the five weeks of rehabilitation were evaluated.

RESULTS

On admission, the PHQ-9 indicated the presence of depressive symptoms in post-COVID patients (PHQ-9 = 15.15 ± 5.11). Over the course of rehabilitation, the depressive symptoms decreased to a sub-clinical level (PHQ-9 = 8.80 ± 4.61), suggesting a strong effect of post-COVID inpatient rehabilitation (Cohen's d = 1.57). At the same time, post-COVID patients showed clinically relevant impairments in attention and working memory that persisted throughout the rehabilitation period despite multimodal post-COVID treatment.

CONCLUSION

Over the course of post-COVID rehabilitation, depressive symptoms appear to be significantly reduced. With regard to cognitive impairment, a comparable effect within the short period of 5 weeks is not evident. Our results suggest the need for specific treatment of persistent neuropsychological deficits following post-COVID rehabilitation.

[Chronic fatigue: What investigations? And what for?]

Chronic fatigue is a frequent complaint, expressed at all levels of the healthcare system. It is perceived as disabling in a high proportion of cases, and internists are frequently called upon to find "the" cause. The etiological diagnostic approach of an unexplained state of fatigue relies on the careful search for more specific clues by questioning and clinical examination. It is necessary to recognize the limited place of complementary examinations apart from the basic biological parameters. Simple rating scales can be useful in the etiological and differential diagnosis of fatigue. Chronic fatigue syndrome (CFS), in the current state of knowledge, cannot be considered as a specific pathological entity distinct from idiopathic chronic fatigue states, and does not have validated biomarkers. It is important to know that a state of chronic asthenia often results from several intricated etiological factors (biological, psychological and social), to be classified as predisposing, precipitating and perpetuating. The metabolic and cardiorespiratory exercise test has a major place in the assessment and management of fatigue, as a prerequisite for personalized retraining or adapted physical activity (APA), which are the treatments of choice for chronic fatigue.

Quantifying the benefits of healthy lifestyle behaviors and emotional expressivity in lowering the risk of COVID-19 infection: a national survey of Chinese population

BACKGROUND

COVID-19 is still prevalent in most countries around the world at the low level. Residents' lifestyle behaviors and emotions are critical to prevent COVID-19 and keep healthy, but there is lacking of confirmative evidence on how residents' lifestyle behaviors and emotional expressivity affected COVID-19 infection.

METHODS

Baseline study was conducted in August 2022 and follow-up study was conducted in February 2023. Baseline survey collected information on residents' basic information, as well as their lifestyle behaviors and emotions. Follow-up study was carried out to gather data on COVID-19 infection condition. Binary logistic regression was utilized to identify factors that may influence COVID-19 infection. Attributable risk (AR) was computed to determine the proportion of unhealthy lifestyle behaviors and emotional factors that could be attributed to COVID-19 infection. Sensitivity analysis was performed to test the robustness of the results.

RESULTS

A total of 5776 participants (46.57% males) were included in this study, yielding an overall COVID-19 infection rate of 54.8% (95%CI: 53.5 - 56.0%). The findings revealed that higher stress levels [aOR = 1.027 (95%CI; 1.005-1.050)] and lower frequency in wearing masks, washing hands, and keeping distance [aOR = 1.615 (95%CI; 1.087-2.401)], were positively associated with an increased likelihood of COVID-19 infection (all P < 0.05). If these associations were causal, 8.1% of COVID-19 infection would have been prevented if all participants had normal stress levels [Attributable Risk Percentage: 8.1% (95%CI: 5.9-10.3%)]. A significant interaction effect between stress and the frequency in wearing masks, washing hands, and keeping distance on COVID-19 infection was observed (β = 0.006, P < 0.001), which also was independent factor of COVID-19 infection.

CONCLUSIONS

The overall COVID-19 infection rate among residents is at a medium level. Residents' increasing stress and decreasing frequency in wearing masks and washing hands and keeping distance contribute to increasing risk of infection, residents should increase the frequency of mask-wearing, practice hand hygiene, keep safe distance from others, ensure stable emotional state, minimize psychological stress, providing evidence support for future responses to emerging infectious diseases.

Physical exercise as a treatment for persisting symptoms post-COVID infection: review of ongoing studies and prospective randomized controlled training study

BACKGROUND AND PURPOSE

No evidence-based treatment is available for patients with persisting symptoms post-COVID-19 infection. We hypothesized that physical exercise may represent a safe and effective treatment option for post-COVID.

METHODS

We performed a systematic search of the literature that revealed a lack of randomized training studies in patients post-COVID. Based on these findings, a prospective randomized controlled study with open-label and blinded endpoint evaluation was designed. 272 patients with symptoms of fatigue persisting over 6 weeks post-COVID infection were screened. Patients with pathological cardiovascular findings were excluded. 57 patients consented and were randomized to 4 weeks of supervised personalized strength and endurance training or usual care. The follow-up period was 3 and 6 months.

RESULTS

There were no adverse events related to the training. Spiroergometry of the training group showed a significantly higher increase in VO2peak (10.0 ± 12.7% vs. 0.1 ± 8.9%, p < 0.01, respectively) and oxygen pulse (9.8 ± 10.8% vs. 0.0 ± 13.9%, p < 0.05, respectively). Parameters of the Multidimensional Fatigue Inventory-20, McGill Quality of Life Questionnaire, and Post-COVID-19 Functional Status were improved after 4 weeks in both groups. In the follow-up period, the total physical activity per week was significantly greater in the exercise group than in controls (1280 ± 1192 min vs. 644 ± 554 min, p < 0.05, respectively). The improvements in fatigue and quality of life were not statistically different between the training and usual care groups.

CONCLUSION

Exercise is safe and improves maximal exercise capacity in post-COVID patients. Fatigue and quality of life improve over time in individuals that are willing to participate in a training study irrespective of their allocation.

REGISTRATION

German Clinical Trials Register: DRKS00026686. Date of registration: 27.09.2021.

A Review Article on Exercise Intolerance in Long COVID: Unmasking the Causes and Optimizing Treatment Strategies

There is a growing body of research on SARS-CoV-2 (PASC), previously known as the post-COVID syndrome, a chronic condition characterized by symptoms that persist after SARS-CoV-2 infection. Among these symptoms, feelings of physical exhaustion and prolonged fatigue are particularly prevalent and can significantly impact patients' quality of life. These symptoms are associated with reduced overall physical capacity, decreased daily physical activity, malaise after intense training, and intolerance to physical activity (IFA). IFA, described as a reduced ability to perform physical activities typical for the patient's age, can often lead to a sedentary lifestyle. Prolonged physical inactivity can cause deterioration in the overall physical condition and disrupt mitochondrial function, triggering a vicious cycle of gradual symptom worsening. The underlying causes of PASC remain unclear; however, several biochemical mechanisms have been discussed to explain the body's energy depletion, and a multidisciplinary approach that combines physical and cognitive rehabilitation and lifestyle interventions such as exercise and diet modifications has been suggested to improve the overall health and well-being of PASC patients. This critical review aims to review the existing research on the possible causes and links among chronic fatigue, reduced physical activity, and exercise intolerance in patients with PASC. Further research into the underlying causes and treatment of PASC and the importance of developing individualized treatment is needed to address each patient's unique health requirements.

A scoping review of 'Pacing' for management of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): lessons learned for the long COVID pandemic

BACKGROUND

Controversy over treatment for people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a barrier to appropriate treatment. Energy management or pacing is a prominent coping strategy for people with ME/CFS. Whilst a definitive definition of pacing is not unanimous within the literature or healthcare providers, it typically comprises regulating activity to avoid post exertional malaise (PEM), the worsening of symptoms after an activity. Until now, characteristics of pacing, and the effects on patients' symptoms had not been systematically reviewed. This is problematic as the most common approach to pacing, pacing prescription, and the pooled efficacy of pacing was unknown. Collating evidence may help advise those suffering with similar symptoms, including long COVID, as practitioners would be better informed on methodological approaches to adopt, pacing implementation, and expected outcomes.

OBJECTIVES

In this scoping review of the literature, we aggregated type of, and outcomes of, pacing in people with ME/CFS.

ELIGIBILITY CRITERIA

Original investigations concerning pacing were considered in participants with ME/CFS.

SOURCES OF EVIDENCE

Six electronic databases (PubMed, Scholar, ScienceDirect, Scopus, Web of Science and the Cochrane Central Register of Controlled Trials [CENTRAL]) were searched; and websites MEPedia, Action for ME, and ME Action were also searched for grey literature, to fully capture patient surveys not published in academic journals.

METHODS

A scoping review was conducted. Review selection and characterisation was performed by two independent reviewers using pretested forms.

RESULTS

Authors reviewed 177 titles and abstracts, resulting in 17 included studies: three randomised control trials (RCTs); one uncontrolled trial; one interventional case series; one retrospective observational study; two prospective observational studies; four cross-sectional observational studies; and five cross-sectional analytical studies. Studies included variable designs, durations, and outcome measures. In terms of pacing administration, studies used educational sessions and diaries for activity monitoring. Eleven studies reported benefits of pacing, four studies reported no effect, and two studies reported a detrimental effect in comparison to the control group.

CONCLUSIONS

Highly variable study designs and outcome measures, allied to poor to fair methodological quality resulted in heterogenous findings and highlights the requirement for more research examining pacing. Looking to the long COVID pandemic, our results suggest future studies should be RCTs utilising objectively quantified digitised pacing, over a longer duration of examination (i.e. longitudinal studies), using the core outcome set for patient reported outcome measures. Until these are completed, the literature base is insufficient to inform treatment practises for people with ME/CFS and long COVID.

People with Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Exhibit Similarly Impaired Vascular Function

BACKGROUND

This study aimed to compare flow-mediated dilation values between individuals with long COVID, individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and healthy age-matched controls to assess the potential implications for clinical management and long-term health outcomes.

METHODS

A case-case-control approach was employed, and flow-mediated dilation measurements were obtained from 51 participants (17 long COVID patients, 17 ME/CFS patients, and 17 healthy age-matched controls). Flow-mediated dilation values were analyzed using 1-way analysis of variance for between-group comparisons.

RESULTS

Results revealed significantly impaired endothelial function in both long COVID and ME/CFS groups compared with healthy age-matched controls as determined by maximum % brachial artery diameter post-occlusion compared with pre-occlusion resting diameter (6.99 ± 4.33% and 6.60 ± 3.48% vs 11.30 ± 4.44%, respectively, both P < .05). Notably, there was no difference in flow-mediated dilation between long COVID and ME/CFS groups (P = .949), despite significantly longer illness duration in the ME/CFS group (ME/CFS: 16 ± 11.15 years vs long COVID: 1.36 ± 0.51 years, P < .0001).

CONCLUSION

The study demonstrates that both long COVID and ME/CFS patients exhibit similarly impaired endothelial function, indicating potential vascular involvement in the pathogenesis of these post-viral illnesses. The significant reduction in flow-mediated dilation values suggests an increased cardiovascular risk in these populations, warranting careful monitoring and the development of targeted interventions to improve endothelial function and mitigate long-term health implications.

Special Issue "Post-COVID-19 Symptoms in Long-Haulers: Definition, Identification, Mechanisms, and Management"

The worldwide spread of coronavirus disease 2019 (COVID-19), a condition caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogen, led to the most unprecedented disease outbreak of this century, provoking around 770 million confirmed cases and nearly 7 million deaths globally [...].

Observational Study of Repeat Immunoadsorption (RIA) in Post-COVID ME/CFS Patients with Elevated ß2-Adrenergic Receptor Autoantibodies-An Interim Report

There is increasing evidence for an autoimmune aetiology in post-infectious Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). SARS-CoV-2 has now become the main trigger for ME/CFS. We have already conducted two small proof-of-concept studies on IgG depletion by immunoadsorption (IA) in post-infectious ME/CFS, which showed efficacy in most patients. This observational study aims to evaluate the efficacy of IA in patients with post-COVID-19 ME/CFS. The primary objective was to assess the improvement in functional ability. Due to the urgency of finding therapies for post-COVID-Syndrome (PCS), we report here the interim results of the first ten patients, with seven responders defined by an increase of between 10 and 35 points in the Short-Form 36 Physical Function (SF36-PF) at week four after IA. The results of this observational study will provide the basis for patient selection for a randomised controlled trial (RCT), including sham apheresis, and for an RCT combining IA with B-cell depletion therapy. Trial registration number: NCT05629988.

The Predictors of Long COVID in Southeastern Italy

INTRODUCTION

Long COVID is now recognized as a common consequence of the SARS-CoV-2 infection, but we are still far from fully understanding its pathogenesis and predictive factors. Many pathophysiological factors have been studied, including ethnicity. To our knowledge, the risk factors for Long COVID have not been studied in Southeastern Italy.

AIMS

The aim of this study was to evaluate the predictive factors of Long COVID in a cohort of patients from Southeastern Italy.

METHODS

We conducted a retrospective longitudinal study, enrolling inpatients and outpatients diagnosed with COVID-19 from June 2021 to March 2022. A total of 436 subjects were evaluated in an outpatient setting 12 weeks after a SARS-CoV-2 infection, recording comorbidities, symptoms, therapy, and clinical information. Univariate and multivariate binomial logistic regression analyses were performed on different risk factors to define the probability of developing Long COVID.

RESULTS

A total of 71.8% of patients (313) developed Long COVID, while the remaining 123 (28.3%) had a complete remission of symptoms 3 months after acute infection. During the acute phase of COVID-19, 68.3% of patients experienced respiratory failure and 81.4% received corticosteroid therapy. In a multivariate analysis, the female sex (SEX M ODD 0.513) and corticosteroids (ODD 2.25) were maintained as predictive values.

CONCLUSIONS

From our data and in line with other studies, the female sex emerges as a risk factor for Long COVID in the population of Southeastern Italy. Corticosteroid therapy administered in the acute phase also appears to be associated with an increased risk of Long COVID. Although indications for the prescription of corticosteroid therapy in the acute phase were indicated by the presence of pneumonia complicated by respiratory insufficiency, there was an over-prescription of corticosteroid therapy in the real life of our cohort, with 64% of patients having respiratory insufficiency and 81% having corticosteroid therapy. We hypothesize that a synergistic link between viral infection and the side effects of corticosteroid therapy may arise in selected cases.

Epstein-Barr virus-acquired immunodeficiency in myalgic encephalomyelitis-Is it present in long COVID?

Both myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) and long COVID (LC) are characterized by similar immunological alterations, persistence of chronic viral infection, autoimmunity, chronic inflammatory state, viral reactivation, hypocortisolism, and microclot formation. They also present with similar symptoms such as asthenia, exercise intolerance, sleep disorders, cognitive dysfunction, and neurological and gastrointestinal complaints. In addition, both pathologies present Epstein-Barr virus (EBV) reactivation, indicating the possibility of this virus being the link between both pathologies. Therefore, we propose that latency and recurrent EBV reactivation could generate an acquired immunodeficiency syndrome in three steps: first, an acquired EBV immunodeficiency develops in individuals with "weak" EBV HLA-II haplotypes, which prevents the control of latency I cells. Second, ectopic lymphoid structures with EBV latency form in different tissues (including the CNS), promoting inflammatory responses and further impairment of cell-mediated immunity. Finally, immune exhaustion occurs due to chronic exposure to viral antigens, with consolidation of the disease. In the case of LC, prior to the first step, there is the possibility of previous SARS-CoV-2 infection in individuals with "weak" HLA-II haplotypes against this virus and/or EBV.

Analyzing the Interplay between COVID-19 Viral Load, Inflammatory Markers, and Lymphocyte Subpopulations on the Development of Long COVID

The global impact of the SARS-CoV-2 infection has been substantial, affecting millions of people. Long COVID, characterized by persistent or recurrent symptoms after acute infection, has been reported in over 40% of patients. Risk factors include age and female gender, and various mechanisms, including chronic inflammation and viral persistence, have been implicated in long COVID's pathogenesis. However, there are scarce studies in which multiple inflammatory markers and viral load are analyzed simultaneously in acute infection to determine how they predict for long COVID at long-term follow-up. This study explores the association between long COVID and inflammatory markers, viral load, and lymphocyte subpopulation during acute infection in hospitalized patients to better understand the risk factors of this disease. This longitudinal retrospective study was conducted in patients hospitalized with COVID-19 in northern Mexico. Inflammatory parameters, viral load, and lymphocyte subpopulation during the acute infection phase were analyzed, and long COVID symptoms were followed up depending on severity and persistence (weekly or monthly) and assessed 1.5 years after the acute infection. This study analyzed 79 patients, among them, 41.8% presented long COVID symptoms, with fatigue being the most common (45.5%). Patients with long COVID had higher lymphocyte levels during hospitalization, and NK cell subpopulation levels were also associated with long COVID. ICU admission during acute COVID-19 was also linked to the development of long COVID symptoms.

New perspective on the immunomodulatory activity of ginsenosides: Focus on effective therapies for post-COVID-19

More than 700 million confirmed cases of Coronavirus Disease-2019 (COVID-19) have been reported globally, and 10-60% of patients are expected to exhibit "post-COVID-19 symptoms," which will continue to affect human life and health. In the absence of safer, more specific drugs, current multiple immunotherapies have failed to achieve satisfactory efficacy. Ginseng, a traditional Chinese medicine, is often used as an immunomodulator and has been used in COVID-19 treatment as a tonic to increase blood oxygen saturation. Ginsenosides are the main active components of ginseng. In this review, we summarize the multiple ways in which ginsenosides affect post-COVID-19 symptoms, including inhibition of lipopolysaccharide, tumor necrosis factor signaling, modulation of chemokine receptors and inflammasome activation, induction of macrophage polarization, effects on Toll-like receptors, nuclear factor kappa-B, the mitogen-activated protein kinase pathway, lymphocytes, intestinal flora, and epigenetic regulation. Ginsenosides affect virus-mediated tissue damage, local or systemic inflammation, immune modulation, and other links, thus alleviating respiratory and pulmonary symptoms, reducing the cardiac burden, protecting the nervous system, and providing new ideas for the rehabilitation of patients with post-COVID-19 symptoms. Furthermore, we analyzed its role in strengthening body resistance to eliminate pathogenic factors from the perspective of ginseng-epidemic disease and highlighted the challenges in clinical applications. However, the benefit of ginsenosides in modulating organismal imbalance post-COVID-19 needs to be further evaluated to better validate the pharmacological mechanisms associated with their traditional efficacy and to determine their role in individualized therapy.

Chronic inflammation, neuroglial dysfunction, and plasmalogen deficiency as a new pathobiological hypothesis addressing the overlap between post-COVID-19 symptoms and myalgic encephalomyelitis/chronic fatigue syndrome

After five waves of coronavirus disease 2019 (COVID-19) outbreaks, it has been recognized that a significant portion of the affected individuals developed long-term debilitating symptoms marked by chronic fatigue, cognitive difficulties ("brain fog"), post-exertional malaise, and autonomic dysfunction. The onset, progression, and clinical presentation of this condition, generically named post-COVID-19 syndrome, overlap significantly with another enigmatic condition, referred to as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Several pathobiological mechanisms have been proposed for ME/CFS, including redox imbalance, systemic and central nervous system inflammation, and mitochondrial dysfunction. Chronic inflammation and glial pathological reactivity are common hallmarks of several neurodegenerative and neuropsychiatric disorders and have been consistently associated with reduced central and peripheral levels of plasmalogens, one of the major phospholipid components of cell membranes with several homeostatic functions. Of great interest, recent evidence revealed a significant reduction of plasmalogen contents, biosynthesis, and metabolism in ME/CFS and acute COVID-19, with a strong association to symptom severity and other relevant clinical outcomes. These bioactive lipids have increasingly attracted attention due to their reduced levels representing a common pathophysiological manifestation between several disorders associated with aging and chronic inflammation. However, alterations in plasmalogen levels or their lipidic metabolism have not yet been examined in individuals suffering from post-COVID-19 symptoms. Here, we proposed a pathobiological model for post-COVID-19 and ME/CFS based on their common inflammation and dysfunctional glial reactivity, and highlighted the emerging implications of plasmalogen deficiency in the underlying mechanisms. Along with the promising outcomes of plasmalogen replacement therapy (PRT) for various neurodegenerative/neuropsychiatric disorders, we sought to propose PRT as a simple, effective, and safe strategy for the potential relief of the debilitating symptoms associated with ME/CFS and post-COVID-19 syndrome.

The Potential Role of Hypothalamic Phospholipid Liposomes in the Supportive Therapy of Some Manifestations of Post-COVID-19 Condition: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Brain Fog

Post-COVID-19 condition (commonly known as Long COVID) is a heterogeneous clinical condition in which Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and brain fog stand out among the different clinical symptoms and syndromes. Cerebral metabolic alterations and neuroendocrine disorders seem to constitute an important part of the pathophysiology of Post-COVID-19 condition (PCC). Given the substantial lack of specific drugs and effective therapeutic strategies, hypothalamic phospholipid liposomes, which have been on the market for several years as adjuvant therapy for cerebral metabolic alterations resulting from neuroendocrine disorders, might represent a potential option in an overall therapeutic strategy that aims to control PCC-associated symptoms and syndromes. Their pharmacological mechanisms and clinical effects strongly support their potential effectiveness in PCC. Our initial clinical experience seems to corroborate this rationale. Further controlled clinical research is warranted in order to verify this hypothesis.

Typing myalgic encephalomyelitis by infection at onset: A DecodeME study

Background

People with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) experience core symptoms of post-exertional malaise, unrefreshing sleep, and cognitive impairment. Despite numbering 0.2-0.4% of the population, no laboratory test is available for their diagnosis, no effective therapy exists for their treatment, and no scientific breakthrough regarding pathogenesis has been made. It remains unknown, despite decades of small-scale studies, whether individuals experience different types of ME/CFS separated by onset-type, sex or age.

Methods

DecodeME is a large population-based study of ME/CFS that recruited 17,074 participants in the first 3 months following full launch. Detailed questionnaire responses from UK-based participants who all reported being diagnosed with ME/CFS by a health professional provided an unparalleled opportunity to investigate, using logistic regression, whether ME/CFS severity or onset type is significantly associated with sex, age, illness duration, comorbid conditions or symptoms.

Results

The well-established sex-bias among ME/CFS patients is evident in the initial DecodeME cohort: 83.5% of participants were females. What was not known previously was that females tend to have more comorbidities than males. Moreover, being female, being older and being over 10 years from ME/CFS onset are significantly associated with greater severity. Five different ME/CFS onset types were examined in the self-reported data: those with ME/CFS onset (i) after glandular fever (infectious mononucleosis); (ii) after COVID-19 infection; (iii) after other infections; (iv) without an infection at onset; and, (v) where the occurrence of an infection at or preceding onset is not known. Among other findings, ME/CFS onset with unknown infection status was significantly associated with active fibromyalgia.

Conclusions

DecodeME participants differ in symptoms, comorbid conditions and/or illness severity when stratified by their sex-at-birth and/or infection around the time of ME/CFS onset.

Typing myalgic encephalomyelitis by infection at onset: A DecodeME study

BACKGROUND

People with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) experience core symptoms of post-exertional malaise, unrefreshing sleep, and cognitive impairment. Despite numbering 0.2-0.4% of the population, no laboratory test is available for their diagnosis, no effective therapy exists for their treatment, and no scientific breakthrough regarding pathogenesis has been made. It remains unknown, despite decades of small-scale studies, whether individuals experience different types of ME/CFS separated by onset-type, sex or age.

METHODS

DecodeME is a large population-based study of ME/CFS that recruited 17,074 participants in the first 3 months following full launch. Detailed questionnaire responses from UK-based participants who all reported being diagnosed with ME/CFS by a health professional provided an unparalleled opportunity to investigate, using logistic regression, whether ME/CFS severity or onset type is significantly associated with sex, age, illness duration, comorbid conditions or symptoms.

RESULTS

The well-established sex-bias among ME/CFS patients is evident in the initial DecodeME cohort: 83.5% of participants were females. What was not known previously was that females tend to have more comorbidities than males. Moreover, being female, being older and being over 10 years from ME/CFS onset are significantly associated with greater severity. Five different ME/CFS onset types were examined in the self-reported data: those with ME/CFS onset (i) after glandular fever (infectious mononucleosis); (ii) after COVID-19 infection; (iii) after other infections; (iv) without an infection at onset; and, (v) where the occurrence of an infection at or preceding onset is not known. Among other findings, ME/CFS onset with unknown infection status was significantly associated with active fibromyalgia.

CONCLUSIONS

DecodeME participants differ in symptoms, comorbid conditions and/or illness severity when stratified by their sex-at-birth and/or infection around the time of ME/CFS onset.

Longterm course of neuropsychological symptoms and ME/CFS after SARS-CoV-2-infection: a prospective registry study

A significant proportion of patients after SARS-CoV-2 infection suffer from long-lasting symptoms. Although many different symptoms are described, the majority of patients complains about neuropsychological symptoms. Additionally, a subgroup of patients fulfills diagnostic criteria for ME/CFS. We analyzed a registry of all patients presenting in the out-patients clinic at a German university center. For patients with more than one visit, changes in reported symptoms from first to second visit were analyzed. A total of 1022 patients were included in the study, 411 of them had more than one visit. 95.5% of the patients reported a polysymptomatic disease. At the first visit 31.3% of the patients fulfilled ME/CFS criteria after a median time of 255 days post infection and and at the second visit after a median of 402 days, 19.4% still suffered from ME/CFS. Self-reported fatigue (83.7-72.7%) and concentration impairment (66.2-57.9%) decreased from first to second visit contrasting non-significant changes in the structured screening. A significant proportion of SARS-CoV-2 survivors presenting with ongoing symptoms present with ME/CFS. Although the proportion of subjective reported symptoms and their severity reduce over time, a significant proportion of patients suffer from long-lasting symptoms necessitating new therapeutic concepts.

Cognitive impairment in post-acute sequelae of COVID-19 and short duration myalgic encephalomyelitis patients is mediated by orthostatic hemodynamic changes

Introduction

Cognitive impairment is experienced by people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-acute sequelae of COVID-19 (PASC). Patients report difficulty remembering, concentrating, and making decisions. Our objective was to determine whether orthostatic hemodynamic changes were causally linked to cognitive impairment in these diseases.

Methods

This prospective, observational cohort study enrolled PASC, ME/CFS, and healthy controls. All participants underwent clinical evaluation and assessment that included brief cognitive testing before and after an orthostatic challenge. Cognitive testing measured cognitive efficiency which is defined as the speed and accuracy of subject's total correct responses per minute. General linear mixed models were used to analyze hemodynamics and cognitive efficiency during the orthostatic challenge. Additionally, mediation analysis was used to determine if hemodynamic instability induced during the orthostatic challenge mediated the relationship between disease status and cognitive impairment.

Results

Of the 276 participants enrolled, 256 were included in this study (34 PASC, 71 < 4 year duration ME/CFS, 69 > 10 year ME/CFS duration, and 82 healthy controls). Compared to healthy controls, the disease cohorts had significantly lower cognitive efficiency scores immediately following the orthostatic challenge. Cognitive efficiency remained low for the >10 year ME/CFS 2 and 7 days after orthostatic challenge. Narrow pulse pressure less than 25% of systolic pressure occurred at 4 and 5 min into the orthostatic challenge for the PASC and ME/CFS cohorts, respectively. Abnormally narrow pulse pressure was associated with slowed information processing in PASC patients compared to healthy controls (-1.5, p = 0.04). Furthermore, increased heart rate during the orthostatic challenge was associated with a decreased procedural reaction time in PASC and < 4 year ME/CFS patients who were 40 to 65 years of age.

Discussion

For PASC patients, both their disease state and hemodynamic changes during orthostatic challenge were associated with slower reaction time and decreased response accuracy during cognitive testing. Reduced cognitive efficiency in <4 year ME/CFS patients was associated with higher heart rate in response to orthostatic stress. Hemodynamic changes did not correlate with cognitive impairment for >10 year ME/CFS patients, but cognitive impairment remained. These findings underscore the need for early diagnosis to mitigate direct hemodynamic and other physiological effects on symptoms of cognitive impairment.

Proteomics and cytokine analyses distinguish myalgic encephalomyelitis/chronic fatigue syndrome cases from controls

BACKGROUND

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex, heterogenous disease characterized by unexplained persistent fatigue and other features including cognitive impairment, myalgias, post-exertional malaise, and immune system dysfunction. Cytokines are present in plasma and encapsulated in extracellular vesicles (EVs), but there have been only a few reports of EV characteristics and cargo in ME/CFS. Several small studies have previously described plasma proteins or protein pathways that are associated with ME/CFS.

METHODS

We prepared extracellular vesicles (EVs) from frozen plasma samples from a cohort of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) cases and controls with prior published plasma cytokine and plasma proteomics data. The cytokine content of the plasma-derived extracellular vesicles was determined by a multiplex assay and differences between patients and controls were assessed. We then performed multi-omic statistical analyses that considered not only this new data, but extensive clinical data describing the health of the subjects.

RESULTS

ME/CFS cases exhibited greater size and concentration of EVs in plasma. Assays of cytokine content in EVs revealed IL2 was significantly higher in cases. We observed numerous correlations among EV cytokines, among plasma cytokines, and among plasma proteins from mass spectrometry proteomics. Significant correlations between clinical data and protein levels suggest roles of particular proteins and pathways in the disease. For example, higher levels of the pro-inflammatory cytokines Granulocyte-Monocyte Colony-Stimulating Factor (CSF2) and Tumor Necrosis Factor (TNFα) were correlated with greater physical and fatigue symptoms in ME/CFS cases. Higher serine protease SERPINA5, which is involved in hemostasis, was correlated with higher SF-36 general health scores in ME/CFS. Machine learning classifiers were able to identify a list of 20 proteins that could discriminate between cases and controls, with XGBoost providing the best classification with 86.1% accuracy and a cross-validated AUROC value of 0.947. Random Forest distinguished cases from controls with 79.1% accuracy and an AUROC value of 0.891 using only 7 proteins.

CONCLUSIONS

These findings add to the substantial number of objective differences in biomolecules that have been identified in individuals with ME/CFS. The observed correlations of proteins important in immune responses and hemostasis with clinical data further implicates a disturbance of these functions in ME/CFS.

Neurorecovery after Critical COVID-19 Illness

With the hundreds of millions of people worldwide who have been, and continue to be, affected by pandemic coronavirus disease (COVID-19) and its chronic sequelae, strategies to improve recovery and rehabilitation from COVID-19 are critical global public health priorities. Neurologic complications have been associated with acute COVID-19 infection, usually in the setting of critical COVID-19 illness. Neurologic complications are also a core feature of the symptom constellation of long COVID and portend poor outcomes. In this article, we review neurologic complications and their mechanisms in critical COVID-19 illness and long COVID. We focus on parallels with neurologic disease associated with non-COVID critical systemic illness. We conclude with a discussion of how recent findings can guide both neurologists working in post-acute neurologic rehabilitation facilities and policy makers who influence neurologic resource allocation.

The Role of Psychotherapy in the Care of Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Myalgic encephalomyelitis/chronic fatigue (ME/CFS) is a post-infectious, chronic disease that can lead to severe impairment and, even, total disability. Although the disease has been known for a long time, and has been coded in the ICD since 1969 (G93.3), medical research has not yet been able to reach a consensus regarding its physiological basis and how best to treat it. Against the background of these shortcomings, psychosomatic disease models have been developed and psychotherapeutic treatments have been derived from them, but their empirical testing has led to sobering results. According to the current state of research, psychotherapy and psychosomatic rehabilitation have no curative effect in the treatment of ME/CFS. Nevertheless, we see numerous patients in practices and outpatient clinics who suffer severely as a result of their illness and whose mental well-being and coping strategies would benefit from psychotherapeutic help. In this article, we outline a psychotherapeutic approach that serves this need, taking into account two basic characteristics of ME/CFS: firstly, the fact that ME/CFS is a physical illness and that curative treatment must therefore be physical; and secondly, the fact that post exertional malaise (PEM) is a cardinal symptom of ME/CFS and thus warrants tailored psychotherapeutic attention.

Towards a Better Understanding of the Complexities of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Long COVID

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex condition arising in susceptible people, predominantly following viral infection, but also other stressful events. The susceptibility factors discussed here are both genetic and environmental although not well understood. While the dysfunctional physiology in ME/CFS is becoming clearer, understanding has been hampered by different combinations of symptoms in each affected person. A common core set of mainly neurological symptoms forms the modern clinical case definition, in the absence of an accessible molecular diagnostic test. This landscape has prompted interest in whether ME/CFS patients can be classified into a particular phenotype/subtype that might assist better management of their illness and suggest preferred therapeutic options. Currently, the same promising drugs, nutraceuticals, or behavioral therapies available can be beneficial, have no effect, or be detrimental to each individual patient. We have shown that individuals with the same disease profile exhibit unique molecular changes and physiological responses to stress, exercise and even vaccination. Key features of ME/CFS discussed here are the possible mechanisms determining the shift of an immune/inflammatory response from transient to chronic in ME/CFS, and how the brain and CNS manifests the neurological symptoms, likely with activation of its specific immune system and resulting neuroinflammation. The many cases of the post viral ME/CFS-like condition, Long COVID, following SARS-CoV-2 infection, and the intense research interest and investment in understanding this condition, provide exciting opportunities for the development of new therapeutics that will benefit ME/CFS patients.

Role of SARS-CoV-2 Spike-Protein-Induced Activation of Microglia and Mast Cells in the Pathogenesis of Neuro-COVID

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). About 45% of COVID-19 patients experience several symptoms a few months after the initial infection and develop post-acute sequelae of SARS-CoV-2 (PASC), referred to as "Long-COVID," characterized by persistent physical and mental fatigue. However, the exact pathogenetic mechanisms affecting the brain are still not well-understood. There is increasing evidence of neurovascular inflammation in the brain. However, the precise role of the neuroinflammatory response that contributes to the disease severity of COVID-19 and long COVID pathogenesis is not clearly understood. Here, we review the reports that the SARS-CoV-2 spike protein can cause blood-brain barrier (BBB) dysfunction and damage neurons either directly, or via activation of brain mast cells and microglia and the release of various neuroinflammatory molecules. Moreover, we provide recent evidence that the novel flavanol eriodictyol is particularly suited for development as an effective treatment alone or together with oleuropein and sulforaphane (ViralProtek®), all of which have potent anti-viral and anti-inflammatory actions.

Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID

A novel syndrome called long-haul COVID or long COVID is increasingly recognized in a significant percentage of individuals within a few months after infection with SARS-CoV-2. This disorder is characterized by a wide range of persisting, returning or even new but related symptoms that involve different tissues and organs, including respiratory, cardiac, vascular, gastrointestinal, musculo-skeletal, neurological, endocrine and systemic. Some overlapping symptomatologies exist between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Very much like with long ME/CFS, infections with herpes family viruses, immune dysregulation, and the persistence of inflammation have been reported as the most common pattern for the development of long COVID. This review describes several factors and determinants of long COVID that have been proposed, elaborating mainly on viral persistence, reactivation of latent viruses such as Epstein-Barr virus and human herpesvirus 6 which are also associated with the pathology of ME/CFS, viral superantigen activation of the immune system, disturbance in the gut microbiome, and multiple tissue damage and autoimmunity. Based on these factors, we propose diagnostic strategies such as the measurement of IgG and IgM antibodies against SARS-CoV-2, EBV, HHV-6, viral superantigens, gut microbiota, and biomarkers of autoimmunity to better understand and manage this multi-factorial disorder that continues to affect millions of people in the world.

European Working Group on SARS-CoV-2: Current Understanding, Unknowns, and Recommendations on the Neurological Complications of COVID-19

The emergence of COVID-19 was rapidly followed by infection and the deaths of millions of people across the globe. With much of the research and scientific advancement rightly focused on reducing the burden of severe and critical acute COVID-19 infection, the long-term effects endured by those who survived the acute infection has been previously overlooked. Now, an appreciation for the post-COVID-19 condition, including its neurological manifestations, is growing, although there remain many unknowns regarding the aetiology and risk factors of the condition, as well as how to effectively diagnose and treat it. Here, drawing upon the experiences and expertise of the clinicians and academics of the European working group on COVID-19, we have reviewed the current literature to provide a comprehensive overview of the neurological sequalae of the post-COVID-19 condition. In this review, we provide a summary of the neurological symptoms associated with the post-COVID-19 condition, before discussing the possible mechanisms which may underly and manifest these symptoms. Following this, we explore the risk factors for developing neurological symptoms as a result of COVID-19 and the post-COVID-19 condition, as well as how COVID-19 infection may itself be a risk factor for the development of neurological disease in the future. Lastly, we evaluate how the post-COVID condition could be accurately diagnosed and effectively treated, including examples of the current guidelines, clinical outcomes and tools that have been developed to aid in this process, as well as addressing the protection provided by COVID-19 vaccines against post-COVID-19 condition. Overall, this review provides a comprehensive overview of the neurological sequalae of the post-COVID-19 condition.

Association between Experimental Pain Measurements and the Central Sensitization Inventory in Patients at Least 3 Months after COVID-19 Infection: A Cross-Sectional Pilot Study

Fatigue, pain, headache, brain fog, anosmia, ageusia, mood symptoms, and sleep disorders are symptoms commonly experienced by people with post-COVID-19 condition. These symptoms could be considered as manifestations of central sensitization. The aim of this study is to evaluate whether there are indicators of central sensitization by using experimental pain measurements and to determine their association with patient-reported outcome measures (PROMs). A cross-sectional study including 42 patients after COVID-19 infection was conducted. The central sensitization inventory (CSI) was administered as a PROM to evaluate central-sensitization-associated symptoms. Pressure pain thresholds (PPT), temporal summation, and descending nociceptive pain inhibition (CPM) were assessed as experimental pain measurements. The median score on the CSI was 46.5 (Q1-Q3: 33-54). The presence of central-sensitization-associated symptoms was seen in 64.3% of patients based on the CSI (≥40/100 points). A deficient CPM was seen in 12% and 14% of patients when measured at the trapezius and rectus femoris, respectively. A negative correlation between pressure sensitivity on the rectus femoris and the CSI score (r = -0.36, 95%CI -0.13 to -0.65, p = 0.007) was observed. Central-sensitization-associated symptoms were present in up to 64.3% of patients post-COVID-19 infection, based on a PROM, i.e., the CSI. A more objective evaluation of nociceptive processing through experimental pain measurements was less suggestive of indicators of central sensitization. Only a small negative correlation between pressure sensitivity and the CSI was observed, thereby pointing towards the discrepancy between the CSI and experimental pain measurements and presumably the complementary need for both to evaluate potential indicators of central sensitization in this population.

Converging Evidence of Similar Symptomatology of ME/CFS and PASC Indicating Multisystemic Dyshomeostasis

The purpose of this article is to review the evidence of similar symptomatology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-acute sequelae of SARS-CoV-2 infection (PASC). Reanalysis of data from a study by Jason comparing symptom reports from two groups of ME/CFS and PASC patients shows a notably similar symptomatology. Symptom scores of the PASC group and the ME/CFS group correlated 0.902 (p < 0.0001) across items. The hypothesis is presented that ME/CFS and PASC are caused by a chronic state of multisystemic disequilibrium including endocrinological, immunological, and/or metabolic changes. The hypothesis holds that a changed set point persistently pushes the organism towards a pathological dysfunctional state which fails to reset. To use an analogy of a thermostat, if the ‘off switch’ of a thermostat intermittently stops working, for periods the house would become warmer and warmer without limit. The hypothesis draws on recent investigations of the Central Homeostasis Network showing multiple interconnections between the autonomic system, central nervous system, and brain stem. The hypothesis helps to explain the shared symptomatology of ME/CFS and PASC and the unpredictable, intermittent, and fluctuating pattern of symptoms of ME/CFS and PASC. The current theoretical approach remains speculative and requires in-depth investigation before any definite conclusions can be drawn.

Effect of using a structured pacing protocol on post-exertional symptom exacerbation and health status in a longitudinal cohort with the post-COVID-19 syndrome

Post-exertional symptom exacerbation (PESE) is a characteristic symptom of post-COVID syndrome (PCS). This prospective study investigated the effect of a 6-week structured World Health Organization (WHO) Borg CR-10 5-phase pacing protocol on PESE episodes and quality of life in a cohort of individuals with long-standing PCS (average duration of symptoms was 17 months). Participants received weekly telephone calls with a clinician to complete the Leeds PESE questionnaire (LPQ) and identify the appropriate phase of the pacing protocol. EQ-5D 5L was completed at the intervention's beginning and end to measure overall health. Thirty-one participants completed the 6-week protocol, with a statistically and clinically significant reduction in the average number of PESE episodes (from 3.4 episodes in Week 1 to 1.1 in Week 6), with an average decrease of 16% (95% CI: 9%-24%; p < 0.001) each week, and reduction across all three exertional triggers (physical, cognitive, and emotional). Physical activity levels showed moderate improvements during the intervention period. Mean EQ-5D 5L scores improved from 51.4 to 60.6 points (paired difference of 9.2 points, 95% CI: 3.2-15.2 points; p = 0.004). A structured pacing protocol significantly reduces PESE episodes and improves overall health in PCS.

Brainstem volume changes in myalgic encephalomyelitis/chronic fatigue syndrome and long COVID patients

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID patients have overlapping neurological, autonomic, pain, and post-exertional symptoms. We compared volumes of brainstem regions for 10 ME/CFS (CCC or ICC criteria), 8 long COVID (WHO Delphi consensus), and 10 healthy control (HC) subjects on 3D, T1-weighted MRI images acquired using sub-millimeter isotropic resolution using an ultra-high field strength of 7 Tesla. Group comparisons with HC detected significantly larger volumes in ME/CFS for pons (p = 0.004) and whole brainstem (p = 0.01), and in long COVID for pons (p = 0.003), superior cerebellar peduncle (p = 0.009), and whole brainstem (p = 0.005). No significant differences were found between ME/CFS and long COVID volumes. In ME/CFS, we detected positive correlations between the pons and whole brainstem volumes with "pain" and negative correlations between the midbrain and whole brainstem volumes with "breathing difficulty." In long COVID patients a strong negative relationship was detected between midbrain volume and "breathing difficulty." Our study demonstrated an abnormal brainstem volume in both ME/CFS and long COVID consistent with the overlapping symptoms.

Genetic risk factors for ME/CFS identified using combinatorial analysis

Background

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease that lacks known pathogenesis, distinctive diagnostic criteria, and effective treatment options. Understanding the genetic (and other) risk factors associated with the disease would begin to help to alleviate some of these issues for patients.

Methods

We applied both GWAS and the PrecisionLife combinatorial analytics platform to analyze ME/CFS cohorts from UK Biobank, including the Pain Questionnaire cohort, in a case–control design with 1000 cycles of fully random permutation. Results from this study were supported by a series of replication and cohort comparison experiments, including use of disjoint Verbal Interview CFS, post-viral fatigue syndrome and fibromyalgia cohorts also derived from UK Biobank, and compared results for overlap and reproducibility.

Results

Combinatorial analysis revealed 199 SNPs mapping to 14 genes that were significantly associated with 91% of the cases in the ME/CFS population. These SNPs were found to stratify by shared cases into 15 clusters (communities) made up of 84 high-order combinations of between 3 and 5 SNPs. p-values for these communities range from 2.3 × 10–10 to 1.6 × 10–72. Many of the genes identified are linked to the key cellular mechanisms hypothesized to underpin ME/CFS, including vulnerabilities to stress and/or infection, mitochondrial dysfunction, sleep disturbance and autoimmune development. We identified 3 of the critical SNPs replicated in the post-viral fatigue syndrome cohort and 2 SNPs replicated in the fibromyalgia cohort. We also noted similarities with genes associated with multiple sclerosis and long COVID, which share some symptoms and potentially a viral infection trigger with ME/CFS.

Conclusions

This study provides the first detailed genetic insights into the pathophysiological mechanisms underpinning ME/CFS and offers new approaches for better diagnosis and treatment of patients.

Transient receptor potential melastatin 3 dysfunction in post COVID-19 condition and myalgic encephalomyelitis/chronic fatigue syndrome patients

Background

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe multisystemic condition associated with post-infectious onset, impaired natural killer (NK) cell cytotoxicity and impaired ion channel function, namely Transient Receptor Potential Melastatin 3 (TRPM3). Long-term effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has resulted in neurocognitive, immunological, gastrointestinal, and cardiovascular manifestations recently recognised as post coronavirus disease 2019 (COVID-19) condition. The symptomatology of ME/CFS overlaps significantly with post COVID-19; therefore, this research aimed to investigate TRPM3 ion channel function in post COVID-19 condition patients.

Methods

Whole-cell patch-clamp technique was used to measure TRPM3 ion channel activity in isolated NK cells of N = 5 ME/CFS patients, N = 5 post COVID-19 patients, and N = 5 healthy controls (HC). The TRPM3 agonist, pregnenolone sulfate (PregS) was used to activate TRPM3 function, while ononetin was used as a TRPM3 antagonist.

Results

As reported in previous research, PregS-induced TRPM3 currents were significantly reduced in ME/CFS patients compared with HC (p = 0.0048). PregS-induced TRPM3 amplitude was significantly reduced in post COVID-19 condition compared with HC (p = 0.0039). Importantly, no significant difference was reported in ME/CFS patients compared with post COVID-19 condition as PregS-induced TRPM3 currents of post COVID-19 condition patients were similar of ME/CFS patients currents (p > 0.9999). Isolated NK cells from post COVID-19 condition and ME/CFS patients were resistant to ononetin and differed significantly with HC (p < 0.0001).

Conclusion

The results of this investigation suggest that post COVID-19 condition patients may have impaired TRPM3 ion channel function and provide further evidence regarding the similarities between post COVID-19 condition and ME/CFS. Impaired TRPM3 channel activity in post COVID-19 condition patients suggest impaired ion mobilisation which may consequently impede cell function resulting in chronic post-infectious symptoms. Further investigation into TRPM3 function may elucidate the pathomechanism, provide a diagnostic and therapeutic target for post COVID-19 condition patients and commonalities with ME/CFS patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00528-y.