Category: Overlapping Illnesses

Dysregulation of lipid metabolism, energy production, and oxidative stress in myalgic encephalomyelitis/chronic fatigue syndrome, Gulf War Syndrome and fibromyalgia

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), Gulf War Syndrome (GWS), and Fibromyalgia (FM) are complex, chronic illnesses with overlapping clinical features. Symptoms that are reported across these conditions include post-exertional malaise (PEM), fatigue, and pain, yet the etiology of these illnesses remains largely unknown. Diagnosis is challenging in patients with these conditions as definitive biomarkers are lacking; patients are required to meet clinical criteria and often undergo lengthy testing to exclude other conditions, a process that is often prolonged, costly, and burdensome for patients.

The identification of reliable validated biomarkers could facilitate earlier and more accurate diagnosis and drive the development of targeted pharmacological therapies that might address the underlying pathophysiology of these diseases. Major driving forces for biomarker identification are the advancing fields of metabolomics and proteomics that allow for comprehensive characterization of metabolites and proteins in biological specimens. Recent technological developments in these areas enable high-throughput analysis of thousands of metabolites and proteins from a variety of biological samples and model systems, that provides a powerful approach to unraveling the metabolic phenotypes associated with these complex diseases.

Emerging evidence suggests that ME/CFS, GWS, and FM are all characterized by disturbances in metabolic pathways, particularly those related to energy production, lipid metabolism, and oxidative stress. Altered levels of key metabolites in these pathways have been reported in studies highlighting potential common biochemical abnormalities. The precise mechanisms driving altered metabolic pathways in ME/CFS, GWS, and FM remain to be elucidated; however, the elevated oxidative stress observed across these illnesses may contribute to symptoms and offer a potential target for therapeutic intervention.

Investigating the mechanisms, and their role in the disease process, could provide insights into disease pathogenesis and reveal novel treatment targets. As such, comprehensive metabolomic and proteomic analyses are crucial for advancing the understanding of these conditions in-order to identify both common, and unique, metabolic alterations that could serve as diagnostic markers or therapeutic targets.

Source: Davis L, Higgs M, Snaith A, Lodge TA, Strong J, Espejo-Oltra JA, Kujawski S, Zalewski P, Pretorius E, Hoerger M, Morten KJ. Dysregulation of lipid metabolism, energy production, and oxidative stress in myalgic encephalomyelitis/chronic fatigue syndrome, Gulf War Syndrome and fibromyalgia. Front Neurosci. 2025 Mar 10;19:1498981. doi: 10.3389/fnins.2025.1498981. PMID: 40129725; PMCID: PMC11931034. https://pmc.ncbi.nlm.nih.gov/articles/PMC11931034/ (Full text)

Health outcomes one year after Omicron infection among 12,789 adults: a community-based cross-sectional study

Summary:

Background: Characterizing the paradigm and impact of long COVID is crucial for addressing this worldwide health challenge. This study aimed to investigate the prevalence of long COVID one year after primary Omicron infection and characterize differences in long-term health consequence between participants with persistent long COVID and those who fully recovered.

Methods: This a community-based cross-sectional study conducted from December 2023 to March 2024 at the China-Japan Friendship Hospital and 16 administrative districts in Beijing. 12,789 participants infected with Omicron between December 2022 and January 2023 were recruited through stratified multistage random sampling and included in the final analysis. Of them, 376 participants with persistent long COVID and 229 without long COVID were matched for further physical examinations. The primary outcome was the prevalence of long COVID one year after infection. Secondary outcomes included muscle strength, exercise capacity, health-related quality of life (HRQoL), mental health, work status, laboratory tests, and examinations.

Findings: Among 12,789 participants (media [IQR] age, 48.4 [37.3 to 61.4] years; 7817 females [61.1%]), 995 of them (7.8%) experienced long COVID within one year, with 651 (5.1%) having persistent symptoms. Fatigue (598/995 [60.1%]) and post-exertional malaise (367/995 [36.9%]) were the most common symptoms. Brain fog had the lowest resolution proportion as 4.2% within one year. The odds of long COVID increased with reinfections (odds ratios for one reinfection 2.592 [95% CI: 2.188 to 3.061]; two or more: 6.171 [3.227 to 11.557]; all p < 0.001). Participants with persistent long COVID had markedly lower muscle strength (upper-limb: 26.9 ± 12.4 vs. 29.1 ± 14.5 Kg; lower-limb: 40.0 [27.0 to 62.0] vs. 43.0 [28.0 to 59.0] s), worse exercise capacity and poorer HRQoL, and meaningful difference in laboratory tests results compared to those without long COVID. They also exhibited significantly higher proportions of abnormal lung function (FEV1 %pred<80%: 13.0% vs. 2.0%; DLco %pred<80%: 32.7% vs. 19.9%) and lung imaging abnormalities (23.5% vs. 13.6%).

Interpretation: The considerable health burden of long COVID and the progression of neurological symptoms following Omicron infection warrant close monitoring. Utilizing professional questionnaires and developing reliable diagnostic tools are necessary for improving diagnosis and treatment of long COVID.

Funding: This work was supported by Beijing Research Center for Respiratory Infectious Diseases (BJRID2024-012), Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (2022-I2M-CoV19-005/CIFMS 2021-I2M-1-048), the National Natural Science Foundation of China (82241056/82200114/82200009), the New Cornerstone Science Foundation.

Source: Zhang, Hui et al.Health outcomes one year after Omicron infection among 12,789 adults: a community-based cross-sectional study. The Lancet Regional Health – Western Pacific, Volume 0, Issue 0, 101507  https://www.thelancet.com/journals/lanwpc/article/PIIS2666-6065(25)00044-6/fulltext (Full text)

Cognitive Impairments in Two Samples of Individuals with ME/CFS and Long COVID: A Comparative Analysis

Abstract:

Cognitive impairments, including memory and concentration difficulties, are common in individuals with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID. These conditions frequently co-occur, but it remains unclear how cognitive difficulties differ between individuals with ME/CFS, long COVID, both, or neither. The purpose of this study was to examine cognitive impairment presence and type for individuals with and without these conditions.

Data from the 2022 and 2023 National Health Interview Survey were analyzed. Participants included 27,512 and 29,404 U.S. adults in 2022 and 2023, respectively. Survey weights and variance estimation variables were utilized and multivariate logistic regression models assessed the likelihood of cognitive difficulty, accounting for sociodemographics and shared variance. Participants from both cohorts were primarily female, white, and non-Hispanic/Latine, with an average age of 48.1 years in both cohorts.

ME/CFS (aOR 6.18; 95% CI 4.82-7.93; aOR 5.33; 95% CI 4.04-7.05) and long COVID (aOR 2.01; 95% CI 1.67-2.44; aOR 2.16; 95% CI 1.82-2.56) were significantly associated with reported cognitive difficulties, after controlling for the other condition and sociodemographic factors. Individuals with ME/CFS, particularly those with comorbid long COVID, are especially prone to memory and concentration difficulties.

Source: Sirotiak Z, Adamowicz JL, Thomas EBK. Cognitive Impairments in Two Samples of Individuals with ME/CFS and Long COVID: A Comparative Analysis. J Clin Psychol Med Settings. 2025 Mar 22. doi: 10.1007/s10880-025-10074-4. Epub ahead of print. PMID: 40120036. https://pubmed.ncbi.nlm.nih.gov/40120036/

Gulf War Illness: A Historical Review and Considerations of a Post-Viral Syndrome

Abstract:

Gulf War Illness (GWI) is a condition that affects 30-40% of nearly 700,000 Veterans who were deployed to Operations Desert Shield/Storm/Sabre (ODS/S/S) between August 1990 and June 1991 and is characterized by a constellation of symptoms, including fatigue, mood/cognition, chronic pain, gastrointestinal (most frequently referred to as “irritable bowel syndrome”), respiratory, and skin issues.

We review the development of various case definitions for GWI, as well as exposure theories. Despite heavy investment in research, both the pathophysiology and underlying cause of GWI remain areas of active inquiry. Similarities have previously been noted in symptomatology between GWI and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and more recently, long COVID (LC), a late effect of infection with the Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2).

These conditions are discussed with respect to the similarities of their symptomatology and pathophysiology. Long COVID is a post-viral syndrome, and ME/CFS is widely considered to be likely post-infectious as well. This comparison leads to the proposal of the hypothesis that GWI may also be post-viral. Given the similarity of GWI and LC, it is possible that Veterans with GWI had an antecedent infection with a virus related to SARS-CoV-2, potentially the Middle East Respiratory Syndrome Coronavirus (MERS) or an ancestor of this virus. The MERS antibodies have been found in dromedary camels in Saudi Arabia since 1983 to the present, including the time of ODS/S/S. There is abundant evidence to support further investigation into this topic.

Source: Bast E, Jester DJ, Palacio A, Krengel M, Reinhard M, Ashford JW. Gulf War Illness: A Historical Review and Considerations of a Post-Viral Syndrome. Mil Med. 2025 Mar 21:usaf092. doi: 10.1093/milmed/usaf092. Epub ahead of print. PMID: 40117126. https://pubmed.ncbi.nlm.nih.gov/40117126/

Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination

Abstract:

Background: Prolonged symptoms have been reported following both COVID-19 infection and vaccination, with some cases leading to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Of 80 patients presenting to our hospital with postvaccination syndrome, 28 met the diagnostic criteria for ME/CFS. We conducted a retrospective study on these 28 patients.

Methods: We measured serum 25-hydroxyvitamin D levels in 28 patients who developed ME/CFS after COVID-19 vaccination between August 2022 and February 2024. Vitamin D replacement therapy included dietary counseling, sun exposure recommendations, and oral vitamin D supplementation. We evaluated changes in blood vitamin D levels and symptom improvement.

Results: At initial visit, 27 of 28 patients diagnosed with ME/CFS had insufficient or deficient serum 25-hydroxyvitamin D levels (16 ± 4 ng/mL, mean ± SD). Following vitamin D replacement therapy, we observed an increase in blood vitamin D levels (28 ± 5 ng/mL) associated with a decrease in ME/CFS diagnostic symptoms (from 10.3 ± 2.1 to 3.3 ± 2.0). Notably, 23 of 28 patients (82%) no longer met ME/CFS diagnostic criteria after the therapy. Among the symptoms, sleep problems showed the most improvement (71%), followed by autonomic symptoms (68%).

Conclusions: For patients developing ME/CFS after COVID-19 vaccination with insufficient or deficient vitamin D levels, appropriate vitamin D replacement therapy under medical guidance may lead to symptomatic relief. We are preparing a randomized controlled trial to evaluate the efficacy of vitamin D replacement therapy in individuals with ME/CFS who have developed vitamin D deficiency following COVID-19 infection or vaccination.

Source: Kodama S, Konishi N, Hirai Y, Fujisawa A, Nakata M, Teramukai S, Fukushima M. Efficacy of vitamin D replacement therapy on 28 cases of myalgic encephalomyelitis/chronic fatigue syndrome after COVID-19 vaccination. Nutrition. 2025 Feb 18;134:112718. doi: 10.1016/j.nut.2025.112718. Epub ahead of print. PMID: 40090177. https://www.sciencedirect.com/science/article/pii/S089990072500036X (Full text)

Health-related quality of life in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Post COVID-19 Condition: a systematic review

Abstract:

Purpose: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Post COVID-19 Condition (PCC) are debilitating, chronic multi-systemic illnesses that require multidisciplinary care. However, people with ME/CFS (pwME/CFS) and people with PCC (pwPCC) are often precluded from accessing necessary disability and social support services. These unmet care needs exacerbate the existing illness burdens experienced by pwME/CFS and pwPCC. To deliver appropriate care and optimise health outcomes for pwME/CFS and pwPCC, the development of evidence-based healthcare policies that recognise the disabling impacts of these illnesses must be prioritised. This systematic review summarises the health-related quality of life (HRQoL) of pwME/CFS and pwPCC when compared with healthy controls (HCs) to elucidate the impacts of these illnesses and guide healthcare policy reform.

Methods: CINAHL, Embase, MEDLINE, PubMed, PsycINFO and the Web of Science Core Collection were systematically searched from 1st January 2003 to 23rd July 2024. Eligible publications included observational studies capturing quantitative HRQoL data among pwME/CFS or pwPCC when compared with HCs. The use of validated patient-reported outcome measures (PROMs) was mandatory. Eligible studies were also required to employ the most stringent diagnostic criteria currently available, including the Canadian Consensus Criteria or International Consensus Criteria for ME/CFS and the World Health Organization case definition for PCC (PROSPERO ID: CRD42024501309).

Results: This review captured 16 studies, including eight studies among pwME/CFS, seven studies among pwPCC and one study among both illness cohorts. Most participants were female and middle-aged. All pwPCC had experienced prolonged COVID-19 symptoms for at least three months. When compared with HCs, all HRQoL domains were significantly impaired among pwME/CFS and pwPCC. Both illnesses had a salient impact on physical health, including pain and ability to perform daily and work activities. While direct comparisons between pwME/CFS and pwPCC were limited by inconsistencies in the PROMs employed, comparable impact trends across HRQoL domain scores were observed.

Conclusion: ME/CFS and PCC have similar, profound impacts on HRQoL that warrant access to multidisciplinary disability and social support services. Future research must harmonise HRQoL data collection and prioritise longitudinal investigations among pwME/CFS and pwPCC to characterise PCC subgroups (including those fulfilling ME/CFS criteria) and predictors of prognosis.

Source: Weigel B, Inderyas M, Eaton-Fitch N, Thapaliya K, Marshall-Gradisnik S. Health-related quality of life in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Post COVID-19 Condition: a systematic review. J Transl Med. 2025 Mar 13;23(1):318. doi: 10.1186/s12967-025-06131-z. PMID: 40075382. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-025-06131-z (Full text)

mTORC1 syndrome (TorS): unifying paradigm for PASC, ME/CFS and PAIS

Abstract:

Post-acute SarS-Cov2 (PASC), Myalgia encephalomyelitis/Chronic fatigue syndrome (ME/CFS) and Post-acute infection syndrome (PAIS) consist of chronic post-acute infectious syndromes, sharing exhaustive fatigue, post exertional malaise, intermittent pain, postural tachycardia and neuro-cognitive-psychiatric dysfunction. However, the concerned shared pathophysiology is still unresolved in terms of upstream drivers and transducers. Also, risk factors which may determine vulnerability/progression to the chronic phase still remain to be defined.

In lack of drivers and a cohesive pathophysiology, the concerned syndromes still remain unmet therapeutic needs. ‘mTORC1 Syndrome’ (TorS) implies an exhaustive disease entity driven by sustained hyper-activation of the mammalian target of rapamycin C1 (mTORC1), and resulting in a variety of disease aspects of the Metabolic Syndrome (MetS), non-alcoholic fatty liver disease, chronic obstructive pulmonary disease, some cancers, neurodegeneration and other [Bar-Tana in Trends Endocrinol Metab 34:135-145, 2023]. TorS may offer a cohesive insight of PASC, ME/CFS and PAIS drivers, pathophysiology, vulnerability and treatment options.

Source: Bar-Tana J. mTORC1 syndrome (TorS): unifying paradigm for PASC, ME/CFS and PAIS. J Transl Med. 2025 Mar 10;23(1):297. doi: 10.1186/s12967-025-06220-z. PMID: 40059164. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-025-06220-z (Full text)

Post-infective myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-COVID as two puzzling faces of the same medal. Recent insights

Background:

How much is truly shared in terms of pathogenesis, symptomatology, and disease progression between the myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-COVID, and why have these two very complex conditions recently been grouped under the same umbrella terms?
The 1st International Conference on Clinical and Scientific Advances of ME/CFS/long COVID”, held in Portugal, on April 3rd and 4th 2024 [1], addressed, for the first time, this concern, shedding light onto two highly…
Source: Chirumbolo S, Franzini M, Tirelli U. Post-infective myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-COVID as two puzzling faces of the same medal. Recent insights. Int Immunopharmacol. 2025 Mar 7:114365. doi: 10.1016/j.intimp.2025.114365. Epub ahead of print. PMID: 40057420. https://www.sciencedirect.com/science/article/abs/pii/S1567576925003558

“I still can’t forget those words”: mixed methods study of the persisting impact on patients reporting psychosomatic and psychiatric misdiagnoses

Abstract:

Objectives: This research aimed to improve understanding of persisting impacts of patient-reported psychosomatic and psychiatric misdiagnoses on patients with systemic autoimmune rheumatic diseases (SARDs).
Methods: Mixed methods data from two SARDs cohorts were analysed (N = 1,543 and N = 1,853). Validated instruments and patient-designed questions were used to measure self-reported depression, anxiety and mental wellbeing, in addition to medical relationships and healthcare behaviours. Comparative tests were used to evaluate differences between patients reporting a psychosomatic and/or psychiatric misdiagnoses and other patients.
Results: Persisting adverse outcomes of perceived psychosomatic and psychiatric misdiagnoses were identified in multiple domains. This included >80% of patients reporting that it had damaged their self-worth, and 72% reporting that it still upset them. Patients reporting psychosomatic and/or psychiatric misdiagnoses had significantly lower mental wellbeing, and higher depression and anxiety levels (all p< 0.001), and lower levels of satisfaction with every aspect of medical care, compared with patients reporting no psychosomatic or psychiatric misdiagnoses. Psychosomatic and psychiatric misdiagnoses had varying associations with healthcare behaviours, including a significantly higher likelihood of under-reporting symptoms (p< 0.001) and healthcare avoidance (p= 0.012), but not with medication adherence (p= 0.2). Thematic analysis of qualitative data revealed that symptom under-reporting and healthcare avoidance often resulted from distrust and fear that symptoms would be disbelieved and misattributed again.
Conclusion: Patient-reported psychosomatic and psychiatric (mis)diagnoses are associated with persisting adverse impacts in multiple domains including mental health, medical relationships, self-worth, and some healthcare behaviours. Health services and clinicians should consider these potential adverse impacts on patients and offer support to reduce any persisting negative impacts.

Source: Melanie Sloan, Michael Bosley, Caroline Gordon, Thomas A Pollak, Farhana Mann, Efthalia Massou, Stephen Morris, Lynn Holloway, Rupert Harwood, Kate Middleton, Wendy Diment, James Brimicombe, Elliott Lever, Lucy Calderwood, Ellie Dalby, Elaine Dunbar, David D’Cruz, Felix Naughton, “I still can’t forget those words”: mixed methods study of the persisting impact on patients reporting psychosomatic and psychiatric misdiagnoses, Rheumatology, 2025;, keaf115, https://doi.org/10.1093/rheumatology/keaf115 https://academic.oup.com/rheumatology/advance-article/doi/10.1093/rheumatology/keaf115/8042899 (Full text available as PDF file)

Direct effects of prolonged TNF-α and IL-6 exposure on neural activity in human iPSC-derived neuron-astrocyte co-cultures

Abstract:

Cognitive impairment is one of the many symptoms reported by individuals suffering from long-COVID and other post-viral infection disorders such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). A common factor among these conditions is a sustained immune response and increased levels of inflammatory cytokines. Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) are two such cytokines that are elevated in patients diagnosed with long-COVID and ME/CFS.

In this study, we characterized the changes in neural functionality, secreted cytokine profiles, and gene expression in co-cultures of human iPSC-derived neurons and primary astrocytes in response to prolonged exposure to TNF-α and IL-6. We found that exposure to TNF-α produced both a concentration-independent and concentration-dependent response in neural activity.

Burst duration was significantly reduced within a few days of exposure regardless of concentration (1 pg/mL – 100 ng/mL) but returned to baseline after 7 days. Treatment with low concentrations of TNF-α (e.g., 1 and 25 pg/mL) did not lead to changes in the secreted cytokine profile or gene expression but still resulted in significant changes to electrophysiological features such as interspike interval and burst duration. Conversely, treatment with high concentrations of TNF-α (e.g., 10 and 100 ng/mL) led to reduced spiking activity, which may be correlated to changes in neural health, gene expression, and increases in inflammatory cytokine secretion (e.g., IL-1β, IL-4, and CXCL-10) that were observed at higher TNF-α concentrations.

Prolonged exposure to IL-6 led to changes in bursting features, with significant reduction in the number of spikes in bursts across a wide range of treatment concentrations (i.e., 1 pg/mL-10 ng/mL). In combination, the addition of IL-6 appears to counteract the changes to neural function induced by low concentrations of TNF-α, while at high concentrations of TNF-α the addition of IL-6 had little to no effect. Conversely, the changes to electrophysiological features induced by IL-6 were lost when the cultures were co-stimulated with TNF-α regardless of the concentration, suggesting that TNF-α may play a more pronounced role in altering neural function.

These results indicate that increased concentrations of key inflammatory cytokines associated with long-COVID can directly impact neural function and may be a component of the cognitive impairment associated with long-COVID and other post-viral infection disorders.

Source: Goshi N, Lam D, Bogguri C, George VK, Sebastian A, Cadena J, Leon NF, Hum NR, Weilhammer DR, Fischer NO, Enright HA. Direct effects of prolonged TNF-α and IL-6 exposure on neural activity in human iPSC-derived neuron-astrocyte co-cultures. Front Cell Neurosci. 2025 Feb 12;19:1512591. doi: 10.3389/fncel.2025.1512591. PMID: 40012566; PMCID: PMC11860967. https://pmc.ncbi.nlm.nih.gov/articles/PMC11860967/ (Full text)