Tag: 2026

Molecular hydrogen as a treatment for ME/CFS: a mini-review of clinical evidence and mechanistic rationale

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating multisystem illness characterized by profound fatigue, post-exertional malaise, cognitive impairment, and autonomic dysfunction, yet it currently lacks FDA-approved treatments. Molecular hydrogen (H2), administered primarily as hydrogen-rich water (HRW), has emerged as a potential therapeutic candidate due to its selective antioxidant effects, anti-inflammatory activity, and support of mitochondrial and cellular homeostasis. These mechanisms align with several biological abnormalities implicated in ME/CFS, including oxidative stress, chronic inflammation, and impaired energy metabolism. This narrative mini-review summarizes mechanistic evidence relevant to ME/CFS and evaluates three developmental clinical studies of HRW in this population.

Although early trials are small and methodologically limited, moderate-dose HRW consumed over extended durations has demonstrated feasibility and preliminary benefits in reducing fatigue and improving physical function, with generally mild side effects. Overlapping findings in Long COVID further suggest potential applicability across related post-viral fatigue conditions. Key limitations include small sample sizes, reliance on self-report outcomes, and the absence of objective biomarkers.

Future research should prioritize larger, rigorously controlled trials incorporating remote biometric and biochemical assessments to clarify mechanisms of action and identify responsive subgroups. Overall, molecular hydrogen represents a promising, low-burden adjunctive therapy warranting further investigation in ME/CFS.

Source:Friedberg F and LeBaron TW (2026) Molecular hydrogen as a treatment for ME/CFS: a mini-review of clinical evidence and mechanistic rationale. Front. Med. 13:1760210. doi: 10.3389/fmed.2026.1760210 https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2026.1760210/full (Full text)

Dysregulated NK-cell gene expression defines the enduring symptoms of long COVID-19

Abstract:

Introduction: Long-term COVID-19 syndrome (LTCS) or “long COVID” is a debilitating post-viral condition affecting approximately 2%–8% of individuals after SARS-CoV-2 infection. It manifests typically ≥3 months post-infection with symptoms persisting for at least 2 months, including fatigue, pulmonary dysfunction, and cognitive impairment, in the absence of alternative diagnoses. The biological mechanisms underlying LTCS remain poorly defined, yet emerging evidence implicates immune dysregulation.

Methods: We profiled plasma antibodies and cytokines from healthy controls (HC, N = 66), convalescents (CONV, N = 24), and LTCS patients (N = 94), followed by multiparametric 14-color flow cytometry of PBMCs from HC (N = 9), CONV (N = 6), and LTCS (N = 23) participants. To gain mechanistic insight, we performed single-cell transcriptomic profiling (scRNA-seq) on PBMCs from HC (N = 8), CONV (N = 6), and LTCS (N = 32) individuals.

Results: LTCS patients exhibited elevated anti-SARS-CoV-2 IgG (spike S1/RBD/N) titers compared with HC, but displayed significantly reduced systemic cytokine levels, including IFN-γ, TNF-α, IL-6, and IL-10. Flow cytometry revealed marked depletion of CD56+CD16+ NK cells and CD56+CD3+ NKT cells, accompanied by altered T-cell activation states. scRNA-seq confirmed NK type I cell loss and uncovered broad transcriptional reprogramming with upregulation of PDCD4, CHD1, CXCR4, and SLC7A5 and downregulation of TGFBR3, RIPOR2, and MBNL1. Gene set enrichment analyses indicated activation of circadian and translational programs and suppression of olfactory receptor, neurotransmitter receptor, and GABA-gated ion-channel pathways. Functional assays validated reduced NK-cell inflammatory capacity in LTCS participants.

Discussion: LTCS is characterized by systemic cytokine attenuation and a quantitative and functional NK-cell deficit coupled to neurosensory pathway suppression. These findings identify NK cells as key sentinels of LTCS pathophysiology and highlight an NK-centric neuroimmune axis as a promising target for biomarker discovery and therapeutic intervention.

Source: Ray U, Schulze Selting A, Perera RP, Yang Z, Lysenkov V, Göpel S, Bitzer M, Salker MS, Ossowski S, Riess O, Casadei N and Singh Y (2026) Dysregulated NK-cell gene expression defines the enduring symptoms of long COVID-19. Front. Immunol. 17:1720551. doi: 10.3389/fimmu.2026.1720551 https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2026.1720551/full?media_id=3855960893360206425_63872469980&media_author_id=63872469980&ranking_info_token=GCBhMjBlODkzODk5NGI0NWIwYjM3MmUwYjkyNDUyYmY5YyWmsvQCJoKX3psNGBMzODU1OTYwODkzMzYwMjA2NDI1KANndG4A&utm_source=ig_text_feed_timeline (Full text)

Extracellular Vesicle Protein and MiRNA Signatures as Biomarkers for Post-Infectious ME/CFS Patients

Abstract:

Post-infectious Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic disease with unresolved pathophysiology and limited diagnostic options. Extracellular vesicles (EVs) carry disease-specific protein and miRNA signatures and may enable improved disease profiling. We aimed to identify novel protein and miRNA markers as potential biomarkers in plasma EVs from female ME/CFS patients, including post-COVID-19 ME/CFS and post-infectious ME/CFS of other origins, compared with healthy controls.

EVs were isolated from plasma by size-exclusion chromatography and characterized for number, size, morphology, and surface marker expression. Flow cytometry showed that small EVs strongly expressed tetraspanins, with only minor differences between ME/CFS patients and healthy donors. Proteomic profiling of EVs from ME/CFS patients identified altered cargo proteins, including hemoglobin subunit alpha and insulin-like growth factor-binding protein acid labile subunit compared with healthy controls (n ≤ 10/cohort). Small RNA sequencing followed by qPCR revealed significant downregulation of hsa-let-7b-5p in EVs from post-COVID-19 ME/CFS patients (n = 12) versus healthy controls (n = 15). Reduced hsa-let-7b-5p expression correlated with impaired physical functioning and increased fatigue, pain, and immune activation.

These findings indicate that EV cargo differences, particularly hemoglobin subunit alpha and insulin-like growth factor-binding protein acid labile subunit, as well as hsa-let-7b-5p, represent promising candidates for ME/CFS diagnosis and patient stratification.

Source: Seifert M, Schäfers J, Douglas FF, Schwarzburg C, Boristowski D, Birke A, Klein O, Sotzny F, Rubarth K, Windzio L, Beez CM, Peters CK, Wittke K, Scheibenbogen C, Greco A. Extracellular Vesicle Protein and MiRNA Signatures as Biomarkers for Post-Infectious ME/CFS Patients. Int J Mol Sci. 2026 Feb 28;27(5):2314. doi: 10.3390/ijms27052314. PMID: 41828537. https://www.mdpi.com/1422-0067/27/5/2314 (Full text)

Clinical relevance of circulating blood microaggregates and reactivation of Epstein Barr Virus in long-term Post-CoVID syndrome patients

Abstract:

Chronic persistence of systemic symptoms after recovery from active CoVID-19 has become a significant disease burden, named post-CoVID syndrome. Among many pathophysiological hypotheses we focus on impaired hemostasis as well as reactivation of latent Epstein-Barr virus.

We now introduce a novel diagnostic morphological approach for visualizing microaggregates circulating in peripheral venous blood, which are large enough to impede capillary blood flow. In addition, secretion of interferon gamma by mononuclear leukocytes in response to peptides of Epstein-Barr virus is increased in these patients.

As a promising therapeutic approach, we provide retrospective data on the effect of anti-thrombotic and virostatic drugs, respectively. In a large number of patients, clinical improvement was observed after platelet inhibition, particularly when EBV was also treated with antiviral therapy.

Source: Wick N, Hermann M, Lisch C, Gerth R, Wick G, Untersmayr E, Marth T, Bachler M, Fries D. Clinical relevance of circulating blood microaggregates and reactivation of Epstein Barr Virus in long-term Post-CoVID syndrome patients. Sci Rep. 2026 Mar 8. doi: 10.1038/s41598-026-42952-8. Epub ahead of print. PMID: 41796205. https://www.nature.com/articles/s41598-026-42952-8 (Full text available as PDF file)

Outcomes of ME/CFS following infectious mononucleosis: seven-year follow-up of a prospective study

Abstract:

Background: Many individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) report experiencing an infectious illness prior to disease onset. Approximately 30% of cases are linked to Epstein–Barr virus (EBV) infection resulting in Infectious Mononucleosis (IM).

Methods: We examined the progression of ME/CFS following IM among a cohort of college students who were recruited before they developed the infection. This sample represented a socioeconomically and ethnically diverse population of young adults who were monitored over a 7-year period. Assessments of health status, psychological functioning, and blood biomarkers were conducted at four time points: (1) baseline, when participants were healthy and at least 6 weeks from IM onset; (2) within 6 weeks of IM diagnosis; (3) 6 months post-IM, when participants had either recovered or met criteria for ME/CFS; and (4) the 7-year follow-up.

Results: At follow-up, 81% of participants who had initially presented with severe ME/CFS continued to fulfill diagnostic criteria. In contrast, only about one-third of those with moderate or lingering symptoms at 6 months still had ME/CFS 7 years later.

Conclusion: These findings indicate that ME/CFS following IM tends to persist over the long term, particularly among those whose illness was more severe at onset.

Source: Jason LA, Furst J, Worth R and Katz BZ (2026) Outcomes of ME/CFS following infectious mononucleosis: seven-year follow-up of a prospective study. Front. Med. 13:1676628. doi: 10.3389/fmed.2026.1676628 https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2026.1676628/full (Full text)

ACHTSAM study protocol: outreach diagnostics and assessment of tolerability in severe ME/CFS-a pilot study

Abstract:

Introduction: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe, multisystem condition that often emerges after viral infections and affects physical and cognitive function. Severely affected patients are underrepresented in research due to immobility and exertional intolerance.

Methods: This is a prospective, non-interventional observational study investigating the feasibility and tolerability of home-based diagnostics in patients with severe and very severe ME/CFS. Phase 1 includes remote identification using validated questionnaires. Phase 2 involves home visits for physiological, cognitive and biological assessments. The primary outcome is feasibility; secondary outcomes include tolerability and methodological barriers.

Ethics/dissemination: The study protocol was approved by the Ethics Committee of the University of Freiburg (No. 25-1031-S1). Written informed consent is obtained from all participants. Results will be disseminated via peer-reviewed publications and patient support groups.

Trial registration number: DRKS00035231; FRKS005506.

Source: Fricke C, Deibert P, Maier P, Kern W, Krumnau O, Barsch F. ACHTSAM study protocol: outreach diagnostics and assessment of tolerability in severe ME/CFS-a pilot study. BMJ Open. 2026 Mar 6;16(3):e113095. doi: 10.1136/bmjopen-2025-113095. PMID: 41791789. https://bmjopen.bmj.com/content/16/3/e113095 (Full text)

Charting the circulating proteome in ME/CFS using cross-system profiling to uncover mechanistic insights

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating condition often triggered by infections, with unclear mechanisms and no established biomarkers or treatments. We apply aptamer-based serum proteomics to 50 ME/CFS patients and 29 healthy controls, analyzing 7,326 protein targets.

We identify 1,823 aptamers with significant differences between the groups (845 after false discovery rate [FDR] correction). Distinct patterns of tissue- and process-specific changes are seen. There is a broad increase in secreted proteins, while intracellular proteins, e.g., from skeletal muscle, particularly show reduction. Immune cell-associated signatures indicate immune reprogramming, including a distinct reduction in proteins secreted by activated neutrophils. Focused secretome analysis supports intensified regulatory interactions related to immune activity, inflammation, vasculature, and metabolism.

Validation of measurements using antibody-based methods confirms findings for a selection of proteins. The uncovered serum proteome patterns in ME/CFS patients may contribute to understanding the pathophysiology and inform future biomarker research and therapeutic development.

Source: Hoel A, Hoel F, Dyrstad SE, Chapola H, Rekeland IG, Risa K, Alme K, Sørland K, Brokstad KA, Marti HP, Mella O, Fluge Ø, Tronstad KJ. Charting the circulating proteome in ME/CFS using cross-system profiling to uncover mechanistic insights. Cell Rep Med. 2026 Mar 4:102647. doi: 10.1016/j.xcrm.2026.102647. Epub ahead of print. PMID: 41785863. https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791(26)00064-9?rss=yes (Full text)

A multiomics recovery factor predicts long COVID in the IMPACC study

Abstract:

BACKGROUND: Following SARS-CoV-2 infection, approximately 10%–35% of patients with COVID-19 experience long COVID (LC), in which debilitating symptoms persist for at least 3 months. Elucidating the biologic underpinnings of LC could identify therapeutic opportunities.

METHODS: We utilized machine learning methods on biologic analytes provided over 12 months after hospital discharge from more than 500 patients with COVID-19 in the IMPACC cohort to identify a multiomics “recovery factor,” trained on patient-reported physical function survey scores. Immune profiling data included PBMC transcriptomics, serum O-link and plasma proteomics, plasma metabolomics, and blood mass cytometry by time of flight (CyTOF) protein levels. Recovery factor scores were tested for association with LC, disease severity, clinical parameters, and immune subset frequencies. Enrichment analyses identified biologic pathways associated with recovery factor scores.

RESULTS: Participants with LC had lower recovery factor scores compared with recovered participants. Recovery factor scores predicted LC as early as hospital admission, irrespective of acute COVID-19 severity. Biologic characterization revealed increased inflammatory mediators, elevated signatures of heme metabolism, and decreased androgenic steroids as predictive and ongoing biomarkers of LC. Lower recovery factor scores were associated with reduced lymphocyte and increased myeloid cell frequencies. The observed signatures are consistent with persistent inflammation driving anemia and stress erythropoiesis as major biologic underpinnings of LC.

CONCLUSION: The multiomics recovery factor identifies patients at risk of LC early after SARS-CoV-2 infection and reveals LC biomarkers and potential treatment targets.

TRIAL REGISTRATION: ClinicalTrials.gov NCT04378777.

FUNDING:

National Institute of Allergy and Infectious Diseases (NIAID), NIH (3U01AI167892-03S2, 3U01AI167892-01S2, 5R01AI135803-03, 5U19AI118608-04, 5U19AI128910-04, 4U19AI090023-11, 4U19AI118610-06, R01AI145835-01A1S1, 5U19AI062629-17, 5U19AI057229-17, 5U19AI057229-18, 5U19AI125357-05, 5U19AI128913-03, 3U19AI077439-13, 5U54AI142766-03, 5R01AI104870-07S1, 3U19AI089992-09, 3U19AI128913-03, and 5T32DA018926-1, 3U19AI1289130, U19AI128913-04S1, R01AI122220); NIH (UM1TR004528); and National Science Foundation (NSF) (DMS2310836).

Source: Gabernet G, Maciuch J, Gygi JP, Moore JF, Hoch A, Syphurs C, Chu T, Doni Jayavelu N, Corry DB, Kheradmand F, Baden LR, Sekaly RP, McComsey GA, Haddad EK, Cairns CB, Rouphael N, Fernandez-Sesma A, Simon V, Metcalf JP, Agudelo Higuita NI, Hough CL, Messer WB, Davis MM, Nadeau KC, Pulendran B, Kraft M, Bime C, Reed EF, Schaenman J, Erle DJ, Calfee CS, Atkinson MA, Brakenridge SC, Melamed E, Shaw AC, Hafler DA, Augustine AD, Becker PM, Ozonoff A, Bosinger SE, Eckalbar W, Maecker HT, Kim-Schulze S, Steen H, Krammer F, Westendorf K; IMPACC Network; Peters B, Fourati S, Altman MC, Levy O, Smolen KK, Montgomery RR, Diray-Arce J, Kleinstein SH, Guan L, Ehrlich LI. A multiomics recovery factor predicts long COVID in the IMPACC study. J Clin Invest. 2025 Sep 9;135(21):e193698. doi: 10.1172/JCI193698. PMID: 40924481; PMCID: PMC12582403. https://pmc.ncbi.nlm.nih.gov/articles/PMC12582403/ (Full text)

Genetic depletion of the early autophagy protein ATG13 impairs mitochondrial energy metabolism, augments oxidative stress, induces the polarization of macrophages to the M1 inflammatory mode, and compromises myelin integrity in skeletal muscle

Abstract:

Objective: M1 macrophage activation is crucial in chronic inflammatory diseases, yet its molecular mechanism is unclear.

Results: Our study showed that hemizygous deletion of the early autophagy gene atg13 (Tg+/-ATG13) disrupts cellular autophagy, hinders mitochondrial oxidative metabolism, and increases reactive oxygen species (ROS) levels in splenic macrophages, leading to M1 polarization. After reducing the expression of the autophagy markers WDFY3 and LC3, flow cytometric analysis of M1/M2 markers (CD40, CD86, CD115, CD163, and CD206), decreasing oxygen metabolism, as evaluated by the ROS-sensor dye DCFDA, and Seahorse oxygen consumption studies revealed that ablation of the atg13 gene impairs mitochondrial function, triggering M1 polarization.

Additionally, redox imbalance may impair Sirtuin-1 activity via nitrosylation, increasing the level of acetylated p65 in macrophages and contributing to the inflammatory response in M1Mφs. Additionally, ablation of the atg13 gene resulted in increased infiltration of M1Mφs into the muscle vasculature, deterioration of myelin integrity in nerve bundles, and a reduction in muscle strength following treadmill exercise.

Conclusions: Our study shows that impaired ATG13-driven autophagy increases inflammation through sirtuin-1 inactivation and NF-κB activation, suggesting a role for ATG13 in post-exertional malaise (PEM).

Source: Toriola MA, Timlin E, Bulbule S, Reyes A, Adedeji OM, Gottschalk CG, Barua A, Arnold LA, Roy A. Genetic depletion of the early autophagy protein ATG13 impairs mitochondrial energy metabolism, augments oxidative stress, induces the polarization of macrophages to the M1 inflammatory mode, and compromises myelin integrity in skeletal muscle. Inflamm Res. 2026 Jan 27;75(1):26. doi: 10.1007/s00011-025-02158-6. PMID: 41591477; PMCID: PMC12847126. https://pmc.ncbi.nlm.nih.gov/articles/PMC12847126/ (Full text)

Is the RACGP HANDI recommendation of incremental physical activity for chronic fatigue syndrome/myalgic encephalomyelitis harming patients?

Opinion:

In April 2024, The Royal Australian College of General Practitioners (RACGP) Handbook of Non-Drug Interventions (HANDI)committee published a guideline: Incremental physical activity for chronic fatigue syndrome/myalgic encephalomyelitis.1 The HANDI committee claims to recommend interventions that are based on ‘solid evidence’.2 But is this always the case?

An evaluation under the AGREE II instrument for assessing guidelines scored the RACGP guideline at only 2% for rigour of development.3 Alarmingly, the guideline provides no evidence of a systematic review of the literature, nor an analysis of the strengths and limitations of the three cited papers: the PACE trial; the Cochrane review, Exercise therapy for chronic fatigue syndrome; and Fawzy et al’s systematic review of treatments for post-acute COVID-19 syndrome [PACS]).1,4,5,6 Indeed, the PACE trial has been heavily criticised for outcome switching and bias.7–9 If the PACE trial had adhered to the original definition of recovery laid out at the beginning of the study, only 4% of graded exercise therapy participants would have been classified as recovered, and the effect would not have been statistically significant.9 After participants had completed therapy, the study’s authors weakened the definition of recovery to encompass values that fall far below healthy norms. In fact, many ‘recovered’ participants were still sick enough to meet the entry requirements to the study.8 Worse, some participants were classified as recovered or improved before undertaking any treatment.10

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Source: Jacqueline Stallard Stephan Praet Sandeep Gupta Angela Smith. Is the RACGP HANDI recommendation of incremental physical activity for chronic fatigue syndrome/myalgic encephalomyelitis harming patients? AJGP, Viewpoint​
Volume 55, Issue 3, March 2026. https://www1.racgp.org.au/ajgp/2026/march/is-the-racgp-handi-recommendation-of-incremental-p (Full text)