Tag: long covid review

Long-term neurological dysfunction associated with COVID-19: Lessons from influenza and inflammatory diseases?

Abstract:

As the COVID-19 pandemic persists, SARS-CoV-2 infection is increasingly associated with long-term neurological side effects including cognitive impairment, fatigue, depression, and anxiety, colloquially known as “long-COVID.” While the full extent of long-COVID neuropathology across years or even decades is not yet known, we can perhaps take direction from long-standing research into other respiratory diseases, such as influenza, that can present with similar long-term neurological consequences.

In this review, we highlight commonalities in the neurological impacts of influenza and COVID-19. We first focus on the common potential mechanisms underlying neurological sequelae of long-COVID and influenza, namely (1) viral neurotropism and (2) dysregulated peripheral inflammation. The latter, namely heightened peripheral inflammation leading to central nervous system dysfunction, is emerging as a shared mechanism in various peripheral inflammatory or inflammation-associated diseases and conditions.

We then discuss historical and modern examples of influenza- and COVID-19-associated cognitive impairment, depression, anxiety, and fatigue, revealing key similarities in their neurological sequelae. Although we are learning that the effects of influenza and COVID differ somewhat in terms of their influence on the brain, as the impacts of long-COVID grow, such comparisons will likely prove valuable in guiding ongoing research into long-COVID, and perhaps foreshadow what could be in store for individuals with COVID-19 and their brain health.

Source: Volk P, Rahmani Manesh M, Warren ME, Besko K, Gonçalves de Andrade E, Wicki-Stordeur LE, Swayne LA. Long-term neurological dysfunction associated with COVID-19: Lessons from influenza and inflammatory diseases? J Neurochem. 2023 Nov 28. doi: 10.1111/jnc.16016. Epub ahead of print. PMID: 38014645. https://onlinelibrary.wiley.com/doi/10.1111/jnc.16016 (Full text)

SGLT2 Inhibitors in Long COVID Syndrome: Is There a Potential Role?

Abstract:

The coronavirus disease (COVID)-19 has turned into a pandemic causing a global public health crisis. While acute COVID-19 mainly affects the respiratory system and can cause acute respiratory distress syndrome, an association with persistent inflammatory stress affecting different organ systems has been elucidated in long COVID syndrome (LCS).
Increased severity and mortality rates have been reported due to cardiophysiological and metabolic systemic disorders as well as multiorgan failure in COVID-19, additionally accompanied by chronic dyspnea and fatigue in LCS. Hence, novel therapies have been tested to improve the outcomes of LCS of which one potential candidate might be sodium–glucose cotransporter 2 (SGLT2) inhibitors.
The aim of this narrative review was to discuss rationales for investigating SGLT2 inhibitor therapy in people suffering from LCS. In this regard, we discuss their potential positive effects—next to the well described “cardio-renal-metabolic” conditions—with a focus on potential anti-inflammatory and beneficial systemic effects in LCS. However, potential beneficial as well as potential disadvantageous effects of SGLT2 inhibitors on the prevalence and long-term outcomes of COVID-19 will need to be established in ongoing research.
Source: Zimmermann P, Sourij H, Aberer F, Rilstone S, Schierbauer J, Moser O. SGLT2 Inhibitors in Long COVID Syndrome: Is There a Potential Role? Journal of Cardiovascular Development and Disease. 2023; 10(12):478. https://doi.org/10.3390/jcdd10120478 https://www.mdpi.com/2308-3425/10/12/478 (Full text)

Drawing the Line Between Postacute Sequelae of COVID-19 and Functional Neurologic Disorders A Daunting Clinical Overlap or Irrelevant Conundrum?

Abstract:

Coronavirus disease 2019 (COVID-19) is an acute infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in its multiple variants that classically presents with cough, fatigue, fever, headache, myalgias, and diarrhea. As vaccination becomes widely available and infection rates facilitate herd immunity across the globe, more attention has been given to long-term symptoms that may persist after the index infection, which include impairments in concentration, executive dysfunction, sensory disturbances, depression, anxiety, fatigue, and cough, among other symptoms classified under the umbrella term of postacute sequelae of SARS-CoV-2 infection (PASC).

Functional neurologic disorder (FND), also known as conversion disorder and functional neurologic symptom disorder, refers to the presence of one or more symptoms of altered voluntary motor or sensory function that are incompatible with and not better explained by a known neurological or medical condition that causes significant distress and functional impairment. Although the diagnosis of FND may not require the identification of an underlying psychological stressor, being diagnosed with an FND can worsen stigma and shift attention and resources away from other medical concerns that should be concomitantly addressed.

This review summarizes the literature on the overlapping nature and discrimination of PASC from FND in COVID-19 survivors. Based on this, we develop a treatment framework that targets unique domains of these complex overlapping presentations, following a multidisciplinary approach with an individualized treatment plan inclusive of physical and psychological interventions focused on functional rehabilitation.

Source: Sales, Paulo M.G. MD, MS∗; Greenfield, Melissa J. PsyD∗; Pinkhasov, Aaron MD†; Viswanathan, Ramaswamy MD, DrMedSc‡; Saunders, Ramotse MD§; Huremović, Damir MD, MPP∥. Drawing the Line Between Postacute Sequelae of COVID-19 and Functional Neurologic Disorders: A Daunting Clinical Overlap or Irrelevant Conundrum?. The Journal of Nervous and Mental Disease 211(12):p 882-889, December 2023. | DOI: 10.1097/NMD.0000000000001643 https://journals.lww.com/jonmd/abstract/2023/12000/drawing_the_line_between_postacute_sequelae_of.2.aspx

Risk Factors for Long COVID in Older Adults

Abstract:

As time has passed following the COVID-19 pandemic, individuals infected with SARS-CoV-2 have gradually exhibited a variety of symptoms associated with long COVID in the postacute phase of infection. Simultaneously, in many countries worldwide, the process of population aging has been accelerating. Within this context, the elderly population has not only become susceptible and high-risk during the acute phase of COVID-19 but also has considerable risks when confronting long COVID.
Elderly individuals possess specific immunological backgrounds, and during the process of aging, their immune systems can enter a state known as “immunosenescence”. This further exacerbates “inflammaging” and the development of various comorbidities in elderly individuals, rendering them more susceptible to long COVID. Additionally, long COVID can inflict both physical and mental harm upon elderly people, thereby reducing their overall quality of life. Consequently, the impact of long COVID on elderly people should not be underestimated.
This review seeks to summarize the infection characteristics and intrinsic factors of older adults during the COVID-19 pandemic, with a focus on the physical and mental impact of long COVID. Additionally, it aims to explore potential strategies to mitigate the risk of long COVID or other emerging infectious diseases among older adults in the future.
Source: Hu Y, Liu Y, Zheng H, Liu L. Risk Factors for Long COVID in Older Adults. Biomedicines. 2023; 11(11):3002. https://doi.org/10.3390/biomedicines11113002 https://www.mdpi.com/2227-9059/11/11/3002 (Full text)

Role of Tau protein in long COVID and potential therapeutic targets

Abstract:

Introduction: Long COVID is an emerging public health burden and has been defined as a syndrome with common symptoms of fatigue, shortness of breath, cognitive dysfunction, and others impacting day-to-day life, fluctuating or relapsing over, occurring for at least two months in patients with a history of probable or confirmed SARS CoV-2 infection; usually three months from the onset of illness and cannot be explained by an alternate diagnosis. The actual prevalence of long-term COVID-19 is unknown, but it is believed that more than 17 million patients in Europe may have suffered from it during pandemic.

Pathophysiology: Currently, there is limited understanding of the pathophysiology of this syndrome, and multiple hypotheses have been proposed. Our literature review has shown studies reporting tau deposits in tissue samples of the brain from autopsies of COVID-19 patients compared to the control group, and the in-vitro human brain organoid model has shown aberrant phosphorylation of tau protein in response to SARS-CoV-2 infection. Tauopathies, a group of neurodegenerative disorders with the salient features of tau deposits, can manifest different symptoms based on the anatomical region of brain involvement and have been shown to affect the peripheral nervous system as well and explained even in rat model studies.

Long COVID has more than 203 symptoms, with predominant symptoms of fatigue, dyspnea, and cognitive dysfunction, which tauopathy-induced CNS and peripheral nervous system dysfunction can explain. There have been no studies up till now to reveal the pathophysiology of long COVID. Based on our literature review, aberrant tau phosphorylation is a promising hypothesis that can be explored in future studies.

Therapeutic approaches for tauopathies have multidimensional aspects, including targeting post-translational modifications, tau aggregation, and tau clearance through the autophagy process with the help of lysosomes, which can be potential targets for developing therapeutic interventions for the long COVID. In addition, future studies can attempt to find the tau proteins in CSF and use those as biomarkers for the long COVID.

Source: Marwaha B. Role of Tau protein in long COVID and potential therapeutic targets. Front Cell Infect Microbiol. 2023 Oct 25;13:1280600. doi: 10.3389/fcimb.2023.1280600. PMID: 37953801; PMCID: PMC10634420. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10634420/ (Full text)

Post-COVID-19 and Irritable Bowel Syndrome: A Literature Review

Abstract:

The emergence of post-COVID-19 syndrome (PCS), a complex and multifactorial condition that follows the acute COVID-19 infection, has raised serious concerns within the global medical community. Concurrently, Irritable Bowel Syndrome (IBS), a widespread chronic gastrointestinal (GI) dysfunction, is considered to be one of the most common disorders of gut–brain interaction (DGBI) that significantly affects the quality of life and social functioning of patients. PCS presents a wide range of symptoms and GI manifestations, including IBS.
This review aims to analyze the GI involvement and the prolonged symptoms of COVID-19 infection as part of PCS, in order to explore the potential development of post-infection IBS (PI-IBS) in COVID-19 patients. Irritating factors such as enteric infection, psychosocial conditions, food antigens, and antibiotics may lead to abnormalities in the physiological function of the GI system and could be involved in the development of PI-IBS. Through the presentation of the pathophysiological mechanisms and epidemiological studies that assessed the prevalence of IBS as part of PCS, we attempted to provide a better understanding of the long-term consequences of COVID-19 and the pathogenesis of PI-IBS.
Even though PI-IBS is becoming a global challenge, there are only a few studies about it and therefore limited knowledge. Currently, the majority of the existing treatment options are referred to non-COVID-19-associated DGBIs. Forthcoming studies may shed light on the mechanisms of PI-IBS that could be targeted for treatment development. Paramythiotis D, Karlafti E, Didagelos M, Fafouti M, Veroplidou K, Protopapas AA, Kaiafa G, Netta S, Michalopoulos A, Savopoulos C. Post-COVID-19 and Irritable Bowel Syndrome: A Literature Review. Medicina. 2023; 59(11):1961. https://doi.org/10.3390/medicina59111961 https://www.mdpi.com/1648-9144/59/11/1961 (Full text)
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Autonomic Manifestations of Long-COVID Syndrome

Abstract:

Purpose of review: Long-COVID is a novel condition emerging from the COVID-19 pandemic. Long-COVID is characterized by symptoms commonly seen in autonomic disorders including fatigue, brain fog, light-headedness, and palpitations. This article will critically evaluate recent findings and studies on Long-COVID and its physiological autonomic manifestations.

Recent findings: Studies have reported on the prevalence of different symptoms and autonomic disorders in Long-COVID cohorts. Autonomic nervous system function, including both the parasympathetic and sympathetic limbs, has been studied using different testing techniques in Long-COVID patients. While numerous mechanisms may contribute to Long-COVID autonomic pathophysiology, it is currently unclear which ones lead to a Long-COVID presentation. To date, studies have not tested treatment options for autonomic disorders in Long-COVID patients. Long-COVID is associated with autonomic abnormalities. There is a high prevalence of clinical autonomic disorders among Long-COVID patients, with limited knowledge of the underlying mechanisms and the effectiveness of treatment options.

Source: Hira R, Karalasingham K, Baker JR, Raj SR. Autonomic Manifestations of Long-COVID Syndrome. Curr Neurol Neurosci Rep. 2023 Nov 10. doi: 10.1007/s11910-023-01320-z. Epub ahead of print. PMID: 37947962. https://pubmed.ncbi.nlm.nih.gov/37947962/

Beyond the acute illness: Exploring long COVID and its impact on multiple organ systems

Abstract:

Unprecedented worldwide health catastrophe due to the COVID-19 pandemic has ended up resulting in high morbidity and mortality rates. Even though many people recover from acute infection, there is rising concern regarding post-COVID-19 conditions (PCCs), often referred to as post-acute sequelae of SARS-CoV-2 infection (PASC) or “long COVID.”

The respiratory, cardiovascular, neurological, and endocrine systems are just a few of the many organ systems that can be impacted by this multifarious, complicated illness. The clinical manifestations of long COVID can vary among individuals and may include fatigue, dyspnea, chest pain, cognitive impairment, and new-onset diabetes, among others.

Although the underlying processes of long COVID are not fully understood, they probably involve unregulated immune response, persistent generation of pro-inflammatory cytokines (chronic inflammation), autoimmune-like reactions, persistent viral replication, and micro-clot formation.

To create successful treatments and care plans, it is essential to comprehend the immunological mechanisms causing these difficulties. The pathogenesis of long COVID should be clarified and potential biomarkers to help with diagnosis and treatment should be sought after. To reduce the burden of long COVID on people and healthcare systems around the world, the need for long-term monitoring and management of long COVID problems should be emphasized. It also underscores the significance of a multidisciplinary approach to patient care. The goal of this review is to carefully evaluate the clinical signs and symptoms of long COVID, their underlying causes, and any potential immunological implications.

Source: Bhattacharjee N, Sarkar P, Sarkar T. Beyond the acute illness: Exploring long COVID and its impact on multiple organ systems. Physiol Int. 2023 Nov 9. doi: 10.1556/2060.2023.00256. Epub ahead of print. PMID: 37943302. https://akjournals.com/view/journals/2060/aop/article-10.1556-2060.2023.00256/article-10.1556-2060.2023.00256.xml (Full text)

From aging to long COVID: exploring the convergence of immunosenescence, inflammaging, and autoimmunity

Abstract:

The process of aging is accompanied by a dynamic restructuring of the immune response, a phenomenon known as immunosenescence. This mini-review navigates through the complex landscape of age-associated immune changes, chronic inflammation, age-related autoimmune tendencies, and their potential links with immunopathology of Long COVID. Immunosenescence serves as an introductory departure point, elucidating alterations in immune cell profiles and their functional dynamics, changes in T-cell receptor signaling, cytokine network dysregulation, and compromised regulatory T-cell function.

Subsequent scrutiny of chronic inflammation, or “inflammaging,” highlights its roles in age-related autoimmune susceptibilities and its potential as a mediator of the immune perturbations observed in Long COVID patients. The introduction of epigenetic facets further amplifies the potential interconnections.

In this compact review, we consider the dynamic interactions between immunosenescence, inflammation, and autoimmunity. We aim to explore the multifaceted relationships that link these processes and shed light on the underlying mechanisms that drive their interconnectedness. With a focus on understanding the immunological changes in the context of aging, we seek to provide insights into how immunosenescence and inflammation contribute to the emergence and progression of autoimmune disorders in the elderly and may serve as potential mediator for Long COVID disturbances.

Source: Müller L, Di Benedetto S. From aging to long COVID: exploring the convergence of immunosenescence, inflammaging, and autoimmunity. Front Immunol. 2023 Oct 24;14:1298004. doi: 10.3389/fimmu.2023.1298004. PMID: 37942323; PMCID: PMC10628127. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10628127/ (Full text)

Core outcome measurement instruments for use in clinical and research settings for adults with post-COVID-19 condition: an international Delphi consensus study

Abstract:

Post-COVID-19 condition (also known as long COVID) is a new, complex, and poorly understood disorder. A core outcome set (COS) for post-COVID-19 condition in adults has been developed and agreement is now required on the most appropriate measurement instruments for these core outcomes.

We conducted an international consensus study involving multidisciplinary experts and people with lived experience of long COVID. The study comprised a literature review to identify measurement instruments for the core outcomes, a three-round online modified Delphi process, and an online consensus meeting to generate a core outcome measurement set (COMS). 594 individuals from 58 countries participated.

The number of potential instruments for the 12 core outcomes was reduced from 319 to 19. Consensus was reached for inclusion of the modified Medical Research Council Dyspnoea Scale for respiratory outcomes. Measures for two relevant outcomes from a previously published COS for acute COVID-19 were also included: time until death, for survival, and the Recovery Scale for COVID-19, for recovery. Instruments were suggested for consideration for the remaining nine core outcomes: fatigue or exhaustion, pain, post-exertion symptoms, work or occupational and study changes, and cardiovascular, nervous system, cognitive, mental health, and physical outcomes; however, consensus was not achieved for instruments for these outcomes.

The recommended COMS and instruments for consideration provide a foundation for the evaluation of post-COVID-19 condition in adults, which should help to optimise clinical care and accelerate research worldwide. Further assessment of this COMS is warranted as new data emerge on existing and novel measurement instruments.

Source: Gorst SL, Seylanova N, Dodd SR, Harman NL, O’Hara M, Terwee CB, Williamson PR, Needham DM, Munblit D, Nicholson TR; PC-COS study group. Core outcome measurement instruments for use in clinical and research settings for adults with post-COVID-19 condition: an international Delphi consensus study. Lancet Respir Med. 2023 Nov 2:S2213-2600(23)00370-3. doi: 10.1016/S2213-2600(23)00370-3. Epub ahead of print. PMID: 37926103. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(23)00370-3/fulltext (Full text)