Welcome to the 93rd Emerge Australia Research Digest, where you will find summaries of some of the latest research and information about ME/CFS, with links to the complete articles.

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Factors Influencing the Prognosis of Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Authors: Ghali A, Lacout C, Fortrat JO, Depres K, Ghali M, Lavigne C (Angers University Hospital, France).

Publication: Diagnostics

Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9600584/pdf/diagnostics-12-02540.pdf

ME/CFS is a condition known to have a poor prognosis, however previous studies into predictors of outcomes have had contradictory results. Previous literature has identified recovery and improvement rates of 0-8% and 17-64% respectively. This study aimed to investigate epidemiological and clinical prognostic factors of ME/CFS. For the purpose of this study, recovery was defined as not experiencing post-exertional malaise for 6 months and being able to perform premorbid levels of activity without pacing or medication. Improvement was defined as not experiencing PEM for 6 months and a substantial reduction to baseline symptoms with partial restoration of everyday activities, with or without pacing or medication.

168 participants (International Consensus Criteria) were drawn from patients who had attended the Angers University Hospital from 2011-2019. Medical records were reviewed for data collection, and participants were monitored until December 2020. Participants were divided into two groups (presence of recovery/improvement vs absence of recovery/improvement) and these groups were compared for epidemiological characteristics, comorbidities, and clinical signs. Participants completed an interview, physical examination, and etiological review, as well as self-reported changes to symptoms.

The authors found that recovery and improvement rates were 8.3% and 4.8% respectively. Older age at disease onset was associated with better outcomes, whereas diagnostic delay was associated with poorer outcomes. The authors note that although the recovery rate was similar to that reported in previous literature, the improvement rates were significantly lower. The authors hypothesise that this may be due to the absence of operationalised definitions of recovery and improvement in previous literature and differences in diagnostic criteria, illness duration and follow-up period.

The authors conclude that this study highlights the poor prognosis of ME/CFS and the importance of prompt diagnosis and implementation of management strategies. The authors propose that increasing health professionals’ understanding of ME/CFS and PEM is essential.

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Muscle sodium content in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Authors: Petter E, Scheibenbogen C, Linz P, Stehning C, Wirth K, Kuehne T, Kelm M (Charite Berlin University of Medicine, Germany)

Publication: Journal of Translational Medicine

Link: https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03616-z

Some of the common symptoms reported by patients with ME/CFS are muscle fatigue and pain. Previous research has established evidence for hypoperfusion of muscles, potentially resulting in electrolyte imbalance and sodium overload within muscles. This preliminary pilot study aimed to compare the sodium content levels in the muscles of patients with ME/CFS and healthy controls both before and after exercise.

Participants for this study included six female patients with ME/CFS (Canadian Consensus Criteria), and six healthy sedentary controls that were matched for age, BMI, and sex. ME/CFS patients were recruited from August-November 2020 from patients attending Institute of Medical Immunology at Charite. All participants underwent Na-MRI of the left lower leg before and after three minutes of plantar flexion exercise. Handgrip strength was also measured and correlated to sodium content levels.

The authors found that the baseline sodium content of tissue was higher in all five lower leg muscle compartments in ME/CFS participants compared to healthy controls. After exercise, sodium content level of tissue increased in all participants over the 40-minute measurement period, with greater increases observed in ME/CFS patients. ME/CFS patients had a lower average handgrip strength compared to healthy controls, which was associated with higher average muscle sodium content.

The authors conclude that these findings show muscle sodium content levels in ME/CFS patients were higher than healthy controls before and after exercise. They conclude that their findings also demonstrate an inverse relationship between handgrip strength and muscle sodium content levels. The authors propose that this may provide evidence of sodium overload is a component of the pathophysiology of ME/CFS and that this should be further investigated, as a potential therapeutic treatment avenue.

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Long COVID: major findings, mechanisms and recommendations

Authors: Davis HE, McCorkell L, Vogel JL, Topol EJ (Scripps Research Translational Institute, USA)

Publication: Nature Reviews Microbiology

Link: https://www.nature.com/articles/s41579-022-00846-2

This review of the Long COVID literature highlights the major findings to date. As most patients with Long COVID were not hospitalised during their SARS-CoV-2 infection, the review focuses on studies that include patients who had mild acute COVID-19.

The authors provide an overview of abnormalities identified in several major systems, including immunological, neurological, reproductive, gastrointestinal and respiratory systems. The authors also note the considerable overlap in symptoms and pathology between Long COVID and other conditions like ME/CFS, POTS and mast cell activation syndrome (MCAS) and recommend that the overlap between these conditions should be explored further.

The authors note that routine medical tests are often normal in Long COVID patients and that clinicians are often unaware of diagnostic tools and recommendations from ME/CFS, which could be utilised. Other tools (such detection of microclots) are still in development. While there are no broadly effective treatments, treatments with some effectiveness are emerging, and these often derive from those used with ME/CFS. The authors note that exercise is harmful to people with Long COVID who experience ME/CFS and post-exertional malaise and should not be recommended.

The evidence of the impact of vaccination on the risk of developing Long COVID is inconsistent, with some studies showing vaccination provides little or no protection and others indicating that it provides at least partial protection. While only preliminary, early research suggests that SARS-CoV-2 reinfection increases the risk of developing Long COVID.

The authors note that testing issues (lack of accurate and available SARS-CoV-2 tests, assumption that everyone retains SARS-CoV-2 antibodies), lack of knowledge of and misinformation about post-viral conditions, and assumptions that COVID-19 sequelae were predominantly respiratory have impacted both Long COVID research and clinical care.

The authors recommend that Long COVID research builds on the existing knowledge base from ME/CFS, dysautonomia and other overlapping conditions. Clinical trials must be prioritised, people of colour must be represented in all Long COVID research, given the disproportionate rates with which they are developing the condition, and Long COVID research must engage with Long COVID patients in a meaningful way. Education of health professionals is crucial to improving clinical care for those living with the condition.

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Griffith University researchers identify similar brain structure changes in both chronic fatigue syndrome and long COVID

Authors: Miles J

Publication: ABC News

Link: https://www.abc.net.au/news/2023-03-14/long-covid-queensland-research-chronic-fatigue-syndrome/102089452

Australian researchers at Griffith University have recently published research indicating that ME/CFS and Long COVID share similar brain changes. Using high-powered MRI machines, researchers have found that people with these conditions have larger brain stems than people who don’t. Lead researcher Dr Thapaliya said these similarities could help explain common symptoms found in both conditions, like brain fog and pain.

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