The persistence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) after SARS-CoV-2 infection: A systematic review and meta-analysis

Highlights:

  • SARS-CoV-2 can trigger Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
  • 51% of Long COVID-19 patients have Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.
  • Long COVID-19 is a new name for an old disease.

Abstract:

Objectives: Long COVID-19 (LC) patients experience a number of chronic idiopathic symptoms that are highly similar to those of post-viral Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). We have therefore performed a systematic review and meta-analysis to determine the proportion of LC patients that satisfy ME/CFS diagnostic criteria.

Methods: Clinical studies published between January 2020 to May 2023 were identified using the PubMed, Web of Science, Embase and CINAHL databases. Publication inclusion/exclusion criteria were formulated using the global CoCoPop framework. Data were pooled using a random-effects model with a restricted maximum-likelihood estimator. Study quality was assessed using the Joanna Briggs Institute critical assessment tool.

Results: We identified 13 eligible studies that reported a total of 1,973 LC patients. Our meta-analysis indicated that 51% (95% CI, 42%-60%) of LC patients satisfied ME/CFS diagnostic criteria with fatigue, sleep disruption, and muscle/joint pain being the most common symptoms. Importantly, LC patients also experienced the ME/CFS hallmark symptom, post-exertional malaise.

Conclusions: Our study not only demonstrates that LC patients exhibit similar symptom clusters to ME/CFS, but that approximately half of LC patients satisfy a diagnosis of ME/CFS. Our findings suggest that current ME/CFS criteria could be adapted to the identification of a subset of LC patients that may facilitate the standardized diagnosis, management and the recruitment for clinical studies in the future.

Source: Ankush Dehlia, Mark A. Guthridge. The persistence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) after SARS-CoV-2 infection: A systematic review and meta-analysis. Journal of Infection, 2024, 106297, ISSN 0163-4453, https://doi.org/10.1016/j.jinf.2024.106297.
https://www.sciencedirect.com/science/article/pii/S0163445324002317 (Full text)

A multimodal approach for treating post-acute infectious syndrome

Abstract:

Long-term complications, such as extensive fatigue and cognitive issues, are known from various infections, including SARS-CoV-2, influenza
virus, or Borrelia burgdorferi. The pathology is mostly unknown and differs between patients. Unfortunately, there is currently no common and
effective treatment. In this perspective, we imply that post-acute infectious syndromes are due to a variety of factors, including among others
diminished tissue perfusion, tissue infiltration by viruses, inflammation, and oxidative stress, and that not one specific biomarker can be used
to measure these syndromes. Thus, we suggest that a score based on a number of criteria/factors should be used to assess post-acute infectious
syndromes.

Consequently, probably not one single treatment can be used to treat this group of patients, and we suggest a multimodal
treatment regimen comprising a combination of pharmacotherapy, such as metformin and naltrexone with anti-inflammatory effects,
alongside physical therapies such as extracorporeal apheresis and transcutaneous neurotherapy. This combined approach aims to reduce
biomarker levels and enhance cognitive functions. This implies that a reset of the systems can be achieved by a multimodal approach based on a
score for post-acute infectious syndromes.

Source:  Charlotte Steenblock, Nicole Toepfner, Yannick P. Kok, Philip Mavberg, Horst Bruckmoser, Alfons Breu, Johannes Korth, Harald Heidecke, Milo A. Puhan, and Stefan R. Bornstein. A multimodal approach for treating post-acute infectious syndrome. Brain Medicine (2024) 1, 1–7; doi: https://doi.org/10.61373/bm024p.0064; Published online: 30 August 2024. https://bm.genomicpress.com/wp-content/uploads/2024/08/BM0064-Steenblock-2024.pdf (Full text)

Long-term symptom profiles after COVID-19 vs other acute respiratory infections: a population-based observational study (COVIDENCE UK)

Abstract:

Summary:

Background: Long COVID is a well recognised, if heterogeneous, entity. Acute respiratory infections (ARIs) due to other pathogens may cause long-term symptoms, but few studies compare post-acute sequelae between SARS-CoV-2 and other ARIs. We aimed to compare symptom profiles between people with previous SARS-CoV-2 infection, people with previous non-COVID-19 ARIs, and contemporaneous controls, and to identify clusters of long-term symptoms.

Methods: COVIDENCE UK is a prospective, population-based UK study of ARIs in adults. We analysed data on 16 potential long COVID symptoms and health-related quality of life (HRQoL), reported in January, 2021, by participants unvaccinated against SARS-CoV-2. We classified participants as having previous SARS-CoV-2 infection or previous non-COVID-19 ARI (≥4 weeks prior) or no reported ARI. We compared symptoms by infection status using logistic and fractional regression, and identified symptom clusters using latent class analysis (LCA).

Findings: We included 10,203 participants (1343 [13.2%] with SARS-CoV-2 infection, 472 [4.6%] with non-COVID-19 ARI). Both types of infection were associated with increased prevalence/severity of most symptoms and decreased HRQoL compared with no infection. Participants with SARS-CoV-2 infection had increased odds of taste/smell problems and hair loss compared with participants with non-COVID-19 ARIs. Separate LCA models identified three symptom severity groups for each infection type. In the most severe groups (including 23% of participants with SARS-CoV-2, and 21% with non-COVID-19 ARI), SARS-CoV-2 infection presented with a higher probability of memory problems, difficulty concentrating, hair loss, and taste/smell problems than non-COVID-19 ARI.

Interpretation: Both SARS-CoV-2 and non-COVID-19 ARIs are associated with a wide range of long-term symptoms. Research on post-acute sequelae of ARIs should extend from SARS-CoV-2 to include other pathogens.

Source: Vivaldi G, Pfeffer PE, Talaei M, et al. Long-term symptom profiles after COVID-19 vs other acute respiratory infections: a population-based observational study (COVIDENCE UK). medRxiv; 2023. DOI: 10.1101/2023.07.06.23292296. https://europepmc.org/article/PPR/ppr687749 (Full text)

Cytometry profiling of ex vivo recall responses to Coxiella burnetii in previously naturally exposed individuals reveals long-term changes in both adaptive and innate immune cellular compartments

Abstract:

Introduction: Q fever, caused by the intracellular bacterium Coxiella burnetii, is considered an occupational and biodefense hazard and can result in debilitating long-term complications. While natural infection and vaccination induce humoral and cellular immune responses, the exact nature of cellular immune responses to C. burnetii is incompletely understood. The current study seeks to investigate more deeply the nature of long-term cellular recall responses in naturally exposed individuals by both cytokine release assessment and cytometry profiling.

Methods: Individuals exposed during the 2007-2010 Dutch Q fever outbreak were grouped in 2015, based on a C. burnetii-specific IFNγ release assay (IGRA), serological status, and self-reported clinical symptoms during initial infection, into asymptomatic IGRA-negative/seronegative controls, and three IGRA-positive groups (seronegative/asymptomatic; seropositive/asymptomatic and seropositive/symptomatic). Recall responses following in vitro re-stimulation with heat-inactivated C. burnetii in whole blood, were assessed in 2016/2017 by cytokine release assays (n=55) and flow cytometry (n=36), and in blood mononuclear cells by mass cytometry (n=36).

Results: Cytokine release analysis showed significantly elevated IL-2 responses in all seropositive individuals and elevated IL-1β responses in those recovered from symptomatic infection. Comparative flow cytometry analysis revealed significantly increased IFNγ, TNFα and IL-2 recall responses by CD4 T cells and higher IL-6 production by monocytes from symptomatic, IGRA-positive/seropositive individuals compared to controls. Mass cytometry profiling and unsupervised clustering analysis confirmed recall responses in seropositive individuals by two activated CD4 T cell subsets, one characterized by a strong Th1 cytokine profile (IFNγ+IL-2+TNFα+), and identified C. burnetii-specific activation of CD8 T cells in all IGRA-positive groups. Remarkably, increased C. burnetii-specific responses in IGRA-positive individuals were also observed in three innate cell subpopulations: one characterized by an IFNγ+IL-2+TNFα+ Th1 cytokine profile and lack of canonical marker expression, and two IL-1β-, IL-6- and IL-8-producing CD14+ monocyte subsets that could be the drivers of elevated secretion of innate cytokines in pre-exposed individuals.

Discussion: These data highlight that there are long-term increased responses to C. burnetii in both adaptive and innate cellular compartments, the latter being indicative of trained immunity. These findings warrant future studies into the protective role of these innate responses and may inform future Q fever vaccine design.

Source: Raju Paul S, Scholzen A, Reeves PM, Shepard R, Hess JM, Dzeng RK, Korek S, Garritsen A, Poznansky MC, Sluder AE. Cytometry profiling of ex vivo recall responses to Coxiella burnetii in previously naturally exposed individuals reveals long-term changes in both adaptive and innate immune cellular compartments. Front Immunol. 2023 Oct 11;14:1249581. doi: 10.3389/fimmu.2023.1249581. PMID: 37885896; PMCID: PMC10598782. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10598782/ (Full text)

Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome – State of the art: Report of the 2nd international meeting at the Charité fatigue center

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a devastating disease affecting millions of people worldwide. Due to the 2019 pandemic of coronavirus disease (COVID-19), we are facing a significant increase of ME/CFS prevalence. On May 11th to 12th, 2023, the second international ME/CFS conference of the Charité Fatigue Center was held in Berlin, Germany, focusing on pathomechanisms, diagnosis, and treatment.

During the two-day conference, more than 100 researchers from various research fields met on-site and over 700 attendees participated online to discuss the state of the art and novel findings in this field. Key topics from the conference included: the role of the immune system, dysfunction of endothelial and autonomic nervous system, and viral reactivation. Furthermore, there were presentations on innovative diagnostic measures and assessments for this complex disease, cutting-edge treatment approaches, and clinical studies.

Despite the increased public attention due to the COVID-19 pandemic, the subsequent rise of Long COVID-19 cases, and the rise of funding opportunities to unravel the pathomechanisms underlying ME/CFS, this severe disease remains highly underresearched. Future adequately funded research efforts are needed to further explore the disease etiology and to identify diagnostic markers and targeted therapies.

Source: Steiner S, Fehrer A, Hoheisel F, Schoening S, Aschenbrenner A, Babel N, Bellmann-Strobl J, Finke C, Fluge Ø, Froehlich L, Goebel A, Grande B, Haas JP, Hohberger B, Jason LA, Komaroff AL, Lacerda E, Liebl M, Maier A, Mella O, Nacul L, Paul F, Prusty BK, Puta C, Riemekasten G, Ries W, Rowe PC, Sawitzki B, Shoenfeld Y, Schultze JL, Seifert M, Sepúlveda N, Sotzny F, Stein E, Stingl M, Ufer F, Veauthier C, Westermeier F, Wirth K, Wolfarth B, Zalewski P, Behrends U, Scheibenbogen C. Understanding, diagnosing, and treating Myalgic encephalomyelitis/chronic fatigue syndrome – State of the art: Report of the 2nd international meeting at the Charité fatigue center. Autoimmun Rev. 2023 Sep 22:103452. doi: 10.1016/j.autrev.2023.103452. Epub ahead of print. PMID: 37742748. https://www.sciencedirect.com/science/article/abs/pii/S1568997223001866

Long-term health outcomes of Q-fever fatigue syndrome patients

Summary:

This study determined long-term health outcomes (≥10 years) of Q-fever fatigue syndrome (QFS). Longterm health complaints, health-related quality of life (HRQL), health status, energy level, fatigue, post exertional malaise, anxiety and depression were assessed. Outcomes and determinants were studied for the total sample and compared among age subgroups: young (<40y), middle-aged (≥40-<65y), and older
(≥65y) patients.

368 QFS patients were included. Participants reported a median number of 12.0 long-term health complaints. Their HRQL (median EQ-5D-5L index: 0.63) and health status (median EQ VAS: 50.0) were low, their level of fatigue was high, and many experienced post-exertional malaise complaints (98.9%). Young and middle-aged patients reported worse health outcomes compared to older patients, with both groups reporting a significantly worse health status, higher fatigue levels and anxiety, and more post-exertional malaise complaints; and middle-aged patients having a lower HRQL and a higher risk of depression.

Multivariate regression analyses confirmed that older age is associated with better outcomes, except for the number of health complaints. QFS has thus a considerable impact on patients’ health more than 10 years after infection. Young and middle-aged patients experience more long-term health consequences compared to older patients. Tailored healthcare is recommended to provide optimal care for each QFS patient.

Source: Spronk, I., Brus, I., Groot, A., Tieleman, P., Olde Loohuis, A., Haagsma, J., & Polinder, S. (2023). Long-term health outcomes of Q-fever fatigue syndrome patients. Epidemiology & Infection, 1-35. doi:10.1017/S0950268823001401 https://www.cambridge.org/core/journals/epidemiology-and-infection/article/longterm-health-outcomes-of-qfever-fatigue-syndrome-patients/99B3D80E172A66619C216506E020BB02 (Full text available as PDF file)

How post-infection status could lead to the increasing risks of chronic fatigue syndrome and the potential mechanisms: A 17-year population based Cohort study

Abstract:

Background: Serological studies have suggested that viruses and atypical pathogens are associated with CFS, but no study has focused on typical and common pathogens. This study aims to assess the association of infections with a variety of common pathogens with the risk of CFS and provide evidence for the hypothesis that infection triggers CFS.

Methods: The nested case-control study identified 2,000,000 adult patients from a nationwide population-based health insurance claims database from January 1, 2000, to December 31, 2017. Each case with a diagnosis of infection by pathogens was matched with one control using a propensity score. Patients with more than one potential pathogen, younger than 20 years old, or with a history of CFS or infection with certain pathogens before the index date were excluded. Univariate and multivariate Cox proportional hazard models were applied to estimate the HR, aHR, and corresponding 95% CI. The multivariate analysis had adjustments for age, sex, comorbidities, and medication confounders.

Results: A total of 395,811 cases with 1: 1 matched controls were included (58.2% female; mean age [standard deviation], 44.15 [17.02]). Among these, the aHR of the pathogen cohort was 1.5 (95% CI, 1.47 to 1.54). Pathogens were positively correlated with CFS, including influenza, candida and others.

Conclusion: The findings of this study demonstrate the association between CFS and infection with common pathogens, including bacteria, virus and fungi.

Source: Hsun Chang; Chien-Feng Kuo; Teng-Shun Yu; Liang-Yin Ke; Chung-Lieh Hung; Shin-Yi Tsai. How post-infection status could lead to the increasing risks of chronic fatigue syndrome and the potential mechanisms: A 17-year population based Cohort study. Research Square, August 30, 2023. https://assets.researchsquare.com/files/rs-3289981/v1/55890598-6f0d-4f73-a9f4-5349e07baac0.pdf (Full text)

The microbiome in post-acute infection syndrome (PAIS)

Abstract:

Post-Acute Infection Syndrome (PAIS) is a relatively new medical terminology that represents prolonged sequelae symptoms after acute infection by numerous pathogenic agents. Imposing a substantial public health burden worldwide, PASC (post-acute sequelae of COVID-19 infection) and ME/CFS (myalgic encephalomyelitis/chronic fatigue syndrome) are two of the most recognized and prevalent PAIS conditions. The presences of prior infections and similar symptom profiles in PAIS reflect a plausible common etiopathogenesis. The human microbiome is known to play an essential role in health and disease.

In this review, we reviewed and summarized available research on oral and gut microbiota alterations in patients with different infections or PAIS conditions. We discussed key theories about the associations between microbiome dysbiosis and PAIS disease development, aiming to explore the mechanistic roles and potential functions the microbiome may have in the process. Additionally, we discuss the areas of knowledge gaps and propose the potential clinical applications of the microbiome for prevention and treatment of PAIS conditions.

Source: Guo C, Yi B, Wu J, Lu J. The microbiome in post-acute infection syndrome (PAIS). Comput Struct Biotechnol J. 2023 Aug 5;21:3904-3911. doi: 10.1016/j.csbj.2023.08.002. PMID: 37602232; PMCID: PMC10432703. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10432703/ (Full text)

Posttreatment Lyme disease syndrome and myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and comparison of pathogenesis

Abstract:

Lyme disease is the most common vector-borne illness in the United States and has been causing significant morbidity since its discovery in 1977. It is well-documented that about 10% of patients properly treated with antibiotics never fully recover, but instead go on to develop a chronic illness dubbed, posttreatment Lyme disease syndrome (PTLDS) characterized by severe fatigue, cognitive slowing, chronic pain, and sleep difficulties. This review includes 18 studies that detail the symptoms of patients with PTLDS and uses qualitative analysis to compare them to myalgic encephalitis/chronic fatigue syndrome (ME/CFS), a strikingly similar syndrome.

In the majority of the PTLDS studies, at least four of the six major symptoms of ME/CFS were also noted, including substantial impairment in activity level and fatigue for more than 6 months, post-exertional malaise, and unrefreshing sleep. In one of the included PTLDS articles, 26 of the 29 ME/CFS symptoms were noted. This study adds to the expanding literature on the post-active phase of infection syndromes, which suggests that chronic illnesses such as PTLDS and ME/CFS have similar pathogenesis despite different infectious origins.

Key points

  • This systematic review uses qualitative analysis to compare posttreatment Lyme disease syndrome to myalgic encephalitis/chronic fatigue syndrome, both of which are post-active phases of infection syndromes.
  • The result of this review suggests that chronic illnesses such as PTLDS and ME/CFS have similar pathogenesis despite different infectious origins.

Source: Bai, NARichardson, CSPosttreatment Lyme disease syndrome and myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and comparison of pathogenesisChronic Dis Transl Med20231– 8doi:10.1002/cdt3.74 https://onlinelibrary.wiley.com/doi/full/10.1002/cdt3.74 (Full text)

Achieving symptom relief in patients with Myalgic encephalomyelitis by targeting the neuro-immune interface and optimizing disease tolerance

Abstract:

Myalgic encephalomyelitis, ME, previously also known as chronic fatigue syndrome (CFS) is a heterogeneous, debilitating syndrome of unknown etiology responsible for long-lasting disability in millions of patients worldwide. The most well-known symptom of ME is post-exertional malaise, but many patients also experience autonomic dysregulation, cranial nerve dysfunction and signs of immune system activation. Many patients also report a sudden onset of disease following an infection.

The brainstem is a suspected focal point in ME pathogenesis and patients with structural impairment to the brainstem often show ME-like symptoms. The brainstem is also where the vagus nerve originates, a critical neuro-immune interface and mediator of the inflammatory reflex which regulate systemic inflammation.

Here we report the results of a randomized, placebo-controlled trial using intranasal mechanical stimulation (INMEST) targeting nerve endings in the nasal cavity, likely from the trigeminal nerve, possibly activating additional centers in the brainstem of ME-patients and correlating with a ∼30% reduction in overall symptom scores after eight weeks of treatment.

By performing longitudinal, systems-level monitoring of the blood immune system in these patients, we uncover signs of chronic immune activation in ME, as well as immunological correlates of improvement that center around gut-homing immune cells and reduced inflammation.

The mechanisms of symptom relief remains to be determined, but transcriptional analyses suggest an upregulation of disease tolerance mechanisms. We believe that these results are suggestive of ME as a condition explained by a maladaptive disease tolerance response following infection.

Source: Lucie Rodriguez, Christian Pou, Tadepally Lakshmikanth, Jingdian Zhang, Constantin Habimana Mugabo, Jun Wang, Jaromir Mikes, Axel Olin, Yang Chen, Joanna Rorbach, Jan-Erik Juto, Tie Qiang Li, Per Julin, Petter Brodin, Achieving symptom relief in patients with Myalgic encephalomyelitis by targeting the neuro-immune interface and optimizing disease tolerance, Oxford Open Immunology, 2023;, iqad003, https://doi.org/10.1093/oxfimm/iqad003 (Full text available as PDF file)