Circulating Reelin promotes inflammation and modulates disease activity in acute and long COVID-19 cases

Abstract:

Thromboembolic complications and excessive inflammation are frequent in severe COVID-19, potentially leading to long COVID. In non-COVID studies, we and others demonstrated that circulating Reelin promotes leukocyte infiltration and thrombosis. Thus, we hypothesized that Reelin participates in endothelial dysfunction and hyperinflammation during COVID-19.

We showed that Reelin was increased in COVID-19 patients and correlated with the disease activity. In the severe COVID-19 group, we observed a hyperinflammatory state, as judged by increased concentration of cytokines (IL-1α, IL-4, IL-6, IL-10 and IL-17A), chemokines (IP-10 and MIP-1β), and adhesion markers (E-selectin and ICAM-1).

Reelin level was correlated with IL-1α, IL-4, IP-10, MIP-1β, and ICAM-1, suggesting a specific role for Reelin in COVID-19 progression. Furthermore, Reelin and all of the inflammatory markers aforementioned returned to normal in a long COVID cohort, showing that the hyperinflammatory state was resolved. Finally, we tested Reelin inhibition with the anti-Reelin antibody CR-50 in hACE2 transgenic mice infected with SARS-CoV-2. CR-50 prophylactic treatment decreased mortality and disease severity in this model.

These results demonstrate a direct proinflammatory function for Reelin in COVID-19 and identify it as a drug target. This work opens translational clinical applications in severe SARS-CoV-2 infection and beyond in auto-inflammatory diseases.

Source: Calvier L, Drelich A, Hsu J, Tseng CT, Mina Y, Nath A, Kounnas MZ, Herz J. Circulating Reelin promotes inflammation and modulates disease activity in acute and long COVID-19 cases. Front Immunol. 2023 Jun 27;14:1185748. doi: 10.3389/fimmu.2023.1185748. PMID: 37441066; PMCID: PMC10333573. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10333573/ (Full text)

Coronary microvascular health in symptomatic patients with prior COVID-19 infection: an updated analysis

Abstract:

Aims: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with endothelial dysfunction. We aimed to determine the effects of prior coronavirus disease 2019 (COVID-19) on the coronary microvasculature accounting for time from COVID-19, disease severity, SARS-CoV-2 variants, and in subgroups of patients with diabetes and those with no known coronary artery disease.

Methods and results: Cases consisted of patients with previous COVID-19 who had clinically indicated positron emission tomography (PET) imaging and were matched 1:3 on clinical and cardiovascular risk factors to controls having no prior infection. Myocardial flow reserve (MFR) was calculated as the ratio of stress to rest myocardial blood flow (MBF) in mL/min/g of the left ventricle. Comparisons between cases and controls were made for the odds and prevalence of impaired MFR (MFR < 2). We included 271 cases matched to 815 controls (mean ± SD age 65 ± 12 years, 52% men). The median (inter-quartile range) number of days between COVID-19 infection and PET imaging was 174 (58-338) days. Patients with prior COVID-19 had a statistically significant higher odds of MFR <2 (adjusted odds ratio 3.1, 95% confidence interval 2.8-4.25 P < 0.001). Results were similar in clinically meaningful subgroups. The proportion of cases with MFR <2 peaked 6-9 months from imaging with a statistically non-significant downtrend afterwards and was comparable across SARS-CoV-2 variants but increased with increasing severity of infection.

Conclusion: The prevalence of impaired MFR is similar by duration of time from infection up to 1 year and SARS-CoV-2 variants, but significantly differs by severity of infection.

Source: Ahmed AI, Al Rifai M, Alahdab F, Saad JM, Han Y, Alfawara MS, Nayfeh M, Malahfji M, Nabi F, Mahmarian JJ, Cooke JP, Zoghbi WA, Al-Mallah MH. Coronary microvascular health in symptomatic patients with prior COVID-19 infection: an updated analysis. Eur Heart J Cardiovasc Imaging. 2023 May 31:jead118. doi: 10.1093/ehjci/jead118. Epub ahead of print. PMID: 37254693. https://pubmed.ncbi.nlm.nih.gov/37254693/

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)

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)

Damage to endothelial barriers and its contribution to long COVID

Abstract:

The world continues to contend with COVID-19, fueled by the emergence of viral variants. At the same time, a subset of convalescent individuals continues to experience persistent and prolonged sequelae, known as long COVID. Clinical, autopsy, animal and in vitro studies all reveal endothelial injury in acute COVID-19 and convalescent patients. Endothelial dysfunction is now recognized as a central factor in COVID-19 progression and long COVID development.

Different organs contain different types of endothelia, each with specific features, forming different endothelial barriers and executing different physiological functions. Endothelial injury results in contraction of cell margins (increased permeability), shedding of glycocalyx, extension of phosphatidylserine-rich filopods, and barrier damage.

During acute SARS-CoV-2 infection, damaged endothelial cells promote diffuse microthrombi and destroy the endothelial (including blood-air, blood-brain, glomerular filtration and intestinal-blood) barriers, leading to multiple organ dysfunction. During the convalescence period, a subset of patients is unable to fully recover due to persistent endothelial dysfunction, contributing to long COVID. There is still an important knowledge gap between endothelial barrier damage in different organs and COVID-19 sequelae. In this article, we mainly focus on these endothelial barriers and their contribution to long COVID.

Source: Wu X, Xiang M, Jing H, Wang C, Novakovic VA, Shi J. Damage to endothelial barriers and its contribution to long COVID. Angiogenesis. 2023 Apr 27:1–18. doi: 10.1007/s10456-023-09878-5. Epub ahead of print. PMID: 37103631; PMCID: PMC10134732. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10134732/ (Full text)

Lung perfusion assessment in children with long-COVID: A pilot study

Abstract:

Background: There is increasing evidence that chronic endotheliopathy can play a role in patients with Post-Covid Condition (PCC, or Long Covid) by affecting peripheral vascularization. This pilot study aimed at assessing lung perfusion in children with Long-COVID with 99m Tc-MAA SPECT/CT.

Materials and methods: lung 99m Tc-MAA SPECT/CT was performed in children with Long-COVID and a pathological cardiopulmonary exercise testing (CPET). Intravenous injections were performed on patients in the supine position immediately before the planar scan according to the EANM guidelines for lung scintigraphy in children, followed by lung SPECT/CT acquisition. Reconstructed studies were visually analyzed.

Results: Clinical and biochemical data were collected during acute infection and follow-up in 14 children (6 females, mean age: 12.6 years) fulfilling Long-COVID diagnostic criteria and complaining of chronic fatigue and postexertional malaise after mild efforts, documented by CPET. Imaging results were compared with clinical scenarios during acute infection and follow-up. Six out of 14 (42.8%) children showed perfusion defects on 99m Tc-MAA SPECT/CT scan, without morphological alterations on coregistered CT.

Conclusions: This pilot investigation confirmed previous data suggesting that a small subgroup of children can develop lung perfusion defects after severe acute respiratory syndrome coronavirus 2 infection. Larger cohort studies are needed to confirm these preliminary results, providing also a better understanding of which children may deserve this test and how to manage those with lung perfusion defects.

Source: Pizzuto DA, Buonsenso D, Morello R, De Rose C, Valentini P, Fragano A, Baldi F, Di Giuda D. Lung perfusion assessment in children with long-COVID: A pilot study. Pediatr Pulmonol. 2023 Apr 25. doi: 10.1002/ppul.26432. Epub ahead of print. PMID: 37097045. https://onlinelibrary.wiley.com/doi/10.1002/ppul.26432 (Full text)

Proteomic profiling demonstrates inflammatory and endotheliopathy signatures associated with impaired cardiopulmonary exercise hemodynamic profile in Post Acute Sequelae of SARS-CoV-2 infection (PASC) syndrome

Abstract:

Approximately 50% of patients who recover from the acute SARS-CoV-2 experience Post Acute Sequelae of SARS-CoV-2 infection (PASC) syndrome. The pathophysiological hallmark of PASC is characterized by impaired system oxygen extraction (EO2) on invasive cardiopulmonary exercise test (iCPET). However, the mechanistic insights into impaired EO2 remain unclear.

We studied 21 consecutive iCPET in PASC patients with unexplained exertional intolerance. PASC patients were dichotomized into mildly reduced (EO2peak-mild) and severely reduced (EO2peak-severe) EO2 groups according to the median peak EO2 value. Proteomic profiling was performed on mixed venous blood plasma obtained at peak exercise during iCPET.

PASC patients as a group exhibited depressed peak exercise aerobic capacity (peak VO2; 85 ± 18 vs. 131 ± 45% predicted; p = 0.0002) with normal systemic oxygen delivery, DO2 (37 ± 9 vs. 42 ± 15 mL/kg/min; p = 0.43) and reduced EO2 (0.4 ± 0.1 vs. 0.8 ± 0.1; p < 0.0001). PASC patients with EO2peak-mild exhibited greater DO2 compared to those with EO2peak-severe [42.9 (34.2-41.2) vs. 32.1 (26.8-38.0) mL/kg/min; p = 0.01]. The proteins with increased expression in the EO2peak-severe group were involved in inflammatory and fibrotic processes. In the EO2peak-mild group, proteins associated with oxidative phosphorylation and glycogen metabolism were elevated.

In PASC patients with impaired EO2, there exist a spectrum of PASC phenotype related to differential aberrant protein expression and cardio-pulmonary physiologic response. PASC patients with EO2peak-severe exhibit a maladaptive physiologic and proteomic signature consistent with persistent inflammatory state and endothelial dysfunction, while in the EO2peak-mild group, there is enhanced expression of proteins involved in oxidative phosphorylation-mediated ATP synthesis along with an enhanced cardiopulmonary physiological response.

Source: Singh I, Leitner BP, Wang Y, Zhang H, Joseph P, Lutchmansingh DD, Gulati M, Possick JD, Damsky W, Hwa J, Heerdt PM, Chun HJ. Proteomic profiling demonstrates inflammatory and endotheliopathy signatures associated with impaired cardiopulmonary exercise hemodynamic profile in Post Acute Sequelae of SARS-CoV-2 infection (PASC) syndrome. Pulm Circ. 2023 Apr 1;13(2):e12220. doi: 10.1002/pul2.12220. PMID: 37091121; PMCID: PMC10113513. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10113513/ (Full text)

Vascular Function, Systemic Inflammation, and Coagulation Activation 18 Months after COVID-19 Infection: An Observational Cohort Study

Abstract:

Introduction: Among its effect on virtually all other organs, COVID-19 affects the cardiovascular system, potentially jeopardizing the cardiovascular health of millions. Previous research has shown no indication of macrovascular dysfunction as reflected by carotid artery reactivity, but has shown sustained microvascular dysfunction, systemic inflammation, and coagulation activation at 3 months after acute COVID-19. The long-term effects of COVID-19 on vascular function remain unknown.
Materials and Methods: This cohort study involved 167 patients who participated in the COVAS trial. At 3 months and 18 months after acute COVID-19, macrovascular dysfunction was evaluated by measuring the carotid artery diameter in response to cold pressor testing. Additionally, plasma endothelin-1, von Willebrand factor, Interleukin(IL)-1ra, IL-6, IL-18, and coagulation factor complexes were measured using ELISA techniques.
Results: The prevalence of macrovascular dysfunction did not differ between 3 months (14.5%) and 18 months (11.7%) after COVID-19 infection (p = 0.585). However, there was a significant decrease in absolute carotid artery diameter change, 3.5% ± 4.7 vs. 2.7% ± 2.5, p—0.001, respectively. Additionally, levels of vWF:Ag were persistently high in 80% of COVID-19 survivors, reflecting endothelial cell damage and possibly attenuated endothelial function. Furthermore, while levels of the inflammatory cytokines interleukin(IL)-1RA and IL-18 were normalized and evidence of contact pathway activation was no longer present, the concentrations of IL-6 and thrombin:antithrombin complexes were further increased at 18 months versus 3 months (2.5 pg/mL ± 2.6 vs. 4.0 pg/mL ± 4.6, p = 0.006 and 4.9 μg/L ± 4.4 vs. 18.2 μg/L ± 11.4, p < 0.001, respectively).
Discussion: This study shows that 18 months after COVID-19 infection, the incidence of macrovascular dysfunction as defined by a constrictive response during carotid artery reactivity testing is not increased. Nonetheless, plasma biomarkers indicate sustained endothelial cell activation (vWF), systemic inflammation (IL-6), and extrinsic/common pathway coagulation activation (FVII:AT, TAT) 18 months after COVID-19 infection.
Source: Willems LH, Jacobs LMC, Groh LA, ten Cate H, Spronk HMH, Wilson-Storey B, Hannink G, van Kuijk SMJ, Ghossein-Doha C, Nagy M, Thijssen DHJ, van Petersen AS, Warlé MC. Vascular Function, Systemic Inflammation, and Coagulation Activation 18 Months after COVID-19 Infection: An Observational Cohort Study. Journal of Clinical Medicine. 2023; 12(4):1413. https://doi.org/10.3390/jcm12041413 https://www.mdpi.com/2077-0383/12/4/1413 (Full text)

Endothelial dysfunction in ME/CFS patients

Abstract:

Objective: A few earlier studies have found impaired endothelial function in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). The present study investigated large-vessel and small-vessel endothelial function in patients with ME/CFS.

Study design: The study was a substudy of the RituxME trial, a national, multicenter, randomized, double-blind, placebo-controlled phase III study on the effect of rituximab vs. placebo in ME/CFS patients in Norway. Flow-mediated dilation (FMD) and post-occlusive reactive hyperemia (PORH) was measured at baseline and after 18 months of treatment in 39 patients and compared with healthy controls. Other outcome measures were symptom severity and various physical function measures.

Results: ME/CFS patients had markedly reduced FMD compared to healthy controls at baseline (5.1% vs. 8.2%, p< 0.0001, adjusted for arterial diameter and sex), and significantly lower microvascular regulation measured by PORH than healthy controls (1354 PU vs. 2208 PU, p = 0.002). There were no differences between the treatment and placebo groups in symptom changes or vascular measures. As a group, the ME/CSF patients experienced a slight, but significant improvement in clinical symptoms after 18 months. PORH, but not FMD, was similarly improved (1360 to 1834 PU, p = 0.028). There was no significant correlation between FMD and PORH. There were non-significant tendencies towards associations between symptom severity/physical function measures and lower FMD and PORH, and a significant correlation between PORH and steps per 24 hours at baseline.

Conclusions: ME/CFS patients had reduced macro- and microvascular endothelial function, indicating that vascular homeostasis may play a role in the clinical presentation of this disease.

Source: Sandvik MK, Sørland K, Leirgul E, Rekeland IG, Stavland CS, Mella O, Fluge Ø. Endothelial dysfunction in ME/CFS patients. PLoS One. 2023 Feb 2;18(2):e0280942. doi: 10.1371/journal.pone.0280942. PMID: 36730360; PMCID: PMC9894436. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9894436/ (Full text)

Vascular “Long COVID”: A New Vessel Disease?

Abstract:

Vascular sequelae following (SARS-CoV-2 coronavirus disease) (COVID)-19 infection are considered as “Long Covid (LC)” disease, when occurring 12 weeks after the original infection. The paucity of specific data can be obviated by translating pathophysiological elements from the original Severe Acute Respiratory Syndrome-Corona Virus (SARS-CoV-2) infection (In a microcirculatory system, a first “endotheliitis,” is often followed by production of “Neutrophil Extracellular Trap,” and can evolve into a more complex leukocytoklastic-like and hyperimmune vasculitis.

In medium/large-sized vessels, this corresponds to endothelial dysfunction, leading to an accelerated progression of pre-existing atherosclerotic plaques through an increased deposition of platelets, circulating inflammatory cells and proteins. Associated dysregulated immune and pro-coagulant conditions can directly cause thrombo-embolic arterial or venous complications. In order to implement appropriate treatment, physicians need to consider vascular pathologies observed after SARS-Cov-2 infections as possible “LC” disease.

Source: Zanini G, Selleri V, Roncati L, Coppi F, Nasi M, Farinetti A, Manenti A, Pinti M, Mattioli AV. Vascular “Long COVID”: A New Vessel Disease? Angiology. 2023 Jan 18:33197231153204. doi: 10.1177/00033197231153204. Epub ahead of print. PMID: 36652923. https://pubmed.ncbi.nlm.nih.gov/36652923/