An Exercise Immune Fitness test to unravel mechanisms of post-acute sequelae of COVID-19

Abstract:

The Post-Acute Sequelae of COVID-19 (PASC) Syndrome is a debilitating syndrome with onset three months post COVID-19 infection, marked by the presence of fatigue, headache, cognitive dysfunction, post-exertional malaise, orthostatic intolerance, and dyspnea that is clinically relevant and is at least as severe as fatigue in several other clinical conditions, including cancer. The onset, progression, and symptom profile of PASC patients have considerable overlap with Myalgic-Encephalopathy/Chronic Fatigue Syndrome (ME/CFS).

In people with ME/CFS, exercise (and other types of exertion) can cause serious setbacks and deterioration in function. Post-exertional malaise (PEM) appears to be a common and a significant challenge for the majority of this patient group. Of the nearly 24 million adults in the U.S. who currently have long COVID, more than 80% are having some trouble carrying out daily activities. Mechanisms of PACS remain poorly understood.

While multi-omic information gathered at the time of acute COVID-19 onset may help predict long COVID outcomes, we here propose to test the hypothesis that additional molecular immunological information collected during standardized exercise-testing for cardio-respiratory fitness after recovery from acute COVID-19 can be used to improve the understanding of mechanisms of PASC.

Source: Deng MC. An Exercise Immune Fitness test to unravel mechanisms of post-acute sequelae of COVID-19. Expert Rev Clin Immunol. 2023 May 16. doi: 10.1080/1744666X.2023.2214364. Epub ahead of print. PMID: 37190994. https://www.tandfonline.com/doi/full/10.1080/1744666X.2023.2214364 (Full text)

Clinical improvement of Long-COVID is associated with reduction in autoantibodies, lipids, and inflammation following therapeutic apheresis

Abstract:

In the aftermath of the COVID-19 pandemic, we are witnessing an unprecedented wave of post-infectious complications. Most prominently, millions of patients with Long-Covid complain about chronic fatigue and severe post-exertional malaise. Therapeutic apheresis has been suggested as an efficient treatment option for alleviating and mitigating symptoms in this desperate group of patients. However, little is known about the mechanisms and biomarkers correlating with treatment outcomes.

Here, we have analyzed in different cohorts of Long-Covid patients specific biomarkers before and after therapeutic apheresis. In patients that reported a significant improvement following two cycles of therapeutic apheresis, there was a significant reduction in neurotransmitter autoantibodies, lipids, and inflammatory markers. Furthermore, we observed a 70% reduction in fibrinogen, and following apheresis, erythrocyte rouleaux formation and fibrin fibers largely disappeared as demonstrated by dark field microscopy.

This is the first study demonstrating a pattern of specific biomarkers with clinical symptoms in this patient group. It may therefore form the basis for a more objective monitoring and a clinical score for the treatment of Long-Covid and other postinfectious syndromes.

Source: Achleitner, M., Steenblock, C., Dänhardt, J. et al. Clinical improvement of Long-COVID is associated with reduction in autoantibodies, lipids, and inflammation following therapeutic apheresis. Mol Psychiatry (2023). https://doi.org/10.1038/s41380-023-02084-1 https://www.nature.com/articles/s41380-023-02084-1 (Full text)

A Mixed Methods System for the Assessment of Post Exertional Malaise in Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Background A central feature of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is post exertional malaise (PEM), which is an acute worsening of symptoms after a physical, emotional and/or mental exertion. PEM is also a feature of Long COVID. Dynamic measures of PEM have historically included scaled questionnaires which have not been validated in ME/CFS. To enhance our understanding of PEM and how best to measure it, we conducted semi-structured qualitative interviews (QIs) at the same intervals as Visual Analog Scale (VAS) measures after a Cardiopulmonary Exercise Test (CPET).

Methods Ten ME/CFS and nine healthy volunteers participated in a CPET. For each participant, PEM symptom VAS (7 symptoms) and semi-structured QIs were administered at six timepoints over 72 hours before and after a single CPET. QI data were used to plot the severity of PEM at each time point and identify the self-described most bothersome symptom for each patient. QI data were used to determine the symptom trajectory and peak of PEM. Performance of QI and VAS data were compared to each other using Spearman correlations.

Results QIs documented that each ME/CFS volunteer had a unique PEM experience, with differences noted in the onset, severity, trajectory over time, and most bothersome symptom. No healthy volunteers experienced PEM. Scaled QI data were able to identify PEM peaks and trajectories, even when VAS scales were unable to do so due to known ceiling and floor effects. QI and VAS fatigue data corresponded well prior to exercise (baseline, r=0.7) but poorly at peak PEM (r=0.28) and with the change from baseline to peak (r=0.20). When the most bothersome symptom identified from QIs was used, these correlations improved (r=.0.77, 0.42. and 0.54 respectively) and reduced the observed VAS scale ceiling and floor effects.

Conclusion QIs were able to capture changes in PEM severity and symptom quality over time in all the ME/CFS volunteers, even when VAS scales failed to do so. Information collected from QIs also improved the performance of VAS. Measurement of PEM can be improved by using a quantitative-qualitative mixed model approach.

Disclaimer This research/work/investigator was supported (in part) by the Division of Intramural Research of the National Institutes of Health, NINDS. The content is solely the responsibility of the author(s) and does not necessarily represent the official views of the National Institutes of Health.

Source: Barbara StussmanBrice CalcoGina NoratoAngelique GavinSnigdha ChigurupatiAvindra NathBrian Walitt. A Mixed Methods System for the Assessment of Post Exertional Malaise in Encephalomyelitis/Chronic Fatigue Syndrome.

Do diagnostic criteria for ME matter to patient experience with services and interventions? Key results from an online RDS survey targeting fatigue patients in Norway

Abstract:

Public health and welfare systems request documentation on approaches to diagnose, treat, and manage myalgic encephalomyelitis and assess disability-benefit conditions. Our objective is to document ME patients’ experiences with services/interventions and assess differences between those meeting different diagnostic criteria, importantly the impact of post-exertional malaise.

We surveyed 660 fatigue patients in Norway using respondent-driven sampling and applied validated DePaul University algorithms to estimate Canadian and Fukuda criteria proxies. Patients on average perceived most interventions as having low-to-negative health effects. Responses differed significantly between sub-groups for some key interventions. The PEM score was strongly associated with the experience of most interventions. Better designed and targeted interventions are needed to prevent harm to the patient group.

The PEM score appears to be a strong determinant and adequate tool for assessing patient tolerance for certain interventions. There is no known treatment for ME, and “do-no-harm” should be a guiding principle in all practice.

Source: Kielland A, Liu J, Jason LA. Do diagnostic criteria for ME matter to patient experience with services and interventions? Key results from an online RDS survey targeting fatigue patients in Norway. J Health Psychol. 2023 Apr 28:13591053231169191. doi: 10.1177/13591053231169191. Epub ahead of print. PMID: 37114822. https://journals.sagepub.com/doi/10.1177/13591053231169191 (Full text)

A review of cytokine-based pathophysiology of Long COVID symptoms

Abstract:

The Long COVID/Post Acute Sequelae of COVID-19 (PASC) group includes patients with initial mild-to-moderate symptoms during the acute phase of the illness, in whom recovery is prolonged, or new symptoms are developed over months. Here, we propose a description of the pathophysiology of the Long COVID presentation based on inflammatory cytokine cascades and the p38 MAP kinase signaling pathways that regulate cytokine production.

In this model, the SARS-CoV-2 viral infection is hypothesized to trigger a dysregulated peripheral immune system activation with subsequent cytokine release. Chronic low-grade inflammation leads to dysregulated brain microglia with an exaggerated release of central cytokines, producing neuroinflammation. Immunothrombosis linked to chronic inflammation with microclot formation leads to decreased tissue perfusion and ischemia. Intermittent fatigue, Post Exertional Malaise (PEM), CNS symptoms with “brain fog,” arthralgias, paresthesias, dysautonomia, and GI and ophthalmic problems can consequently arise as result of the elevated peripheral and central cytokines.

There are abundant similarities between symptoms in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). DNA polymorphisms and viral-induced epigenetic changes to cytokine gene expression may lead to chronic inflammation in Long COVID patients, predisposing some to develop autoimmunity, which may be the gateway to ME/CFS.

Source: Low RN, Low RJ, Akrami A. A review of cytokine-based pathophysiology of Long COVID symptoms. Front Med (Lausanne). 2023 Mar 31;10:1011936. doi: 10.3389/fmed.2023.1011936. PMID: 37064029; PMCID: PMC10103649. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10103649/ (Full text)

Exercise Pathophysiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Post-Acute Sequelae of SARS-CoV-2: More in Common Than Not?

Abstract:

Topic importance: Post-Acute Sequelae of SARS-CoV-2 (PASC) is a long-term consequence of acute infection from coronavirus disease 2019 (COVID-19). Clinical overlap between PASC and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has been observed, with shared symptoms including intractable fatigue, postexertional malaise, and orthostatic intolerance. The mechanistic underpinnings of such symptoms are poorly understood.

Review findings: Early studies suggest deconditioning as the primary explanation for exertional intolerance in PASC. Cardiopulmonary exercise testing (CPET) reveals perturbations related to systemic blood flow and ventilatory control associated with acute exercise intolerance in PASC, which are not typical of simple detraining. Hemodynamic and gas exchange derangements in PASC have substantial overlap with those observed with ME/CFS, suggestive of shared mechanisms.

Summary: This review aims to illustrate exercise pathophysiologic commonalities between PASC and ME/CFS that will help guide future diagnostics and treatment.

Source: Joseph P, Singh I, Oliveira R, Capone CA, Mullen MP, Cook DB, Stovall MC, Squires J, Madsen K, Waxman AB, Systrom DM. Exercise Pathophysiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Post-Acute Sequelae of SARS-CoV-2: More in Common Than Not? Chest. 2023 Apr 11:S0012-3692(23)00502-0. doi: 10.1016/j.chest.2023.03.049. Epub ahead of print. PMID: 37054777; PMCID: PMC10088277. https://pubmed.ncbi.nlm.nih.gov/37054777/

Cardiovascular Considerations in the Management of People with Suspected Long COVID

Abstract:

Approximately 15% of adult Canadians with SARS-CoV-2 infection develop lingering symptoms beyond 12 weeks post-acute infection, known as post-COVID condition or long COVID. Some of the commonly reported long COVID cardiovascular symptoms include fatigue, shortness of breath, chest pain, and palpitations. Suspected long-term cardiovascular complications of SARS-CoV-2 infection may present as a constellation of symptoms that can be challenging for clinicians to diagnose and treat.

When assessing patients with these symptoms, clinicians need to keep in mind Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), post-exertional malaise and post-exertional symptom exacerbation (PEM/PESE), cardiac dysautonomia such as Inappropriate Sinus Tachycardia (IST), and Postural Orthostatic Tachycardia Syndrome (POTS), and occasionally Mast Cell Activation Syndrome (MCAS).

This paper summarizes the globally evolving evidence around management of cardiac sequelae of long COVID. In addition, this review includes a Canadian perspective, consisting of a panel of expert opinions from experienced clinicians across Canada who have been involved in management of long COVID. The objective of this review is to offer some practical guidance to cardiologists and generalist clinicians regarding diagnostic and treatment approaches for adult patients with suspected long COVID who continue to experience unexplained cardiac symptoms.

Source: Quinn KL, Lam GY, Walsh JF, Bhéreur A, Brown AD, Chow CW, Christie Chung KY, Cowan J, Crampton N, Décary S, Falcone EL, Graves L, Gross DP, Hanneman K, Harvey PJ, Holmes S, Katz GM, Parhizgar P, Sharkawy A, Tran KC, Waserman S, Zannella VE, Cheung AM. Cardiovascular Considerations in the Management of People with Suspected Long COVID. Can J Cardiol. 2023 Apr 6:S0828-282X(23)00303-3. doi: 10.1016/j.cjca.2023.04.003. Epub ahead of print. PMID: 37030518. Quinn KL, Lam GY, Walsh JF, Bhéreur A, Brown AD, Chow CW, Christie Chung KY, Cowan J, Crampton N, Décary S, Falcone EL, Graves L, Gross DP, Hanneman K, Harvey PJ, Holmes S, Katz GM, Parhizgar P, Sharkawy A, Tran KC, Waserman S, Zannella VE, Cheung AM. Cardiovascular Considerations in the Management of People with Suspected Long COVID. Can J Cardiol. 2023 Apr 6:S0828-282X(23)00303-3. doi: 10.1016/j.cjca.2023.04.003. Epub ahead of print. PMID: 37030518. https://www.onlinecjc.ca/article/S0828-282X(23)00303-3/fulltext (Full text)

Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

To assess biobehavioral sex differences in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) utilizing a low burden exercise protocol, 22 females and 15 males with ME/CFS and 14 healthy controls underwent two six-min walk tests.

Fifteen daily assessments were scheduled for fatigue and function ratings and heart monitoring. Six-min walk tests were conducted on days 8 and 9. The ME/CFS group showed high self-report fatigue and impaired physical function, whereas healthy controls did not show fatigue or function abnormalities.

In patients, no significant post-exercise changes were found for heart rate variability (HRV); however, heart rate decreased in ME/CFS males from Day 14 to Day 15 (p = 0.046). Female patients showed increased fatigue (p = 0.006) after the initial walk test, but a downward slope (p = 0.008) in fatigue following the second walk test. Male patients showed a decrease in self-report work limitation in the days after exercise (p = 0.046). The healthy control group evidenced a decrease in HRV after the walk tests from Day 9-14 (p = 0.038).

This pilot study did not confirm hypotheses that females as compared to males would show slower exercise recovery on autonomic or self-report (e.g. fatigue) measures. A more exertion-sensitive test may be required to document prolonged post-exertional abnormalities in ME/CFS.

Trial registration: NCT NCT03331419.

Source: Friedberg F, Adamowicz JL, Bruckenthal P, Milazzo M, Ramjan S, Zhang X, Yang J. Sex differences in post-exercise fatigue and function in myalgic encephalomyelitis/chronic fatigue syndrome. Sci Rep. 2023 Apr 3;13(1):5442. doi: 10.1038/s41598-023-32581-w. PMID: 37012343. https://www.nature.com/articles/s41598-023-32581-w (Full text)

An international survey of experiences and attitudes towards pacing using a heart rate monitor for people with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Myalgic encephalomyelitis (ME) is a complex, multi-system neurological condition. The defining feature of ME is post-exertional malaise (PEM) with over 30 symptoms triggered by physical, cognitive, emotional and social activity.

The cause of PEM is unclear but one area of research using cardio-pulmonary exercise tests show a reduced ventilatory anaerobic threshold (VAT) with repeated tests leading to PEM.

Pacing with heart rate monitoring (HRM) provides feedback to maintain activity intensity below the VAT. There is only one piece of research investigating the use of HRM although a number of guidelines recommend it.

Objective: To identify the experiences and attitudes of people with ME towards HRM.

Methods: A 40 question online survey was devised and released on ME websites, Twitter and Facebook pages. People with ME read the information sheet and followed an online link to the survey. The survey was open for three weeks and all answers were anonymous.

Results: 488 people with ME completed the survey. Most participants were female, 35-50 years and with a reported illness of greater than 5 years. Over 100 types of HR monitor used. Over 30 benefits and over 30 negatives identified. HRM reduced severity of ME and severity and duration of PEM.

Conclusion: Although there are limitations, HRM has many benefits including helping PwME to understand and manage their PEM and support them to increase their activities, including work. There is a need for more research and education of healthcare professionals in the safe use of HRM.

Source: Clague-Baker N, Davenport TE, Madi M, Dickinson K, Leslie K, Bull M, Hilliard N. An international survey of experiences and attitudes towards pacing using a heart rate monitor for people with myalgic encephalomyelitis/chronic fatigue syndrome. Work. 2023 Mar 13. doi: 10.3233/WOR-220512. Epub ahead of print. PMID: 36938766. https://content.iospress.com/articles/work/wor220512 (Full text)

Development and measurement properties of the PEM/PESE activity questionnaire (PAQ)

Abstract:

Background: Existing instruments often are inappropriate to measure the effects of post-exertional malaise (PEM) and post-exertional symptom exacerbation (PESE) on activities of daily living (ADLs). A validated questionnaire to measure self-reported ability with ADLs would advance research and clinical practice in conditions like myalgic encephalomyelitis and Long Covid.

Objective: Determine the measurement properties of the PEM/PESE Activity Questionnaire (PAQ).

Methods: The PAQ is adapted from the Patient Specific Functional Scale. Respondents rated three self-selected ADLs on two 0-100 scales, including current performance compared to (1) a ‘good day’ and (2) before illness. Respondents provided a Burden of Functioning rating on a 0-100 scale, anchored at 0 being the activity took “No time, effort, and resources at all” and 10 being “All of my time, effort, and resources.” Respondents took the PAQ twice, completing a demographic questionnaire after the first PAQ and before the second PAQ. Descriptive statistics and intraclass correlation coefficients were calculated for each scale to assess test-retest reliability. Minimum detectable change outside the 95% confidence interval (MDC95) was calculated. Ceiling and floor effects were determined when the MDC95 for average and function scores crossed 0 and 100, respectively.

Results: n = 981 responses were recorded, including n = 675 complete surveys. Test-retest reliability was generally fair to excellent, depending on function and scale. MDC95 values generally indicated scale responsiveness. Ceiling and floor effects were noted infrequently for specific functions.

Conclusion: The PAQ is valid, reliable, and sensitive. Additional research may explore measurement properties involving functions that were infrequently selected in this sample.

Source: Davenport TE, Stevens SR, Stevens J, Snell CR, Van Ness JM. Development and measurement properties of the PEM/PESE activity questionnaire (PAQ). Work. 2023 Mar 13. doi: 10.3233/WOR-220553. Epub ahead of print. PMID: 36938768. https://content.iospress.com/articles/work/wor220553 (Full text)