A Short Corticosteroid Course Reduces Symptoms and Immunological Alterations Underlying Long-COVID

Peripheral Blood Mononuclear Cells and Serum Cytokines in Patients with Lupus Nephritis after COVID-19

Systemic lupus erythematosus (SLE) patients have an increased risk of infections and infection-related mortality. Therefore, during the global SARS-CoV-2 pandemic, SLE patients were particularly vulnerable to SARS-CoV-2 infections. Also, compared to other patients, SLE patients seem to develop more severe manifestations of coronavirus disease 2019 (COVID-19), with higher rates of hospitalization, invasive ventilation requirements, or death. This study evaluated the immune parameters after SARS-CoV-2 infection in SLE patients. We analyzed subpopulations of peripheral blood cells collected from patients with renal manifestation of SLE (lupus nephritis, LN). LN patients were divided into two subgroups: those unexposed to SARS-CoV-2 (LN CoV-2(-)) and those who had confirmed COVID-19 (LN-CoV-2(+)) six months earlier. We analyzed basic subpopulations of T cells, B cells, monocytes, dendritic cells (DCs), and serum cytokines using flow cytometry. All collected data were compared to a healthy control group without SARS-CoV-2 infection in medical history. LN patients were characterized by a decreased percentage of helper T (Th) cells and an increased percentage of cytotoxic T (Tc) cells regardless of SARS-CoV-2 infection. LN CoV-2(+) patients had a higher percentage of regulatory T cells (Tregs) and plasmablasts (PBs) and a lower percentage of non-switched memory (NSM) B cells compared to LN CoV-2(-) patients or healthy controls (HC CoV-2(-)). LN patients had a higher percentage of total monocytes compared with HC CoV-2(-). LN CoV-2(+) patients had a higher percentage of classical and intermediate monocytes than LN CoV-2(-) patients and HC CoV-2(-). LN CoV-2(+) patients had higher serum IL-6 levels than HC CoV-2(-), while LN CoV-2(-) patients had higher levels of serum IL-10. LN patients are characterized by disturbances in the blood's basic immunological parameters. However, SARS-CoV-2 infection influences B-cell and monocyte compartments.

Premature Ovarian Insufficiency After Coronavirus Disease 2019 (COVID-19): Autoimmune Follicle-Stimulating Hormone (FSH) and FSH Receptor Blockade

BACKGROUND

Since the onset of the coronavirus disease (COVID-19) pandemic, a variety of long-COVID-19 symptoms and autoimmune complications have been recognized.

CASES

We report three cases of autoimmune premature poor ovarian response in patients aged 30-37 years after mild to asymptomatic COVID-19 before vaccination, with nucleotide antibody confirmation. Two patients failed to respond to maximum-dose gonadotropins for more than 4 weeks, despite a recent history of response before having COVID-19. After a month of prednisone 30 mg, these two patients had normal follicle-stimulating hormone (FSH) levels, high oocyte yield, and blastocyst formation in successful in vitro fertilization cycles. All three patients have above-average anti-müllerian hormone levels that persisted throughout their clinical ovarian insufficiency. Two patients had elevated FSH levels, perhaps resulting from FSH receptor blockade. One patient, with a history of high response to gonadotropins 75 international units per day and below-normal FSH levels, had no ovarian response to more than a month of gonadotropins (525 international units daily), suggesting autoimmune block of the FSH glycoprotein and possible FSH receptor blockade.

CONCLUSION

Auto-antibody production in response to COVID-19 before vaccination may be a rare cause of autoimmune poor ovarian response. Although vaccination is likely protective, further study will be required to evaluate the effect of vaccination and duration of autoimmune FSH or FSH receptor blockade.

Global respiratory health priorities at the beginning of the 21st century

Respiratory health has become a prevailing priority amid the diverse global health challenges that the 21st century brings, due to its substantial impact on individuals and communities on a global scale. Due to rapid advances in medicine, emerging knowledge gaps appear along with new challenges and ethical considerations. While breakthroughs in medical science can bring about encouraging possibilities for better treatments and interventions, they also lead to unanswered questions and areas where further research is warranted. A PubMed search on the topic "global respiratory health priorities" between the years 2000 and 2023 was conducted, which returned 236 articles. Of these, 55 were relevant and selected for inclusion in this article. The selection process took into account literature reviews, opinions from expert groups and careful analysis of existing gaps and challenges within the field; our selection encompasses specific infectious and noninfectious respiratory conditions in both adults and children. The global respiratory health priorities identified were selected on the basis that they have been recognised as critical areas of investigation and potential advancement and they span across clinical, translational, epidemiological and population health domains. Implementing these priorities will require a commitment to fostering collaboration and knowledge-sharing among experts in different fields with the ultimate aim to improve respiratory health outcomes for individuals and communities alike.

Substantial health and economic burden of COVID-19 during the year after acute illness among US adults not at high risk of severe COVID-19

BACKGROUND

Patients recovering from SARS-CoV-2 infection and acute COVID-19 illness can experience a range of long-term post-acute effects. The potential clinical and economic burden of these outcomes in the USA is unclear. We evaluated diagnoses, medications, healthcare utilization, and medical costs before and after acute COVID-19 illness in US patients who were not at high risk of severe COVID-19.

METHODS

This study included eligible adults who were diagnosed with COVID-19 from April 1 to May 31, 2020, who were 18 - 64 years of age, and enrolled within Optum's de-identified Clinformatics® Data Mart Database for 12 months before and 13 months after COVID-19 diagnosis. Patients with any condition or risk factor placing them at high risk of progression to severe COVID-19 were excluded. Percentages of diagnoses, medications, healthcare utilization, and costs were calculated during baseline (12 months preceding diagnosis) and the post-acute phase (12 months after the 30-day acute phase of COVID-19). Data were stratified into 3 cohorts according to disposition during acute COVID-19 illness (i.e., not hospitalized, hospitalized without intensive care unit [ICU] admission, or admitted to the ICU).

RESULTS

The study included 3792 patients; 56.5% of patients were men, 44% were White, and 94% did not require hospitalization. Compared with baseline, patients during the post-acute phase had percentage increases in the diagnosis of the following disorders: blood (166%), endocrine and metabolic (123%), nervous system (115%), digestive system (76%), and mental and behavioral (75%), along with increases in related prescriptions. Substantial increases in all measures of healthcare utilization were observed among all 3 cohorts. Total medical costs increased by 178% during the post-acute phase. Those who were hospitalized with or without ICU admission during the acute phase had the greatest increases in comorbidities and healthcare resource utilization. However, the burden was apparent across all cohorts.

CONCLUSIONS

As evidenced by resource use in the post-acute phase, COVID-19 places a significant long-term clinical and economic burden among US individuals, even among patients whose acute infection did not merit hospitalization.

Feasibility, safety and effectiveness of prednisolone and vitamin B1, B6, and B12 in patients with post-COVID-19-syndrome (PreVitaCOV) - protocol of a randomised, double-blind, placebo-controlled multicentre trial in primary care (phase IIIb)

BACKGROUND

After infection with SARS-CoV-2 a relevant proportion of patients complains about persisting symptoms, a condition termed Post-COVID-19-syndrome (PC19S). So far, possible treatments are under investigation. Among others, neurotropic vitamins and anti-inflammatory substances are potential options. Thus, the PreVitaCOV trial aims to assess feasibility, safety, and effectiveness of treating patients in primary care with prednisolone and/or vitamin B1, B6 and B12.

METHODS

The phase IIIb, multi-centre randomised, double-blind, and placebo-controlled PreVitaCOV trial has a factorial design and is planned as a two-phase approach. The pilot phase assessed feasibility and safety and was transformed into a confirmatory phase to evaluate effectiveness since feasibility was proven. Adult patients with PC19S after a documented SARS-CoV-2 infection at least 12 weeks ago are randomly assigned to 4 parallel treatments: prednisolone 20 mg for five days followed by 5 mg for 23 days (trial drug 1), B vitamins (B1 (100 mg OD), B6 (50 mg OD), and B12 (500 µg OD)) for 28 days (trial drug 2), trial drugs 1 and 2, or placebo. The primary outcome of the pilot phase was defined as the retention rate of the first 100 patients. Values of ≥ 85% were considered as confirmation of feasibility, this criterion was even surpassed by a retention rate of 98%. After transformation, the confirmatory phase proceeds by enrolling 240 additional patients. The primary outcome for the study is the change of symptom severity from baseline to day 28 as assessed by a tailored Patient Reported Outcomes Measurement Information System (PROMIS) total score referring to five symptom domains known to be typical for PC19S (fatigue, dyspnoea, cognition, anxiety, depression). The confirmatory trial is considered positive if superiority of any treatment is demonstrated over placebo operationalised by an improvement of at least 3 points on the PROMIS total score (t-score).

DISCUSSION

The PreVitaCOV trial may contribute to the understanding of therapeutic approaches in PC19S in a primary care context.

TRIAL REGISTRATION

EudraCT: 2022-001041-20. DRKS: DRKS00029617.

CLINICALTRIALS

gov: F001AM02222_1 (registered: 05 Dec 2022).

Correlations of Long COVID Symptoms and Inflammatory Markers of Complete Blood Count (CBC): A Cross-sectional Study

Background

Long-COVID refers to lasting unspecific symptoms like fatigue, decreased concentration and sleep issues after infection which persist for at least three months and cannot be attributed to other causes. Previous studies surveyed the association between inflammatory markers like C - reactive protein (CRP) at hospital admission and long-COVID symptoms in the preceding months. Post-COVID syndrome can affect one-third of patients. Thus early diagnosis can assist in reducing burdens on public health. We attempted to see any correlations between complete blood count (CBC) markers (like red blood cell (RBC), white blood cell (WBC), Neutrophil to lymphocyte ratio (NLR), etc.) at hospital admission and long COVID symptoms at a 6-month follow-up.

Methods

167 patients (44.9% females, mean age 49 years old) answered semi-structural interviews through telemedicine which focused on the three prominent symptoms: fatigue, loss of concentration and decreased libido. Results: Two third of patients have symptoms of long COVID and others do not have. NLR in the symptomatic group was statically higher. Patients who underwent decreased libido at a 6-month follow-up had significantly more severe lymphopenia (p = 0.028) and higher NLR values (p-value = 0.007). Poor mental concentration is associated with high WBC in numbers and polymorphonuclear (PMN) count. Other symptoms do not correlate with blood markers.

Conclusion

Utilizing available data like CBC can help predict the upcoming symptoms of previously hospitalized patients and further measures like rehabilitation. Additional investigations should be done on the effect of COVID vaccination on converting long COVID. Different variants of the virus may have different results.

Cardiorespiratory dysautonomia in post-COVID-19 condition: Manifestations, mechanisms and management

A significant proportion of COVID-19 patients experience debilitating symptoms for months after the acute infection. According to recent estimates, approximately 1 out of 10 COVID-19 convalescents reports persistent health issues more than 3 months after initial recovery. This 'post-COVID-19 condition' may include a large variety of symptoms from almost all domains and organs, and for some patients it may mean prolonged sick-leave, homestay and strongly limited activities of daily life. In this narrative review, we focus on the symptoms and signs of post-COVID-19 condition in adults - particularly those associated with cardiovascular and respiratory systems, such as postural orthostatic tachycardia syndrome or airway disorders - and explore the evidence for chronic autonomic dysfunction as a potential underlying mechanism. The most plausible hypotheses regarding cellular and molecular mechanisms behind the wide spectrum of observed symptoms - such as lingering viruses, persistent inflammation, impairment in oxygen sensing systems and circulating antibodies directed to blood pressure regulatory components - are discussed. In addition, an overview of currently available pharmacological and non-pharmacological treatment options is presented.

Predictive models of long COVID

BACKGROUND

The cause and symptoms of long COVID are poorly understood. It is challenging to predict whether a given COVID-19 patient will develop long COVID in the future.

METHODS

We used electronic health record (EHR) data from the National COVID Cohort Collaborative to predict the incidence of long COVID. We trained two machine learning (ML) models - logistic regression (LR) and random forest (RF). Features used to train predictors included symptoms and drugs ordered during acute infection, measures of COVID-19 treatment, pre-COVID comorbidities, and demographic information. We assigned the 'long COVID' label to patients diagnosed with the U09.9 ICD10-CM code. The cohorts included patients with (a) EHRs reported from data partners using U09.9 ICD10-CM code and (b) at least one EHR in each feature category. We analysed three cohorts: all patients (n = 2,190,579; diagnosed with long COVID = 17,036), inpatients (149,319; 3,295), and outpatients (2,041,260; 13,741).

FINDINGS

LR and RF models yielded median AUROC of 0.76 and 0.75, respectively. Ablation study revealed that drugs had the highest influence on the prediction task. The SHAP method identified age, gender, cough, fatigue, albuterol, obesity, diabetes, and chronic lung disease as explanatory features. Models trained on data from one N3C partner and tested on data from the other partners had average AUROC of 0.75.

INTERPRETATION

ML-based classification using EHR information from the acute infection period is effective in predicting long COVID. SHAP methods identified important features for prediction. Cross-site analysis demonstrated the generalizability of the proposed methodology.

FUNDING

NCATS U24 TR002306, NCATS UL1 TR003015, Axle Informatics Subcontract: NCATS-P00438-B, NIH/NIDDK/OD, PSR2015-1720GVALE_01, G43C22001320007, and Director, Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy Contract No. DE-AC02-05CH11231.

Molecular mimicry and autoimmunity in the time of COVID-19

Infectious diseases are commonly implicated as potential initiators of autoimmune diseases (ADs) and represent the most commonly known factor in the development of autoimmunity in susceptible individuals. Epidemiological data and animal studies on multiple ADs suggest that molecular mimicry is one of the likely mechanisms for the loss of peripheral tolerance and the development of clinical disease. Besides molecular mimicry, other mechanisms such as defects in central tolerance, nonspecific bystander activation, epitope-determinant spreading, and/or constant antigenic stimuli, may also contribute for breach of tolerance and to the development of ADs. Linear peptide homology is not the only mechanism by which molecular mimicry is established. Peptide modeling (i.e., 3D structure), molecular docking analyses, and affinity estimation for HLAs are emerging as critical strategies when studying the links of molecular mimicry in the development of autoimmunity. In the current pandemic, several reports have confirmed an influence of SARS-CoV-2 on subsequent autoimmunity. Bioinformatic and experimental evidence support the potential role of molecular mimicry. Peptide dimensional analysis requires more research and will be increasingly important for designing and distributing vaccines and better understanding the role of environmental factors related to autoimmunity.

Long COVID, the Brain, Nerves, and Cognitive Function

SARS-CoV-2, a single-stranded RNA coronavirus, causes an illness known as coronavirus disease 2019 (COVID-19). Long-term complications are an increasing issue in patients who have been infected with COVID-19 and may be a result of viral-associated systemic and central nervous system inflammation or may arise from a virus-induced hypercoagulable state. COVID-19 may incite changes in brain function with a wide range of lingering symptoms. Patients often experience fatigue and may note brain fog, sensorimotor symptoms, and sleep disturbances. Prolonged neurological and neuropsychiatric symptoms are prevalent and can interfere substantially in everyday life, leading to a massive public health concern. The mechanistic pathways by which SARS-CoV-2 infection causes neurological sequelae are an important subject of ongoing research. Inflammation- induced blood-brain barrier permeability or viral neuro-invasion and direct nerve damage may be involved. Though the mechanisms are uncertain, the resulting symptoms have been documented from numerous patient reports and studies. This review examines the constellation and spectrum of nervous system symptoms seen in long COVID and incorporates information on the prevalence of these symptoms, contributing factors, and typical course. Although treatment options are generally lacking, potential therapeutic approaches for alleviating symptoms and improving quality of life are explored.

Experimental drugs in randomized controlled trials for long-COVID: what's in the pipeline? A systematic and critical review

INTRODUCTION

Over three years have passed since the emergence of coronavirus disease 2019 (COVID-19), and yet the treatment for long-COVID, a post-COVID-19 syndrome, remains long overdue. Currently, there is no standardized treatment available for long-COVID, primarily due to the lack of funding for post-acute infection syndromes (PAIS). Nevertheless, the past few years have seen a renewed interest in long-COVID research, with billions of dollars allocated for this purpose. As a result, multiple randomized controlled trials (RCTs) have been funded in the quest to find an effective treatment for long-COVID.

AREAS COVERED

This systematic review identified and evaluated the potential of current drug treatments for long-COVID, examining both completed and ongoing RCTs.

EXPERT OPINION

We identified four completed and 22 ongoing RCTs, investigating 22 unique drugs. However, most drugs were deemed to not have high potential for treating long-COVID, according to three pre-specified domains, a testament to the ordeal of treating long-COVID. Given that long-COVID is highly multifaceted with several proposed subtypes, treatments likely need to be tailored accordingly. Currently, rintatolimod appears to have modest to high potential for treating the myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) subtype, LTY-100 and Treamid for pulmonary fibrosis subtype, and metformin for general long-COVID prevention.

Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges

Long COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far it has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including viral persistence; a chronic, low-grade inflammatory response; immune dysregulation and a defective immune response; the reactivation of latent viruses; autoimmunity; persistent endothelial dysfunction and coagulopathy; gut dysbiosis; hormonal and metabolic dysregulation; mitochondrial dysfunction; and autonomic nervous system dysfunction. There are no specific tests for the diagnosis of LC, and clinical features including laboratory findings and biomarkers may not specifically relate to LC. Therefore, it is of paramount importance to develop and validate biomarkers that can be employed for the prediction, diagnosis and prognosis of LC and its therapeutic response, although this effort may be hampered by challenges pertaining to the non-specific nature of the majority of clinical manifestations in the LC spectrum, small sample sizes of relevant studies and other methodological issues. Promising candidate biomarkers that are found in some patients are markers of systemic inflammation, including acute phase proteins, cytokines and chemokines; biomarkers reflecting SARS-CoV-2 persistence, the reactivation of herpesviruses and immune dysregulation; biomarkers of endotheliopathy, coagulation and fibrinolysis; microbiota alterations; diverse proteins and metabolites; hormonal and metabolic biomarkers; and cerebrospinal fluid biomarkers. At present, there are only two reviews summarizing relevant biomarkers; however, they do not cover the entire umbrella of current biomarkers, their link to etiopathogenetic mechanisms or the diagnostic work-up in a comprehensive manner. Herein, we aim to appraise and synopsize the available evidence on the typical laboratory manifestations and candidate biomarkers of LC, their classification based on pathogenetic mechanisms and the main LC symptomatology in the frame of the epidemiological and clinical aspects of the syndrome and furthermore assess limitations and challenges as well as potential implications in candidate therapeutic interventions.

Fighting Post-COVID and ME/CFS - development of curative therapies

The sequela of COVID-19 include a broad spectrum of symptoms that fall under the umbrella term post-COVID-19 condition or syndrome (PCS). Immune dysregulation, autoimmunity, endothelial dysfunction, viral persistence, and viral reactivation have been identified as potential mechanisms. However, there is heterogeneity in expression of biomarkers, and it is unknown yet whether these distinguish different clinical subgroups of PCS. There is an overlap of symptoms and pathomechanisms of PCS with postinfectious myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). No curative therapies are available for ME/CFS or PCS. The mechanisms identified so far provide targets for therapeutic interventions. To accelerate the development of therapies, we propose evaluating drugs targeting different mechanisms in clinical trial networks using harmonized diagnostic and outcome criteria and subgrouping patients based on a thorough clinical profiling including a comprehensive diagnostic and biomarker phenotyping.

A review of cytokine-based pathophysiology of Long COVID symptoms

The Long COVID/Post Acute Sequelae of COVID-19 (PASC) group includes patients with initial mild-to-moderate symptoms during the acute phase of the illness, in whom recovery is prolonged, or new symptoms are developed over months. Here, we propose a description of the pathophysiology of the Long COVID presentation based on inflammatory cytokine cascades and the p38 MAP kinase signaling pathways that regulate cytokine production. In this model, the SARS-CoV-2 viral infection is hypothesized to trigger a dysregulated peripheral immune system activation with subsequent cytokine release. Chronic low-grade inflammation leads to dysregulated brain microglia with an exaggerated release of central cytokines, producing neuroinflammation. Immunothrombosis linked to chronic inflammation with microclot formation leads to decreased tissue perfusion and ischemia. Intermittent fatigue, Post Exertional Malaise (PEM), CNS symptoms with "brain fog," arthralgias, paresthesias, dysautonomia, and GI and ophthalmic problems can consequently arise as result of the elevated peripheral and central cytokines. There are abundant similarities between symptoms in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). DNA polymorphisms and viral-induced epigenetic changes to cytokine gene expression may lead to chronic inflammation in Long COVID patients, predisposing some to develop autoimmunity, which may be the gateway to ME/CFS.

Regulatory T Cells (Tregs) and COVID-19: Unveiling the Mechanisms, and Therapeutic Potentialities with a Special Focus on Long COVID

The COVID-19 pandemic has caused havoc all around the world. The causative agent of COVID-19 is the novel form of the coronavirus (CoV) named SARS-CoV-2, which results in immune system disruption, increased inflammation, and acute respiratory distress syndrome (ARDS). T cells have been important components of the immune system, which decide the fate of the COVID-19 disease. Recent studies have reported an important subset of T cells known as regulatory T cells (Tregs), which possess immunosuppressive and immunoregulatory properties and play a crucial role in the prognosis of COVID-19 disease. Recent studies have shown that COVID-19 patients have considerably fewer Tregs than the general population. Such a decrement may have an impact on COVID-19 patients in a number of ways, including diminishing the effect of inflammatory inhibition, creating an inequality in the Treg/Th17 percentage, and raising the chance of respiratory failure. Having fewer Tregs may enhance the likelihood of long COVID development in addition to contributing to the disease's poor prognosis. Additionally, tissue-resident Tregs provide tissue repair in addition to immunosuppressive and immunoregulatory activities, which may aid in the recovery of COVID-19 patients. The severity of the illness is also linked to abnormalities in the Tregs' phenotype, such as reduced expression of FoxP3 and other immunosuppressive cytokines, including IL-10 and TGF-beta. Hence, in this review, we summarize the immunosuppressive mechanisms and their possible roles in the prognosis of COVID-19 disease. Furthermore, the perturbations in Tregs have been associated with disease severity. The roles of Tregs are also explained in the long COVID. This review also discusses the potential therapeutic roles of Tregs in the management of patients with COVID-19.

Cystatin-c May Indicate Subclinical Renal Involvement, While Orosomucoid Is Associated with Fatigue in Patients with Long-COVID Syndrome

Long-COVID syndrome is associated with high healthcare costs, but its pathophysiology is not yet fully understood. Inflammation, renal impairment or disturbance of the NO system emerge as potential pathogenetic factors. We aimed to investigate the relationship between symptoms of long-COVID syndrome and serum levels of cystatin-c (CYSC), orosomucoid (ORM), l-arginine, symmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA). A total of 114 patients suffering from long-COVID syndrome were included in this observational cohort study. We found that serum CYSC was independently associated with the anti-spike immunoglobulin (S-Ig) serum level (OR: 5.377, 95% CI: 1.822-12.361; p = 0.02), while serum ORM (OR: 9.670 (95% CI: 1.34-9.93; p = 0.025) independently predicted fatigue in patients with long-COVID syndrome, both measured at baseline visit. Additionally, the serum CYSC concentrations measured at the baseline visit showed a positive correlation with the serum SDMA levels. The severity of abdominal and muscle pain indicated by patients at the baseline visit showed a negative correlation with the serum level of L-arginine. In summary, serum CYSC may indicate subclinical renal impairment, while serum ORM is associated with fatigue in long-COVID syndrome. The potential role of l-arginine in alleviating pain requires further studies.

European Working Group on SARS-CoV-2: Current Understanding, Unknowns, and Recommendations on the Neurological Complications of COVID-19

The emergence of COVID-19 was rapidly followed by infection and the deaths of millions of people across the globe. With much of the research and scientific advancement rightly focused on reducing the burden of severe and critical acute COVID-19 infection, the long-term effects endured by those who survived the acute infection has been previously overlooked. Now, an appreciation for the post-COVID-19 condition, including its neurological manifestations, is growing, although there remain many unknowns regarding the aetiology and risk factors of the condition, as well as how to effectively diagnose and treat it. Here, drawing upon the experiences and expertise of the clinicians and academics of the European working group on COVID-19, we have reviewed the current literature to provide a comprehensive overview of the neurological sequalae of the post-COVID-19 condition. In this review, we provide a summary of the neurological symptoms associated with the post-COVID-19 condition, before discussing the possible mechanisms which may underly and manifest these symptoms. Following this, we explore the risk factors for developing neurological symptoms as a result of COVID-19 and the post-COVID-19 condition, as well as how COVID-19 infection may itself be a risk factor for the development of neurological disease in the future. Lastly, we evaluate how the post-COVID condition could be accurately diagnosed and effectively treated, including examples of the current guidelines, clinical outcomes and tools that have been developed to aid in this process, as well as addressing the protection provided by COVID-19 vaccines against post-COVID-19 condition. Overall, this review provides a comprehensive overview of the neurological sequalae of the post-COVID-19 condition.

A scoping review of regulatory T cell dynamics in convalescent COVID-19 patients - indications for their potential involvement in the development of Long COVID?

Background

Recovery from coronavirus disease 2019 (COVID-19) can be impaired by the persistence of symptoms or new-onset health complications, commonly referred to as Long COVID. In a subset of patients, Long COVID is associated with immune system perturbations of unknown etiology, which could be related to compromised immunoregulatory mechanisms.

Objective

The objective of this scoping review was to summarize the existing literature regarding the frequency and functionality of Tregs in convalescent COVID-19 patients and to explore indications for their potential involvement in the development of Long COVID.

Design

A systematic search of studies investigating Tregs during COVID-19 convalescence was conducted on MEDLINE (via Pubmed) and Web of Science.

Results

The literature search yielded 17 relevant studies, of which three included a distinct cohort of patients with Long COVID. The reviewed studies suggest that the Treg population of COVID-19 patients can reconstitute quantitatively and functionally during recovery. However, the comparison between recovered and seronegative controls revealed that an infection-induced dysregulation of the Treg compartment can be sustained for at least several months. The small number of studies investigating Tregs in Long COVID allowed no firm conclusions to be drawn about their involvement in the syndrome's etiology. Yet, even almost one year post-infection Long COVID patients exhibit significantly altered proportions of Tregs within the CD4+ T cell population.

Conclusions

Persistent alterations in cell frequency in Long COVID patients indicate that Treg dysregulation might be linked to immune system-associated sequelae. Future studies should aim to address the association of Treg adaptations with different symptom clusters and blood parameters beyond the sole quantification of cell frequencies while adhering to consensualized phenotyping strategies.

Relationship between the severity of persistent symptoms, physical fitness, and cardiopulmonary function in post-COVID-19 condition. A population-based analysis

The aim of this study was to determine the relationship between physical fitness, cardiopulmonary function and patient-reported severity of symptoms in people with post-COVID-19 condition. We examined ambulatory patients (n = 72) with post-COVID-19 condition who had a chronic symptomatic phase lasting > 12 weeks from the onset of symptoms, but had not been hospitalized for acute COVID-19. A comprehensive medical screening was conducted, including clinical history, symptomatology, comorbidities, body composition and physical activity levels. We then identified the relationship between physical fitness (cardiorespiratory fitness and muscular strength), cardiopulmonary function (echocardiographic and spirometry parameters) and patient-reported severity of symptoms (fatigue, dyspnea, health-related quality of life, anxiety, and depression). Age, body mass index, sex, number of comorbidities and duration of symptoms were included as potential confounders. Results showed that greater physical fitness and cardiopulmonary function were associated with lower severity of symptoms in people with post-COVID-19 condition. Cardiorespiratory fitness, lower-limb muscle strength, maximal voluntary ventilation and left ventricular ejection fraction account for reducing fatigue and dyspnea. Greater physical activity levels were associated with fewer symptoms and less-severe fatigue and dyspnea. In conclusion, preserving better cardiopulmonary health and physical condition during the course of the disease-even in mild cases-was related to a lower intensity of symptoms in non-hospitalized people with post-COVID-19 condition. It is probable that exercise and physical conditioning are valuable pre- and post-COVID-19 countermeasures that could help decrease the severity, not only of acute infection, but of post-COVID-19 persistent symptoms and prognosis.

Characterization of autonomic symptom burden in long COVID: A global survey of 2,314 adults

BACKGROUND

Autonomic dysfunction is a known complication of post-acute sequelae of SARS-CoV-2 (PASC)/long COVID, however prevalence and severity are unknown.

OBJECTIVE

To assess the frequency, severity, and risk factors of autonomic dysfunction in PASC, and to determine whether severity of acute SARS-CoV-2 infection is associated with severity of autonomic dysfunction.

DESIGN

Cross-sectional online survey of adults with PASC recruited through long COVID support groups between October 2020 and August 2021.

PARTICIPANTS

2,413 adults ages 18-64 years with PASC including patients who had a confirmed positive test for COVID-19 (test-confirmed) and participants who were diagnosed with COVID-19 based on clinical symptoms alone.

MAIN MEASURES

The main outcome measure was the Composite Autonomic Symptom 31 (COMPASS-31) total score, used to assess global autonomic dysfunction. Test-confirmed hospitalized vs. test-confirmed non-hospitalized participants were compared to determine if the severity of acute SARS-CoV-2 infection was associated with the severity autonomic dysfunction.

KEY RESULTS

Sixty-six percent of PASC patients had a COMPASS-31 score >20, suggestive of moderate to severe autonomic dysfunction. COMPASS-31 scores did not differ between test-confirmed hospitalized and test-confirmed non-hospitalized participants [28.95 (15.62, 46.60) vs. 26.4 (13.75, 42.10); p = 0.06].

CONCLUSIONS

Evidence of moderate to severe autonomic dysfunction was seen in 66% of PASC patients in our study, independent of hospitalization status, suggesting that autonomic dysfunction is highly prevalent in the PASC population and independent of the severity of acute COVID-19 illness.

Is post-COVID syndrome an autoimmune disease?

INTRODUCTION

: Coronavirus disease 2019 (COVID-19) causes a long-term and persistent condition with clinical features similar to previous virulent outbreaks and other epidemics. Currently, post-COVID syndrome (PCS) is recognized as a new entity in the context of SARS-CoV-2 infection. Though its pathogenesis is not completely understood, persistent inflammation from acute illness and the development of autoimmunity play a critical role in its development. As the pandemic develops, the increasing latent and overt autoimmunity cases indicate that PCS is at the intersection of autoimmunity.

AREAS COVERED

The mechanisms involved in the emergence of PCS, their similarities with post-viral and post-care syndromes, its inclusion in the spectrum of autoimmunity and possible targets for its treatment.

EXPERT OPINION

An autoimmune phenomenon plays a major role in most causative theories explaining PCS. Due to the wide scope of symptoms and pathophysiology associated with PCS, there is a need for both PCS definition and classification criteria (including severity scores). Longitudinal and controlled studies are necessary to better understand this new entity, and to confirm that PCS is the chronic phase of COVID-19 as well as to find what additional factors participate into its development. With the high prevalence of COVID-19 cases worldwide, together with the current evidence on latent autoimmunity in PCS, we may observe an increase of autoimmune diseases (ADs) in the coming years. Vaccination's effect on the development of PCS and ADs will also receive attention in the future. Health and social care services need to develop a new framework to deal with PCS.

A Scoping Review of Pharmacological Management of Postacute Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 Infection in 2021

BACKGROUND

Postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection (PASC), or long-COVID, are signs and symptoms that persist after the acute phase of Coronavirus disease 2019 infection has passed. PASC is newly recognized, and research is ongoing to answer questions about pathology, symptoms, diagnosis, and optimal treatment.

AREAS OF UNCERTAINTY

Use of pharmacologic treatment for symptoms of PASC is currently evolving. This scoping review aims to assess medical literature for any evidence supporting or refuting use of any medications to specifically treat PASC.

DATA SOURCES

PubMed, EMBASE, Web of Science, and gray literature sources were searched for any study of medication use for PASC. Studies were included if they described medication use in patients with PASC. There were no exclusion criteria based on study type or if results were reported. Studies were divided into completed works and ongoing research.

RESULTS

Fifty-two records were included in final analysis from an initial 3524 records found, including 2 randomized controlled trials, 7 prospective, open-label or observational studies, 14 case reports or case series, 1 survey, 1 correspondence, 1 retrospective analysis, and 26 studies in progress. Seven of the 26 completed works investigate ivabradine or beta-blockers, whereas 7 investigate local or systemic corticosteroids. Three investigate multi-ingredient nutritional supplements. The other 9 completed works as well as the 26 studies in progress investigate a wide variety of other treatments including drugs in development, drugs used for other conditions, herbals, supplements, and vitamins.

CONCLUSIONS

There is limited, but evolving, literature on medication treatment for PASC. Providers who opt to use pharmacologic therapy for PASC need to be vigilant in their knowledge of these evolving data.