Long COVID from rheumatology perspective - a narrative review

Post-acute sequelae of SARS-CoV-2 mimic: An important neurological condition

BACKGROUND AND OBJECTIVES

In 2024, the sequalae of the acute phase of coronavirus disease-19 (COVID-19) infection, which include neurological symptoms and are commonly referred to as long COVID or post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC), continue to be a substantial health concern; however, similar symptoms are observed in individuals with no previous COVID-19 infection.

METHODS

This was a single-center, retrospective, descriptive case series study. Data were obtained from patients who visited our outpatient clinic specializing in PASC between June 1, 2021, and May 31, 2023. We compared antibody test results between patients with confirmed acute phase infection and those without. We compared differences in demographic and clinical characteristics between patients with positive results during the acute phase of COVID-19 infection and positive anti-SARS-CoV-2 antibody tests (true-PASC), and those with neither (PASC-mimic).

RESULTS

Of 437 patients diagnosed with PASC according to World Health Organization criteria, 222 underwent COVID-19 antibody tests. Of these, 193 patients (86.9%) had a history of confirmed acute phase infection, whereas 29 (13.1%) did not. Of the former, 186 patients (96.4%) were seropositive for anti-nucleotide SARS-CoV-2 antibodies (true-PASC), whereas 19 of the latter tested seronegative for anti-nucleotide SARS-CoV-2 antibodies (PASC-mimic). There were no significant differences in symptom characteristics between true-PASC and PASC-mimic participants.

CONCLUSIONS

It was difficult to identify any clinical features to aid in diagnosing PASC without confirmation of acute COVID-19 infection. The findings indicate the existence of a "PASC-mimic" condition that should be acknowledged and excluded in future PASC-related research studies.

Exploring the role of galectin-9 and artemin as biomarkers in long COVID with chronic fatigue syndrome: links to inflammation and cognitive function

This study aimed to assess plasma galectin-9 (Gal-9) and artemin (ARTN) concentrations as potential biomarkers to differentiate individuals with Long COVID (LC) patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) from SARS-CoV-2 recovered (R) and healthy controls (HCs). Receiver operating characteristic (ROC) curve analysis determined a cut-off value of plasma Gal-9 and ARTN to differentiate LC patients from the R group and HCs in two independent cohorts. Positive correlations were observed between elevated plasma Gal-9 levels and inflammatory markers (e.g. SAA and IP-10), as well as sCD14 and I-FABP in LC patients. Gal-9 also exhibited a positive correlation with cognitive failure scores, suggesting its potential role in cognitive impairment in LC patients with ME/CFS. This study highlights plasma Gal-9 and/or ARTN as sensitive screening biomarkers for discriminating LC patients from controls. Notably, the elevation of LPS-binding protein in LC patients, as has been observed in HIV infected individuals, suggests microbial translocation. However, despite elevated Gal-9, we found a significant decline in ARTN levels in the plasma of people living with HIV (PLWH). Our study provides a novel and important role for Gal-9/ARTN in LC pathogenesis.

Advance in the mechanism and clinical research of myalgia in long COVID

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve, mortality rates of coronavirus disease 2019 (COVID-19) have significantly decreased. However, a variable proportion of patients exhibit persistent prolonged symptoms of COVID-19 infection (long COVID). This virus primarily attacks respiratory system, but numerous individuals complain persistent skeletal muscle pain or worsening pre-existing muscle pain post COVID-19, which severely affects the quality of life and recovery. Currently, there is limited research on the skeletal muscle pain in long COVID. In this brief review, we review potential pathological mechanisms of skeletal muscle pain in long COVID, and summarize the various auxiliary examinations and treatments for skeletal muscle pain in long COVID. We consider abnormal activation of inflammatory response, myopathy, and neurological damages as pivotal pathological mechanisms of skeletal muscle pain in long COVID. A comprehensive examination is significantly important in order to work out effective treatment plans and relieve skeletal muscle pain. So far, rehabilitation interventions for myalgia in long COVID contain but are not limited to drug, nutraceutical therapy, gut microbiome-targeted therapy, interventional therapy and strength training. Our study provides a potential mechanism reference for clinical researches, highlighting the importance of comprehensive approach and management of skeletal muscle pain in long COVID. The relief of skeletal muscle pain will accelerate rehabilitation process, improve activities of daily living and enhance the quality of life, promoting individuals return to society with profound significance.

Examining the Trajectory of Health-Related Quality of Life among Coronavirus Disease Patients

BACKGROUND

Recent studies have reported a reduction in health-related quality of life (HR-QoL) among post-coronavirus disease 2019 (COVID-19) patients. However, there remains a gap in research examining the heterogeneity and determinants of HR-QoL trajectory in these patients.

OBJECTIVE

To describe and identify factors explaining the variability in HR-QoL trajectories among a cohort of patients with history of COVID-19.

DESIGN

A prospective study using data from a cohort of COVID-19 patients enrolled into a registry established at a health system in New York City.

PARTICIPANTS

Participants were enrolled from July 2020 to June 2022, and completed a baseline evaluation and two follow-up visits at 6 and 12 months.

METHODS

We assessed HR-QoL with the 29-item Patient Reported Outcomes Measurement Information System instrument, which was summarized into mental and physical health domains. We performed latent class growth and multinomial logistic regression to examine trajectories of HR-QoL and identify factors associated with specific trajectories.

RESULTS

The study included 588 individuals with a median age of 52 years, 65% female, 54% White, 18% Black, and 18% Hispanic. We identified five physical health trajectories and four mental health trajectories. Female gender, having pre-existing hypertension, cardiovascular disease, asthma, and hospitalization for acute COVID-19 were independently associated with lower physical health. In addition, patients with increasing body mass index were more likely to experience lower physical health over time. Female gender, younger age, pre-existing asthma, arthritis and cardiovascular disease were associated with poor mental health.

CONCLUSIONS

We found significant heterogeneity of HR-QoL after COVID-19, with women and patients with specific comorbidities at increased risk of lower HR-QoL. Implementation of targeted psychological and physical interventions is crucial for enhancing the quality of life of this patient population.

Addressing Post-Acute COVID-19 Syndrome in Cancer Patients, from Visceral Obesity and Myosteatosis to Systemic Inflammation: Implications in Cardio-Onco-Metabolism

Cardiovascular disease and cancer are the two leading causes of morbidity and mortality in the world. The emerging field of cardio-oncology described several shared risk factors that predispose patients to both cardiovascular disease and cancer. Post-acute COVID-19 syndrome is a chronic condition that occurs in many patients who have experienced a SARS-CoV-2 infection, mainly based on chronic fatigue, sedentary lifestyle, cramps, breathing difficulties, and reduced lung performance. Post-acute COVID-19 exposes patients to increased visceral adiposity, insulin resistance, myosteatosis, and white adipose tissue content (surrounded by M1 macrophages and characterized by a Th1/Th17 phenotype), which increases the risk of cardiovascular mortality and cancer recurrence. In this review, the main metabolic affections of post-acute COVID-19 syndrome in cancer patients at low and high risk of cardiomyopathies will be summarized. Furthermore, several non-pharmacological strategies aimed at reducing atherosclerotic and cardiac risk will be provided, especially through anti-inflammatory nutrition with a low insulin and glycemic index, appropriate physical activity, and immune-modulating bioactivities able to reduce visceral obesity and myosteatosis, improving insulin-related signaling and myocardial metabolism.

Interplay between Comorbidities and Long COVID: Challenges and Multidisciplinary Approaches

Long COVID, a name often given to the persistent symptoms following acute SARS-CoV-2 infection, poses a multifaceted challenge for health. This review explores the intrinsic relationship between comorbidities and autoimmune responses in shaping the trajectory of long COVID. Autoantibodies have emerged as significant players in COVID-19 pathophysiology, with implications for disease severity and progression. Studies show immune dysregulation persisting months after infection, marked by activated innate immune cells and high cytokine levels. The presence of autoantibodies against various autoantigens suggests their potential as comorbid factors in long COVID. Additionally, the formation of immune complexes may lead to severe disease progression, highlighting the urgency for early detection and intervention. Furthermore, long COVID is highly linked to cardiovascular complications and neurological symptoms, posing challenges in diagnosis and management. Multidisciplinary approaches, including vaccination, tailored rehabilitation, and pharmacological interventions, are used for mitigating long COVID's burden. However, numerous challenges persist, from evolving diagnostic criteria to addressing the psychosocial impact and predicting disease outcomes. Leveraging AI-based applications holds promise in enhancing patient management and improving our understanding of long COVID. As research continues to unfold, unravelling the complexities of long COVID remains paramount for effective intervention and patient care.

Exploring the Pathophysiology of Long COVID: The Central Role of Low-Grade Inflammation and Multisystem Involvement

Long COVID (LC), also referred to as Post COVID-19 Condition, Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), and other terms, represents a complex multisystem disease persisting after the acute phase of COVID-19. Characterized by a myriad of symptoms across different organ systems, LC presents significant diagnostic and management challenges. Central to the disorder is the role of low-grade inflammation, a non-classical inflammatory response that contributes to the chronicity and diversity of symptoms observed. This review explores the pathophysiological underpinnings of LC, emphasizing the importance of low-grade inflammation as a core component. By delineating the pathogenetic relationships and clinical manifestations of LC, this article highlights the necessity for an integrated approach that employs both personalized medicine and standardized protocols aimed at mitigating long-term consequences. The insights gained not only enhance our understanding of LC but also inform the development of therapeutic strategies that could be applicable to other chronic conditions with similar pathophysiological features.

Long COVID-19 Enigma: Unmasking the Role of Distinctive Personality Profiles as Risk Factors

Background: The COVID-19 (Coronavirus disease 2019) pandemic has prompted extensive research into lingering effects, especially in 'Long COVID' patients. Despite exploration, contributing factors remain elusive; Objective: This study explores the potential link between distinctive personality profiles, particularly type D personality, and an increased risk of Long COVID; Methods: A retrospective cross-sectional study at Tel-Aviv Sourasky Medical Center's Post-COVID clinic analyzed data from 373 Long COVID patients through comprehensive questionnaires covering Long COVID syndrome, Fibromyalgia criteria, personality assessments, social support, and subjective evaluations of cognitive decline, health and life quality. In total, 116 out of 373 patients completed the questionnaire, yielding a 31% participation rate; Results: Cluster analysis revealed two groups, with Cluster 1 (N = 58) exhibiting Type D personality traits while Cluster 2 (N = 56) not meeting criteria for Type D personality. In comparison to Cluster 2, Cluster 1 patients reported heightened anxiety, depression, reduced social support, increased pain symptoms, manifestations of fibromyalgia, cognitive decline, and poor sleep quality, contributing to a diminished quality-of-life perception; Conclusions: findings highlight diverse personality profiles among Long COVID patients, emphasizing the need for tailored care. This approach shows potential for improving Long COVID patient care, aligning with the evolving personalized medicine paradigm.

Multidisciplinary Management Strategies for Long COVID: A Narrative Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of infections to date and has led to a worldwide pandemic. Most patients had a complete recovery from the acute infection, however, a large number of the affected individuals experienced symptoms that persisted more than 3 months after diagnosis. These symptoms most commonly include fatigue, memory difficulties, brain fog, dyspnea, cough, and other less common ones such as headache, chest pain, paresthesias, mood changes, muscle pain, and weakness, skin rashes, and cardiac, endocrine, renal and hepatic manifestations. The treatment of this syndrome remains challenging. A multidisciplinary approach to address combinations of symptoms affecting multiple organ systems has been widely adopted. This narrative review aims to bridge the gap surrounding the broad treatment approaches by providing an overview of multidisciplinary management strategies for the most common long COVID conditions.

LC risk score - development and evaluation of a scale for assessing the risk of developing long COVID

INTRODUCTION

The aim of the study was to create a valuable practical tool for evaluating the risk of developing long COVID.

MATERIAL AND METHODS

1150 patients from the Polish STOP-COVID registry (PoLoCOV study) were used to develop the risk score. The patients were ill between 03/2020 and 04/2022. To develop a clinically useful scoring model, the LC risk score was generated using the machine learning-based framework AutoScore. Patient data were first randomised into a training (70% of output) and a test (30% of output) cohort. Due to the relatively small study group, cross-validation was used. Model predictive ability was evaluated based on the ROC curve and the AUC value. The result of the risk score for a given patient was the total value of points assigned to selected variables.

RESULTS

To create the LC risk score, eight variables were ultimately selected due to their significance and clinical value. Female gender significantly contributed to higher final outcome values, with age range 40-49, body mass index < 18.5 kg/m2, hospitalisation during active disease, arthralgia, myalgia as well as loss of taste and smell during infection, COVID-19 symptoms lasting at least 14 days, and unvaccinated status. The final predictive value of the developed LC risk score for a cut-off of 58 points was AUC = 0.630 (95% CI: 0.571-0.688) with sensitivity 39.80%, specificity 85.1%, positive predictive value 80.8%, and negative predictive value 47.3%.

CONCLUSIONS

The LC risk score may be a practical and undemanding utility that employs basic sociodemographic data, vaccination status, and symptoms during COVID-19 to assess the risk of long COVID.

The knowns and unknowns of long COVID-19: from mechanisms to therapeutical approaches

The coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has been defined as the greatest global health and socioeconomic crisis of modern times. While most people recover after being infected with the virus, a significant proportion of them continue to experience health issues weeks, months and even years after acute infection with SARS-CoV-2. This persistence of clinical symptoms in infected individuals for at least three months after the onset of the disease or the emergence of new symptoms lasting more than two months, without any other explanation and alternative diagnosis have been named long COVID, long-haul COVID, post-COVID-19 conditions, chronic COVID, or post-acute sequelae of SARS-CoV-2 (PASC). Long COVID has been characterized as a constellation of symptoms and disorders that vary widely in their manifestations. Further, the mechanisms underlying long COVID are not fully understood, which hamper efficient treatment options. This review describes predictors and the most common symptoms related to long COVID's effects on the central and peripheral nervous system and other organs and tissues. Furthermore, the transcriptional markers, molecular signaling pathways and risk factors for long COVID, such as sex, age, pre-existing condition, hospitalization during acute phase of COVID-19, vaccination, and lifestyle are presented. Finally, recommendations for patient rehabilitation and disease management, as well as alternative therapeutical approaches to long COVID sequelae are discussed. Understanding the complexity of this disease, its symptoms across multiple organ systems and overlapping pathologies and its possible mechanisms are paramount in developing diagnostic tools and treatments.

Metabolomic and immune alterations in long COVID patients with chronic fatigue syndrome

Introduction

A group of SARS-CoV-2 infected individuals present lingering symptoms, defined as long COVID (LC), that may last months or years post the onset of acute disease. A portion of LC patients have symptoms similar to myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), which results in a substantial reduction in their quality of life. A better understanding of the pathophysiology of LC, in particular, ME/CFS is urgently needed.

Methods

We identified and studied metabolites and soluble biomarkers in plasma from LC individuals mainly exhibiting ME/CFS compared to age-sex-matched recovered individuals (R) without LC, acute COVID-19 patients (A), and to SARS-CoV-2 unexposed healthy individuals (HC).

Results

Through these analyses, we identified alterations in several metabolomic pathways in LC vs other groups. Plasma metabolomics analysis showed that LC differed from the R and HC groups. Of note, the R group also exhibited a different metabolomic profile than HC. Moreover, we observed a significant elevation in the plasma pro-inflammatory biomarkers (e.g. IL-1α, IL-6, TNF-α, Flt-1, and sCD14) but the reduction in ATP in LC patients. Our results demonstrate that LC patients exhibit persistent metabolomic abnormalities 12 months after the acute COVID-19 disease. Of note, such metabolomic alterations can be observed in the R group 12 months after the acute disease. Hence, the metabolomic recovery period for infected individuals with SARS-CoV-2 might be long-lasting. In particular, we found a significant reduction in sarcosine and serine concentrations in LC patients, which was inversely correlated with depression, anxiety, and cognitive dysfunction scores.

Conclusion

Our study findings provide a comprehensive metabolomic knowledge base and other soluble biomarkers for a better understanding of the pathophysiology of LC and suggests sarcosine and serine supplementations might have potential therapeutic implications in LC patients. Finally, our study reveals that LC disproportionally affects females more than males, as evidenced by nearly 70% of our LC patients being female.

Long COVID in Persons With Self-Reported Arthritis: Symptoms, Associated Factors, and Functional Limitations

OBJECTIVE

The aim is to describe both long COVID symptoms and associated factors in a cohort of individuals with a self-reported history of arthritis as well as change in function in persons with arthritis and long COVID compared to pre-COVID status.

METHODS

Among 2,764 persons with a confirmed COVID-19 diagnosis who responded to an online survey at least 12 weeks post-infection, 171 reported a history of arthritis and formed our study sample. We calculated the frequency of long COVID defined as troubled by persistent symptoms and evaluated associated factors using bivariate analysis and multivariable logistic regression. Among those with long COVID, we describe limitations in activity and function in comparison to pre-COVID status.

RESULTS

In our sample, 53.5% (n = 91) reported being troubled by ongoing symptoms at the time of completing the questionnaire (long COVID), with the most frequent symptoms as the following: fatigue, myalgia, weakness, breathlessness, low mood, anxiety, and sleep disturbance. Factors associated with long COVID were female sex, having been hospitalized for COVID, and having at least 1 other chronic disease. Persons with long COVID had substantial declines in function, notably in global health status, usual activities, mobility, personal care, and employment status. Also, 37% of those with long COVID reported moderate to severe increase in pain.

CONCLUSION

Persons with arthritis who have long COVID have substantial limitations in function compared to their pre-COVID status. There is a need to implement effective interventions to improve functional status in persons with arthritis and long COVID.

Evolution of musculoskeletal symptoms in Long COVID syndrome: a lexical analysis to approach requirements for an interdisciplinary management

Long COVID syndrome is characterized by new, returning, or persistent symptoms after the initial SARS-CoV-2 infection. Among the potential long-term effects of COVID-19, several different musculoskeletal symptoms have been reported in many patients with an important impact on quality of life. The rehabilitation needs of Long COVID patients could be dynamic. However, to date there are no studies that have evaluated how the rehabilitation needs of patients with Long COVID syndrome have changed over time. We conducted a literature review to summarize the most recurrent manifestations of the Long COVID syndrome during the three years of the pandemic, as well as the evolution of musculoskeletal symptoms, through lexical analysis. This approach allowed us to investigate the literature, highlighting how the most used words to describe Long COVID symptoms and outcomes have changed over different periods. Our analysis showed an increasing involvement of the musculoskeletal system in Long COVID symptomatology, as evidenced by the progressive growth of fatigue and weakness symptoms over time. In addition, arthralgia has always been associated with Long COVID. The lexical analysis we conducted emphasizes the need for interdisciplinary management, as the symptoms reported are interconnected. Moreover, this novel approach highlights that the Long COVID syndrome can be interpreted as a dynamic entity requiring up-to-date rehabilitative interventions. The worldwide healthcare systems should be founded on multidisciplinary teams to guarantee early and comprehensive rehabilitation to reduce the socio-sanitary burden associated with this syndrome.

Incident autoimmune diseases in association with SARS-CoV-2 infection: a matched cohort study

OBJECTIVES

To investigate whether the risk of developing an incident autoimmune disease is increased in patients with prior COVID-19 disease compared to those without COVID-19, a large cohort study was conducted.

METHOD

A cohort was selected from German routine health care data. Based on documented diagnoses, we identified individuals with polymerase chain reaction (PCR)-confirmed COVID-19 through December 31, 2020. Patients were matched 1:3 to control patients without COVID-19. Both groups were followed up until June 30, 2021. We used the four quarters preceding the index date until the end of follow-up to analyze the onset of autoimmune diseases during the post-acute period. Incidence rates (IR) per 1000 person-years were calculated for each outcome and patient group. Poisson models were deployed to estimate the incidence rate ratios (IRRs) of developing an autoimmune disease conditional on a preceding diagnosis of COVID-19.

RESULTS

In total, 641,704 patients with COVID-19 were included. Comparing the incidence rates in the COVID-19 (IR=15.05, 95% CI: 14.69-15.42) and matched control groups (IR=10.55, 95% CI: 10.25-10.86), we found a 42.63% higher likelihood of acquiring autoimmunity for patients who had suffered from COVID-19. This estimate was similar for common autoimmune diseases, such as Hashimoto thyroiditis, rheumatoid arthritis, or Sjögren syndrome. The highest IRR was observed for autoimmune diseases of the vasculitis group. Patients with a more severe course of COVID-19 were at a greater risk for incident autoimmune disease.

CONCLUSIONS

SARS-CoV-2 infection is associated with an increased risk of developing new-onset autoimmune diseases after the acute phase of infection. Key Points • In the 3 to 15 months after acute infection, patients who had suffered from COVID-19 had a 43% (95% CI: 37-48%) higher likelihood of developing a first-onset autoimmune disease, meaning an absolute increase in incidence of 4.50 per 1000 person-years over the control group. • COVID-19 showed the strongest association with vascular autoimmune diseases.

Long COVID-19 Pathophysiology: What Do We Know So Far?

Long COVID-19 is a recognized entity that affects millions of people worldwide. Its broad clinical symptoms include thrombotic events, brain fog, myocarditis, shortness of breath, fatigue, muscle pains, and others. Due to the binding of the virus with ACE-2 receptors, expressed in many organs, it can potentially affect any system; however, it most often affects the cardiovascular, central nervous, respiratory, and immune systems. Age, high body mass index, female sex, previous hospitalization, and smoking are some of its risk factors. Despite great efforts to define its pathophysiology, gaps remain to be explained. The main mechanisms described in the literature involve viral persistence, hypercoagulopathy, immune dysregulation, autoimmunity, hyperinflammation, or a combination of these. The exact mechanisms may differ from system to system, but some share the same pathways. This review aims to describe the most prevalent pathophysiological pathways explaining this syndrome.

Epstein-Barr virus-acquired immunodeficiency in myalgic encephalomyelitis-Is it present in long COVID?

Both myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS) and long COVID (LC) are characterized by similar immunological alterations, persistence of chronic viral infection, autoimmunity, chronic inflammatory state, viral reactivation, hypocortisolism, and microclot formation. They also present with similar symptoms such as asthenia, exercise intolerance, sleep disorders, cognitive dysfunction, and neurological and gastrointestinal complaints. In addition, both pathologies present Epstein-Barr virus (EBV) reactivation, indicating the possibility of this virus being the link between both pathologies. Therefore, we propose that latency and recurrent EBV reactivation could generate an acquired immunodeficiency syndrome in three steps: first, an acquired EBV immunodeficiency develops in individuals with "weak" EBV HLA-II haplotypes, which prevents the control of latency I cells. Second, ectopic lymphoid structures with EBV latency form in different tissues (including the CNS), promoting inflammatory responses and further impairment of cell-mediated immunity. Finally, immune exhaustion occurs due to chronic exposure to viral antigens, with consolidation of the disease. In the case of LC, prior to the first step, there is the possibility of previous SARS-CoV-2 infection in individuals with "weak" HLA-II haplotypes against this virus and/or EBV.

Acute bone loss following SARS-CoV-2 infection in mice

The novel coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has infected more than 650 million people worldwide. Approximately 23% of these patients developed lasting "long-haul" COVID symptoms, including fatigue, joint pain, and systemic hyperinflammation. However, the direct clinical impact of SARS-CoV-2 infection on the skeletal system including bone and joint health has not been determined. Utilizing a humanized mouse model of COVID-19, this study provides the first direct evidence that SARS-CoV-2 infection leads to acute bone loss, increased osteoclast number, and thinner growth plates. This bone loss could decrease whole-bone mechanical strength and increase the risk of fragility fractures, particularly in older patients, while thinner growth plates may create growth disturbances in younger patients. Evaluating skeletal health in patients that have recovered from COVID-19 will be crucial to identify at-risk populations and develop effective countermeasures.

Factors Associated with Long COVID-19 in a French Multicentric Prospective Cohort Study

(1) Background: A substantial proportion of COVID-19 patients continue to experience long-lasting effects that hamper their quality of life. The objectives of this study were (1) to report the prevalence of persistent clinical symptoms 6-12 months after the onset of COVID-19 and (2) to identify potential factors at admission associated with the occurrence of long COVID. (2) Methods: A prospective study was conducted among COVID-19 adult patients, hospitalized in four French university hospitals. Patients were invited to two ambulatory follow-up medical visits, 6-8 months (visit #1) and one year (visit #2) after the onset of their COVID-19. A multivariate logistic regression was performed to assess factors associated with long COVID. (3) Results: In total, 189 patients participated in this study (mean age of 63.4 years). BMI > 30 kg/m2 (aOR 3.52), AST levels between 31 and 42 U/L (aOR 8.68), and AST levels > 42 U/L (aOR 3.69) were associated with persistent clinical symptoms at visit #1. Anosmia (aOR 13.34), AST levels between 31 and 42 U/L (aOR 10.27), stay in ICU (aOR 5.43), pain (aOR 4.31), and longer time before hospitalization (aOR 1.14) were significantly associated with persistent clinical symptoms at visit #2. Patients with ageusia (aOR 0.17) had a lower risk of long COVID. (4) Conclusions: This study showed that some patients experienced persistent clinical symptoms one year after COVID-19 onset that were associated with some determinants at the acute phase/stage.

Predictive Role of Cytokine and Adipokine Panel in Hospitalized COVID-19 Patients: Evaluation of Disease Severity, Survival and Lung Sequelae

Coronavirus disease 2019 (COVID-19) may determine a multisystemic chronic syndrome after resolution of SARS-CoV-2 infection in a significant percentage of patients. Persistent cytokine dysregulation can contribute to long-lasting inflammation and tissue damage, resulting in the diverse, often debilitating symptoms experienced by some patients (so-called long COVID syndrome). The aim of our study was to evaluate the value of a panel of serum biomarkers of severity and prognosis in patients hospitalized for COVID-19 and also as predictive factors for the development of post-COVID lung sequelae after discharge from the hospital. All blood sampling was performed in the first 24 h after admission to the hospital. Serum analyte concentrations of IL-4, IL-2, CXCL10 (IP-10), IL-1β, TNF-α, CCL2 (MCP-1), IL-17A, IL-6, IL-10, IFN-γ, IL-12p70 and TGF-β1 were quantified by bead-based multiplex LEGENDplex™ analysis and commercially available ELISA kits. A total of 108 COVID-19 patients were enrolled in the study. Comparative analysis of these proteins showed higher levels of TGF-β and IL-6 and lower levels of RBP-4 and IL-10 in the severe group. Age, adiponectin, IL-8 and IL-32 resulted as the best predictors for survival. Moreover, IL-1β, IL17A, TNF-α, TGF-β, IL-4 and IL-6 were significantly higher in patients who showed HRCT evidence of fibrotic interstitial alterations at follow-up than patients who did not. The initial inflammatory status of patients on admission to the hospital with COVID-19, as reflected by the present panel of adipose tissue-related biomarkers and cytokines, offered insights into medium-term prognosis.

Role of Janus Kinase inhibitors in the management of pulmonary involvement due to Long COVID-19 disease: A case control study

OBJECTIVES

Ongoing symptomatic coronavirus disease 2019 (OSC) is defined as persistent symptoms beyond 4 weeks of acute illness. OSC leads to prolonged hospitalization and oxygen dependence. We aimed to find the outcome of Janus kinase inhibitors (JAKi) as a steroid-sparing agent to treat OSC.

METHODS

In this single-center case-controlled study comparing JAKi and corticosteroids in OSC cases, data of 41 cases out of 86 were included - 21 in the JAKi group and 20 in the corticosteroid group from 4 weeks of acute illness to the next 4 weeks. Clinical parameters and inflammatory markers were recorded. The primary outcome was to compare the proportion of patients who were able to maintain oxygen saturation ≥95% with any oxygen supplementation in the two groups.

RESULTS

The baseline clinical and demographic characteristics were similar in the two groups. The age was 53.65 ± 9.8 years and 51.48 ± 14.0 years in the corticosteroid group and JAKi group, respectively. At the baseline, 85% of patients in the corticosteroid group and 85.8% in the JAKi group were on oxygen support. The most common symptom in both groups was breathlessness followed by cough. Twenty percent of patients in the JAKi group received baricitinib and the remaining were given tofacitinib. At the time of follow-up, the majority of cases had a significant reduction in C-reactive protein (CRP) and D-dimer; however, the change in CRP and D-dimer was similar in both groups. The number of patients off oxygen support at 4 weeks was higher in the JAKi group (85% in the corticosteroid group vs. 95.2% in the JAKi group, P = 0.269), and the median time to liberation from oxygen support was significantly lower in JAKi group (19 days in corticosteroid group vs. 9 days in JAKi group, P < 0.001). The frequency of any adverse event was also higher in the corticosteroid group (70% vs. 23.8%, P = 0.003).

CONCLUSION

JAKi can be used as immunomodulatory drugs in hypoxic OSC cases having evidence of ongoing inflammation.

Persistent immune and clotting dysfunction detected in saliva and blood plasma after COVID-19

A growing number of studies indicate that coronavirus disease 2019 (COVID-19) is associated with inflammatory sequelae, but molecular signatures governing the normal versus pathologic convalescence process have not been well-delineated. Here, we characterized global immune and proteome responses in matched plasma and saliva samples obtained from COVID-19 patients collected between 20 and 90 days after initial clinical symptoms resolved. Convalescent subjects showed robust total IgA and IgG responses and positive antibody correlations in saliva and plasma samples. Shotgun proteomics revealed persistent inflammatory patterns in convalescent samples including dysfunction of salivary innate immune cells, such as neutrophil markers (e.g., myeloperoxidase), and clotting factors in plasma (e.g., fibrinogen), with positive correlations to acute COVID-19 disease severity. Saliva samples were characterized by higher concentrations of IgA, and proteomics showed altered myeloid-derived pathways that correlated positively with SARS-CoV-2 IgA levels. Beyond plasma, our study positions saliva as a viable fluid to monitor normal and aberrant immune responses including vascular, inflammatory, and coagulation-related sequelae.

A cross-sectional study of the mental health burden among COVID-19 survivors

Introduction

Coronavirus disease 2019 (COVID-19) pandemic has had a significant impact on mental health, including stress, anxiety, and depression. This study aimed to assess the incidence and severity of mental health issues among individuals diagnosed with COVID-19 infection.

Methods

A semi-structured proforma for socio-demographic and clinical parameters was used to collect cross-sectional hospital-based data of subjects who tested positive for COVID-19 infection. The Modified Fatigue Impact Scale (MFIS), Hospital Anxiety and Depression Scale (HADS), and Perceived Stress Scale (PSS) were used to assess the presence of physical, psychological, and cognitive symptoms. The presence of anxiety, depression, and stress was based on the cut-off scores for HADS-A (≥8), HADS-D (≥8), and PSS (≥14), respectively.

Results

A total of 101 patients comprising 39 (38.6%) males were recruited. Compared to nuclear families, we observed that patients living in joint families had significantly greater severity scores for fatigue [MFIS (p = 0.04)], anxiety [HADS-A (p = 0.004)], depression [HADS-D (p = 0.004)], and stress [PSS (p = 0.02)]. Based on the cut-off scores, we found that 44 (43.6%) patient had anxiety, 41 (40.6%) had depressive, and 72 (71.3%) had moderate to high stress symptoms, respectively. We also observed significantly greater fatigue and anxiety scores, that is, MFIS (p = 0.008) and HADS-A (p = 0.03) in those who received oxygen therapy compared to those who did not. The subjects who received corticosteroids were older (p = 0.01) and had significantly higher stress scores [PSS (p < 0.001)]. The study showed that patients who were assessed more than 3 months post-COVID-19 infection had higher fatigue and depression scores; however, the difference did not reach statistical significance (MFIS P = 0.058; HADS P = 0.059).

Conclusion

Our study confirms that COVID-19 infection can cause various adverse mental health issues. Mitigating the hazardous effects of COVID-19 pandemic on mental health should be a top priority for public health to prevent long-term complications.

Therapeutics for COVID-19

Vaccines and monoclonal antibody treatments to prevent severe coronavirus disease 2019 (COVID-19) illness were available within a year of the pandemic being declared but there remained an urgent need for therapeutics to treat patients who were not vaccinated, were immunocompromised or whose vaccine immunity had waned. Initial results for investigational therapies were mixed. AT-527, a repurposed nucleoside inhibitor for hepatitis C virus, enabled viral load reduction in a hospitalized cohort but did not reduce viral load in outpatients. The nucleoside inhibitor molnupiravir prevented death but failed to prevent hospitalization. Nirmatrelvir, an inhibitor of the main protease (Mpro), co-dosed with the pharmacokinetic booster ritonavir, reduced hospitalization and death. Nirmatrelvir-ritonavir and molnupiravir received an Emergency Use Authorization in the United States at the end of 2021. Immunomodulatory drugs such as baricitinib, tocilizumab and corticosteroid, which target host-driven COVID-19 symptoms, are also in use. We highlight the development of COVID-19 therapies and the challenges that remain for anticoronavirals.

Long COVID: a review and proposed visualization of the complexity of long COVID

Post-Acute Sequelae of Severe Acute Respiratory Syndrome Coronavirus - 2 (SARS-CoV-2) infection, or Long COVID, is a prevailing second pandemic with nearly 100 million affected individuals globally and counting. We propose a visual description of the complexity of Long COVID and its pathogenesis that can be used by researchers, clinicians, and public health officials to guide the global effort toward an improved understanding of Long COVID and the eventual mechanism-based provision of care to afflicted patients. The proposed visualization or framework for Long COVID should be an evidence-based, dynamic, modular, and systems-level approach to the condition. Furthermore, with further research such a framework could establish the strength of the relationships between pre-existing conditions (or risk factors), biological mechanisms, and resulting clinical phenotypes and outcomes of Long COVID. Notwithstanding the significant contribution that disparities in access to care and social determinants of health have on outcomes and disease course of long COVID, our model focuses primarily on biological mechanisms. Accordingly, the proposed visualization sets out to guide scientific, clinical, and public health efforts to better understand and abrogate the health burden imposed by long COVID.

Post-acute sequelae of COVID-19 is characterized by diminished peripheral CD8+β7 integrin+ T cells and anti-SARS-CoV-2 IgA response

Several millions of individuals are estimated to develop post-acute sequelae SARS-CoV-2 condition (PASC) that persists for months after infection. Here we evaluate the immune response in convalescent individuals with PASC compared to convalescent asymptomatic and uninfected participants, six months following their COVID-19 diagnosis. Both convalescent asymptomatic and PASC cases are characterised by higher CD8⁺ T cell percentages, however, the proportion of blood CD8⁺ T cells expressing the mucosal homing receptor β7 is low in PASC patients. CD8 T cells show increased expression of PD-1, perforin and granzyme B in PASC, and the plasma levels of type I and type III (mucosal) interferons are elevated. The humoral response is characterized by higher levels of IgA against the N and S viral proteins, particularly in those individuals who had severe acute disease. Our results also show that consistently elevated levels of IL-6, IL-8/CXCL8 and IP-10/CXCL10 during acute disease increase the risk to develop PASC. In summary, our study indicates that PASC is defined by persisting immunological dysfunction as late as six months following SARS-CoV-2 infection, including alterations in mucosal immune parameters, redistribution of mucosal CD8⁺β7Integrin⁺ T cells and IgA, indicative of potential viral persistence and mucosal involvement in the etiopathology of PASC.

Systemic sclerosis following COVID-19 infection with recurrent corticosteroid-induced scleroderma renal crisis

Systemic sclerosis is a complex multisystem connective tissue disease resulting in fibrosis of the skin and internal organs. Exposure to corticosteroids can trigger scleroderma renal crisis, a life-threatening complication of the disease. Autoimmune disease following infection with COVID-19 is being increasingly recognised. The mechanisms of post-COVID-19 autoimmunity are likely multifactorial, involving immune dysregulation, molecular mimicry and the development of cross-reactive antibodies. There are currently only two reported cases of systemic sclerosis occurring post-COVID-19 infection.We present the case of a female patient who developed systemic sclerosis post-COVID-19 infection. Following exposure to corticosteroids, the patient developed scleroderma renal crisis complicated by thrombotic microangiopathy, seizures and acute renal failure. Despite an antibody profile not typically associated with renal crisis (anti-topoisomerase positive, anti-RNA-polymerase III negative), the patient developed recurrent renal crisis with repeated exposure to corticosteroid therapy, highlighting the risk of steroid use in all patients with systemic sclerosis.

Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID

A novel syndrome called long-haul COVID or long COVID is increasingly recognized in a significant percentage of individuals within a few months after infection with SARS-CoV-2. This disorder is characterized by a wide range of persisting, returning or even new but related symptoms that involve different tissues and organs, including respiratory, cardiac, vascular, gastrointestinal, musculo-skeletal, neurological, endocrine and systemic. Some overlapping symptomatologies exist between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Very much like with long ME/CFS, infections with herpes family viruses, immune dysregulation, and the persistence of inflammation have been reported as the most common pattern for the development of long COVID. This review describes several factors and determinants of long COVID that have been proposed, elaborating mainly on viral persistence, reactivation of latent viruses such as Epstein-Barr virus and human herpesvirus 6 which are also associated with the pathology of ME/CFS, viral superantigen activation of the immune system, disturbance in the gut microbiome, and multiple tissue damage and autoimmunity. Based on these factors, we propose diagnostic strategies such as the measurement of IgG and IgM antibodies against SARS-CoV-2, EBV, HHV-6, viral superantigens, gut microbiota, and biomarkers of autoimmunity to better understand and manage this multi-factorial disorder that continues to affect millions of people in the world.

Musculoskeletal complications in long COVID-19: A systematic review

BACKGROUND

Coronavirus disease 2019 (COVID-19) has crippled humanity since early 2020. Various sequelae of COVID-19 have been reported in different body systems. Musculoskeletal symptoms are widely reported during COVID-19 infection, but musculoskeletal complications in long COVID-19 are underreported. However, post-COVID-19 survivors have reported complaints of persisting or new-onset fatigue, myalgia, arthralgia, arthritis, muscle weakness, etc in clinical practice. The well-known detrimental effects of steroids on the musculoskeletal system coupled with their over-the-counter availability can also be anticipated since they were the cornerstone of life-saving management in this pandemic.

AIM

To determine the musculoskeletal complications in long COVID.

METHODS

We performed a systematic review of 'systematic reviews and meta-analyses'.

RESULTS

Of the 63 articles screened, 24 articles were included. Two articles specifically discussed children and adolescents. One article discussed rehabilitation intervention. No article addressed rehabilitation of musculoskeletal issues in long COVID-19 in particular. Fatigue was the most common musculoskeletal complication.

CONCLUSION

Fatigue is found to be very common along with myalgia and arthralgia. There were no studies on rehabilitation intervention in musculoskeletal complications specifically. Considering the lacuna in literature and the needs of the current situation, further studies are warranted to standardize effective rehabilitation interventions in musculoskeletal complications. More homogenous studies are needed. Studies on functional impairment due to musculoskeletal involvement are essential.

Long COVID and rheumatology: Clinical, diagnostic, and therapeutic implications

As of this writing, it is estimated that there have been nearly 600 million cases of coronavirus disease 2019 (COVID-19) around the world with over six million deaths. While shocking, these figures do not fully illustrate the morbidity associated with this disease. It is also estimated that between 10% and 30% of those who survive COVID-19 develop persistent symptoms after the acute infection has passed. These individuals, who most often experienced initial infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) considered mild to moderate in severity, often display a broad array of symptoms. Collectively, this disorder or syndrome is now referred to as Long COVID (among other designations), and it represents a national/international health crisis. The most frequently reported symptoms associated with Long COVID include chronic fatigue with post exertional features, neurocognitive dysfunction, breathlessness, and somatic pain. Long COVID can range in severity from mild to severely debilitating, with resultant loss of quality of life and productivity. For now, there are many unanswered questions surrounding Long COVID: how can it be best defined, what is needed for accurate diagnosis, what is causing it, and how should it be best managed. How rheumatologists will engage in the Long COVID pandemic is another question; at the minimum, we will be called upon to evaluate and manage our own patients with immune-mediated inflammatory diseases who have developed it. This review focuses on addressing the disease essentials, providing both declarative and procedural knowledge to prepare rheumatologists for how to address Long COVID: understanding its origins, its current case definitions, epidemiology, pathobiology and clinical manifestations. Finally, it will provide an outline on how to clinically approach patients with possible Long COVID and initiate treatment and/or guide them on how to best manage it.

Low perforin expression in CD8+ T lymphocytes during the acute phase of severe SARS-CoV-2 infection predicts long COVID

T cell cytotoxicity plays a major role in antiviral immunity. Anti-SARS-CoV-2 immunity may determine acute disease severity, but also the potential persistence of symptoms (long COVID). We therefore measured the expression of perforin, a cytotoxic mediator, in T cells of patients recently hospitalized for SARS-CoV-2 infection. We recruited 54 volunteers confirmed as being SARS-CoV-2-infected by RT-PCR and admitted to Intensive Care Units (ICUs) or non-ICU, and 29 age- and sex-matched healthy controls (HCs). Amounts of intracellular perforin and granzyme-B, as well as cell surface expression of the degranulation marker CD107A were determined by flow cytometry. The levels of 15 cytokines in plasma were measured by Luminex. The frequency of perforin-positive T4 cells and T8 cells was higher in patients than in HCs (9.9 ± 10.1% versus 4.6 ± 6.4%, p = 0.006 and 46.7 ± 20.6% vs 33.3 ± 18.8%, p = 0.004, respectively). Perforin expression was neither correlated with clinical and biological markers of disease severity nor predictive of death. By contrast, the percentage of perforin-positive T8 cells in the acute phase of the disease predicted the onset of long COVID one year later. A low T8 cytotoxicity in the first days of SARS-CoV-2 infection might favor virus replication and persistence, autoimmunity, and/or reactivation of other viruses such as Epstein-Barr virus or cytomegalovirus, paving the way for long COVID. Under this hypothesis, boosting T cell cytotoxicity during the acute phase of the infection could prevent delayed sequelae.

Herpesvirus infections and post-COVID-19 manifestations: a pilot observational study

The global spread of SARS-CoV-2 points to unrivaled mutational variation of the virus, contributing to a variety of post-COVID sequelae in immunocompromised subjects and high mortality. Numerous studies have reported the reactivation of "sluggish" herpes virus infections in COVID-19, which exaggerate the course of the disease and complicate with lasting post-COVID manifestations CMV, EBV, HHV6). This study aimed to describe clinical and laboratory features of post-COVID manifestations accompanied by the reactivation of herpes virus infections (CMV, EBV, HHV6). 88 patients were recruited for this study, including subjects with reactivation of herpes viruses, 68 (72.3%) (main group) and 20 (27.7%) subjects without detectable DNA of herpesviruses (control group): 46 (52.3%) female and 42 (47.7%) male; median age was 41.4 ± 6.7 years. Patients with post-COVID manifestations presented with reactivation of EBV in 42.6%, HHV6 in 25.0%, and EBV plus HHV6 in 32.4%. Compared with controls, patients with herpes virus infections presented with more frequent slight fever temperature, headache, psycho-neurological disorders, pulmonary abnormalities and myalgia (p < 0.01), activation of liver enzymes, elevated CRP and D-dimer, and suppressed cellular immune response (p ≤ 0.05). Preliminary results indicate a likely involvement of reactivated herpes virus infections, primarily EBV infections in severe COVID-19 and the formation of the post-COVID syndrome. Patients with the post-COVID syndrome and reactivation of EBV and HHV6 infections are at high risk of developing various pathologies, including rheumatologic diseases.

The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications

Ischaemia-reperfusion (I-R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I-R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.

Rheumatoid arthritis and post-COVID-19 syndrome

In the third year of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2, COVID-19) pandemic doctors are encountering a new pathology – post-COVID-19 syndrome (PCS, long covid). Musculoskeletal manifestations are among the most common and may present as myalgia, arthralgia, or arthritis. Currently, there is no generally accepted definition of the disease, its duration, classification, or diagnostic criteria, and no single view on the “content” of musculoskeletal manifestations of PCS. We have enough descriptions of the debut of rheumatoid arthritis (RA) after SARS-CoV-2. That is a question: it is a coincidence, or COVID-19 may be a trigger factor of RA? We thought that SARS-CoV-2 infection may be a trigger factor for new rheumatic musculoskeletal diseases, including rheumatoid arthritis or COVID-19 can unmask previously undetected RA. The occurrence of arthritis may be a sign of PCS with transient character. So arthritis in the post covid period may induce problems in differential diagnosis of rheumatic diseases. 

Rheumatoid arthritis and post-COVID-19 syndrome

In the third year of the SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2, COVID-19) pandemic doctors are encountering a new pathology – post-COVID-19 syndrome (PCS, long covid). Musculoskeletal manifestations are among the most common and may present as myalgia, arthralgia, or arthritis. Currently, there is no generally accepted definition of the disease, its duration, classification, or diagnostic criteria, and no single view on the “content” of musculoskeletal manifestations of PCS. We have enough descriptions of the debut of rheumatoid arthritis (RA) after SARS-CoV-2. That is a question: it is a coincidence, or COVID-19 may be a trigger factor of RA? We thought that SARS-CoV-2 infection may be a trigger factor for new rheumatic musculoskeletal diseases, including rheumatoid arthritis or COVID-19 can unmask previously undetected RA. The occurrence of arthritis may be a sign of PCS with transient character. So arthritis in the post covid period may induce problems in differential diagnosis of rheumatic diseases. 

Neurological Sequelae of COVID-19

BACKGROUND

Though primarily a pulmonary disease, Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus can generate devastating disease states that affect multiple organ systems including the central nervous system (CNS). The various neurological disorders associated with COVID-19 range in severity from mild symptoms such as headache, or myalgias to more severe symptoms such as stroke, psychosis, and anosmia. While some of the COVID-19 associated neurological complications are mild and reversible, a significant number of patients suffer from stroke. Studies have shown that COVID-19 infection triggers a wave of inflammatory cytokines that induce endothelial cell dysfunction and generate coagulopathy that increases the risk of stroke or thromboses. Inflammation of the endothelium following infection may also destabilize atherosclerotic plaque and induce thrombotic stroke. Although uncommon, there have also been reports of hemorrhagic stroke associated with COVID-19. The proposed mechanisms include a blood pressure increase caused by infection leading to a reduction in angiotensin converting enzyme-2 (ACE-2) levels that results in an imbalance of the renin-angiotensin system ultimately manifesting inflammation and vasoconstriction. Coagulopathy, as demonstrated by elevated prothrombin time (PT), has also been posited as a factor contributing to hemorrhagics stroke in patients with COVID-19. Other neurological conditions associated with COVID-19 include encephalopathy, anosmia, encephalitis, psychosis, brain fog, headache, depression, and anxiety. Though there are several hypotheses reported in the literature, a unifying pathophysiological mechanism of many of these disorders remains unclear. Pulmonary dysfunction leading to poor oxygenation of the brain may explain encephalopathy and other disorders in COVID-19 patients. Alternatively, a direct invasion of the CNS by the virus or breach of the blood-brain barrier by the systemic cytokines released during infection may be responsible for these conditions. Notwithstanding, the relationship between the inflammatory cytokine levels and conditions such as depression and anxiety is contradictory and perhaps the social isolation during the pandemic may in part be a contributing factor to some of the reported CNS disorders.

OBJECTIVE

In this article, we review the current literature pertaining to some of the most significant and common neurological disorders such as ischemic and hemorrhagic stroke, encephalopathy, encephalitis, brain fog, Long COVID, headache, Guillain-Barre syndrome, depression, anxiety, and sleep disorders in the setting of COVID-19. We summarize some of the most relevant literature to provide a better understanding of the mechanistic details regarding these disorders in order to help physicians monitor and treat patients for significant COVID-19 associated neurologic impairments.

METHODS

A literature review was carried out by the authors using PubMed with the search terms "COVID-19" and "Neurology", "Neurological Manifestations", "Neuropsychiatric Manifestations", "Stroke", "Encephalopathy", "Headache", "Guillain-Barre syndrome", "Depression", "Anxiety", "Encephalitis", "Seizure", "Spasm", and "ICUAW". Another search was carried out for "Long-COVID" and "Post-Acute COVID-19" and "Neurological Manifestations" or "Neuropsychiatric Manifestations". Articles such as case reports, case series, and cohort studies were included as references. No language restrictions were enforced. In the case of anxiety and depression, attempts were made to focus mainly on articles describing these conditions in infected patients.

RESULTS

A total of 112 articles were reviewed. The incidence, clinical outcomes, and pathophysiology of selected neurological disorders are discussed below. Given the recent advent of this disease, the incidence of certain neurologic sequelae was not always available. Putative mechanisms for each condition in the setting of COVID-19 are outlined.

NETosis and Neutrophil Extracellular Traps in COVID-19: Immunothrombosis and Beyond

Infection with SARS-CoV-2, the causative agent of the Coronavirus disease 2019 (COVID-19) pandemic, causes respiratory problems and multifaceted organ dysfunction. A crucial mechanism of COVID-19 immunopathy is the recruitment and activation of neutrophils at the infection site, which also predicts disease severity and poor outcomes. The release of neutrophil extracellular traps (NETs), occurring during a regulated form of neutrophil cell death known as NETosis, is a key effector function that mediates harmful effects caused by neutrophils. Abundant NETosis and NET generation have been observed in the neutrophils of many COVID-19 patients, leading to unfavorable coagulopathy and immunothrombosis. Moreover, excessive NETosis and NET generation are now more widely recognized as mediators of additional pathophysiological abnormalities following SARS-CoV-2 infection. In this minireview, we introduce subtypes of NET-producing neutrophils (e.g., low-density granulocytes) and explain the biological importance of NETs and the protein cargos of NETs in COVID-19. In addition, we discuss the mechanisms by which SARS-CoV-2 causes NETosis by upregulating viral processes (e.g., viral entry and replication) as well as host pro-NET mechanisms (e.g., proinflammatory mediator release, platelet activation, and autoantibody production). Furthermore, we provide an update of the main findings of NETosis and NETs in immunothrombosis and other COVID-19-related disorders, such as aberrant immunity, neurological disorders, and post COVID-19 syndromes including lung fibrosis, neurological disorder, tumor progression, and deteriorated chronic illness. Finally, we address potential prospective COVID-19 treatment strategies that target dysregulated NETosis and NET formation via inhibition of NETosis and promotion of NET degradation, respectively.

VIEW OF THE PATHOGENETIC MECHANISMS OF JOINT DAMAGE IN CORONAVIRUS DISEASE 2019

The Сoronavirus disease 2019 (COVID-19) pandemic has had an extremely serious impact on the livelihoods of people worldwide. Despite the mainly respiratory manifestations of SARS-CoV-2 infection, its consequences can affect the functioning of most systems of organism, including the musculoskeletal, dysfunction of which is a leading factor in disability of the population. Diseases of the joints are one of the most common pathologie of modernity, which in the last decade are increasingly found in young people and even children. The musculoskeletal symptoms can be observed as isolated clinical signs and expressed regardless of the severity of the viral disease. Chronic fatigue, myalgia, swelling and joint pain may occur during the acute phase of COVID-19 and as short-term or long-term complications, but their prevalence has not been systematically studied. Considering the wide range of clinical manifestations of SARS-CoV-2 infection and the complexity of their pathogenesis, the mechanisms underlying lesions of musculoskeletal system and rheumatological complications remain unclear. Today, the main research in this direction is focused mainly on a complete understanding of the regulatory pathways of immune dysregulation and inflammation. Excessive secretion of pro-inflammatory cytokines, disruption of signal transduction and immune response are the result of the severe impact of SARS-CoV-2 infection on most organs, including joints, as well as the use of corticosteroids for the treatment of patients with COVID-19. The presented review highlights generalized information on the main pathophysiological processes that can occur in the joints as a manifestation of the impact of SARS-CoV-2 infection, and possible key mechanisms which contribute to the progression of pathological changes.