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

A review of intravenous immunoglobulin in the treatment of neuroimmune conditions, acute COVID-19 infection, and post-acute sequelae of COVID-19 Syndrome

Intravenous immunoglobulin (IVIG) is an immunomodulatory therapy that has been studied in several neuroimmune conditions, such as Guillain-Barré Syndrome, chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, and multiple sclerosis. It has also been proposed as a potential treatment option for acute COVID-19 infection and post-acute sequelae of SARS-CoV-2 infection (PASC). IVIG is thought to function by providing the recipient with a pool of antibodies, which can, in turn, modulate immune responses through multiple mechanisms including neutralization of cytokines and autoantibodies, saturation of neonatal fragment crystallizable receptors, inhibition of complement activation, and regulation of T and B cell mediated inflammation. In acute COVID-19, studies have shown that early administration of IVIG and plasmapheresis in severe cases can reduce the need for mechanical ventilation, shorten ICU and hospital stays, and lower mortality. Similarly, in PASC, while research is still in early stages, IVIG has been shown to alleviate persistent symptoms in small patient cohorts. Furthermore, IVIG has shown benefits in another condition which has symptomatic overlap with PASC, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), though studies have yielded mixed results. It is important to note that IVIG can be associated with several potential adverse effects, such as anaphylaxis, headaches, thrombosis, liver enzyme elevations and renal complications. In addition, the high cost of IVIG can be a deterrent for payers and patients. This review provides a comprehensive update on the use of IVIG in multiple neuroimmune conditions, ME/CFS, acute COVID-19, and PASC, as well as covers its history, production, pricing, and mechanisms of action. We also identify key areas of future research, including the need to optimize the use of Ig product dosing, timing, and patient selection across conditions, particularly in the context of COVID-19 and PASC.

Conceptual foundations of acetylcarnitine supplementation in neuropsychiatric long COVID syndrome: a narrative review

Post-acute sequelae of COVID-19 can present as multi-organ pathology, with neuropsychiatric symptoms being the most common symptom complex, characterizing long COVID as a syndrome with a significant disease burden for affected individuals. Several typical symptoms of long COVID, such as fatigue, depressive symptoms and cognitive impairment, are also key features of other psychiatric disorders such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and major depressive disorder (MDD). However, clinically successful treatment strategies are still lacking and are often inspired by treatment options for diseases with similar clinical presentations, such as ME/CFS. Acetylcarnitine, the shortest metabolite of a class of fatty acid metabolites called acylcarnitines and one of the most abundant blood metabolites in humans can be used as a dietary/nutritional supplement with proven clinical efficacy in the treatment of MDD, ME/CFS and other neuropsychiatric disorders. Basic research in recent decades has established acylcarnitines in general, and acetylcarnitine in particular, as important regulators and indicators of mitochondrial function and other physiological processes such as neuroinflammation and energy production pathways. In this review, we will compare the clinical basis of neuropsychiatric long COVID with other fatigue-associated diseases. We will also review common molecular disease mechanisms associated with altered acetylcarnitine metabolism and the potential of acetylcarnitine to interfere with these as a therapeutic agent. Finally, we will review the current evidence for acetylcarnitine as a supplement in the treatment of fatigue-associated diseases and propose future research strategies to investigate the potential of acetylcarnitine as a treatment option for long COVID.

Psychometric evaluation of the DePaul Symptom Questionnaire-Short Form (DSQ-SF) among adults with Long COVID, ME/CFS, and healthy controls: A machine learning approach

Long COVID shares a number of clinical features with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), including post-exertional malaise, severe fatigue, and neurocognitive deficits. Utilizing validated assessment tools that accurately and efficiently screen for these conditions can facilitate diagnostic and treatment efforts, thereby improving patient outcomes. In this study, we generated a series of random forest machine learning algorithms to evaluate the psychometric properties of the DePaul Symptom Questionnaire-Short Form (DSQ-SF) in classifying large groups of adults with Long COVID, ME/CFS (without Long COVID), and healthy controls. We demonstrated that the DSQ-SF can accurately classify these populations with high degrees of sensitivity and specificity. In turn, we identified the particular DSQ-SF symptom items that best distinguish Long COVID from ME/CFS, as well as those that differentiate these illness groups from healthy controls.

Homeostasis Theory of Well-being

The Homeostasis Theory of Well-being proposes a homeostatic modular system for the creation of human well-being. This article aims to: (i) provide a proof-of-concept demonstration of the feasibility of the theory in its biopsychosocial context; (ii) indicate prima facie empirical support for the homeostatic nature of the 16 proposed modules; (iii) discuss the similarities to and differences from other homeostasis theories of well-being. Following the Central Limit Theorem, any homeostatic system with multiple inputs produces outputs with a Gaussian distribution. The data-base of studies contains approximately 2000 publications reporting U- or inverse U-shaped curves for the 16 homeostatic domains specified in the theory. The Homeostasis Theory of Well-being remains speculative and requires controlled longitudinal study to determine the scientific validity of the causal network proposed by the theory. The theory has implications for our understanding of humans' drive for balance, equilibrium and stability in this increasingly uncertain world.

Post-COVID dysautonomias: what we know and (mainly) what we don't know

Following on from the COVID-19 pandemic is another worldwide public health challenge that is referred to variously as long COVID, post-COVID syndrome or post-acute sequelae of SARS-CoV-2 infection (PASC). PASC comes in many forms and affects all body organs. This heterogeneous presentation suggests involvement of the autonomic nervous system (ANS), which has numerous roles in the maintenance of homeostasis and coordination of responses to various stressors. Thus far, studies of ANS dysregulation in people with PASC have been largely observational and descriptive, based on symptom inventories or objective but indirect measures of cardiovascular function, and have paid little attention to the adrenomedullary, hormonal and enteric nervous components of the ANS. Such investigations do not consider the syndromic nature of autonomic dysfunction. This Review provides an update on the literature relating to ANS abnormalities in people with post-COVID syndrome and presents a theoretical perspective on how the ANS might participate in common features of PASC.

Focus on post-exertional malaise when approaching ME/CFS in specialist healthcare improves satisfaction and reduces deterioration

Background

Post-exertional malaise (PEM) is considered a hallmark characteristic of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This may also apply to subgroups of patients with long COVID-induced ME/CFS. However, it is uncertain to what extent PEM is acknowledged in routine specialist healthcare for ME/CFS patients, and how this affects patient outcomes.

Objective

This study aims to evaluate to what extent ME/CFS patients experienced focus on PEM in specialist healthcare practice and its significance for outcome and care quality.

Methods

Data from two online cross-sectional surveys covering specialist healthcare services for ME/CFS patients at rehabilitation institutes in Norway and two regional hospitals, respectively, were analyzed. Evaluations of 788 rehabilitation stays, 86 hospital consultations, and 89 hospital interventions were included. Logistic regression models and Mann-Whitney U-tests were used to quantify the impact of addressing PEM on health and functioning, care satisfaction, or benefit. Spearman's rank correlation and Cronbach's alpha of focus on PEM with the respondents' perception of healthcare providers' knowledge, symptom acknowledgment, and suitability of intervention were assessed as measures for care quality and their internal consistency, respectively.

Results

PEM was addressed in 48% of the rehabilitation stays, 43% of the consultations, and 65% of the hospital interventions. Failure to address PEM roughly doubled the risk of health deterioration, following rehabilitation (OR = 0.39, 95% CI 0.29-0.52; 40.1% vs. 63.2% P = <0.001) and hospital intervention (OR = 0.34, 95% CI 0.13-0.89; 22.4% vs. 45.2%, p = 0.026). The focus on PEM (PEM-focus) during the clinical contact was associated with significantly higher scores on patients' rated care satisfaction and benefit of both consultation and intervention. Furthermore, addressing PEM was (inter)related to positive views about healthcare providers' level of knowledge of ME/CFS, their acknowledgment of symptoms, obtained knowledge, and the perceived suitability of intervention (Cronbach's alpha ≥0.80).

Discussion

PEM is still frequently not acknowledged in specialist healthcare practice for ME/CFS patients in Norway. Not addressing PEM substantially increased the probability of a decline in health and functioning following the intervention and was strongly associated with reduced perceived care quality, satisfaction, and benefit. These findings may be related to the applied explanatory models for ME/CFS and are most likely of relevance to long COVID.

Comments on: Effect of physical activity on long COVID fatigue

The authors of the Comments on: Effect of physical activity on long COVID fatigue by Daungsupawong F. and Wiwanitkit V. (2023) have highlighted certain aspects of future research that need to be considered before any conclusions can be drawn regarding the effect of previous physical activity and/or fitness on the course of long-COVID. We can only agree with this need, although we hope that the effects of SARS-CoV-2 infection will become less and less burdensome to manage. As we hypothesise in the last part of the article by Coscia et al. (2023), we think it is crucial to identify the molecular mechanism underlying the atrophic effect (if any) of the described disease states, which could originate from a local inflammatory storm induced by Spike binding to the ACE-2 receptor in muscle. When studies on muscle from patients will be available in sufficient numbers, we will be able to try to answer the still open questions.

Hypothalamus volumes in adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): impact of self-reported fatigue and illness duration

Adolescent Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex illness of unknown aetiology. Emerging theories suggest ME/CFS may reflect a progressive, aberrant state of homeostasis caused by disturbances within the hypothalamus, yet few studies have investigated this using magnetic resonance imaging in adolescents with ME/CFS. We conducted a volumetric analysis to investigate whether whole and regional hypothalamus volumes in adolescents with ME/CFS differed compared to healthy controls, and whether these volumes were associated with fatigue severity and illness duration. 48 adolescents (25 ME/CFS, 23 controls) were recruited. Lateralised whole and regional hypothalamus volumes, including the anterior-superior, superior tubular, posterior, anterior-inferior and inferior tubular subregions, were calculated from T1-weighted images. When controlling for age, sex and intracranial volume, Bayesian linear regression models revealed no evidence for differences in hypothalamus volumes between groups. However, in the ME/CFS group, a weak linear relationship between increased right anterior-superior volumes and fatigue severity was identified, which was absent in controls. In addition, Bayesian quantile regression revealed a likely-positive association between illness duration and right superior tubular volumes in the ME/CFS group. While these findings suggest overall comparability in regional and whole hypothalamus volumes between adolescents with ME/CFS and controls, preliminary evidence was identified to suggest greater fatigue severity and longer illness duration were associated with greater right anterior-superior and superior-tubular volumes, respectively. These regions contain the anterior and superior divisions of the paraventricular nucleus, involved in the neuroendocrine response to stress, suggesting involvement in ME/CFS pathophysiology. However, replication in a larger, longitudinal cohort is required.