Tag: endothelial function

Blood–brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment

Abstract:

Vascular disruption has been implicated in coronavirus disease 2019 (COVID-19) pathogenesis and may predispose to the neurological sequelae associated with long COVID, yet it is unclear how blood–brain barrier (BBB) function is affected in these conditions. Here we show that BBB disruption is evident during acute infection and in patients with long COVID with cognitive impairment, commonly referred to as brain fog. Using dynamic contrast-enhanced magnetic resonance imaging, we show BBB disruption in patients with long COVID-associated brain fog.

Transcriptomic analysis of peripheral blood mononuclear cells revealed dysregulation of the coagulation system and a dampened adaptive immune response in individuals with brain fog. Accordingly, peripheral blood mononuclear cells showed increased adhesion to human brain endothelial cells in vitro, while exposure of brain endothelial cells to serum from patients with long COVID induced expression of inflammatory markers. Together, our data suggest that sustained systemic inflammation and persistent localized BBB dysfunction is a key feature of long COVID-associated brain fog.

Source: Greene, C., Connolly, R., Brennan, D. et al. Blood–brain barrier disruption and sustained systemic inflammation in individuals with long COVID-associated cognitive impairment. Nat Neurosci (2024). https://doi.org/10.1038/s41593-024-01576-9 https://www.nature.com/articles/s41593-024-01576-9 (Full text)

Association of circulating biomarkers with illness severity measures differentiates myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID-19 condition: a prospective cohort study

Abstract:

Background: Accumulating evidence suggests that autonomic dysfunction and persistent systemic inflammation are common clinical features in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and long COVID. However, there is limited knowledge regarding their potential association with circulating biomarkers and illness severity status.

Methods: This prospective, cross-sectional, case-control cohort study aimed to distinguish between the two patient populations by using self-reported outcome measures and circulating biomarkers to assess endothelial function and systemic inflammation. Thirty-one individuals with ME/CFS, 23 individuals with long COVID, and 31 matched healthy subjects were included. Regression analysis was used to examine associations between self-reported outcome measures and circulating biomarkers in study participants. Classification across groups was based on principal component and discriminant analyses.

Results: Four ME/CFS patients (13%), 1 with long COVID (4%), and 1 healthy control (3%) presented postural orthostatic tachycardia syndrome (POTS) with the 10-min NASA lean test. Compared with healthy controls, ME/CFS and long COVID subjects showed higher levels of ET-1 (p < 0.05) and VCAM-1 (p < 0.001), and lower levels of nitrites (NOx assessed as NO2– + NO3–) (p < 0.01). ME/CFS patients also showed higher levels of serpin E1 (PAI-1) and E-selectin than did both long COVID and control subjects (p < 0.01 in all cases). Long COVID patients had lower TSP-1 levels than did ME/CFS patients and healthy controls (p < 0.001). As for inflammation biomarkers, both long COVID and ME/CFS subjects had higher levels of TNF-α than did healthy controls (p < 0.01 in both comparisons). Compared with controls, ME/CFS patients had higher levels of IL-1β (p < 0.001), IL-4 (p < 0.001), IL-6 (p < 0.01), IL-10 (p < 0.001), IP-10 (p < 0.05), and leptin (p < 0.001). Principal component analysis supported differentiation between groups based on self-reported outcome measures and endothelial and inflammatory biomarkers.

Conclusions: Our findings revealed that combining biomarkers of endothelial dysfunction and inflammation with outcome measures differentiate ME/CFS and Long COVID using robust discriminant analysis of principal components. Further research is needed to provide a more comprehensive characterization of these underlying pathomechanisms, which could be promising targets for therapeutic and preventive strategies in these conditions.

Source: Joan Carles Domingo, Federica Battistini, Begoña Cordobilla et al. Association of circulating biomarkers with illness severity measures differentiates myalgic encephalomyelitis/chronic fatigue syndrome and post-COVID-19 condition: a prospective cohort study, 16 December 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3736031/v1] https://www.researchsquare.com/article/rs-3736031/v1 (Full text)

Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial

Abstract:

Long COVID, a condition characterized by symptom and/or sign persistence following an acute COVID-19 episode, is associated with reduced physical performance and endothelial dysfunction. Supplementation of l-arginine may improve endothelial and muscle function by stimulating nitric oxide synthesis.

A single-blind randomized, placebo-controlled trial was conducted in adults aged between 20 and 60 years with persistent fatigue attending a post-acute COVID-19 outpatient clinic. Participants were randomized 1:1 to receive twice-daily orally either a combination of 1.66 g l-arginine plus 500 mg liposomal vitamin C or a placebo for 28 days. The primary outcome was the distance walked on the 6 min walk test. Secondary outcomes were handgrip strength, flow-mediated dilation, and fatigue persistence.

Fifty participants were randomized to receive either l-arginine plus vitamin C or a placebo. Forty-six participants (median (interquartile range) age 51 (14), 30 [65%] women), 23 per group, received the intervention to which they were allocated and completed the study. At 28 days, l-arginine plus vitamin C increased the 6 min walk distance (+30 (40.5) m; placebo: +0 (75) m, p = 0.001) and induced a greater improvement in handgrip strength (+3.4 (7.5) kg) compared with the placebo (+1 (6.6) kg, p = 0.03).

The flow-mediated dilation was greater in the active group than in the placebo (14.3% (7.3) vs. 9.4% (5.8), p = 0.03). At 28 days, fatigue was reported by two participants in the active group (8.7%) and 21 in the placebo group (80.1%; p &lt; 0.0001). l-arginine plus vitamin C supplementation improved walking performance, muscle strength, endothelial function, and fatigue in adults with long COVID. This supplement may, therefore, be considered to restore physical performance and relieve persistent symptoms in this patient population.

Source: Tosato M, Calvani R, Picca A, Ciciarello F, Galluzzo V, Coelho-Júnior HJ, Di Giorgio A, Di Mario C, Gervasoni J, Gremese E, Leone PM, Nesci A, Paglionico AM, Santoliquido A, Santoro L, Santucci L, Tolusso B, Urbani A, Marini F, Marzetti E, Landi F; Gemelli against COVID-19 Post-Acute Care Team. Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial. Nutrients. 2022 Nov 23;14(23):4984. doi: 10.3390/nu14234984. PMID: 36501014; PMCID: PMC9738241. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9738241/ (Full text)

Elevated vascular transformation blood biomarkers in Long-COVID indicate angiogenesis as a key pathophysiological mechanism

Abstract:

Background: Long-COVID is characterized by prolonged, diffuse symptoms months after acute COVID-19. Accurate diagnosis and targeted therapies for Long-COVID are lacking. We investigated vascular transformation biomarkers in Long-COVID patients.

Methods: A case–control study utilizing Long-COVID patients, one to six months (median 98.5 days) post-infection, with multiplex immunoassay measurement of sixteen blood biomarkers of vascular transformation, including ANG-1, P-SEL, MMP-1, VE-Cad, Syn-1, Endoglin, PECAM-1, VEGF-A, ICAM-1, VLA-4, E-SEL, thrombomodulin, VEGF-R2, VEGF-R3, VCAM-1 and VEGF-D.

Results: Fourteen vasculature transformation blood biomarkers were significantly elevated in Long-COVID outpatients, versus acutely ill COVID-19 inpatients and healthy controls subjects (P < 0.05). A unique two biomarker profile consisting of ANG-1/P-SEL was developed with machine learning, providing a classification accuracy for Long-COVID status of 96%. Individually, ANG-1 and P-SEL had excellent sensitivity and specificity for Long-COVID status (AUC = 1.00, P < 0.0001; validated in a secondary cohort). Specific to Long-COVID, ANG-1 levels were associated with female sex and a lack of disease interventions at follow-up (P < 0.05).

Conclusions: Long-COVID patients suffer prolonged, diffuse symptoms and poorer health. Vascular transformation blood biomarkers were significantly elevated in Long-COVID, with angiogenesis markers (ANG-1/P-SEL) providing classification accuracy of 96%. Vascular transformation blood biomarkers hold potential for diagnostics, and modulators of angiogenesis may have therapeutic efficacy.

Source: Patel, M.A., Knauer, M.J., Nicholson, M. et al. Elevated vascular transformation blood biomarkers in Long-COVID indicate angiogenesis as a key pathophysiological mechanism. Mol Med 28, 122 (2022). https://doi.org/10.1186/s10020-022-00548-8 https://molmed.biomedcentral.com/articles/10.1186/s10020-022-00548-8 (Full text)

Sulodexide: A Benefit for Cardiovascular Sequelae of Long COVID Patients?

Dear Editor,

The elaborate and precise review of Harry N. Magnani didactically demonstrates the complex pathophysiological aspects of coronavirus disease 2019 (COVID-19) emphasizing the roles of vascular endothelial dysfunction and coagulation cascade as key features of disease progression.  Moreover, this article brings up that glycosaminoglycane (GAG) antithrombotics likely interfere with inflammatory and coagulation activity in an effective fashion.  Thereafter this postulate has become advocated as the application of sulodexide (Vessel Due F; ALFASIGMA, Italy) (SDX), an unexpensive and orally administrable GAG antithrombotic drug reduced the necessity for both hospital admission and oxygen supplementation in the early phase of SARS-Cov-2 infection under a randomized placebo-controlled out-patient trial.  Interestingly, these patients also showed lower serum levels of C-reactive protein (CRP) and D-dimer as markers of inflammation and prothrombotic state. Of note, instead of regularly recommended and prescribed 250 RLU twice-daily dose, the clinical trial applied the higher, 500 RLU twice-daily dosing regimen in which an antithrombotic effect was safely achieved in a clinical setting.

Read the rest of this article HERE.

Source: Szolnoky G, González-Ochoa AJ. Sulodexide: A Benefit for Cardiovascular Sequelae of Long COVID Patients? Clin Appl Thromb Hemost. 2022 Jan-Dec;28:10760296221084300. doi: 10.1177/10760296221084300. PMID: 35333125; PMCID: PMC8961374. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8961374/ (Full text)

Endothelial dysfunction is the key of long COVID-19 symptoms: The results of TUN-EndCOV study

Abstract:

Background: The COVID-19 disease is a multisystem disease due to in part to the vascular endothelium injury. Lasting effects and long-term sequalae could persist after the infection and may be due to persistent endothelial dysfunction.

Purpose: Our study focused on the study of endothelial function measurement by digital thermal monitoring (DTM) of endothelial quality index with E4 diagnosis Polymath in a large cohort of long COVID-19 patients to determine whether long COVID-19 symptoms are due to endothelial dysfunction.

Methods: This is a prospective multicenter longitudinal observational cohort study. Endothelial function was evaluated with “E4-Diagnose” Polymath Tunisia based on the Endothelium Quality Index (EQI). A complete echocardiographic evaluation analysis was performed. Primary outcomes were defined as the occurrence of long COVID-19 symptoms in patients with endothelial dysfunction measured by EQI.

Results: A total of 798 patients were included in this study. Patients were included at an average time of 68.93 ± 43.1 days. The mean EQI was 2.02 ± 0.99 [0–5]. A total of 397 (49.7%) patients had poor or very poor EQI and 211 (26.4%) patients had very poor EQI. The median age was 49.94 ± 14.2 (18–80) years. A total of 618 patients (77.4%) had long COVID-19 symptoms. Patients with long COVID-19 symptoms had a reduced EQI (1.99 ± 0.97 vs. 2.09 ± 1.05, P = 0.24). Among long COVID-19 symptoms, fatigue was the most common symptom reported in 42.2%. Fatigue and chest pain were significantly associated to the endothelial dysfunction (P = 0.04 and 0.001 respectively). Patients with chest pain had significantly lower EQI (1.74 ± 1.0 vs. 2.09 ± 0.9, P ≤ 10−3) and LVGLS (−16.35 ± 3.0 vs. −17.16 ± 2.5, P = 0.04).

Conclusion: Long COVID-19 symptoms specifically chest pain and fatigue are due to persistent poor endothelial quality index. These findings allow a better care of patients with long COVID-19 symptoms.

Source: S. Charfeddine, H. Ibnhadjamor, S. Torjmen, S. Kraiem, R. Hammami, A. Bahloul, N. Kallel, N. Moussa, I. Touil, S. Milouchi, J. Elghoul, Z. Meddeb, Y. Thabet, J. Jdidi, K. Bouslema, S. Abdesselem, L. Abid. Endothelial dysfunction is the key of long COVID-19 symptoms: The results of TUN-EndCOV study. Archives of Cardiovascular Diseases Supplements, Volume 14, Issue 1, 2022, Page 126, ISSN 1878-6480, https://doi.org/10.1016/j.acvdsp.2021.10.004. (https://www.sciencedirect.com/science/article/pii/S187864802100642X)

Endothelial Senescence and Chronic Fatigue Syndrome, a COVID-19 Based Hypothesis

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome is a serious illness of unknown etiology, characterized by debilitating exhaustion, memory impairment, pain and sleep abnormalities. Viral infections are believed to initiate the pathogenesis of this syndrome although the definite proof remains elusive. With the unfolding of COVID-19 pandemic, the interest in this condition has resurfaced as excessive tiredness, a major complaint of patients infected with the SARS-CoV-2 virus, often lingers for a long time, resulting in disability, and poor life quality.

In a previous article, we hypothesized that COVID-19-upregulated angiotensin II triggered premature endothelial cell senescence, disrupting the intestinal and blood brain barriers. Here, we hypothesize further that post-viral sequelae, including myalgic encephalomyelitis/chronic fatigue syndrome, are promoted by the gut microbes or toxin translocation from the gastrointestinal tract into other tissues, including the brain. This model is supported by the SARS-CoV-2 interaction with host proteins and bacterial lipopolysaccharide. Conversely, targeting microbial translocation and cellular senescence may ameliorate the symptoms of this disabling illness.

Source: Sfera A, Osorio C, Zapata Martín Del Campo CM, Pereida S, Maurer S, Maldonado JC, Kozlakidis Z. Endothelial Senescence and Chronic Fatigue Syndrome, a COVID-19 Based Hypothesis. Front Cell Neurosci. 2021 Jun 25;15:673217. doi: 10.3389/fncel.2021.673217. PMID: 34248502; PMCID: PMC8267916. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8267916/ (Full study)

Altered endothelial dysfunction-related miRs in plasma from ME/CFS patients

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease characterized by unexplained debilitating fatigue. Although the etiology is unknown, evidence supports immunological abnormalities, such as persistent inflammation and immune-cell activation, in a subset of patients. Since the interplay between inflammation and vascular alterations is well-established in other diseases, endothelial dysfunction has emerged as another player in ME/CFS pathogenesis.

Endothelial nitric oxide synthase (eNOS) generates nitric oxide (NO) that maintains endothelial homeostasis. eNOS is activated by silent information regulator 1 (Sirt1), an anti-inflammatory protein. Despite its relevance, no study has addressed the Sirt1/eNOS axis in ME/CFS. The interest in circulating microRNAs (miRs) as potential biomarkers in ME/CFS has increased in recent years. Accordingly, we analyze a set of miRs reported to modulate the Sirt1/eNOS axis using plasma from ME/CFS patients.

Our results show that miR-21, miR-34a, miR-92a, miR-126, and miR-200c are jointly increased in ME/CFS patients compared to healthy controls. A similar finding was obtained when analyzing public miR data on peripheral blood mononuclear cells. Bioinformatics analysis shows that endothelial function-related signaling pathways are associated with these miRs, including oxidative stress and oxygen regulation. Interestingly, histone deacetylase 1, a protein responsible for epigenetic regulations, represented the most relevant node within the network.

In conclusion, our study provides a basis to find endothelial dysfunction-related biomarkers and explore novel targets in ME/CFS.

Source: Blauensteiner J, Bertinat R, León LE, Riederer M, Sepúlveda N, Westermeier F. Altered endothelial dysfunction-related miRs in plasma from ME/CFS patients. Sci Rep. 2021 May 19;11(1):10604. doi: 10.1038/s41598-021-89834-9. PMID: 34011981. https://pubmed.ncbi.nlm.nih.gov/34011981/

Reduced Endothelial Function in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-Results From Open-Label Cyclophosphamide Intervention Study

Abstract:

Introduction: Patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) present with a range of symptoms including post-exertional malaise (PEM), orthostatic intolerance, and autonomic dysfunction. Dysfunction of the blood vessel endothelium could be an underlying biological mechanism, resulting in inability to fine-tune regulation of blood flow according to the metabolic demands of tissues. The objectives of the present study were to investigate endothelial function in ME/CFS patients compared to healthy individuals, and assess possible changes in endothelial function after intervention with IV cyclophosphamide.

Methods: This substudy to the open-label phase II trial “Cyclophosphamide in ME/CFS” included 40 patients with mild-moderate to severe ME/CFS according to Canadian consensus criteria, aged 18-65 years. Endothelial function was measured by Flow-mediated dilation (FMD) and Post-occlusive reactive hyperemia (PORH) at baseline and repeated after 12 months. Endothelial function at baseline was compared with two cohorts of healthy controls (N = 66 and N = 30) from previous studies. Changes in endothelial function after 12 months were assessed and correlated with clinical response to cyclophosphamide. Biological markers for endothelial function were measured in serum at baseline and compared with healthy controls (N = 30).

Results: Baseline FMD was significantly reduced in patients (median FMD 5.9%, range 0.5-13.1, n = 35) compared to healthy individuals (median FMD 7.7%, range 0.7-21, n = 66) (p = 0.005), as was PORH with patient score median 1,331 p.u. (range 343-4,334) vs. healthy individuals 1,886 p.u. (range 808-8,158) (p = 0.003). No significant associations were found between clinical response to cyclophosphamide intervention (reported in 55% of patients) and changes in FMD/PORH from baseline to 12 months. Serum levels of metabolites associated with endothelial dysfunction showed no significant differences between ME/CFS patients and healthy controls.

Conclusions: Patients with ME/CFS had reduced endothelial function affecting both large and small vessels compared to healthy controls. Changes in endothelial function did not follow clinical responses during follow-up after cyclophosphamide IV intervention.

Source: Sørland K, Sandvik MK, Rekeland IG, Ribu L, Småstuen MC, Mella O, Fluge Ø. Reduced Endothelial Function in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-Results From Open-Label Cyclophosphamide Intervention Study. Front Med (Lausanne). 2021 Mar 22;8:642710. doi: 10.3389/fmed.2021.642710. PMID: 33829023; PMCID: PMC8019750. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8019750/ (Full text)

Angina Simultaneously Diagnosed with the Recurrence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) mainly affects young adults and can have a potential impact on social functioning. As this syndrome is associated with endothelial dysfunction, the heart can be damaged via ischemia due to endothelial damage. This might potentially lead to heart failure, which accounts for approximately 20% of deaths among patients with ME/CFS. While cardiac ischemia is thought be a pathophysiologically important manifestation of this syndrome, this is not yet reported. Herein, we present a case of a young female with newly diagnosed vasospastic or microvascular angina and concurrent exacerbation of ME/CFS severity. Her anginal symptoms, including exertional chest pain and transient chest discomfort, mimicked those of ME/CFS but were relieved after the administration of a calcium channel blocker. We emphasize the possibility of concurrent angina and exacerbation of ME/CFS and the importance of detecting cardiac ischemia to avoid unfavorable outcomes.

Source: Li K, Otsuka Y, Nakano Y, Omura D, Hasegawa K, Obika M, Ueda K, Kataoka H, Otsuka F. Angina Simultaneously Diagnosed with the Recurrence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Diagnostics (Basel). 2021 Mar 6;11(3):460. doi: 10.3390/diagnostics11030460. PMID: 33800953. https://pubmed.ncbi.nlm.nih.gov/33800953/