COVID-19 and the Brain

COVID-19 and Long COVID: Disruption of the Neurovascular Unit, Blood-Brain Barrier, and Tight Junctions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), could affect brain structure and function. SARS-CoV-2 can enter the brain through different routes, including the olfactory, trigeminal, and vagus nerves, and through blood and immunocytes. SARS-CoV-2 may also enter the brain from the peripheral blood through a disrupted blood-brain barrier (BBB). The neurovascular unit in the brain, composed of neurons, astrocytes, endothelial cells, and pericytes, protects brain parenchyma by regulating the entry of substances from the blood. The endothelial cells, pericytes, and astrocytes highly express angiotensin converting enzyme 2 (ACE2), indicating that the BBB can be disturbed by SARS-CoV-2 and lead to derangements of tight junction and adherens junction proteins. This leads to increased BBB permeability, leakage of blood components, and movement of immune cells into the brain parenchyma. SARS-CoV-2 may also cross microvascular endothelial cells through an ACE2 receptor-associated pathway. The exact mechanism of BBB dysregulation in COVID-19/neuro-COVID is not clearly known, nor is the development of long COVID. Various blood biomarkers could indicate disease severity and neurologic complications in COVID-19 and help objectively diagnose those developing long COVID. This review highlights the importance of neurovascular and BBB disruption, as well as some potentially useful biomarkers in COVID-19, and long COVID/neuro-COVID.

Hospital outcomes of acute COVID-19 infection among patients with neurological conditions: a single-center study

Background

Coronavirus disease 2019 (COVID-19) infection has been associated with severe neurological consequences, including stroke or seizures, and less severe neurological sequelae, including headaches, dizziness, and anosmia. Earlier COVID-19 variants were associated with high morbidity and mortality; however, knowledge of the impact of neurological conditions in the setting of COVID-19 on healthcare outcomes is limited. We sought to determine the impact of acute neurological conditions and acute COVID-19 infection on inpatient hospitalization outcomes.

Methods

This was a retrospective, observational study of adult patients who were admitted to a large academic medical center in the Southeastern US between April 2020 and December 2021 with acute COVID-19 infection and a neurological diagnosis. Patient demographics, medical history, neurological diagnoses, and hospitalization outcomes were obtained from the medical record. Descriptive statistics and unadjusted and adjusted logistic regression analyses were performed.

Results

Of the 1,387 patients included in this study, 27% died and 23% were kept under ventilation during hospitalization. The mean +/- standard deviation (SD) age was 64.6+/-16.9 years, with 52.8% women and 30.1% identifying as Black/African American. The most common neurological conditions included ischemic stroke (35.0%), movement disorder (12.0%), and hemorrhagic stroke (10.7%). In-hospital death was most common among those with epilepsy (p = 0.024), headache (p = 0.026), and dementia (p < 0.0001) compared to individuals without those conditions. Ventilation support was given more commonly to dementia patients (p = 0.020). Age was a significant risk factor for death (p < 0.001) and hospital length of stay (LOS) for ventilation (p < 0.001), but no neurological condition was a significant factor in adjusted logistic regression analyses.

Discussion

Mortality was high in this study, with more than one-quarter of patients dying in the hospital. Death was the most common among those with epilepsy, headache, or dementia, but no neurological condition increased the risk of in-hospital mortality or ventilation. Future studies would determine the long-term neurological sequelae of those discharged from the hospital with COVID-19 and a neurological condition.

Potential pathophysiological role of the ion channel TRPM3 in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and the therapeutic effect of low-dose naltrexone

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating disease with a broad overlap of symptomatology with Post-COVID Syndrome (PCS). Despite the severity of symptoms and various neurological, cardiovascular, microvascular, and skeletal muscular findings, no biomarkers have been identified. The Transient receptor potential melastatin 3 (TRPM3) channel, involved in pain transduction, thermosensation, transmitter and neuropeptide release, mechanoregulation, vasorelaxation, and immune defense, shows altered function in ME/CFS. Dysfunction of TRPM3 in natural killer (NK) cells, characterized by reduced calcium flux, has been observed in ME/CFS and PCS patients, suggesting a role in ineffective pathogen clearance and potential virus persistence and autoimmunity development. TRPM3 dysfunction in NK cells can be improved by naltrexone in vitro and ex vivo, which may explain the moderate clinical efficacy of low-dose naltrexone (LDN) treatment. We propose that TRPM3 dysfunction may have a broader involvement in ME/CFS pathophysiology, affecting other organs. This paper discusses TRPM3's expression in various organs and its potential impact on ME/CFS symptoms, with a focus on small nerve fibers and the brain, where TRPM3 is involved in presynaptic GABA release.

LIMBIC-CENC: Successfully conducting longitudinal mTBI research during the COVID-19 pandemic

BACKGROUND

Conducting mild traumatic brain injury (mTBI) longitudinal studies across multiple sites is a challenging endeavor which has been made more challenging because of COVID-19.

OBJECTIVE

This article briefly describes several concerns that need to be addressed during the conduct of research to account for COVID-19's impact.

METHODS

The recent actions and steps taken by the Long-term Impact of Military-relevant Brain Injury Consortium (LIMBIC)-Chronic Effects of Neurotrauma Consortium (CENC) researchers are reviewed.

RESULTS

COVID-19's effects on the conduct of LIMBIC-CENC for the short-term and long-term were considered to ensure the study continued safely for participants and researchers. COVID-19 may have long-lasting health and especially neurological effects which may confound the quantitative and qualitative measures of this any comparable longitudinal studies.

CONCLUSION

The recognition, understanding, and preparation of COVID-19's impact on a longitudinal military and veteran mTBI population is crucial to successfully conducting LIMBIC-CENC and similar neurological research studies. Developing a plan based on the best available information while remaining agile as new information about COVID-19 emerge, is essential. Research presented in this special issue underscores the complexity of studying long-term effects of mTBI, in a population exposed to and symptomatic from COVID-19.

Unmasking the mental health scars of COVID-19: A longitudinal investigation of children and adolescents in post-lockdown China

The long-term mental health consequences of COVID-19 in children and adolescents remain unclear. We investigated the impact of COVID-19 infection on mental health after China's zero-COVID policy relaxation, focusing on symptom-specific and social-family risk factors for mental health issues in children and adolescents. In a longitudinal study, 8348 youths (aged 10-18) were assessed twice (T1: September to October 2022 and T2: April to May 2023). Mental health changes (Δ=T1-T2) were compared between COVID-19-infected (COVID+, n = 4108) and non-infected (COVID-, n = 4240). After balancing social-family confounding factors at T1 with propensity score-based inverse probability weights, multivariable logistic regression was employed to assess associations between COVID-19 infection and the onset/worsening of mental health symptoms. Multivariable logistic regression was conducted to explore specific acute COVID-19 symptoms and social-family risk factors associated with the onset/worsening of mental health symptoms in COVID + group. Compared to COVID- group, COVID + group exhibited lower overall mental health improvement (Δ). COVID + group was associated with increased risks of depression worsening (OR 1.20, 95 % CI 1.04-1.39), anxiety worsening (OR 1.30, 95 % CI 1.15-1.47), stress worsening (OR 1.23, 95 % CI 1.03-1.46), insomnia worsening (OR 1.21, 95 % CI 1.05-1.39), and emotional symptoms worsening (OR 1.72, 95 % CI 1.27-2.33). Moderate-to-severe difficulty thinking, breathlessness, and gastrointestinal symptoms were specific COVID-19 symptoms associated with worsening of various mental health outcomes. Furthermore, academic difficulties, economic disadvantages, family conflicts, food addiction, and alcohol consumption were identified as social-family risk factors for worsening mental health symptoms in COVID + youths. COVID-19 infection leaves lasting mental health scars in youths, extending beyond the acute phase. Specific symptoms, particularly cognitive dysfunction and respiratory/gastrointestinal distress play a significant role in this vulnerability. Social-family factors further modulate these effects, highlighting the need for comprehensive interventions that address both biological and psychosocial aspects. This study provides valuable insights for tailoring mental health support to youths navigating the consequences of the COVID-19 pandemic.

A prospects tool in virus research: Analyzing the applications of organoids in virus studies

Organoids have emerged as a powerful tool for understanding the biology of the respiratory, digestive, nervous as well as urinary system, investigating infections, and developing new therapies. This article reviews recent progress in the development of organoid and advancements in virus research. The potential applications of these models in studying virul infections, pathogenesis, and antiviral drug discovery are discussed.

The prognostic value of prognostic nutritional index and renal function indicators for mortality prediction in severe COVID-19 elderly patients: A retrospective study

Identifying prognostic factors in elderly patients with severe coronavirus disease 2019 (COVID-19) is crucial for clinical management. Recent evidence suggests malnutrition and renal dysfunction are associated with poor outcome. This study aimed to develop a prognostic model incorporating prognostic nutritional index (PNI), estimated glomerular filtration rate (eGFR), and other parameters to predict mortality risk. This retrospective analysis included 155 elderly patients with severe COVID-19. Clinical data and outcomes were collected. Logistic regression analyzed independent mortality predictors. A joint predictor "L" incorporating PNI, eGFR, D-dimer, and lactate dehydrogenase (LDH) was developed and internally validated using bootstrapping. Decreased PNI (OR = 1.103, 95% CI: 0.78-1.169), decreased eGFR (OR = 0.964, 95% CI: 0.937-0.992), elevated D-dimer (OR = 1.001, 95% CI: 1.000-1.004), and LDH (OR = 1.005, 95% CI: 1.001-1.008) were independent mortality risk factors (all P < .05). The joint predictor "L" showed good discrimination (area under the curve [AUC] = 0.863) and calibration. The bootstrapped area under the curve was 0.858, confirming model stability. A combination of PNI, eGFR, D-dimer, and LDH provides useful prognostic information to identify elderly patients with severe COVID-19 at highest mortality risk for early intervention. Further external validation is warranted.

Precision Phenotyping for Curating Research Cohorts of Patients with Post-Acute Sequelae of COVID-19 (PASC) as a Diagnosis of Exclusion

Scalable identification of patients with the post-acute sequelae of COVID-19 (PASC) is challenging due to a lack of reproducible precision phenotyping algorithms and the suboptimal accuracy, demographic biases, and underestimation of the PASC diagnosis code (ICD-10 U09.9). In a retrospective case-control study, we developed a precision phenotyping algorithm for identifying research cohorts of PASC patients, defined as a diagnosis of exclusion. We used longitudinal electronic health records (EHR) data from over 295 thousand patients from 14 hospitals and 20 community health centers in Massachusetts. The algorithm employs an attention mechanism to exclude sequelae that prior conditions can explain. We performed independent chart reviews to tune and validate our precision phenotyping algorithm. Our PASC phenotyping algorithm improves precision and prevalence estimation and reduces bias in identifying Long COVID patients compared to the U09.9 diagnosis code. Our algorithm identified a PASC research cohort of over 24 thousand patients (compared to about 6 thousand when using the U09.9 diagnosis code), with a 79.9 percent precision (compared to 77.8 percent from the U09.9 diagnosis code). Our estimated prevalence of PASC was 22.8 percent, which is close to the national estimates for the region. We also provide an in-depth analysis outlining the clinical attributes, encompassing identified lingering effects by organ, comorbidity profiles, and temporal differences in the risk of PASC. The PASC phenotyping method presented in this study boasts superior precision, accurately gauges the prevalence of PASC without underestimating it, and exhibits less bias in pinpointing Long COVID patients. The PASC cohort derived from our algorithm will serve as a springboard for delving into Long COVID's genetic, metabolomic, and clinical intricacies, surmounting the constraints of recent PASC cohort studies, which were hampered by their limited size and available outcome data.

Developmental priming of early cerebrovascular ageing: Implications across a lifetime

INTRODUCTION

Neurological conditions such as Alzheimer's disease and stroke represent a substantial health burden to the world's ageing population. Cerebrovascular dysfunction is a key contributor to these conditions, affecting an individual's risk profile, age of onset, and severity of neurological disease. Recent data shows that early-life events, such as maternal health during pregnancy, birth weight and exposure to environmental toxins can 'prime' the vascular system for later changes. With age, blood vessels can become less flexible and more prone to damage. This can lead to reduced blood flow to the brain, which is associated with cognitive decline and an increased risk of stroke and other cerebrovascular diseases. These in turn increase the risk of vascular dementia and Alzheimer's disease.

OBJECTIVES

We aim to explore how early life factors influence cerebrovascular health, ageing and disease.

METHODS

We have reviewed recently published literature from epidemiological studies, clinical cases and basic research which explore mechanisms that contribute to cerebrovascular and blood-brain barrier dysfunction, with a particularly focus on those that assess contribution of early-life events or vascular priming to subsequent injury.

RESULTS

Perinatal events have been linked to acute cerebrovascular dysfunction and long-term structural reorganisation. Systemic disease throughout the lifetime that produce inflammatory or oxidative stress may further sensitise the cerebrovasculature to disease and contribute to neurodegeneration.

CONCLUSIONS

By identifying these early-life determinants and understanding their mechanisms, scientists aim to develop strategies for preventing or mitigating cerebrovascular ageing-related issues.

Precision nutrition to reset virus-induced human metabolic reprogramming and dysregulation (HMRD) in long-COVID

SARS-CoV-2, the etiological agent of COVID-19, is devoid of any metabolic capacity; therefore, it is critical for the viral pathogen to hijack host cellular metabolic machinery for its replication and propagation. This single-stranded RNA virus with a 29.9 kb genome encodes 14 open reading frames (ORFs) and initiates a plethora of virus-host protein-protein interactions in the human body. These extensive viral protein interactions with host-specific cellular targets could trigger severe human metabolic reprogramming/dysregulation (HMRD), a rewiring of sugar-, amino acid-, lipid-, and nucleotide-metabolism(s), as well as altered or impaired bioenergetics, immune dysfunction, and redox imbalance in the body. In the infectious process, the viral pathogen hijacks two major human receptors, angiotensin-converting enzyme (ACE)-2 and/or neuropilin (NRP)-1, for initial adhesion to cell surface; then utilizes two major host proteases, TMPRSS2 and/or furin, to gain cellular entry; and finally employs an endosomal enzyme, cathepsin L (CTSL) for fusogenic release of its viral genome. The virus-induced HMRD results in 5 possible infectious outcomes: asymptomatic, mild, moderate, severe to fatal episodes; while the symptomatic acute COVID-19 condition could manifest into 3 clinical phases: (i) hypoxia and hypoxemia (Warburg effect), (ii) hyperferritinemia ('cytokine storm'), and (iii) thrombocytosis (coagulopathy). The mean incubation period for COVID-19 onset was estimated to be 5.1 days, and most cases develop symptoms after 14 days. The mean viral clearance times were 24, 30, and 39 days for acute, severe, and ICU-admitted COVID-19 patients, respectively. However, about 25-70% of virus-free COVID-19 survivors continue to sustain virus-induced HMRD and exhibit a wide range of symptoms that are persistent, exacerbated, or new 'onset' clinical incidents, collectively termed as post-acute sequelae of COVID-19 (PASC) or long COVID. PASC patients experience several debilitating clinical condition(s) with >200 different and overlapping symptoms that may last for weeks to months. Chronic PASC is a cumulative outcome of at least 10 different HMRD-related pathophysiological mechanisms involving both virus-derived virulence factors and a multitude of innate host responses. Based on HMRD and virus-free clinical impairments of different human organs/systems, PASC patients can be categorized into 4 different clusters or sub-phenotypes: sub-phenotype-1 (33.8%) with cardiac and renal manifestations; sub-phenotype-2 (32.8%) with respiratory, sleep and anxiety disorders; sub-phenotype-3 (23.4%) with skeleto-muscular and nervous disorders; and sub-phenotype-4 (10.1%) with digestive and pulmonary dysfunctions. This narrative review elucidates the effects of viral hijack on host cellular machinery during SARS-CoV-2 infection, ensuing detrimental effect(s) of virus-induced HMRD on human metabolism, consequential symptomatic clinical implications, and damage to multiple organ systems; as well as chronic pathophysiological sequelae in virus-free PASC patients. We have also provided a few evidence-based, human randomized controlled trial (RCT)-tested, precision nutrients to reset HMRD for health recovery of PASC patients.

COVID-19 and the brain: understanding the pathogenesis and consequences of neurological damage

SARS-CoV-2 has been known remarkably since December 2019 as a strain of pathogenic coronavirus. Starting from the earlier stages of the COVID-19 pandemic until now, we have witnessed many cases of neurological damage caused by SARS-CoV-2. There are many studies and research conducted on COVID-19-positive-patients that have found brain-related abnormalities with clear neurological symptoms, ranging from simple headaches to life-threatening strokes. For treating neurological damage, knowing the actual pathway or mechanism of causing brain damage via SARS-CoV-2 is very important. For this reason, we have tried to explain the possible pathways of brain damage due to SARS-CoV-2 with mechanisms and illustrations. The SARS-CoV-2 virus enters the human body by binding to specific ACE2 receptors in the targeted cells, which are present in the glial cells and CNS neurons of the human brain. It is found that direct and indirect infections with SARS-CoV-2 in the brain result in endothelial cell death, which alters the BBB tight junctions. These probable alterations can be the reason for the excessive transmission and pathogenicity of SARS-CoV-2 in the human brain. In this precise review, we have tried to demonstrate the neurological symptoms in the case of COVID-19-positive-patients and the possible mechanisms of neurological damage, along with the treatment options for brain-related abnormalities. Knowing the transmission mechanism of SARS-CoV-2 in the human brain can assist us in generating novel treatments associated with neuroinflammation in other brain diseases.

Changes in sensitivity and hedonic rating to transcutaneous electrical nerve stimulation following COVID-19

COVID-19 affects not only the respiratory system but also other biological systems such as the nervous system. Usually, these changes are reported based on the patient's subjective description. The aim of our study, therefore, was to objectively determine the effect that the SARS-CoV-2 virus and COVID-19 disease has on sensory threshold and the hedonic and subjective perception of an electrical stimulus. The sensory threshold was tested on the inner forearm by applying non-invasive transcutaneous electrical nerve stimulation (TENS) with 100 Hz and 100 µs parameters and a biphasic current waveform. The study involved 211 participants, aged 22-79 years, with a mean age of 56.9 ± 12.1 years. There were 131 subjects in the COVID group, while the NON-COVID group, the control group, was matched to the COVID group in terms of gender, age, body mass index and presence of chronic diseases. The research was carried out in 2022. Sensory sensitivity was highest in the group that had suffered with COVID-19. The median sensory sensitivity was 11 mA in the COVID group and 14 mA (p < 0.001) in the NON-COVID group, however, the current sensitivity threshold decreased over time (R = 0.52, p < 0.001). Post COVID-19, the electrical stimulus was more often perceived as unpleasant: COVID versus NON-COVID (23% vs. 3%, p < 0.001) and as a different sensation to tingling (27% vs. 2%, p < 0.001). Post-COVID-19 patients have a lower sensory threshold, the electrical stimulus is more often described as unpleasant and in subjective feelings it is more often described as pinching. The differences between COVID and NON-COVID decrease with time since the onset of COVID symptoms.

A Population-Based Outcome-Wide Association Study of the Comorbidities and Sequelae Following COVID-19 Infection

BACKGROUND

Immense attention has been given to the outcome of COVID-19 infection. However, comprehensive studies based on large populational cohort with long-term follow-up are still lacking. This study aimed to investigate the risk of various short-term comorbidities (within one month) and long-term sequelae (above one month) after COVID-19 infection.

METHODS

In this large prospective cohort study with 14 months follow-up information based on UK biobank, we included 16,776 COVID-19-positive participants and 58,281 COVID-19-negative participants matched for comparison. The risk of each comorbidity and sequela was evaluated by multivariable logistic regression analysis and presented as hazard ratio (HR) and 95% confidence interval (95% CI).

RESULTS

COVID-19-positive individuals had a higher risk of 47 types of comorbidities within one month following COVID-19 infection, especially those who were older, male, overweight/obese, ever-smoked, with more pre-existing comorbidities and hospitalized. About 70.37% of COVID-19 patients with comorbidities had more than one co-occurring comorbidities. Additionally, only 6 high-risk sequelae were observed after one month of COVID-19 infection, and the incidence was relatively low (< 1%).

CONCLUSION

In addition to long-term sequelae following COVID-19 infection, plenty of comorbidities were observed, especially in patients with older age, male gender, overweight/obese, more pre-existing comorbidities and severe COVID-19, indicating that more attention should be given to these susceptible persons within this period.

Evaluation of semen DNA integrity and related parameters with COVID-19 infection: a prospective cohort study

BACKGROUND

In the context of Corona Virus Disease 2019 (COVID-19) global pandemic, Its impact on male reproductive function should be concerned.

METHODS

Our study is a prospective cohort study that recruited participants infected or uninfected with COVID-19 between December 2022 and March 2023. All laboratory tests and questionnaire data were completed at the First Affiliated Hospital of Nanchang University. A total of 132 participants were enrolled, with 78 COVID-19 positive patients as the positive group and 54 COVID-19 negative participants as the negative group. Semen quality was assessed by the fifth World Health Organization criteria. The general characteristics of semen samples were assessed using CASA (computer-assisted sperm analysis). DNA damage and the high density stainability was assessed by sperm chromatin structure analysis (SCSA) based on flowcytometry.

RESULTS

The sperm concentration, progressive motility and motility in COVID-19 negative group were significantly higher than positive group. In the following DNA damage analysis, a remarkably lower sperm DNA fragmentation index (DFI) in the COVID-19 negative group. In the positive group, unhealthy lifestyles had no significant effect on semen parameters, DNA fragmentation and nuclear compaction.

CONCLUSIONS

After excluding the interference of unhealthy lifestyle, the COVID-19 infection can have a significant impact on the quality of semen, especially the DFI,. Therefore, it shows that COVID-19 can adversely affects male fertility, and this result provides advisory guidance for clinicians.

Neuroprotective potentials of ferulic acid against intracerebral hemorrhage COVID-19 through using network pharmacology approach and molecular docking analysis

Intracerebral hemorrhage (ICH) refers to severe stroke subtype that may be life-threatening or even cause death. It is clinically observed that coronavirus disease 2019 (COVID-19) may be associated with the high mortality in ICH patients. Ferulic acid, one of the functional bioactive ingredients from medicinal herbs, has been preclinically proven with beneficial activities, including neuroprotection and anti-inflammation actions. Based on current findings, we assumed that ferulic acid may play the potentials against COVID-19 when ICH. In this study, preclinical approach including network pharmacology and molecular docking was applied to detect and identify the core targets and pharmacological mechanisms involved in ferulic acid on COVID-19 and ICH. The network pharmacology analysis identified total eleven core targets in ferulic acid and COVID-19/ICH. The molecular mechanisms of ferulic acid against COVID-19 and ICH were mostly involved in induction of antiviral activity, modulation of inflammatory reaction. Molecular docking model revealed that ferulic acid might effectively bind to epidermal growth factor receptor (EGFR) protein based on strong binding capability. Current findings reflected the preclinical pharmacological activities of ferulic acid that might use for management of COVID-19 and ICH. Although there are the limitations that are absence of experimental validation, these bioinformatic results underline that ferulic acid may exert simultaneous potentials against COVID-19 and ICH through modulating integrative mechanisms and key biotargets.

Substances of abuse and their effect on SAR-CoV-2 pathogenesis

Following the emergence of SARS-CoV-2, various reports suggest that there has been a significant increase in substance abuse due to social distancing and related issues. Several reports have suggested the impact of chronic substance use on individuals' physiological and psychological health. Therefore, there is a need to know the impact of SARS-CoV-2 on persons with substance use disorders. Individuals with substance use disorders are the most vulnerable groups and are at a high risk of SARS-CoV-2 infection due to their already existing health issues associated with substance use. This review discusses some of the molecular and systemic/organic effects chronic substance use such as alcohol, nicotine, marijuana (cannabis), opioids, methamphetamine, and cocaine have on SARS-CoV-2 infectivity and its potential cause for worsened disease outcomes in persons with substance use disorder. This will provide healthcare providers, public health policies, and researchers with the needed knowledge to address some of the many challenges faced during the Covid-19 pandemic to facilitate treatment strategies for persons with substance use disorders.

COVID-19 susceptibility and severity for dyslipidemia: A mendelian randomization investigation

Background

The severe acute respiratory syndrome coronavirus in 2019 (COVID-19) is still spreading and causing deaths worldwide, which further increased the burden of chronic diseases. Dyslipidemia is a common metabolic syndrome, which is a major risk factor for cardiovascular disease. However, studies on whether there is a direct causal relationship between COVID-19 and the exacerbation of hyperlipidemia are still scarce.

Methods

Two-sample Mendelian randomization was conducted using publicly available summary statistics from independent cohorts of European ancestry. For COVID-19 and hyperlipidemia, we used data from the ieu open GWAS project database. Inverse variance-weighted, mendelian randomization Egger, weighted median, simple mode, and weighted mode mendelian randomization analyses were performed, together with a range of sensitivity analyses.

Results

There is no direct causal relationship between COVID-19 and dyslipidemia, regardless of COVID-19 severity or either dyslipidemic outcome. In combination with previous studies, the reason for the clinical outcome that COVID-19 increased the burden of dyslipidemia may be due to the exacerbation of pre-existing disease caused by COVID-19.

Conclusions

COVID-19 has no direct causal relationship with dyslipidemia.

Recapitulation of pathophysiological features of AD in SARS-CoV-2-infected subjects

Infection with the etiological agent of COVID-19, SARS-CoV-2, appears capable of impacting cognition in some patients with post-acute sequelae of SARS-CoV-2 (PASC). To evaluate neuropathophysiological consequences of SARS-CoV-2 infection, we examine transcriptional and cellular signatures in the Brodmann area 9 (BA9) of the frontal cortex and the hippocampal formation (HF) in SARS-CoV-2, Alzheimer's disease (AD), and SARS-CoV-2-infected AD individuals compared to age- and gender-matched neurological cases. Here, we show similar alterations of neuroinflammation and blood-brain barrier integrity in SARS-CoV-2, AD, and SARS-CoV-2-infected AD individuals. Distribution of microglial changes reflected by the increase in Iba-1 reveals nodular morphological alterations in SARS-CoV-2-infected AD individuals. Similarly, HIF-1α is significantly upregulated in the context of SARS-CoV-2 infection in the same brain regions regardless of AD status. The finding may help in informing decision-making regarding therapeutic treatments in patients with neuro-PASC, especially those at increased risk of developing AD.

Long-term central nervous system (CNS) consequences of COVID-19 in children

INTRODUCTION

Neurological/neuropsychiatric symptoms are commonly reported by children/young people with long COVID, especially headache, fatigue, cognitive deficits, anosmia and ageusia, dizziness, mood symptoms, and sleep problems. However, reported prevalence estimates are highly variable due to study heterogeneity and often small sample size; most studies only considered short-term follow-ups; and, apart from mood and sleep problems, neuropsychiatric conditions have received less attention. Considering the potential debilitating effects of neurological/neuropsychiatric conditions, a comprehensive review of the topic is timely, and needed to support clinical recognition as well as to set the direction for future research.

AREAS COVERED

The authors discuss neurological/neuropsychiatric manifestations of long COVID in pediatric populations, with a focus on prevalence, associated demographic characteristics, and potential pathogenetic mechanisms.

EXPERT OPINION

Children/young people may develop persistent neurological/neuropsychiatric symptoms following acute SARS-CoV-2 infection, which may affect daily functioning and well-being. Studies in larger samples with longer follow-ups are needed to clarify prevalence and symptom duration; as well as less investigated risk factors, including genetic predisposition, ethnicity, and comorbidities. Controlled studies may help separate infection-related direct effects from pandemic-related psychosocial stressors. Clarifying pathogenetic mechanisms is paramount to develop more targeted and effective treatments; whilst screening programs and psychoeducation may enhance early recognition.

Cognitive impairment in post-acute sequelae of COVID-19 and short duration myalgic encephalomyelitis patients is mediated by orthostatic hemodynamic changes

Introduction

Cognitive impairment is experienced by people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-acute sequelae of COVID-19 (PASC). Patients report difficulty remembering, concentrating, and making decisions. Our objective was to determine whether orthostatic hemodynamic changes were causally linked to cognitive impairment in these diseases.

Methods

This prospective, observational cohort study enrolled PASC, ME/CFS, and healthy controls. All participants underwent clinical evaluation and assessment that included brief cognitive testing before and after an orthostatic challenge. Cognitive testing measured cognitive efficiency which is defined as the speed and accuracy of subject's total correct responses per minute. General linear mixed models were used to analyze hemodynamics and cognitive efficiency during the orthostatic challenge. Additionally, mediation analysis was used to determine if hemodynamic instability induced during the orthostatic challenge mediated the relationship between disease status and cognitive impairment.

Results

Of the 276 participants enrolled, 256 were included in this study (34 PASC, 71 < 4 year duration ME/CFS, 69 > 10 year ME/CFS duration, and 82 healthy controls). Compared to healthy controls, the disease cohorts had significantly lower cognitive efficiency scores immediately following the orthostatic challenge. Cognitive efficiency remained low for the >10 year ME/CFS 2 and 7 days after orthostatic challenge. Narrow pulse pressure less than 25% of systolic pressure occurred at 4 and 5 min into the orthostatic challenge for the PASC and ME/CFS cohorts, respectively. Abnormally narrow pulse pressure was associated with slowed information processing in PASC patients compared to healthy controls (-1.5, p = 0.04). Furthermore, increased heart rate during the orthostatic challenge was associated with a decreased procedural reaction time in PASC and < 4 year ME/CFS patients who were 40 to 65 years of age.

Discussion

For PASC patients, both their disease state and hemodynamic changes during orthostatic challenge were associated with slower reaction time and decreased response accuracy during cognitive testing. Reduced cognitive efficiency in <4 year ME/CFS patients was associated with higher heart rate in response to orthostatic stress. Hemodynamic changes did not correlate with cognitive impairment for >10 year ME/CFS patients, but cognitive impairment remained. These findings underscore the need for early diagnosis to mitigate direct hemodynamic and other physiological effects on symptoms of cognitive impairment.

Identifying hub genes and common biological pathways between COVID-19 and benign prostatic hyperplasia by machine learning algorithms

Background

COVID-19, a serious respiratory disease that has the potential to affect numerous organs, is a serious threat to the health of people around the world. The objective of this article is to investigate the potential biological targets and mechanisms by which SARS-CoV-2 affects benign prostatic hyperplasia (BPH) and related symptoms.

Methods

We downloaded the COVID-19 datasets (GSE157103 and GSE166253) and the BPH datasets (GSE7307 and GSE132714) from the Gene Expression Omnibus (GEO) database. In GSE157103 and GSE7307, differentially expressed genes (DEGs) were found using the "Limma" package, and the intersection was utilized to obtain common DEGs. Further analyses followed, including those using Protein-Protein Interaction (PPI), Gene Ontology (GO) function enrichment analysis, and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Potential hub genes were screened using three machine learning methods, and they were later verified using GSE132714 and GSE166253. The CIBERSORT analysis and the identification of transcription factors, miRNAs, and drugs as candidates were among the subsequent analyses.

Results

We identified 97 common DEGs from GSE157103 and GSE7307. According to the GO and KEGG analyses, the primary gene enrichment pathways were immune-related pathways. Machine learning methods were used to identify five hub genes (BIRC5, DNAJC4, DTL, LILRB2, and NDC80). They had good diagnostic properties in the training sets and were validated in the validation sets. According to CIBERSORT analysis, hub genes were closely related to CD4 memory activated of T cells, T cells regulatory and NK cells activated. The top 10 drug candidates (lucanthone, phytoestrogens, etoposide, dasatinib, piroxicam, pyrvinium, rapamycin, niclosamide, genistein, and testosterone) will also be evaluated by the P value, which is expected to be helpful for the treatment of COVID-19-infected patients with BPH.

Conclusion

Our findings reveal common signaling pathways, possible biological targets, and promising small molecule drugs for BPH and COVID-19. This is crucial to understand the potential common pathogenic and susceptibility pathways between them.

Neurological Manifestations and Complications of the Central Nervous System as Risk Factors and Predictors of Mortality in Patients Hospitalized with COVID-19: A Cohort Study

The aim of this study was to analyze the risk factors and predictors of mortality in a retrospective cohort of patients with coronavirus disease (COVID-19) who presented central nervous system (CNS) manifestations and complications when admitted to hospital. Patients hospitalized from 2020 to 2022 were selected. Demographic variables; history of neurological, cardiological and pulmonary manifestations; comorbidities; prognostic severity scales; and laboratory tests were included. Univariate and adjusted analyses were performed to determine risk factors and predictors of mortality. A forest plot diagram was used to show the strength of the associated risk factors. The cohort included 991 patients; at admission, 463 patients presented CNS damage and of these, 96 hospitalized patients presented de novo CNS manifestations and complications. We estimate a general mortality of 43.7% (433/991) and 77.1% (74/96), for hospitalized patients with de novo CNS manifestations and complications, respectively. The following were identified as risks for the development of hospital CNS manifestations and complications when in hospital: an age of ≥64 years, a history of neurological disease, de novo deep vein thrombosis, D-dimer ≥ 1000 ng/dL, a SOFA ≥ 5, and a CORADS 6. In a multivariable analysis, the mortality predictors were an age of ≥64 years, a SOFA ≥ 5, D-dimer ≥ 1000 ng/mL and hospital CNS manifestations and complications when admitted to hospital. Old age, being hospitalized in critical condition, and having CNS manifestations and complications in hospital are predictors of mortality in hospitalized patients with COVID-19.

COVID-19 and Multiorgan Response: The Long-Term Impact

In late December 2019, severe acute respiratory syndrome coronavirus type-2 (SARS-CoV-2) was discovered following a cluster of pneumonia cases in Wuhan, China. During the early stages of the COVID-19 pandemic in 2020, it was unclear how this virus would manifest into a multiorgan impacting disease. After over 750 million cases worldwide, it has become increasingly evident that SARS-CoV-2 is a complex multifaceted disease we continue to develop our understanding of. The pathophysiology of COVID-19 and how it affects these systems has many theories, ranging from direct viral infection via ACE2 receptor binding, to indirect coagulation dysfunction, cytokine storm, and pathological activation of the complement system. Since the onset of the pandemic, disease presentation, management and manifestation have changed significantly. This paper intends to expand on the long-term impacts of COVID-19 on the cardiovascular, respiratory, urinary, gastrointestinal, and vascular systems of the body and the changes in clinical management. It is evident that the pharmacological, non-pharmacological and psychological management of COVID-19 patients require clearer guidelines to improve the survival odds and long-term clinical outcomes of those presenting with severe disease.

Application of weighted gene co-expression network and immune infiltration for explorations of key genes in the brain of elderly COVID-19 patients

Introduction

Although many studies have demonstrated the existing neurological symptoms in COVID-19 patients, the mechanisms are not clear until now. This study aimed to figure out the critical molecular and immune infiltration situations in the brain of elderly COVID-19 patients.

Methods

GSE188847 was used for the differential analysis, WGCNA, and immune infiltration analysis. We also performed GO, KEGG, GSEA, and GSVA for the enrich analysis.

Results

266 DEGs, obtained from the brain samples of COVID-19 and non-COVID-19 patients whose ages were over 70 years old, were identified. GO and KEGG analysis revealed the enrichment in synapse and neuroactive ligand-receptor interaction in COVID-19 patients. Further analysis found that asthma and immune system signal pathways were significant changes based on GSEA and GSVA. Immune infiltration analysis demonstrated the imbalance of CD8+ T cells, neutrophils, and HLA. The MEpurple module genes were the most significantly different relative to COVID-19. Finally, RPS29, S100A10, and TIMP1 were the critical genes attributed to the progress of brain damage.

Conclusion

RPS29, S100A10, and TIMP1 were the critical genes in the brain pathology of COVID-19 in elderly patients. Our research has revealed a new mechanism and a potential therapeutic target.

COVID-19 immunopathology: From acute diseases to chronic sequelae

The clinical manifestation of coronavirus disease 2019 (COVID-19) mainly targets the lung as a primary affected organ, which is also a critical site of immune cell activation by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, recent reports also suggest the involvement of extrapulmonary tissues in COVID-19 pathology. The interplay of both innate and adaptive immune responses is key to COVID-19 management. As a result, a robust innate immune response provides the first line of defense, concomitantly, adaptive immunity neutralizes the infection and builds memory for long-term protection. However, dysregulated immunity, both innate and adaptive, can skew towards immunopathology both in acute and chronic cases. Here we have summarized some of the recent findings that provide critical insight into the immunopathology caused by SARS-CoV-2, in acute and post-acute cases. Finally, we further discuss some of the immunomodulatory drugs in preclinical and clinical trials for dampening the immunopathology caused by COVID-19.

Molecular and cellular similarities in the brain of SARS-CoV-2 and Alzheimer's disease individuals

Infection with the etiological agent of COVID-19, SARS-CoV-2, appears capable of impacting cognition, which some patients with Post-acute Sequelae of SARS-CoV-2 (PASC). To evaluate neuro-pathophysiological consequences of SARS-CoV-2 infection, we examine transcriptional and cellular signatures in the Broadman area 9 (BA9) of the frontal cortex and the hippocampal formation (HF) in SARS-CoV-2, Alzheimer's disease (AD) and SARS-CoV-2 infected AD individuals, compared to age- and gender-matched neurological cases. Here we show similar alterations of neuroinflammation and blood-brain barrier integrity in SARS-CoV-2, AD, and SARS-CoV-2 infected AD individuals. Distribution of microglial changes reflected by the increase of Iba-1 reveal nodular morphological alterations in SARS-CoV-2 infected AD individuals. Similarly, HIF-1α is significantly upregulated in the context of SARS-CoV-2 infection in the same brain regions regardless of AD status. The finding may help to inform decision-making regarding therapeutic treatments in patients with neuro-PASC, especially those at increased risk of developing AD.

TEASER

SARS-CoV-2 and Alzheimer's disease share similar neuroinflammatory processes, which may help explain neuro-PASC.

Association between Brain Injury Markers and Testosterone in Critically-Ill COVID-19 Male Patients

Accumulating data suggest that various neurologic manifestations are reported in critically-ill COVID-19 patients. Although low testosterone levels were associated with poor outcomes, the relationship between testosterone levels and indices of brain injury are still poorly understood. Therefore, we aimed to explore whether testosterone levels are associated with glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), biomarkers of brain injury, in patients with a severe form of COVID-19. The present study was conducted on 65 male patients aged 18−65 with severe COVID-19. Blood samples were collected at three time points: upon admission to ICU, 7 days after, and 14 days after. In patients with neurological sequels (n = 20), UCH-L1 serum concentrations at admission were markedly higher than in patients without them (240.0 (155.4−366.4) vs. 146.4 (92.5−243.9) pg/mL, p = 0.022). GFAP concentrations on admission did not differ between the groups (32.2 (24.2−40.1) vs. 29.8 (21.8−39.4) pg/mL, p = 0.372). Unlike GFAP, UCH-L1 serum concentrations exhibited a negative correlation with serum testosterone in all three time points (r = −0.452, p < 0.001; r = −0.430, p < 0.001 and r = −0.476, p = 0.001, respectively). The present study suggests that the traumatic brain injury biomarker UCH-L1 may be associated with neurological impairments seen in severe COVID-19. Moreover, a negative correlation between UCH-L1 and serum testosterone concentrations implies that testosterone may have a role in the development of neurological sequels in critically-ill COVID-19 patients.

Association Between Previous Stroke and Severe COVID-19: A Retrospective Cohort Study and an Overall Review of Meta-Analysis

Objective

The objective of this study was to investigate the association between previous stroke and the risk of severe coronavirus disease 2019 (COVID-19).

Methods

We included 164 (61.8 ± 13.6 years) patients with COVID-19 in a retrospective study. We evaluated the unadjusted and adjusted associations between previous stroke and severe COVID-19, using a Cox regression model. We conducted an overall review of systematic review and meta-analysis to investigate the relationship of previous stroke with the unfavorable COVID-19 outcomes.

Results

The rate of severe COVID-19 in patients with previous stroke was 28.37 per 1,000 patient days (95% confidence interval [CI]: 10.65–75.59), compared to 3.94 per 1,000 patient days (95% CI: 2.66–5.82) in those without previous stroke (p < 0.001). Previous stroke was significantly associated with severe COVID-19 using a Cox regression model (unadjusted [hazard ratio, HR]: 6.98, 95% CI: 2.42–20.16, p < 0.001; adjusted HR [per additional 10 years]: 4.62, 95% CI: 1.52–14.04, p = 0.007). An overall review of systematic review and meta-analysis showed that previous stroke was significantly associated with severe COVID-19, mortality, need for intensive care unit admission, use of mechanical ventilation, and an unfavorable composite outcome.

Conclusion

Previous stroke seems to influence the course of COVID-19 infection; such patients are at high risk of severe COVID-19 and might benefit from early hospital treatment measures and preventive strategies.