Tag: covid-19

Neuroinflammation After COVID-19 With Persistent Depressive and Cognitive Symptoms

Abstract:

Importance: Persistent depressive symptoms, often accompanied by cognitive symptoms, commonly occur after COVID-19 illness (hereinafter termed COVID-DC, DC for depressive and/or cognitive symptoms). In patients with COVID-DC, gliosis, an inflammatory change, was suspected, but measurements of gliosis had not been studied in the brain for this condition.

Objective: To determine whether translocator protein total distribution volume (TSPO VT), a marker of gliosis that is quantifiable with positron emission tomography (PET), is elevated in the dorsal putamen, ventral striatum, prefrontal cortex, anterior cingulate cortex, and hippocampus of persons with COVID-DC.

Design, setting, and participants: This case-control study conducted at a tertiary care psychiatric hospital in Canada from April 1, 2021, to June 30, 2022, compared TSPO VT of specific brain regions in 20 participants with COVID-DC with that in 20 healthy controls. The TSPO VT was measured with fluorine F 18-labeled N-(2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]FEPPA) PET.

Main outcomes and measures: The TSPO VT was measured in the dorsal putamen, ventral striatum, prefrontal cortex, anterior cingulate cortex, and hippocampus. Symptoms were measured with neuropsychological and psychological tests, prioritizing outcomes related to striatal function.

Results: The study population included 40 participants (mean [SD] age, 32.9 [12.3] years). The TSPO VT across the regions of interest was greater in persons with COVID-DC (mean [SD] age, 32.7 [11.4] years; 12 [60%] women) compared with healthy control participants (mean [SD] age, 33.3 [13.9] years; 11 [55%] women): mean (SD) difference, 1.51 (4.47); 95% CI, 0.04-2.98; 1.51 divided by 9.20 (17%). The difference was most prominent in the ventral striatum (mean [SD] difference, 1.97 [4.88]; 95% CI, 0.36-3.58; 1.97 divided by 8.87 [22%]) and dorsal putamen (mean difference, 1.70 [4.25]; 95% CI, 0.34-3.06; 1.70 divided by 8.37 [20%]). Motor speed on the finger-tapping test negatively correlated with dorsal putamen TSPO VT (r, -0.53; 95% CI, -0.79 to -0.09), and the 10 persons with the slowest speed among those with COVID-DC had higher dorsal putamen TSPO VT than healthy persons by 2.3 (2.30 divided by 8.37 [27%]; SD, 2.46; 95% CI, 0.92-3.68).

Conclusions and relevance: In this case-control study, TSPO VT was higher in patients with COVID-DC. Greater TSPO VT is evidence for an inflammatory change of elevated gliosis in the brain of an individual with COVID-DC. Gliosis may be consequent to inflammation, injury, or both, particularly in the ventral striatum and dorsal putamen, which may explain some persistent depressive and cognitive symptoms, including slowed motor speed, low motivation or energy, and anhedonia, after initially mild to moderate COVID-19 illness.

Source: Braga J, Lepra M, Kish SJ, Rusjan PM, Nasser Z, Verhoeff N, Vasdev N, Bagby M, Boileau I, Husain MI, Kolla N, Garcia A, Chao T, Mizrahi R, Faiz K, Vieira EL, Meyer JH. Neuroinflammation After COVID-19 With Persistent Depressive and Cognitive Symptoms. JAMA Psychiatry. 2023 May 31:e231321. doi: 10.1001/jamapsychiatry.2023.1321. Epub ahead of print. PMID: 37256580; PMCID: PMC10233457. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10233457/ (Full text)

Recovery and symptom trajectories up to two years after SARS-CoV-2 infection: population based, longitudinal cohort study

Abstract:

Objective: To evaluate longer term symptoms and health outcomes associated with post-covid-19 condition within a cohort of individuals with a SARS-CoV-2 infection.

Design: Population based, longitudinal cohort.

Setting: General population of canton of Zurich, Switzerland.

Participants: 1106 adults with a confirmed SARS-CoV-2 infection who were not vaccinated before infection and 628 adults who did not have an infection.

Main outcome measures: Trajectories of self-reported health status and covid-19 related symptoms between months six, 12, 18, and 24 after infection and excess risk of symptoms at six months after infection compared with individuals who had no infection.

Results: 22.9% (95% confidence interval 20.4% to 25.6%) of individuals infected with SARS-CoV-2 did not fully recover by six months. The proportion of individuals who had an infection who reported not having recovered decreased to 18.5% (16.2% to 21.1%) at 12 months and 17.2% (14.0% to 20.8%) at 24 months after infection. When assessing changes in self-reported health status, most participants had continued recovery (68.4% (63.8% to 72.6%)) or had an overall improvement (13.5% (10.6% to 17.2%)) over time. Yet, 5.2% (3.5% to 7.7%) had a worsening in health status and 4.4% (2.9% to 6.7%) had alternating periods of recovery and health impairment. The point prevalence and severity of covid-19 related symptoms also decreased over time, with 18.1% (14.8% to 21.9%) reporting symptoms at 24 months. 8.9% (6.5% to 11.2%) of participants reported symptoms at all four follow-up time points, while in 12.5% (9.8% to 15.9%) symptoms were alternatingly absent and present. Symptom prevalence was higher among individuals who were infected compared with those who were not at six months (adjusted risk difference 17.0% (11.5% to 22.4%)). Excess risk (adjusted risk difference) for individual symptoms among those infected ranged from 2% to 10%, with the highest excess risks observed for altered taste or smell (9.8% (7.7% to 11.8%)), post-exertional malaise (9.4% (6.1% to 12.7%)), fatigue (5.4% (1.2% to 9.5%)), dyspnoea (7.8% (5.2% to 10.4%)), and reduced concentration (8.3% (6.0% to 10.7%)) and memory (5.7% (3.5% to 7.9%)).

Conclusions: Up to 18% of individuals who were not vaccinated before infection had post-covid-19 condition up to two years after infection, with evidence of excess symptom risk compared with controls. Effective interventions are needed to reduce the burden of post-covid-19 condition. Use of multiple outcome measures and consideration of the expected rates of recovery and heterogeneity in symptom trajectories are important in the design and interpretation of clinical trials.

Registrations: ISRCTN18181860

Source: Ballouz T, Menges D, Anagnostopoulos A, Domenghino A, Aschmann HE, Frei A, Fehr JS, Puhan MA. Recovery and symptom trajectories up to two years after SARS-CoV-2 infection: population based, longitudinal cohort study. BMJ. 2023 May 31;381:e074425. doi: 10.1136/bmj-2022-074425. PMID: 37257891. https://www.bmj.com/content/381/bmj-2022-074425 (Full text)

Long-Term Adverse Effects of Mild COVID-19 Disease on Arterial Stiffness, and Systemic and Central Hemodynamics: A Pre-Post Study

Abstract:

COVID-19-associated vascular disease complications are primarily associated with endothelial dysfunction; however, the consequences of disease on vascular structure and function, particularly in the long term (>7 weeks post-infection), remain unexplored. Individual pre- and post-infection changes in arterial stiffness as well as central and systemic hemodynamic parameters were measured in patients diagnosed with mild COVID-19.
As part of in-laboratory observational studies, baseline measurements were taken up to two years before, whereas the post-infection measurements were made 2–3 months after the onset of COVID-19. We used the same measurement protocol throughout the study as well as linear and mixed-effects regression models to analyze the data. Patients (N = 32) were predominantly healthy and young (mean age ± SD: 36.6 ± 12.6). We found that various parameters of arterial stiffness and central hemodynamics—cfPWV, AIx@HR75, and cDBP as well as DBP and MAP—responded to a mild COVID-19 disease.
The magnitude of these responses was dependent on the time since the onset of COVID-19 as well as age (pregression_models ≤ 0.013). In fact, mixed-effects models predicted a clinically significant progression of vascular impairment within the period of 2–3 months following infection (change in cfPWV by +1.4 m/s, +15% in AIx@HR75, approximately +8 mmHg in DBP, cDBP, and MAP).
The results point toward the existence of a widespread and long-lasting pathological process in the vasculature following mild COVID-19 disease, with heterogeneous individual responses, some of which may be triggered by an autoimmune response to COVID-19.
Source: Podrug M, Koren P, Dražić Maras E, Podrug J, Čulić V, Perissiou M, Bruno RM, Mudnić I, Boban M, Jerončić A. Long-Term Adverse Effects of Mild COVID-19 Disease on Arterial Stiffness, and Systemic and Central Hemodynamics: A Pre-Post Study. Journal of Clinical Medicine. 2023; 12(6):2123. https://doi.org/10.3390/jcm12062123 https://www.mdpi.com/2077-0383/12/6/2123 (Full text)

Maintained imbalance of triglycerides, apolipoproteins, energy metabolites and cytokines in long-term COVID-19 syndrome patients

Abstract:

Background: Deep metabolomic, proteomic and immunologic phenotyping of patients suffering from an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have matched a wide diversity of clinical symptoms with potential biomarkers for coronavirus disease 2019 (COVID-19). Several studies have described the role of small as well as complex molecules such as metabolites, cytokines, chemokines and lipoproteins during infection and in recovered patients. In fact, after an acute SARS-CoV-2 viral infection almost 10-20% of patients experience persistent symptoms post 12 weeks of recovery defined as long-term COVID-19 syndrome (LTCS) or long post-acute COVID-19 syndrome (PACS). Emerging evidence revealed that a dysregulated immune system and persisting inflammation could be one of the key drivers of LTCS. However, how these biomolecules altogether govern pathophysiology is largely underexplored. Thus, a clear understanding of how these parameters within an integrated fashion could predict the disease course would help to stratify LTCS patients from acute COVID-19 or recovered patients. This could even allow to elucidation of a potential mechanistic role of these biomolecules during the disease course.

Methods: This study comprised subjects with acute COVID-19 (n=7; longitudinal), LTCS (n=33), Recov (n=12), and no history of positive testing (n=73). 1H-NMR-based metabolomics with IVDr standard operating procedures verified and phenotyped all blood samples by quantifying 38 metabolites and 112 lipoprotein properties. Univariate and multivariate statistics identified NMR-based and cytokine changes.

Results: Here, we report on an integrated analysis of serum/plasma by NMR spectroscopy and flow cytometry-based cytokines/chemokines quantification in LTCS patients. We identified that in LTCS patients lactate and pyruvate were significantly different from either healthy controls (HC) or acute COVID-19 patients. Subsequently, correlation analysis in LTCS group only among cytokines and amino acids revealed that histidine and glutamine were uniquely attributed mainly with pro-inflammatory cytokines. Of note, triglycerides and several lipoproteins (apolipoproteins Apo-A1 and A2) in LTCS patients demonstrate COVID-19-like alterations compared with HC. Interestingly, LTCS and acute COVID-19 samples were distinguished mostly by their phenylalanine, 3-hydroxybutyrate (3-HB) and glucose concentrations, illustrating an imbalanced energy metabolism. Most of the cytokines and chemokines were present at low levels in LTCS patients compared with HC except for IL-18 chemokine, which tended to be higher in LTCS patients.

Conclusion: The identification of these persisting plasma metabolites, lipoprotein and inflammation alterations will help to better stratify LTCS patients from other diseases and could help to predict ongoing severity of LTCS patients.

Source: Berezhnoy G, Bissinger R, Liu A, Cannet C, Schäfer H, Kienzle K, Bitzer M, Häberle H, Göpel S, Trautwein C, Singh Y. Maintained imbalance of triglycerides, apolipoproteins, energy metabolites and cytokines in long-term COVID-19 syndrome patients. Front Immunol. 2023 May 9;14:1144224. doi: 10.3389/fimmu.2023.1144224. PMID: 37228606; PMCID: PMC10203989. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10203989/ (Full text)

Long-Term Headache and Cognitive Complaints Among Health Care Workers Who Acquired SARS-CoV-2

Abstract:

Introduction: Neurological manifestations are frequent after acquiring COVID-19 and may persist long-term as part of post-COVID-19 syndrome. Cognitive impairment, chronic fatigue, sleep disturbances, and headache complaints are the most reported neurological features. During the COVID-19 pandemic, health care workers were particularly vulnerable due to the high workload and levels of stress associated with this period, but acquiring severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may also contribute. The authors aimed to evaluate the neurological involvement of acquiring SARS-CoV-2 in a population of hospital health care workers and its impact on their personal and professional lives.

Methods: A sample of health care workers who did and did not acquire SARS-CoV-2 matched by age and sociodemographic variables was studied. Through an online questionnaire, data were collected regarding the symptoms in the acute phase of the disease (for those who acquired it) and for all in the last 6 months of the study period. Proportion of neurological complaints were compared between groups, adjusting for age, sex, and professional class (using a rate ratio (RR)).

Results: This study included 326 participants (174 cases and 152 controls). The mean age (standard deviation) was 39.7 (10.2) years, and the female:male ratio was 3:1. Headache and cognitive complaints were the most prevalent neurological complaints in the last 6 months of the study period. The health care workers who acquired SARS-CoV-2 were more likely to report headache and cognitive complaints than the control group (RR = 1.51, 95% confidence interval = 1.17-1.9 and RR = 2.02, 95% confidence interval = 1.53-2.65, respectively).

Conclusion: In a population of health care workers, those who acquired SARS-CoV-2 were more likely to have long-term cognitive complaints and persistent headaches.

Source: Marques AJ, Costa A, Almendra R, Maia L, Magalhães R, Cavaco S, Oliveira V, Correia M, Mendes M, Veiga A. Long-Term Headache and Cognitive Complaints Among Health Care Workers Who Acquired SARS-CoV-2. Perm J. 2023 May 29:1-8. doi: 10.7812/TPP/22.171. Epub ahead of print. PMID: 37246366. https://www.thepermanentejournal.org/doi/10.7812/TPP/22.171 (Full text)

The association between the number of symptoms and the severity of Post-COVID-Fatigue after SARS-CoV-2 infection treated in an outpatient setting

Abstract:

Background: Post-COVID-Fatigue (PCF) is one of the most reported symptoms following SARS-CoV-2 infection. Currently, research on persistent symptoms focuses mainly on severe infections, while outpatients are rarely included in observations.

Objective: To investigate whether the severity of PCF is related to the number of acute and persistent symptoms due to mild-to-moderate COVID-19 and to compare the most common symptoms during acute infection with the persistent symptoms in PCF patients.

Methods: A total of 425 participants were examined after COVID-19 treated as an outpatient (median 249 days [IQR: 135; 322] after acute disease) at the site of University Hospital Augsburg, Germany. The Fatigue Assessment Scale (FAS) was used to quantify the severity of PCF. The number of symptoms (maximum 41) during acute infection and persistent symptoms (during the last 14 days before examination) were added up to sum scores. Multivariable linear regression models were used to show the association between the number of symptoms and PCF.

Results: Of the 425 participants, 37% (n = 157) developed PCF; most were women (70%). The median number of symptoms was significantly higher in the PCF group than in the non-PCF group at both time points. In multivariable linear regression models, both sum scores were associated with PCF (acute symptoms: β-estimate per additional symptom [95%-CI]: 0.48 [0.39; 0.57], p < 0.0001); persistent symptoms: β-estimate per additional symptom [95%-CI]: 1.18 [1.02; 1.34], p < 0.0001). The acute symptoms strongest associated with PCF severity were difficulty concentrating, memory problems, dyspnea or shortness of breath on exertion, palpitations, and problems with movement coordination.

Conclusion: Each additional symptom that occurs in COVID-19 increases the likelihood of suffering a higher severity of PCF. Further research is needed to identify the aetiology of PCF.

Source: Schmidbauer L, Kirchberger I, Goßlau Y, Warm TD, Hyhlik-Dürr A, Linseisen J, Meisinger C. The association between the number of symptoms and the severity of Post-COVID-Fatigue after SARS-CoV-2 infection treated in an outpatient setting. J Neurol. 2023 May 23:1–9. doi: 10.1007/s00415-023-11752-9. Epub ahead of print. PMID: 37219607; PMCID: PMC10204671. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10204671/ (Full text)

Parasympathetic autonomic dysfunction is more often evidenced than sympathetic autonomic dysfunction in fluctuating and polymorphic symptoms of “long-COVID” patients

Abstract:

Several disabling symptoms potentially related to dysautonomia have been reported in “long-COVID” patients. Unfortunately, these symptoms are often nonspecific, and autonomic nervous system explorations are rarely performed in these patients. This study aimed to evaluate prospectively a cohort of long-COVID patients presenting severe disabling and non-relapsing symptoms of potential dysautonomia and to identify sensitive tests.

Autonomic function was assessed by clinical examination, the Schirmer test; sudomotor evaluation, orthostatic blood pressure (BP) variation, 24-h ambulatory BP monitoring for sympathetic evaluation, and heart rate variation during orthostatism, deep breathing and Valsalva maneuvers for parasympathetic evaluation. Test results were considered abnormal if they reached the lower thresholds defined in publications and in our department. We also compared mean values for autonomic function tests between patients and age-matched controls.

Sixteen patients (median age 37 years [31–43 years], 15 women) were included in this study and referred 14.5 months (median) [12.0–16.5 months] after initial infection. Nine had at least one positive SARS-CoV-2 RT-PCR or serology result. Symptoms after SARS-CoV-2 infection were severe, fluctuating and disabling with effort intolerance. Six patients (37.5%) had one or several abnormal test results, affecting the parasympathetic cardiac function in five of them (31%). Mean Valsalva score was significantly lower in patients than in controls.

In this cohort of severely disabled long-COVID patients, 37.5% of them had at least one abnormal test result showing a possible contribution of dysautonomia to these nonspecific symptoms. Interestingly, mean values of the Valsalva test were significantly lower in patients than in control subjects, suggesting that normal values thresholds might not be appropriate in this population.

Source: Zanin, A., Amah, G., Chakroun, S. et al. Parasympathetic autonomic dysfunction is more often evidenced than sympathetic autonomic dysfunction in fluctuating and polymorphic symptoms of “long-COVID” patients. Sci Rep 13, 8251 (2023). https://doi.org/10.1038/s41598-023-35086-8 https://www.nature.com/articles/s41598-023-35086-8 (Full text)

Multidisciplinary Center Care for Long COVID Syndrome – a Retrospective Cohort Study

Abstract:

Background: Persistent multi-organ symptoms after COVID-19 have been termed “long COVID” or “post-acute sequelae of SARS-CoV-2 infection” (PASC). The complexity of these clinical manifestations posed challenges early in the pandemic as different ambulatory models formed out of necessity to manage the influx of patients. Little is known about the characteristics and outcomes of patients seeking care at multidisciplinary post-COVID centers.

Methods: We performed a retrospective cohort study of patients evaluated at our multidisciplinary Comprehensive COVID-19 Center (CCC) in Chicago, IL, between May 2020 and February 2022. We analyzed specialty clinic utilization and clinical test results according to severity of acute COVID-19.

Results: We evaluated 1802 patients a median of 8 months from acute COVID-19 onset, including 350 post-hospitalization and 1452 non-hospitalized patients. Patients were seen in 2361 initial visits in 12 specialty clinics, with 1151 (48.8%) in neurology, 591 (25%) in pulmonology, and 284 (12%) in cardiology. Among patients tested, 742/878(85%) reported decreased quality of life, 284/553(51%) had cognitive impairment, 195/434(44.9%) had alteration of lung function, 249/299(83.3%) had abnormal CT chest scans, and 14/116(12.1%) had elevated heart rate on rhythm monitoring. Frequency of cognitive impairment and pulmonary dysfunction was associated with severity of acute COVID-19. Non-hospitalized patients with positive SARS-CoV-2 testing had similar findings than those with negative or no test results.

Conclusions: The CCC experience shows common utilization of multiple specialists by long COVID patients, who harbor frequent neurologic, pulmonary, and cardiologic abnormalities. Differences in post-hospitalization and non-hospitalized groups suggest distinct pathogenic mechanisms of long COVID in these populations.

Source: Bailey J, Lavelle B, Miller J, Jimenez M, Lim PH, Orban ZS, Clark JR, Tomar R, Ludwig A, Ali ST, Lank GK, Zielinski A, Mylvaganam R, Kalhan R, Muayed ME, Mutharasan RK, Liotta EM, Sznajder JI, Davidson C, Koralnik IJ, Sala MA; Northwestern Medicine Comprehensive COVID Center Investigators. Multidisciplinary Center Care for Long COVID Syndrome – a Retrospective Cohort Study. Am J Med. 2023 May 21:S0002-9343(23)00328-5. doi: 10.1016/j.amjmed.2023.05.002. Epub ahead of print. PMID: 37220832; PMCID: PMC10200714. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10200714/ (Full text)

Ginkgo Biloba and Long COVID: In Vivo and In Vitro Models for the Evaluation of Nanotherapeutic Efficacy

Abstract:

Coronavirus infections are neuroinvasive and can provoke injury to the central nervous system (CNS) and long-term illness consequences. They may be associated with inflammatory processes due to cellular oxidative stress and an imbalanced antioxidant system. The ability of phytochemicals with antioxidant and anti-inflammatory activities, such as Ginkgo biloba, to alleviate neurological complications and brain tissue damage has attracted strong ongoing interest in the neurotherapeutic management of long COVID.
Ginkgo biloba leaf extract (EGb) contains several bioactive ingredients, e.g., bilobalide, quercetin, ginkgolides A–C, kaempferol, isorhamnetin, and luteolin. They have various pharmacological and medicinal effects, including memory and cognitive improvement. Ginkgo biloba, through its anti-apoptotic, antioxidant, and anti-inflammatory activities, impacts cognitive function and other illness conditions like those in long COVID. While preclinical research on the antioxidant therapies for neuroprotection has shown promising results, clinical translation remains slow due to several challenges (e.g., low drug bioavailability, limited half-life, instability, restricted delivery to target tissues, and poor antioxidant capacity).
This review emphasizes the advantages of nanotherapies using nanoparticle drug delivery approaches to overcome these challenges. Various experimental techniques shed light on the molecular mechanisms underlying the oxidative stress response in the nervous system and help comprehend the pathophysiology of the neurological sequelae of SARS-CoV-2 infection.
To develop novel therapeutic agents and drug delivery systems, several methods for mimicking oxidative stress conditions have been used (e.g., lipid peroxidation products, mitochondrial respiratory chain inhibitors, and models of ischemic brain damage). We hypothesize the beneficial effects of EGb in the neurotherapeutic management of long-term COVID-19 symptoms, evaluated using either in vitro cellular or in vivo animal models of oxidative stress.
Source: Akanchise T, Angelova A. Ginkgo Biloba and Long COVID: In Vivo and In Vitro Models for the Evaluation of Nanotherapeutic Efficacy. Pharmaceutics. 2023; 15(5):1562. https://doi.org/10.3390/pharmaceutics15051562 https://www.mdpi.com/1999-4923/15/5/1562 (Full text)

Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation

Abstract:

Background: Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians.

Methods: In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n=41, matched out of n = 204).

Measurements and main results: PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vmax; 3.42% ± 1.77% vs. 4.64 % ± 2.59%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5 – 190.2] vs. 189.1 [179.4 – 197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8 – 0.9] vs. 0.88 [0.8 – 0.9], p = 0.007). When combining AVR and vmax, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R= -0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters.

Conclusion: Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management.

Source: Timon Kuchler, Roman Günthner, Andrea Ribeiro et al. Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation, 22 May 2023, PREPRINT (Version 1) available at Research Square https://doi.org/10.21203/rs.3.rs-2952588/v1 (Full text)