Pulmonary embolism in patients in acute COVID-19, long-COVID and post-COVID syndrome

Abstract:

COVID-19 is a disease caused by the SARS-CoV-2 virus, which, after entering a living organism, uses the ACE-2 protein as a receptor and several other proteins as cofactors of infection. Disease symptomatology is extensive, involving mostly predominant respiratory symptoms, as well as those of the nervous, gastrointestinal, circulatory and other systems. Incidence of COVID-19 also results in markedly different laboratory findings on the hemostatic system with the predominant feature of increased D-dimer levels.

In the pathogenesis of thromboembolic complications in COVID-19, all elements of Virchow’s triad are involved: endothelial damage, coagulation disorders and blood flow disorders. Coagulopathy increases with the severity of the clinical course of COVID-19.

One of the causes of mortality associated with COVID-19 is pulmonary embolism. SARS-CoV-2 infection increases the risk of thromboembolic complications not only in the acute period of the disease. Also in the period of about a month after recovery, there is an increased risk of venous thrombosis and consequently, life-threatening pulmonary embolism.

The classic biomarker of pulmonary embolism in the general population is D-dimers. Among imaging studies, the gold standard for diagnosing this disease is computed tomography of the pulmonary arteries (CTPA). Other useful diagnostic tests are ventilation-perfusion lung scintigraphy (VQ Scans) or echocardiography. Currently reviewed guidelines and recommendations recommend extensive thromboprophylaxis in COVID-19 patients in both acute and chronic phases of the disease.

Source: Tomczyk P, Tomczyk D. Pulmonary embolism in patients in acute COVID-19, long-COVID and post-COVID syndrome. Przegl Epidemiol. 2023;77(2):172-184. doi: 10.32394/pe.77.17. PMID: 37846660. https://pubmed.ncbi.nlm.nih.gov/37846660/

Gut-brain pathogenesis of post-acute COVID-19 neurocognitive symptoms

Approximately one third of non-hospitalized coronavirus disease of 2019 (COVID-19) patients report chronic symptoms after recovering from the acute stage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Some of the most persistent and common complaints of this post-acute COVID-19 syndrome (PACS) are cognitive in nature, described subjectively as “brain fog” and also objectively measured as deficits in executive function, working memory, attention, and processing speed. The mechanisms of these chronic cognitive sequelae are currently not understood.

SARS-CoV-2 inflicts damage to cerebral blood vessels and the intestinal wall by binding to angiotensin-converting enzyme 2 (ACE2) receptors and also by evoking production of high levels of systemic cytokines, compromising the brain’s neurovascular unit, degrading the intestinal barrier, and potentially increasing the permeability of both to harmful substances. Such substances are hypothesized to be produced in the gut by pathogenic microbiota that, given the profound effects COVID-19 has on the gastrointestinal system, may fourish as a result of intestinal post-COVID-19 dysbiosis. COVID-19 may therefore create a scenario in which neurotoxic and neuroinflammatory substances readily proliferate from the gut lumen and encounter a weakened neurovascular unit, gaining access to the brain and subsequently producing cognitive deficits.

Here, we review this proposed PACS pathogenesis along the gut-brain axis, while also identifying specific methodologies that are currently available to experimentally measure each individual component of the model.

Source: Plummer Allison M., Matos Yvette L., Lin Henry C., Ryman Sephira G., Birg Aleksandr, Quinn Davin K., Parada Alisha N., Vakhtin Andrei A. Gut-brain pathogenesis of post-acute COVID-19 neurocognitive symptoms. Frontiers in Neuroscience, Vol 17, 2023. DOI=10.3389/fnins.2023.1232480 ISSN=1662-453X  https://www.frontiersin.org/articles/10.3389/fnins.2023.1232480 (Full text)

Neuroinflammation in post-acute sequelae of COVID-19 (PASC) as assessed by [11C]PBR28 PET correlates with vascular disease measures

Abstract:

The COVID-19 pandemic caused by SARS-CoV-2 has triggered a consequential public health crisis of post-acute sequelae of COVID-19 (PASC), sometimes referred to as long COVID. The mechanisms of the heterogeneous persistent symptoms and signs that comprise PASC are under investigation, and several studies have pointed to the central nervous and vascular systems as being potential sites of dysfunction.

In the current study, we recruited individuals with PASC with diverse symptoms, and examined the relationship between neuroinflammation and circulating markers of vascular dysfunction. We used [11C]PBR28 PET neuroimaging, a marker of neuroinflammation, to compare 12 PASC individuals versus 43 normative healthy controls.

We found significantly increased neuroinflammation in PASC versus controls across a wide swath of brain regions including midcingulate and anterior cingulate cortex, corpus callosum, thalamus, basal ganglia, and at the boundaries of ventricles. We also collected and analyzed peripheral blood plasma from the PASC individuals and found significant positive correlations between neuroinflammation and several circulating analytes related to vascular dysfunction.

These results suggest that an interaction between neuroinflammation and vascular health may contribute to common symptoms of PASC.

Source: Michael B VanElzakkerHannah F BuesLudovica BrusaferriMinhae KimDeena SaadiEva-Maria RataiDarin D DoughertyMarco L Loggia. Neuroinflammation in post-acute sequelae of COVID-19 (PASC) as assessed by [11C]PBR28 PET correlates with vascular disease measures. https://www.biorxiv.org/content/10.1101/2023.10.19.563117v1 (Full text available as PDF file)

Vitamin B12 as an epidrug for regulating peripheral blood biomarkers in long COVID-associated visuoconstructive deficit

Abstract:

Approximately four months after recovering from a mild COVID-19 infection, around 25% of individuals developed visuoconstructive deficit (VCD), which was found to be correlated with an increase in peripheral immune markers and alterations in structural and metabolic brain imaging. Recently, it has been demonstrated that supplemental vitamin B12 regulates hyperinflammation during moderate and severe COVID-19 through methyl-dependent epigenetic mechanisms.

Herein, whole peripheral blood cultures were produced using samples obtained from patients with confirmed persistent VCD, and controls without impairment, between 10 and 16 months after mild COVID-19. This experimental model was used to assess the leukocyte expression patterns of 11 biomarkers previously associated with VCD in long COVID and explore the potential of pharmacological B12 in regulating these genes. The results showed that patients with persistent VCD displayed continued upregulation of CCL11 and LIF compared to controls.

It is worth noting that elevated serum levels of CCL11 have been previously linked to age-related neurodegenerative diseases. Notably, the addition of 1 nM of vitamin B12 to blood cultures from individuals with VCD normalized the mRNA levels of CCL11, upregulated the neuroprotective HGF, and, to a lesser extent, downregulated CSF2 and CXCL10. There was an inverse correlation observed between CCL11 mRNA levels and methylation levels of specific cytosines in its promoter region.

These findings underscore the significance of systemic inflammation in persistent VCD associated with long COVID. Moreover, the study provides evidence suggesting that B12, acting as an epidrug, shows promise as a therapeutic approach for addressing this cognitive impairment.

Source: Larissa Cassiano, Jonas Paula, Daniela Rosa et al. Vitamin B12 as an epidrug for regulating peripheral blood biomarkers in long COVID-associated visuoconstructive deficit, 11 October 2023, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3158180/v1] https://www.researchsquare.com/article/rs-3158180/v1 (Full text)

Genomic communication via circulating extracellular vesicles and long-term health consequences of COVID-19

Abstract:

COVID-19 continues to affect an unprecedented number of people with the emergence of new variants posing a serious challenge to global health. There is an expansion of knowledge in understanding the pathogenesis of Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the impact of the acute disease on multiple organs. In addition, growing evidence reports that the impact of COVID-19 on different organs persists long after the recovery phase of the disease, leading to long-term consequences of COVID-19.

These long-term consequences involve pulmonary as well as extra-pulmonary sequelae of the disease. Noteably, recent research has shown a potential association between COVID-19 and change in the molecular cargo of extracellular vesicles (EVs). EVs are vesicles released by cells and play an important role in cell communication by transfer of bioactive molecules between cells. Emerging evidence shows a strong link between EVs and their molecular cargo, and regulation of metabolism in health and disease.

This review focuses on current knowledge about EVs and their potential role in COVID-19 pathogenesis, their current and future implications as tools for biomarker and therapeutic development and their possible effects on long-term impact of COVID-19.

Source: Nair, S., Nova-Lamperti, E., Labarca, G. et al. Genomic communication via circulating extracellular vesicles and long-term health consequences of COVID-19. J Transl Med 21, 709 (2023). https://doi.org/10.1186/s12967-023-04552-2 https://link.springer.com/article/10.1186/s12967-023-04552-2 (Full text)

 

Role of Microglia, Decreased Neurogenesis and Oligodendrocyte Depletion in Long COVID-Mediated Brain Impairments

Abstract:

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a recent worldwide coronavirus disease-2019 (COVID-19) pandemic. SARS-CoV-2 primarily causes an acute respiratory infection but can progress into significant neurological complications in some. Moreover, patients with severe acute COVID-19 could develop debilitating long-term sequela.

Long-COVID is characterized by chronic symptoms that persist months after the initial infection. Common complaints are fatigue, myalgias, depression, anxiety, and “brain fog,” or cognitive and memory impairments. A recent study demonstrated that a mild COVID-19 respiratory infection could generate elevated proinflammatory cytokines and chemokines in the cerebral spinal fluid.

This commentary discusses findings from this study, demonstrating that even a mild respiratory SARS-CoV-2 infection can cause considerable neuroinflammation with microglial and macrophage reactivity. Such changes could also be gleaned by measuring chemokines and cytokines in the circulating blood. Moreover, neuroinflammation caused by mild SARS-CoV-2 infection can also impair hippocampal neurogenesis, deplete oligodendrocytes, and decrease myelinated axons.

All these changes likely contribute to cognitive deficits in long-COVID syndrome. Therefore, strategies capable of restraining neuroinflammation, maintaining better hippocampal neurogenesis, and preserving oligodendrocyte lineage differentiation and maturation may prevent or reduce the incidence of long-COVID after SARS-CoV-2 respiratory infection.

Source: Wei ZD, Liang K, Shetty AK. Role of Microglia, Decreased Neurogenesis and Oligodendrocyte Depletion in Long COVID-Mediated Brain Impairments. Aging Dis. 2023 Sep 24. doi: 10.14336/AD.2023.10918. Epub ahead of print. PMID: 37815903. https://www.aginganddisease.org/EN/10.14336/AD.2023.10918 (Full text)

Acupuncture as an Additional Method of Rehabilitation Post-COVID-19: a randomized controlled trial

Abstract:

Objectives: The purpose of this study was to evaluate the effectiveness of complex rehabilitation with and without acupuncture in a hospital setting.

Methods: A randomized clinical trial was performed at Rehabilitation center “Kamenskoe Plato” in Almaty, Kazakhstan. 160 patients with Post COVID-19 condition were randomly equally divided into an acupuncture with complex rehabilitation methods and a only complex rehabilitation methods group in the period from March 1, 2022 to July 1, 2022. Either groups was performed for an 10-14 days period. The outcome measures were the Bartel index, the Borg scale, Modified Dyspnea Scale and the 6-minute walking test. Adverse events also were monitored and documented.

Results: We found statistically significant improvement after the rehabilitation course with acupuncture in the all scales. And in the group without acupuncture, only on two scales MDS and Borg scale.

Conclusion: Rehabilitation with acupuncture is possible and effective in patients recovering from post-COVID-19. Our findings may be useful to guide clinicians taking care of patients with post-COVID-19.

Source: Omarova I, Akanova A, Kurmanova A, Kurmanova G, Glushkova N, Seidanova A, Turysbekov K. Acupuncture as an Additional Method of Rehabilitation Post-COVID-19: a randomized controlled trial. J Pharmacopuncture. 2023 Sep 30;26(3):238-246. doi: 10.3831/KPI.2023.26.3.238. PMID: 37799621; PMCID: PMC10547817. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10547817/ (Full text)

From ‘mental fog’ to post-acute COVID-19 syndrome’s executive function alteration: Implications for clinical approach

Abstract:

A common symptom of the neuropsychiatric Post-Acute COVID-19 syndrome (neuro-PACS) is the so called ‘brain fog’. Patients describe the brain fog as problems with attention, memory and mental fatigue. Brain fog is experienced by 9-55% of people for months after having contracted SARS-CoV-2 virus. Several theories have been proposed to explain PACS’s brain fog, including a neuroinflammatory hypothesis, but the hypothesis remains to be proven. Here, we examined inflammatory and immunological blood profile in a cohort of patients with PACS to investigate the association between executive functions and blood inflammatory markers.

Executive function was assessed by the Trail Making Test (TMT) Part A and Part B, as well as the Barkley Deficits in Executive Functioning Scale (BDEFS), in 71 patients (36 men), average age of 40 years (range: 15-82, SD: 15.7). Impairment in executive functioning (BDEFS scores and TMT B scores) correlated with increased levels of Interleukin-6 (IL-6), fibrinogen and ferritin. Moreover, elevated levels of Il-6, fibrinogen, ferritin, tumor necrosis factor-alpha and C-reactive protein have been observed in PACS.

These findings demonstrate that PACS is characterized by the presence of an immuno-inflammatory process, which is associated with diminished executive functioning. Here, we argue in favour of a shift from the non-descriptive definition of ‘mental fog’ to a characterization of a subtype of PACS, associated with alteration in executive functioning. Implication for clinical settings and prevention are discussed.

Source: Pallanti S, Di Ponzio M, Gavazzi G, Gasic G, Besteher B, Heller C, Kikinis R, Makris N, Kikinis Z. From ‘mental fog’ to post-acute COVID-19 syndrome’s executive function alteration: Implications for clinical approach. J Psychiatr Res. 2023 Sep 30;167:10-15. doi: 10.1016/j.jpsychires.2023.09.017. Epub ahead of print. PMID: 37804756. https://pubmed.ncbi.nlm.nih.gov/37804756/

Monocytes subpopulations pattern in the acute respiratory syndrome coronavirus 2 virus infection and after long COVID-19

Abstract:

Introduction and objective: The present study sought to characterize the pattern of monocyte subpopulations in patients during the course of the infections caused by SARS-CoV-2 virus or who presented long COVID-19 syndrome compared to monocytes from patients with zika virus (Zika) or chikungunya virus (CHIKV).

Casuistry: Study with 89 peripheral blood samples from patients, who underwent hemogram and serology (IgG and IgM) for detection of Zika (Control Group 1, n = 18) or CHIKV (Control Group 2, n = 9), and from patients who underwent hemogram and reverse transcription polymerase chain reaction for detection of SARS-CoV-2 at the acute phase of the disease (Group 3, n = 19); and of patients who presented long COVID-19 syndrome (Group 4, n = 43). The monocyte and subpopulations counts were performed by flow cytometry.

Results: No significant difference was observed in the total number of monocytes between the groups. The classical (CD14++CD16) and intermediate (CD14+CD16+) monocytes counts were increased in patients with acute infection or with long COVID-19 syndrome. The monocytes subpopulations counts were lower in patients with infection Zika or CHIKV.

Conclusion: Increase in the monocyte subpopulations in patients with acute infection or with long COVID-19 syndrome may be an important finding of differentiated from the infection Zika or CHIKV.

Source: Pereira VIC, de Brito Junior LC, Falcão LFM, da Costa Vasconcelos PF, Quaresma JAS, Berg AVVD, Paixão APS, Ferreira RIS, Diks IBC. Monocytes subpopulations pattern in the acute respiratory syndrome coronavirus 2 virus infection and after long COVID-19. Int Immunopharmacol. 2023 Oct 5;124(Pt B):110994. doi: 10.1016/j.intimp.2023.110994. Epub ahead of print. PMID: 37804653. https://www.sciencedirect.com/science/article/abs/pii/S156757692301319X

Unraveling Post-COVID-19 Immune Dysregulation Using Machine Learning-based Immunophenotyping

Abstract:

The COVID-19 pandemic has left a significant mark on global healthcare, with many individuals experiencing lingering symptoms long after recovering from the acute phase of the disease, a condition often referred to as “long COVID.” This study delves into the intricate realm of immune dysregulation that ensues in 509 post-COVID-19 patients across multiple Iraqi regions during the years 2022 and 2023.

Utilizing advanced machine learning techniques for immunophenotyping, this research aims to shed light on the diverse immune dysregulation patterns present in long COVID patients. By analyzing a comprehensive dataset encompassing clinical, immunological, and demographic information, the study provides valuable insights into the complex interplay of immune responses following COVID-19 infection.

The findings reveal that long COVID is associated with a spectrum of immune dysregulation phenomena, including persistent inflammation, altered cytokine profiles, and abnormal immune cell subsets. These insights highlight the need for personalized interventions and tailored treatment strategies for individuals suffering from long COVID-19.

This research represents a significant step forward in our understanding of the post-COVID-19 immune landscape and opens new avenues for targeted therapies and clinical management of long COVID patients. As the world grapples with the long-term implications of the pandemic, these findings offer hope for improving the quality of life for those affected by this enigmatic condition.

Source: Maitham G. Yousif, Ghizal Fatima and Hector J. Castro et al. Unraveling Post-COVID-19 Immune Dysregulation Using Machine Learning-based Immunophenotyping. 2023. https://arxiv.org/ftp/arxiv/papers/2310/2310.01428.pdf (Full text)