Tag: Scheibenbogen

Post-COVID syndrome is associated with capillary alterations, macrophage infiltration and distinct transcriptomic signatures in skeletal muscles

Abstract:

The SARS-CoV-2 pandemic not only resulted in millions of acute infections worldwide, but also caused innumerable cases of post-infectious syndromes, colloquially referred to as “long COVID”. Due to the heterogeneous nature of symptoms and scarcity of available tissue samples, little is known about the underlying mechanisms. We present an in-depth analysis of skeletal muscle biopsies obtained from eleven patients suffering from enduring fatigue and post-exertional malaise after an infection with SARS-CoV-2.

Compared to two independent historical control cohorts, patients with post-COVID exertion intolerance had fewer capillaries, thicker capillary basement membranes and increased numbers of CD169+ macrophages. SARS-CoV-2 RNA could not be detected in the muscle tissues, but transcriptomic analysis revealed distinct gene signatures compared to the two control cohorts, indicating immune dysregulations and altered metabolic pathways.

We hypothesize that the initial viral infection may have caused immune-mediated structural changes of the microvasculature, potentially explaining the exercise-dependent fatigue and muscle pain.

Source: Tom Aschman, Emanuel Wyler, Oliver Baum, Andreas Hentschel, Franziska Legler, Corinna Preusse, Lil Meyer-Arndt, Ivana Büttnerova, Alexandra Förster, Derya Cengiz, Luiz Gustavo Teixeira Alves, Julia Schneider, Claudia Kedor, Rebecca Rust, Judith Bellmann-Strobl, Sanchin Aminaa, Peter Vajkoczy, Hans-Hilmar Goebel, Markus Landthaler, Victor Corman, Andreas Roos, Frank L. Heppner, Helena Radbruch, Friedemann Paul, Carmen Scheibenbogen, Werner Stenzel, Nora F. Dengler. Post-COVID syndrome is associated with capillary alterations, macrophage infiltration and distinct transcriptomic signatures in skeletal muscles. medRxiv 2023.02.15.23285584; doi: https://doi.org/10.1101/2023.02.15.23285584 https://www.medrxiv.org/content/10.1101/2023.02.15.23285584v1.full-text (Full text)

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

Abstract:

Background: Muscle fatigue and pain are key symptoms of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Although the pathophysiology is not yet fully understood, there is ample evidence for hypoperfusion which may result in electrolyte imbalance and sodium overload in muscles. Therefore, the aim of this study was to assess levels of sodium content in muscles of patients with ME/CFS and to compare these to healthy controls.

Methods: Six female patients with ME/CFS and six age, BMI and sex matched controls underwent 23Na-MRI of the left lower leg using a clinical 3T MR scanner before and after 3 min of plantar flexion exercise. Sodium reference phantoms with solutions of 10, 20, 30 and 40 mmol/L NaCl were used for quantification. Muscle sodium content over 40 min was measured using a dedicated plugin in the open-source DICOM viewer Horos. Handgrip strength was measured and correlated with sodium content.

Results: Baseline tissue sodium content was higher in all 5 lower leg muscle compartments in ME/CFS compared to controls. Within the anterior extensor muscle compartment, the highest difference in baseline muscle sodium content between ME/CFS and controls was found (mean ± SD; 12.20 ± 1.66 mM in ME/CFS versus 9.38 ± 0.71 mM in controls, p = 0.0034). Directly after exercise, tissue sodium content increased in gastrocnemius and triceps surae muscles with + 30% in ME/CFS (p = 0.0005) and + 24% in controls (p = 0.0007) in the medial gastrocnemius muscle but not in the extensor muscles which were not exercised. Compared to baseline, the increase of sodium content in medial gastrocnemius muscle was stronger in ME/CFS than in controls with + 30% versus + 17% to baseline at 12 min (p = 0.0326) and + 29% versus + 16% to baseline at 15 min (p = 0.0265). Patients had reduced average handgrip strength which was associated with increased average muscle tissue sodium content (p = 0.0319, R2 = 0.3832).

Conclusion: Muscle sodium content before and after exercise was higher in ME/CFS than in healthy controls. Furthermore, our findings indicate an inverse correlation between muscle sodium content and handgrip strength. These findings provide evidence that sodium overload may play a role in the pathophysiology of ME/CFS and may allow for potential therapeutic targeting.

Source: Petter E, Scheibenbogen C, Linz P, Stehning C, Wirth K, Kuehne T, Kelm M. Muscle sodium content in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. J Transl Med. 2022 Dec 9;20(1):580. doi: 10.1186/s12967-022-03616-z. PMID: 36494667. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03616-z (Full text)

Dysregulated autoantibodies targeting vaso- and immunoregulatory receptors in Post COVID Syndrome correlate with symptom severity

Most patients with Post COVID Syndrome (PCS) present with a plethora of symptoms without clear evidence of organ dysfunction. A subset of them fulfills diagnostic criteria of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Symptom severity of ME/CFS correlates with natural regulatory autoantibody (AAB) levels targeting several G-protein coupled receptors (GPCR).

In this exploratory study, we analyzed serum AAB levels against vaso- and immunoregulatory receptors, mostly GPCRs, in 80 PCS patients following mild-to-moderate COVID-19, with 40 of them fulfilling diagnostic criteria of ME/CFS. Healthy seronegative (n=38) and asymptomatic post COVID-19 controls (n=40) were also included in the study as control groups.

We found lower levels for various AABs in PCS compared to at least one control group, accompanied by alterations in the correlations among AABs. Classification using random forest indicated AABs targeting ADRB2, STAB1, and ADRA2A as the strongest classifiers (AABs stratifying patients according to disease outcomes) of post COVID-19 outcomes. Several AABs correlated with symptom severity in PCS groups. Remarkably, severity of fatigue and vasomotor symptoms were associated with ADRB2 AAB levels in PCS/ME/CFS patients.

Our study identified dysregulation of AAB against various receptors involved in the autonomous nervous system (ANS), vaso-, and immunoregulation and their correlation with symptom severity, pointing to their role in the pathogenesis of PCS.

Source: Franziska Sotzny, Igor Salerno Filgueiras, Claudia Kedor, Helma Freitag, Kirsten Wittke, Sandra Bauer, Nuno Sepúlveda, Dennyson Leandro Mathias da Fonseca, Gabriela Crispim Baiocchi, Alexandre H. C. Marques, Myungjin Kim, Tanja Lange, Desirée Rodrigues Plaça, Finn Luebber, Frieder M. Paulus, Roberta De Vito, Igor Jurisica, Kai Schulze-Forster, Friedemann Paul, Judith Bellmann-Strobl, Rebekka Rust, Uta Hoppmann, Yehuda Shoenfeld, Gabriela Riemekasten, Harald Heidecke, Otavio Cabral-Marques, Carmen Scheibenbogen. Dysregulated autoantibodies targeting vaso- and immunoregulatory receptors in Post COVID Syndrome correlate with symptom severity. Front. Immunol., 27 September 2022
Sec. Autoimmune and Autoinflammatory Disorders https://doi.org/10.3389/fimmu.2022.981532 (Full text)

A prospective observational study of post-COVID-19 chronic fatigue syndrome following the first pandemic wave in Germany and biomarkers associated with symptom severity

Abstract:

A subset of patients has long-lasting symptoms after mild to moderate Coronavirus disease 2019 (COVID-19). In a prospective observational cohort study, we analyze clinical and laboratory parameters in 42 post-COVID-19 syndrome patients (29 female/13 male, median age 36.5 years) with persistent moderate to severe fatigue and exertion intolerance six months following COVID-19. Further we evaluate an age- and sex-matched postinfectious non-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome cohort comparatively.

Most post-COVID-19 syndrome patients are moderately to severely impaired in daily live. 19 post-COVID-19 syndrome patients fulfill the 2003 Canadian Consensus Criteria for myalgic encephalomyelitis/chronic fatigue syndrome. Disease severity and symptom burden is similar in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome and non-COVID-19/myalgic encephalomyelitis/chronic fatigue syndrome patients. Hand grip strength is diminished in most patients compared to normal values in healthy.

Association of hand grip strength with hemoglobin, interleukin 8 and C-reactive protein in post-COVID-19 syndrome/non-myalgic encephalomyelitis/chronic fatigue syndrome and with hemoglobin, N-terminal prohormone of brain natriuretic peptide, bilirubin, and ferritin in post-COVID-19 syndrome/myalgic encephalomyelitis/chronic fatigue syndrome may indicate low level inflammation and hypoperfusion as potential pathomechanisms.

Source: Kedor C, Freitag H, Meyer-Arndt L, Wittke K, Hanitsch LG, Zoller T, Steinbeis F, Haffke M, Rudolf G, Heidecker B, Bobbert T, Spranger J, Volk HD, Skurk C, Konietschke F, Paul F, Behrends U, Bellmann-Strobl J, Scheibenbogen C. A prospective observational study of post-COVID-19 chronic fatigue syndrome following the first pandemic wave in Germany and biomarkers associated with symptom severity. Nat Commun. 2022 Aug 30;13(1):5104. doi: 10.1038/s41467-022-32507-6. PMID: 36042189. https://www.nature.com/articles/s41467-022-32507-6 (Full text)

Post-COVID syndrome with fatigue and exercise intolerance: myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

in English, German

Background: A sizable part of post-COVID syndrome meets the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). A doubling of cases of ME/CFS within the next years is therefore projected.

Objectives: Presentation of the current state of knowledge on ME/CFS.

Materials and methods: Unsystematic review of the literature and of own contributions in research and patient care.

Results and conclusions: ME/CFS is a neuroimmunological disease, mostly infection-induced, usually persisting throughout life. Clinically it is characterized by fatigue lasting at least 6 months and the defining core feature of exercise intolerance (post-exertional malaise, PEM). Exercise intolerance is defined as a worsening of symptoms after (even mild) everyday exertion, which usually begins after several hours or on the following day, is still noticeable at least 14 h after exertion, and often lasts for several days (up to weeks or longer). Furthermore, ME/CFS is characterized by pain, disturbances of sleep, thinking and memory, and dysregulation of the circulatory, endocrine, and immune systems.

As a separate clinical entity, ME/CFS should be distinguished from chronic fatigue, which occurs as a symptom of a range of very different diseases. The diagnosis of ME/CFS is made clinically using established international diagnostic criteria and requires careful stepwise diagnosis to exclude other diagnoses. A causal therapy for ME/CFS has not been established; the focus is on symptoms relief, treatment of the often accompanying orthostatic intolerance, and assistance with anticipatory energy management (pacing).

Source: Renz-Polster H, Scheibenbogen C. Post-COVID-Syndrom mit Fatigue und Belastungsintoleranz: Myalgische Enzephalomyelitis bzw. Chronisches Fatigue-Syndrom [Post-COVID syndrome with fatigue and exercise intolerance: myalgic encephalomyelitis/chronic fatigue syndrome]. Inn Med (Heidelb). 2022 Aug;63(8):830-839. German. doi: 10.1007/s00108-022-01369-x. Epub 2022 Jul 13. PMID: 35925074. https://pubmed.ncbi.nlm.nih.gov/35925074/  https://link.springer.com/article/10.1007/s00108-022-01369-x (Full text in German)

Serum of Post-COVID-19 Syndrome patients with or without ME/CFS differentially affects endothelial cell function in vitro

Abstract:

A proportion of COVID-19 reconvalescent patients develop post-COVID-19 syndrome (PCS) including a subgroup fulfilling diagnostic criteria of Myalgic encephalomyelitis/Chronic Fatigue Syndrome (PCS/CFS). Recently, endothelial dysfunction (ED) has been demonstrated in these patients, but the mechanisms remain elusive. Therefore, we investigated the effects of patients’ sera on endothelia cells (ECs) in vitro.
PCS (n = 17), PCS/CFS (n = 13), and healthy controls (HC, n = 14) were screened for serum anti-endothelial cell autoantibodies (AECAs) and dysregulated cytokines. Serum-treated ECs were analysed for the induction of activation markers and the release of small molecules by flow cytometry. Moreover, the angiogenic potential of sera was measured in a tube formation assay.
While only marginal differences between patient groups were observed for serum cytokines, AECA binding to ECs was significantly increased in PCS/CFS patients. Surprisingly, PCS and PCS/CFS sera reduced surface levels of several EC activation markers. PCS sera enhanced the release of molecules associated with vascular remodelling and significantly promoted angiogenesis in vitro compared to the PCS/CFS and HC groups. Additionally, sera from both patient cohorts induced the release of molecules involved in inhibition of nitric oxide-mediated endothelial relaxation.
Overall, PCS and PCS/CFS patients′ sera differed in their AECA content and their functional effects on ECs, i.e., secretion profiles and angiogenic potential. We hypothesise a pro-angiogenic effect of PCS sera as a compensatory mechanism to ED which is absent in PCS/CFS patients.
Source: Flaskamp L, Roubal C, Uddin S, Sotzny F, Kedor C, Bauer S, Scheibenbogen C, Seifert M. Serum of Post-COVID-19 Syndrome Patients with or without ME/CFS Differentially Affects Endothelial Cell Function In Vitro. Cells. 2022; 11(15):2376. https://doi.org/10.3390/cells11152376  https://www.mdpi.com/2073-4409/11/15/2376/htm (Full text)

Revisiting IgG antibody reactivity to Epstein-Barr virus in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and its potential application to disease diagnosis

Abstract:

Infections by the Epstein-Barr virus (EBV) are often at the disease onset of patients suffering from Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). However, serological analyses of these infections remain inconclusive when comparing patients with healthy controls. In particular, it is unclear if certain EBV-derived antigens eliciting antibody responses have a biomarker potential for disease diagnosis. With this purpose, we re-analysed a previously published microarray data on the IgG antibody responses against 3,054 EBV-related antigens in 92 patients with ME/CFS and 50 HCs.

This re-analysis consisted of constructing different regression models for binary outcomes with the ability to classify patients and HCs. In these models, we tested for a possible interaction of different antibodies with age and gender. When analyzing the whole data set, there were no antibody responses that could be used to distinguish patients from healthy controls. A similar finding was obtained when comparing patients with noninfectious or unknown disease trigger to healthy controls.

However, when data analysis was restricted to the comparison between HCs and patients with a putative infection at disease onset, we could identify stronger antibody responses against two candidate antigens (EBNA4_0529 and EBNA6_0070). Using antibody responses to these two antigens together with age and gender, the final classification model had an estimated sensitivity and specificity of 0.833 and 0.720, respectively.

This reliable case-control discrimination suggested the use of the antibody levels related to these candidate viral epitopes as biomarkers for disease diagnosis in this subgroup of patients. When a bioinformatic analysis was performed on these epitopes, it revealed a potential molecular mimicry with several human proteins. To confirm these promising findings, a follow-up study will be conducted in a separate cohort of patients.

Source: Nuno Sepúlveda, João Malato, Franziska Sotzny, Anna D Grabowska, André Fonseca, Clara Cordeiro, Luís Graça, Przemyslaw Biecek, Uta Behrends, Josef Mautner, Francisco Westermeier, Eliana M Lacerda, Carmen Scheibenbogen. Revisiting IgG antibody reactivity to Epstein-Barr virus in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and its potential application to disease diagnosis, medRxiv 2022.04.20.22273990; doi: https://doi.org/10.1101/2022.04.20.22273990 https://www.medrxiv.org/content/10.1101/2022.04.20.22273990v1.full-text (Full text)

Dyspnea in Post-COVID Syndrome following Mild Acute COVID-19 Infections: Potential Causes and Consequences for a Therapeutic Approach

Abstract:

Dyspnea, shortness of breath, and chest pain are frequent symptoms of post-COVID syndrome (PCS). These symptoms are unrelated to organ damage in most patients after mild acute COVID infection. Hyperventilation has been identified as a cause of exercise-induced dyspnea in PCS. Since there is a broad overlap in symptomatology with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), causes for dyspnea and potential consequences can be deduced by a stringent application of assumptions made for ME/CFS in our recent review papers.

One of the first stimuli of respiration in exercise is caused by metabolic feedback via skeletal muscle afferents. Hyperventilation in PCS, which occurs early on during exercise, can arise from a combined disturbance of a poor skeletal muscle energetic situation and autonomic dysfunction (overshooting respiratory response), both found in ME/CFS. The exaggerated respiratory response aggravating dyspnea does not only limit the ability to exercise but further impairs the muscular energetic situation: one of the buffering mechanisms to respiratory alkalosis is a proton shift from intracellular to extracellular space via the sodium-proton-exchanger subtype 1 (NHE1), thereby loading cells with sodium. This adds to two other sodium loading mechanisms already operative, namely glycolytic metabolism (intracellular acidosis) and impaired Na+/K+ATPase activity.

High intracellular sodium has unfavorable effects on mitochondrial calcium and metabolism via sodium-calcium-exchangers (NCX). Mitochondrial calcium overload by high intracellular sodium reversing the transport mode of NCX to import calcium is a key driver for fatigue and chronification. Prevention of hyperventilation has a therapeutic potential by keeping intracellular sodium below the threshold where calcium overload occurs.

Source: Wirth KJ, Scheibenbogen C. Dyspnea in Post-COVID Syndrome following Mild Acute COVID-19 Infections: Potential Causes and Consequences for a Therapeutic Approach. Medicina (Kaunas). 2022 Mar 12;58(3):419. doi: 10.3390/medicina58030419. PMID: 35334595. https://www.mdpi.com/1648-9144/58/3/419/htm (Full text)

Endothelial dysfunction and altered endothelial biomarkers in patients with post-COVID-19 syndrome and chronic fatigue syndrome (ME/CFS)

Abstract:

Background: Fatigue, exertion intolerance and post-exertional malaise are among the most frequent symptoms of Post-COVID Syndrome (PCS), with a subset of patients fulfilling criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). As SARS-CoV-2 infects endothelial cells, causing endotheliitis and damaging the endothelium, we investigated endothelial dysfunction (ED) and endothelial biomarkers in patients with PCS.

Methods: We studied the endothelial function in 30 PCS patients with persistent fatigue and exertion intolerance as well as in 15 age- and sex matched seronegative healthy controls (HCs). 14 patients fulfilled the diagnostic criteria for ME/CFS. The other patients were considered to have PCS. Peripheral endothelial function was assessed by the reactive hyperaemia index (RHI) using peripheral arterial tonometry (PAT) in patients and HCs. In a larger cohort of patients and HCs, including post-COVID reconvalescents (PCHCs), Endothelin-1 (ET-1), Angiopoietin-2 (Ang-2), Endocan (ESM-1), IL-8, Angiotensin-Converting Enzyme (ACE) and ACE2 were analysed as endothelial biomarkers.

Results: Five of the 14 post-COVID ME/CFS patients and five of the 16 PCS patients showed ED defined by a diminished RHI (< 1.67), but none of HCs exhibited this finding. A paradoxical positive correlation of RHI with age, blood pressure and BMI was found in PCS but not ME/CFS patients. The ET-1 concentration was significantly elevated in both ME/CFS and PCS patients compared to HCs and PCHCs. The serum Ang-2 concentration was lower in both PCS patients and PCHCs compared to HCs.

Conclusion: A subset of PCS patients display evidence for ED shown by a diminished RHI and altered endothelial biomarkers. Different associations of the RHI with clinical parameters as well as varying biomarker profiles may suggest distinct pathomechanisms among patient subgroups.

Source: Haffke M, Freitag H, Rudolf G, Seifert M, Doehner W, Scherbakov N, Hanitsch L, Wittke K, Bauer S, Konietschke F, Paul F, Bellmann-Strobl J, Kedor C, Scheibenbogen C, Sotzny F. Endothelial dysfunction and altered endothelial biomarkers in patients with post-COVID-19 syndrome and chronic fatigue syndrome (ME/CFS). J Transl Med. 2022 Mar 22;20(1):138. doi: 10.1186/s12967-022-03346-2. PMID: 35317812. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03346-2 (Full text)

Editorial: Current Insights Into Complex Post-infection Fatigue Syndromes With Unknown Aetiology: The Case of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Beyond

Introduction:

Black plague epidemics in Medieval Europe, the Spanish Flu pandemic during the first world war, and the pandemic of COVID-19 disease are just three devastating examples of the fragile co-existence between human beings and the microbial world. Remarkably, the human immune system with its innate and adaptive arms recognizes and clears the invading pathogens in most cases. However, like a scar after an injury, some people who had suffered from acute infections remain ill long after the clearance of the pathogen itself. These individuals develop complex fatigue-related syndromes whose pathological mechanisms remain poorly understood. A prime example of such syndromes is the Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) characterized by persistent fatigue and post-exertional malaise among other symptoms (1). Unfortunately, its diagnosis remains challenging due to the inexistence of objective biomarkers that could identify cases. However, researchers are gathering around multidisciplinary networks, such as the US ME/CFS Clinician Coalition and the European Network on ME/CFS, with the aim of fostering collaboration, standardizing research and clinical practices, while accelerating biomarker discovery (2–5). Less-known fatigue-related syndromes have been recently reported after the outbreaks of Ebola virus, Dengue virus, and Chikungunya virus in the Tropics (6–8). However, it is still unclear whether these syndromes constitute clinical entities beyond ME/CFS itself.

Read the rest of this article HERE.

Source: Westermeier F, Lacerda EM, Scheibenbogen C and Sepúlveda N (2022) Editorial: Current Insights Into Complex Post-infection Fatigue Syndromes With Unknown Aetiology: The Case of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Beyond. Front. Med. 9:862953. doi: 10.3389/fmed.2022.862953  https://www.frontiersin.org/articles/10.3389/fmed.2022.862953/full (Full text)