Tag: long covid pathophysiology

Organ and cell-specific biomarkers of Long-COVID identified with targeted proteomics and machine learning

Abstract:

Background: Survivors of acute COVID-19 often suffer prolonged, diffuse symptoms post-infection, referred to as “Long-COVID”. A lack of Long-COVID biomarkers and pathophysiological mechanisms limits effective diagnosis, treatment and disease surveillance. We performed targeted proteomics and machine learning analyses to identify novel blood biomarkers of Long-COVID.

Methods: A case-control study comparing the expression of 2925 unique blood proteins in Long-COVID outpatients versus COVID-19 inpatients and healthy control subjects. Targeted proteomics was accomplished with proximity extension assays, and machine learning was used to identify the most important proteins for identifying Long-COVID patients. Organ system and cell type expression patterns were identified with Natural Language Processing (NLP) of the UniProt Knowledgebase.

Results: Machine learning analysis identified 119 relevant proteins for differentiating Long-COVID outpatients (Bonferonni corrected P < 0.01). Protein combinations were narrowed down to two optimal models, with nine and five proteins each, and with both having excellent sensitivity and specificity for Long-COVID status (AUC = 1.00, F1 = 1.00). NLP expression analysis highlighted the diffuse organ system involvement in Long-COVID, as well as the involved cell types, including leukocytes and platelets, as key components associated with Long-COVID.

Conclusions: Proteomic analysis of plasma from Long-COVID patients identified 119 highly relevant proteins and two optimal models with nine and five proteins, respectively. The identified proteins reflected widespread organ and cell type expression. Optimal protein models, as well as individual proteins, hold the potential for accurate diagnosis of Long-COVID and targeted therapeutics.

Source: Patel MA, Knauer MJ, Nicholson M, Daley M, Van Nynatten LR, Cepinskas G, Fraser DD. Organ and cell-specific biomarkers of Long-COVID identified with targeted proteomics and machine learning. Mol Med. 2023 Feb 21;29(1):26. doi: 10.1186/s10020-023-00610-z. PMID: 36809921; PMCID: PMC9942653. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9942653/ (Full text)

Left atrial longitudinal strain analysis in long Covid-19 syndrome

Abstract:

It is known that during the active course of Coronavirus disease 2019 (COVID-19), myocardial injury has an established pathological base, while its myocardial injury post-recovery is still obscured.

The aim of this study was to evaluate the longitudinal left atrial strain (LAS) using speckle tracking echocardiography (STE) in COVID-19-recovered patients who are previously healthy without confounder comorbidities to detect the potential cardiac dysfunction. 200 patients were prospectively included and examined 4?12 weeks after recovery from COVID-19 infection. 137 participants with comorbidities or previous history of cardiopulmonary disease were excluded from the analysis. A total of 63 patients who fulfilled our inclusion criteria were recruited into two groups according to the presence or absence of persistent dyspnoea and exercise intolerance. Clinical, laboratory & comprehensive echocardiographic examinations were done for all.

We observed that 31.7% of the previously healthy individuals developed dyspnoea & exercise intolerance post-COVID-19 infection. There were significantly impaired LAS parameters in the symptomatic group (LA reservoir, contraction & conduit strain, 22.7%, -6.6% & -16.1% versus 40%, -12%, and ? 27% in the asymptomatic group with P < 0.000).

Only LA reservoir strain and LA stiffness can independently predict the development of dyspnoea & exercise intolerance post-COVID-19 at cut-off values of 30% & 24.5% respectively with a sensitivity of 90% and a specificity of 91%, P < 0.001. These impaired LAS parameters could explain the developed symptoms post-COVID-19 recovery, even before disturbed conventional diastolic echocardiographic parameters. LAS parameters are significantly associated with the developed exertional dyspnoea & exercise intolerance post-COVID-19. LA reservoir strain & LA stiffness could provide a simple, easily available tool that points to early LV diastolic dysfunction and may direct the therapy in this subset of the population.

Source: ZeinElabdeen SG, Sherif A, Kandil NT, Altabib AMO, Abdelrashid MA. Left atrial longitudinal strain analysis in long Covid-19 syndrome. Int J Cardiovasc Imaging. 2023 Feb 14:1–6. doi: 10.1007/s10554-023-02801-5. Epub ahead of print. PMID: 36786877; PMCID: PMC9927057. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9927057/ (Full text)

Unfavorable Outcome and Long-Term Sequelae in Cases with Severe COVID-19

Abstract:

Emerging evidence shows that individuals with COVID-19 who survive the acute phase of illness may experience lingering symptoms in the following months. There is no clear indication as to whether these symptoms persist for a short time before resolving or if they persist for a long time. In this review, we will describe the symptoms that persist over time and possible predictors in the acute phase that indicate long-term persistence.
Based on the literature available to date, fatigue/weakness, dyspnea, arthromyalgia, depression, anxiety, memory loss, slowing down, difficulty concentrating and insomnia are the most commonly reported persistent long-term symptoms. The extent and persistence of these in long-term follow-up is not clear as there are still no quality studies available.
The evidence available today indicates that female subjects and those with a more severe initial disease are more likely to suffer permanent sequelae one year after the acute phase. To understand these complications, and to experiment with interventions and treatments for those at greater risk, we must first understand the physio-pathological mechanisms that sustain them.
Source: Fabbri A, Voza A, Riccardi A, Vanni S, De Iaco F on behalf of the Study & Research Center of the Italian Society of Emergency Medicine (SIMEU). Unfavorable Outcome and Long-Term Sequelae in Cases with Severe COVID-19. Viruses. 2023; 15(2):485. https://doi.org/10.3390/v15020485 (Full text)

Potential molecular mechanisms of chronic fatigue in long haul COVID and other viral diseases

Abstract:

Historically, COVID-19 emerges as one of the most devastating diseases of humankind, which creates an unmanageable health crisis worldwide. Until now, this disease costs millions of lives and continues to paralyze human civilization’s economy and social growth, leaving an enduring damage that will take an exceptionally long time to repair.

While a majority of infected patients survive after mild to moderate reactions after two to six weeks, a growing population of patients suffers for months with severe and prolonged symptoms of fatigue, depression, and anxiety. These patients are no less than 10% of total COVID-19 infected individuals with distinctive chronic clinical symptomatology, collectively termed post-acute sequelae of COVID-19 (PASC) or more commonly long-haul COVID. Interestingly, Long-haul COVID and many debilitating viral diseases display a similar range of clinical symptoms of muscle fatigue, dizziness, depression, and chronic inflammation.

In our current hypothesis-driven review article, we attempt to discuss the molecular mechanism of muscle fatigue in long-haul COVID, and other viral diseases as caused by HHV6, Powassan, Epstein-Barr virus (EBV), and HIV. We also discuss the pathological resemblance of virus-triggered muscle fatigue with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Source: Gottschalk CG, Peterson D, Armstrong J, Knox K, Roy A. Potential molecular mechanisms of chronic fatigue in long haul COVID and other viral diseases. Infect Agent Cancer. 2023 Feb 7;18(1):7. doi: 10.1186/s13027-023-00485-z. PMID: 36750846; PMCID: PMC9902840. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9902840/ (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)

Post-acute sequelae of SARS-CoV-2 (PASC) syndrome presenting as postural orthostatic tachycardia syndrome (POTS)

Abstract:

The novel SARS-CoV-2 emerged in 2019, and the global COVID-19 pandemic continues into 2022. It has been known that a subset of patients develops chronic, debilitating symptoms after otherwise complete recovery from acute infection of COVID-19.

Multiple terms have been used to describe this constellation of symptoms, including long COVID, long-haul COVID, and post-acute sequelae of SARS-CoV-2 syndrome (PASC). PASC is broadly defined as a wide range of new, returning, or ongoing symptoms at least four weeks after infection. Those patients are often seen in emergency departments after acute COVID- 19 infection, but their symptoms are not adequately managed because the underlying pathophysiology of PASC is not well understood.

Among patients with PASC, postural orthostatic tachycardic syndrome (POTS) has been increasingly recognized. POTS is one of the most common forms of autonomic dysfunction and defined by a sustained orthostatic tachycardia during active standing or head-up tilt test in the absence of orthostatic hypotension or other cardiopulmonary diseases. Because POTS is a treatable condition, it is important to recognize POTS among PASC patients. Herein, we reviewed the current literature on POTS and dysautonomia in PASC in order to better understand the overlap and distinction between these pathologies.

Source: Diekman S, Chung T. Post-acute sequelae of SARS-CoV-2 (PASC) syndrome presenting as postural orthostatic tachycardia syndrome (POTS). Clin Exp Emerg Med. 2023 Jan 30. doi: 10.15441/ceem.22.409. Epub ahead of print. PMID: 36718484. https://pubmed.ncbi.nlm.nih.gov/36718484/ (Full text available as PDF file)

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/

Investigating the possible mechanisms of autonomic dysfunction post-COVID-19

Abstract:

Patients with long COVID suffer from many neurological manifestations that persist for 3 months following infection by SARS-CoV-2. Autonomic dysfunction (AD) or dysautonomia is one complication of long COVID that causes patients to experience fatigue, dizziness, syncope, dyspnea, orthostatic intolerance, nausea, vomiting, and heart palpitations. The pathophysiology behind AD onset post-COVID is largely unknown. As such, this review aims to highlight the potential mechanisms by which AD occurs in patients with long COVID.

The first proposed mechanism includes the direct invasion of the hypothalamus or the medulla by SARS-CoV-2. Entry to these autonomic centers may occur through the neuronal or hematogenous routes. However, evidence so far indicates that neurological manifestations such as AD are caused indirectly.

Another mechanism is autoimmunity whereby autoantibodies against different receptors and glycoproteins expressed on cellular membranes are produced. Additionally, persistent inflammation and hypoxia can work separately or together to promote sympathetic overactivation in a bidirectional interaction. Renin-angiotensin system imbalance can also drive AD in long COVID through the downregulation of relevant receptors and formation of autoantibodies. Understanding the pathophysiology of AD post-COVID-19 may help provide early diagnosis and better therapy for patients.

Source: Jammoul M, Naddour J, Madi A, Reslan MA, Hatoum F, Zeineddine J, Abou-Kheir W, Lawand N. Investigating the possible mechanisms of autonomic dysfunction post-COVID-19. Auton Neurosci. 2022 Dec 24;245:103071. doi: 10.1016/j.autneu.2022.103071. Epub ahead of print. PMID: 36580747; PMCID: PMC9789535. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9789535/ (Full text)

Long Covid: Untangling the Complex Syndrome and the Search for Therapeutics

Abstract:

Long Covid can affect anyone who has previously had acute COVID-19. The root causes of this syndrome are still unknown, and no effective therapeutics are available. This complex syndrome, with a wide array of symptoms, is still evolving. Given the dire situation, it is important to identify the causes of Long Covid and the changes occurring within the immune system of affected patients to figure out how to treat it.
The immune system intersects with the persistent viral fragments and blood clots that are implicated in this syndrome; understanding how these complex systems interact may help in untangling the puzzling physiopathology of Long Covid and identifying mitigation measures to provide patients some relief. In this paper, we discuss evidence-based findings and formulate hypotheses on the mechanisms underlying Long Covid’s physiopathology and propose potential therapeutic options.
Source: Haque A, Pant AB. Long Covid: Untangling the Complex Syndrome and the Search for Therapeutics. Viruses. 2023; 15(1):42. https://doi.org/10.3390/v15010042 https://www.mdpi.com/1999-4915/15/1/42 (Full text)

Hyperbaric oxygen treatment for long coronavirus disease-19: a case report

Abstract:

Background: The coronavirus disease 2019 pandemic has resulted in a growing population of individuals who experience a wide range of persistent symptoms referred to as “long COVID.” Symptoms include neurocognitive impairment and fatigue. Two potential mechanisms could be responsible for these long-term unremitting symptoms: hypercoagulability, which increases the risk of blood vessel occlusion, and an uncontrolled continuous inflammatory response. Currently, no known treatment is available for long COVID. One of the options to reverse hypoxia, reduce neuroinflammation, and induce neuroplasticity is hyperbaric oxygen therapy. In this article, we present the first case report of a previously healthy athletic individual who suffered from long COVID syndrome treated successfully with hyperbaric oxygen therapy.

Case presentation: A previously healthy 55-year-old Caucasian man presented 3 months after severe coronavirus disease 2019 infection with long COVID syndrome. His symptoms included a decline in memory, multitasking abilities, energy, breathing, and physical fitness. After evaluation that included brain perfusion magnetic resonance imaging, diffusion tensor imaging, computerized cognitive tests, and cardiopulmonary test, he was treated with hyperbaric oxygen therapy. Each session included exposure to 90 minutes of 100% oxygen at 2 atmosphere absolute pressure with 5-minute air breaks every 20 minutes for 60 sessions, 5 days per week. Evaluation after completing the treatment showed significant improvements in brain perfusion and microstructure by magnetic resonance imaging and significant improvement in memory with the most dominant effect being on nonverbal memory, executive functions, attention, information procession speed, cognitive flexibility, and multitasking. The improved cognitive functions correlated with the increased cerebral blood flow in brain regions as measured by perfusion magnetic resonance imaging. With regard to physical capacity, there was a 34% increase in the maximum rate of oxygen consumed during exercise and a 44% improvement in forced vital capacity. The improved physical measurements correlated with the regain of his pre-COVID physical capacity.

Conclusions: We report the first case of successfully treated long COVID symptoms with hyperbaric oxygen therapy with improvements in cognition and cardiopulmonary function. The beneficial effects of hyperbaric oxygen shed additional light on the pathophysiology of long COVID. As this is a single case report, further prospective randomized control studies are needed.

Source: Bhaiyat AM, Sasson E, Wang Z, Khairy S, Ginzarly M, Qureshi U, Fikree M, Efrati S. Hyperbaric oxygen treatment for long coronavirus disease-19: a case report. J Med Case Rep. 2022 Feb 15;16(1):80. doi: 10.1186/s13256-022-03287-w. PMID: 35168680; PMCID: PMC8848789. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8848789/ (Full text)