Microgliosis, astrogliosis and loss of aquaporin-4 polarity in frontal cortex of COVID-19 patients (preprint)

The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), causing human coronavirus disease 2019 (COVID-19), not only affects the respiratory tract, but also impacts other organs including the brain. A considerable number of COVID-19 patients develop neuropsychiatric symptoms that may linger for weeks and months and contribute to \"long-COVID\". While the neurological symptoms of COVID-19 are well described, the cellular mechanisms of neurologic disorders attributed to the infection are still enigmatic. Here, we studied the effect of an infection with SARS-CoV-2 on the structure and expression of marker proteins of astrocytes and microglial cells in the frontal cortex of patients who died from COVID-19 in comparison to non-COVID-19 controls. Most of COVID-19 patients had microglial cells with retracted processes and rounded and enlarged cell bodies in both gray and white matter, as visualized by anti-Iba1 staining and confocal fluorescence microscopy. In addition, gray matter astrocytes in COVID-19 patients were frequently labeled by intense anti-GFAP staining, whereas in non-COVID-19 controls, most gray matter astrocytes expressed little GFAP. The most striking difference between astrocytes in COVID-19 patients and controls was found by anti-aquaporin-4 (AQP4) staining. In COVID-19 patients, a large number of gray matter astrocytes showed an increase in AQP4. In addition, AQP4 polarity was lost and AQP4 covered the entire cell, including the cell body and all cell processes, while in controls, AQP4 immunostaining was mainly detected in endfeet around blood vessels and did not visualize the cell body. In summary, our data suggest neuroinflammation upon SARS-CoV-2 infection including microgliosis and astrogliosis, including loss of AQP4 polarity.

PFC/M1 activation and excitability: a longitudinal cohort study on fatigue symptoms in healthcare workers post-COVID-19 (preprint)

Background Fatigue is one of the most common neurological symptoms reported post coronavirus disease 2019 (COVID-19) infection. In order to establish effective early intervention strategies, more emphasis should be placed on the correlation between fatigue and cortical neurophysiological changes, especially in healthcare workers, who are at a heightened risk of COVID-19 infection.Methods A prospective cohort study was conducted involving 29 COVID-19 medical workers and 24 healthy controls. The assessment included fatigue, sleep and health quality, psychological status, and physical capacity. Functional near-infrared spectroscopy (fNIRS) was employed to detect activation of brain regions. Bilateral primary motor cortex (M1) excitabilities were measured using single- and paired-pulse transcranial magnetic stimulation. Outcomes were assessed at 1, 3, and 6 months into the disease course.Results At 1-month post-COVID-19 infection, 37.9% of patients experienced severe fatigue symptoms, dropping to 10.3% at 3 months. Interestingly, the remarkable decreased activation/excitability of bilateral prefrontal lobe (PFC) and M1 were closely linked to fatigue symptoms after COVID-19. Notably, greater increase in M1 region excitability correlated with more significant fatigue improvement. Re-infected patients exhibited lower levels of brain activation and excitability compared to single-infection patients.Conclusions Both single infection and reinfection of COVID-19 lead to decreased activation and excitability of the PFC and M1. The degree of excitability improvement in the M1 region correlates with a greater recovery in fatigue. Based on these findings, targeted interventions to enhance and regulate the excitability of M1 may represent a novel strategy for COVID-19 early rehabilitation.Trial registration The Ethics Review Committee of Xijing Hospital, No. KY20232051-F-1, registered February 3, 2023. The Chinese Clinical Trial Registry, ChiCTR2300068444, registered February 20, 2023. https://www.chictr.org.cn

Neurosyphilis with Concomitant Cryptococcal Meningitis in a Patient with AIDS after COVID-19: a case report (preprint)

Background The common infections agents causing meningitis in patients with human immunodeficiency virus (HIV) include Cryptococcus neoformans and Treponema pallidum. Furthermore, there is an elevated risk of meningitis in patients with HIV concomitantly infected with SARS-CoV-2.Case presentation: A 38-year-old male presented with headache and dizziness. After hospitalization, polymerase chain reaction test for SARS-CoV-2 in nasopharyngeal swab was positive, and lumbar puncture revealed neurosyphilis with concomitant cryptococcal meningitis. He underwent Paxlovid, penicillin, antifungal and antiretroviral treatment. The patient had no other neurological symptoms and was stable during the 6-month follow-up period.Conclusions During the COVID-19 pandemic, patients with HIV, particularly those not underwent antiretroviral therapy, are at higher risk for severe infections, including central nervous system complications, due to their compromised immune systems.

The Role of Furin on the Pathogenesis of COVID-19 Associated Neurological Disorders (preprint)

Neurological disorders have been reported in a large number of coronavirus disease 2019 (COVID-19) patients, suggesting that this disease may have long-term adverse neurological consequences. COVID-19 occurs from the infection by a positive-sense single-stranded RNA virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The membrane fusion protein of SARS-CoV-2, the spike protein, binds to its human host receptor, angiotensin-converting enzyme 2 (ACE2), to initiate membrane fusion between the virus and host cell. The spike protein of SARS-CoV-2 contains the furin protease recognition site and its cleavage enhances the infectivity of this virus. The binding of SARS-CoV-2 to the ACE2 receptor has been shown to downregulate ACE2, thereby increasing the levels of pathogenic angiotensin II (Ang II). The furin protease cleaves between the S1 subunit of the spike protein with the binding domain toward ACE2 and the S2 subunit with the transmembrane domain that anchors to the viral membrane, and this activity releases the S1 subunit into the blood circulation. The released S1 subunit of the spike protein also binds to and downregulates ACE2, in turn, increasing the level of Ang II. Considering that a viral particle contains many spike protein molecules, furin-dependent cleavage would release many free S1 protein molecules each of which can downregulate ACE2, while the infection with a viral particle only affects one ACE2 molecule. Therefore, the furin-dependent release of S1 protein would dramatically amplify the ability to downregulate ACE2 and produce Ang II. We hypothesize that this amplification mechanism that the virus possesses, but not the infection per se, is the major driving force behind COVID-19 associated neurological disorders.

Functional and Morphological Disorders of Taste and Olfaction in COVID-19-Patients (preprint)

Objectives: To test the prevalence and evolution of acute olfactory and gustatory functional impairment and of their morphologic correlates in COVID-19 patients who require hospitalization due to COVID-19-related respiratory conditions. Key-words: COVID-19, taste, olfaction, electrogustometry, contact endoscopy Design: Electrogustometric (EGM) - thresholds at the tongue area supplied by the chorda tympani, at the soft palate and at the vallate papillae area were recorded bilaterally. Olfaction was examined by Sniffin’ sticks. The patients’ nasal and oral mucosa (fungiform papillae, fpap) were examined by contact endoscopy. Setting: Tertiary referral medical centre. Patients: 53 consecutive hospitalized patients (23 males, 30 females, age 42,54 ± 10, 95 yrs) with RT-PCR-confirmed COVID-19 diagnosis were included. Patients have been examined twice: just after hospital discharge and 4-6 weeks later. Main outcome measures: EGM-thresholds and taste strips, Schniffin-Sticks, Contact-Endoscopyesults: EGM-thresholds in patients were significantly higher at both instances than those of healthy subjects. EGM-thresholds at the second measurement were significantly lower than those at the first measurement. Accordingly, patient-reported gustatory outcomes were improved at the second measurement. The same pattern has been found using Sniffin’ sticks. Significant alterations in form and vascularization of fPap have been detected in patients, especially at the first instance. Conclusions: COVID-19 affects both gustatory and olfactory functions. It also affects in parallel the structure and vascularization of both nasal and oral mucosa, although the nasal mucosa to a much less, non-significant, extent. Our findings suggest that COVID-19 may cause a mild to profound neuropathy of multiple cranial nerves.

Risk Factors for Pediatric Critical COVID-19: A Systematic Review and Meta-Analysis (preprint)

BackgroundRisk stratification is a cornerstone of the Pediatric Infectious Diseases Society COVID-19 treatment guidance. This systematic review and meta-analysis aimed to define the clinical characteristics and comorbidities associated with critical COVID-19 in children and adolescents. MethodsTwo independent reviewers screened the literature (Medline and EMBASE) for studies published through August 2023 that reported outcome data on patients aged [≤]21 years with COVID-19. Critical disease was defined as an invasive mechanical ventilation requirement, intensive care unit admission, or death. Random effects models were used to estimate pooled odds ratios (OR) with 95% confidence intervals (CI), and heterogeneity was explored through subgroup analyses. ResultsAmong 10,178 articles, 136 studies met the inclusion criteria for review. Data from 70 studies, which collectively examined 172,165 children and adolescents with COVID-19, were pooled for meta-analysis. In previously healthy children, the absolute risk of critical disease from COVID-19 was 4% (95% CI, 1%-10%). Compared with no comorbidities, the pooled OR for critical disease was 3.95 (95% CI, 2.78-5.63) for presence of one comorbidity and 9.51 (95% CI, 5.62-16.06) for [≥]2 comorbidities. Key risk factors included cardiovascular and neurological disorders, chronic pulmonary conditions (excluding asthma), diabetes, obesity, and immunocompromise, all with statistically significant ORs >2.00. ConclusionsWhile the absolute risk for critical COVID-19 in children and adolescents without underlying health conditions is relatively low, the presence of one or more comorbidities was associated with markedly increased risk. These findings support the importance of risk stratification in tailoring pediatric COVID-19 management. SummaryThis systematic review with meta-analysis integrated data from 136 studies (172,165 patients) and identified diabetes; obesity; immunocompromise; and cardiovascular, neurological, and pulmonary disease as predictors of severe pediatric COVID-19. The presence of multiple comorbidities increases the risk of critical outcomes.

A Murine Model of Post-acute Neurological Sequelae Following SARS-CoV-2 Variant Infection (preprint)

Viral variant is one known risk factor associated with post-acute sequelae of COVID-19 (PASC), yet the pathogenesis is largely unknown. Here, we studied SARS-CoV-2 Delta variant-induced PASC in K18-hACE2 mice. The virus replicated productively, induced robust inflammatory responses in lung and brain tissues, and caused weight loss and mortality during the acute infection. Longitudinal behavior studies in surviving mice up to 4 months post-acute infection revealed persistent abnormalities in neuropsychiatric state and motor behaviors, while reflex and sensory functions recovered over time. Surviving mice showed no detectable viral RNA in the brain and minimal neuroinflammation post-acute infection. Transcriptome analysis revealed persistent activation of immune pathways, including humoral responses, complement, and phagocytosis, and reduced levels of genes associated with ataxia telangiectasia, impaired cognitive function and memory recall, and neuronal dysfunction and degeneration. Furthermore, surviving mice maintained potent T helper 1 prone cellular immune responses and high neutralizing antibodies against Delta and Omicron variants in the periphery for months post-acute infection. Overall, infection in K18-hACE2 mice recapitulates the persistent clinical symptoms reported in long COVID patients and may be useful for future assessment of the efficacy of vaccines and therapeutics against SARS-CoV-2 variants.

Xenosialylation: Role in SARS/CoV-2 Post-infectious and Post-vaccination Complications and Common Cause of Hyperimmune/Autoimmune Diseases (preprint)

The host glycosylation mechanism synthesizes the carbohydrates of glycoproteins of viral envelopes. Due to the loss of the Cytidine Monophospho-N-Acetylneuraminic Acid Hydroxylase gene by some mammalian species, including humans (negative-CMAH), Neu5Gc is no longer synthesized. Uptake of Neu5Gc by negative-CMAH species, through the intake of food products derived from positive-CMAH mammals, leads to incorporating Neu5Gc-glycans in the glycocalyx (xenosialylation). Neu5Gc, being a Mammalian-associated Carbohydrate Antigen (MCA), acts as a non-self-antigen, inducing an inflammatory reaction (Xenosialitis), and triggering the production of circulating antiNeu5Gc antibodies to attack/remove all incorporated Neu5Gc. In the state of Xenosialitis, the virus-neutralizing antibodies produced by a heavily xenosialylated patient following exposure to viral infection (including SarsCoV2) or anti SarsCoV2 vaccination cross-react against all incorporated non-self Neu5Gc-MCA glycans due to their resemblance with viral envelope antigens synthesized by the host glycosylation mechanism. In addition, the circulating anti-XeSias antibodies determine the massive removal of the circulating neutralizing FC-xeno-contaminated antibodies by the serum, living only the hyper-inflammatory agalattosylated antiviral IgG antibodies. Therefore, we hypothesize that the combination of antibody cross-reaction against non-self Neu5Gc-MCA glycans and the massive removal of the xeno-contaminated newly formed neutralizing antibodies in favor of hyper reactive antibodies, could be the cause of the massive inflammatory reaction (cytokine storm, coagulopathies, neuropathies) observed in Covid 19 patients or after anti-SarsCoV2 vaccination. This analysis is an invitation to investigate the post-infectious and/or post-vaccination adverse phenomena in the light of xenosialization as a key to understanding the severe post viral and post vaccine complications, including SARS-CoV2 infection or related vaccination.

G6PD deficiency mediated impairment of iNOS and lysosomal acidification affecting phagocytotic clearance in microglia in response to SARS-CoV-2 (preprint)

The glucose-6-phosphate dehydrogenase (G6PD) deficiency is X-linked and is the most common enzymatic deficiency disorder globally. It is a crucial enzyme for the pentose phosphate pathway and produces NADPH, which plays a vital role in the regulation of oxidative stress of many cell types. The deficiency of G6PD causes hemolytic anemia, diabetes, cardiovascular and neurological disorders. Notably, the patient with G6PD deficiency was severely affected by SARS-CoV-2 and showed prolonged COVID-19 symptoms, neurological impacts, and high mortality. However, the mechanism of COVID-19 severity in G6PD deficient patients is still ambiguous. Here, using a CRISPR-edited G6PD deficient human microglia cell culture model, we observed a significant reduction in NADPH and an increase in basal reactive oxygen species (ROS) in microglia. Interestingly, the deficiency of the G6PD-NAPDH axis impairs induced nitric oxide synthase (iNOS) mediated nitric oxide (NO) production which plays a fundamental role in inhibiting viral replication. Surprisingly, we also observed that the deficiency of the G6PD-NADPH axis reduced lysosomal acidification, which further abrogates the lysosomal clearance of viral particles. Thus, impairment of NO production and lysosomal acidification as well as redox dysregulation in G6PD deficient microglia altered innate immune response, promoting the severity of SARS-CoV-2 pathogenesis.

CLUSTER ANALYSIS IDENTIFIES LONG COVID SUBTYPES IN BELGIAN PATIENTS (preprint)

SARS CoV-2 infection presents complications known as long Covid, a multisystemic organ disease which allow multidimensional analysis. ObjectivesThis study aims to identify Long Covid clusters and to relate them to the clinical classification devised at the Clinical Research Unit of Brugmann University Hospital, Brussels. MethodA two-stage multidimensional exploratory analysis was performed on a cohort of 205 long Covid patients, involving a Factorial Analysis of Mixed Data (FAMD), and then Hierarchical Clustering Post Component Analysis (HCPC). ResultsThe studys sample comprised 76% women, with an average age of 44.5 years. Three clinical forms were identified: long, persistent, and post-viral syndrome. Multidimensional analysis identified three clusters: cluster 1 (myalgia-like pain) associated with the persistent clinical form; cluster 2 (neurocognitive disorders) linked to the long clinical form; cluster 3 (neurocognitive disorders, anxio-depressive syndrome, joint pain and myalgia, peripheral nervous system disorders with dysautonomia, including Postural Orthostatic Tachycardia Syndrome, along with digestive system disorders). However, biological data did not provide sufficient differentiation between the clusters. ConclusionLong Covid phenotypes, as well as clinical forms, appear to be associated with distinct pathophysiological mechanisms or genetic predisposition, warranting further investigation.

A bioactive peptide from the pearl has dual roles in resisting SARS-CoV-2 infection and its complications (preprint)

Angiotensin-converting enzyme 2 (ACE2) is a critical receptor for the entry of the SARS-CoV-2 virus into cells. Moreover, a decrease in ACE2 level and its activity due to SARS-CoV-2 infection is considered a crucial reason for the development of Covid-19-associated complications. Here, we report a bioactive peptide derived from the seawater pearl oyster Pinctada fucata, named SCOL polypeptide, which binds strongly to ACE2 and effectively inhibits 65% of the binding of the SARS-CoV-2 S protein to ACE2; thus, this peptide can be used as a blocker to enable cells to resist SARS-CoV-2 infection. The SCOL polypeptide also increases ACE2 enzyme activity by 3.76 times. Previous studies have shown that ACE2 deficiency is associated with inflammation, pain, cardiovascular diseases, insulin resistance, and nervous system injury. Therefore, the SCOL polypeptide can be used to treat or alleviate complications such as lung inflammation, pain, diabetes, cardiovascular diseases, and loss of taste or smell caused by SARS-CoV-2 infection. Thus, the SCOL polypeptide can play a dual role in resisting SARS-CoV-2 infection.

Did long COVID increase road deaths in the U.S.? (preprint)

Objective To examine data on COVID-19 disease associated with a 10 percent increase in U.S. road deaths from 2020 to 2021 that raises the question of the potential effect of pandemic stress and neurological damage from COVID-19 disease. Methods Poisson regression was used to estimate the association of recent COVID-19 cases, accumulated cases, maximum temperatures, truck registrations, and gasoline prices with road deaths monthly among U.S. states in 2021. Using the regression coefficients, changes in each risk factor from 2020 to 2021 were used to calculate expected deaths in 2021 if each factor had remained the same as in 2020. Results Corrected for the other risk factors, road deaths were associated with accumulated COVID-19 cases but not cases in the previous month More than 20,700 road deaths were associated with the changes in accumulated COVID-19 cases but were substantially offset by about 19,100 less-than-expected deaths associated with increased gasoline prices. Conclusions While more research is needed, the data are sufficient to warn people with long COVID to minimize driving.

Impact of age and sex on neuroinflammation following SARS-CoV-2 infection in a murine model (preprint)

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the etiological agent for the worldwide COVID-19 pandemic, is known to infect people of all ages and both sexes. Senior populations have the greatest risk of severe disease, and sexual dimorphism in clinical outcomes has been reported in COVID-19. SARS-CoV-2 infection in humans can cause damage to multiple organ systems, including the brain. Neurological symptoms are widely observed in patients with COVID-19, with many survivors suffering from persistent neurological and cognitive impairment, potentially accelerating Alzheimer's disease. The present study aims to investigate the impact of age and sex on the neuroinflammatory response to SARS-CoV-2 infection using a mouse model. Wild-type C57BL/6 mice were inoculated, by intranasal route, with SARS-CoV-2 lineage B.1.351 variant known to infect mice. Older animals and in particular males exhibited a significantly greater weight loss starting at 4 dpi. In addition, male animals exhibited higher viral RNA loads and higher titers of infectious virus in the lung, which was particularly evident in males at 16 months of age. Notably, no viral RNA was detected in the brains of infected mice, regardless of age or sex. Nevertheless, expression of IL-6, TNF-, and CCL-2 in the lung and brain was increased with viral infection. An unbiased brain RNA-seq/transcriptomic analysis showed that SARS-CoV-2 infection caused significant changes in gene expression profiles in the brain, with innate immunity, defense response to virus, cerebravascular and neuronal functions, as the major molecular networks affected. The data presented in this study show that SARS-CoV-2 infection triggers a neuroinflammatory response despite the lack of detectable virus in the brain. Age and sex have a modifying effect on this pathogenic process. Aberrant activation of innate immune response, disruption of blood-brain barrier and endothelial cell integrity, and supression of neuronal activity and axonogenesis underlie the impact of SARS-CoV-2 infection on the brain. Understanding the role of these affected pathways in SARS-CoV-2 pathogenesis helps identify appropriate points of therapeutic interventions to alleviate neurological dysfunction observed during COVID-19.

Prolonged exposure to lung-derived cytokines is associated with inflammatory activation of microglia in patients with COVID-19 (preprint)

Neurological impairment is the most common finding in patients with post-acute sequelae of COVID-19. Furthermore, survivors of pneumonia from any cause have an elevated risk of dementia. Dysfunction in microglia, the primary immune cell in the brain, has been linked to cognitive impairment in murine models of dementia and in humans. Here, we report a transcriptional response in human microglia collected from patients who died following COVID-19 suggestive of their activation by TNF- and other circulating pro-inflammatory cytokines. Consistent with these findings, the levels of 55 alveolar and plasma cytokines were elevated in a cohort of 341 patients with respiratory failure, including 93 unvaccinated patients with COVID-19 and 203 patients with other causes of pneumonia. While peak levels of pro-inflammatory cytokines were similar in patients with pneumonia irrespective of etiology, cumulative cytokine exposure was higher in patients with COVID-19. Corticosteroid treatment, which has been shown to be beneficial in patients with COVID-19, was associated with lower levels of CXCL10, CCL8, and CCL2 - molecules that sustain inflammatory circuits between alveolar macrophages harboring SARS-CoV-2 and activated T cells. These findings suggest that corticosteroids may break this cycle and decrease systemic exposure to lung-derived cytokines and inflammatory activation of microglia in patients with COVID-19.

Identification of predictive patient characteristics for assessing the probability of COVID-19 in-hospital mortality (preprint)

As the world emerges from the COVID-19 pandemic, there is an urgent need to understand patient factors that may be used to predict the occurrence of severe cases and patient mortality. Approximately 20% of SARS-CoV-2 infections lead to acute respiratory distress syndrome caused by the harmful actions of inflammatory mediators. Patients with severe COVID-19 are often afflicted with neurologic symptoms, and individuals with pre-existing neurodegenerative disease have an increased risk of severe COVID-19. Although collectively, these observations point to a bidirectional relationship between severe COVID-19 and neurologic disorders, little is known about the underlying mechanisms. Here, we analyzed the electronic health records of 471 patients with severe COVID-19 to identify clinical characteristics most predictive of mortality. Feature discovery was conducted by training a regularized logistic regression classifier that serves as a machine-learning model with an embedded feature selection capability. SHAP analysis using the trained classifier revealed that a small ensemble of readily observable clinical features, including characteristics associated with cognitive impairment, could predict in-hospital mortality with an accuracy greater than 0.85 (expressed as the area under the ROC curve of the classifier). These findings have important implications for the prioritization of clinical measures used to identify patients with COVID-19 (and, potentially, other forms of acute respiratory distress syndrome) having an elevated risk of death.

Genetic Risk Factors for Severe and Fatigue Dominant Long COVID and Commonalities with ME/CFS Identified by Combinatorial Analysis (preprint)

Background Long COVID is a debilitating chronic condition that has affected over 100 million people globally. It is characterized by a diverse array of symptoms, including fatigue, cognitive dysfunction and respiratory problems. Studies have so far largely failed to identify genetic associations, the mechanisms behind the disease, or any common pathophysiology with other conditions such as ME/CFS that present with similar symptoms. Methods We used a combinatorial analysis approach to identify combinations of genetic variants significantly associated with the development of long COVID and to examine the biological mechanisms underpinning its various symptoms. We compared two subpopulations of long COVID patients from Sano Genetics' Long COVID GOLD study cohort, focusing on patients with severe or fatigue dominant phenotypes. We evaluated the genetic signatures previously identified in an ME/CFS population against this long COVID population to understand similarities with other fatigue disorders that may be triggered by a prior viral infection. Finally, we also compared the output of this long COVID analysis against known genetic associations in other chronic diseases, including a range of metabolic and neurological disorders, to understand the overlap of pathophysiological mechanisms. Results Combinatorial analysis identified 73 genes that were highly associated with at least one of the long COVID populations included in this analysis. Of these, 9 genes have prior associations with acute COVID-19, and 14 were differentially expressed in a transcriptomic analysis of long COVID patients. A pathway enrichment analysis revealed that the biological pathways most significantly associated with the 73 long COVID genes were mainly aligned with neurological and cardiometabolic diseases. Expanded genotype analysis suggests that specific SNX9 genotypes are a significant contributor to the risk of or protection against severe long COVID infection, but that the gene-disease relationship is context dependent and mediated by interactions with KLF15 and RYR3. Comparison of the genes uniquely associated with the Severe and Fatigue Dominant long COVID patients revealed significant differences between the pathways enriched in each subgroup. The genes unique to Severe long COVID patients were associated with immune pathways such as myeloid differentiation and macrophage foam cells. Genes unique to the Fatigue Dominant subgroup were enriched in metabolic pathways such as MAPK/JNK signaling. We also identified overlap in the genes associated with Fatigue Dominant long COVID and ME/CFS, including several involved in circadian rhythm regulation and insulin regulation. Overall, 39 SNPs associated in this study with long COVID can be linked to 9 genes identified in a recent combinatorial analysis of ME/CFS patient from UK Biobank. Among the 73 genes associated with long COVID, 42 are potentially tractable for novel drug discovery approaches, with 13 of these already targeted by drugs in clinical development pipelines. From this analysis for example, we identified TLR4 antagonists as repurposing candidates with potential to protect against long term cognitive impairment pathology caused by SARS-CoV-2. We are currently evaluating the repurposing potential of these drug targets for use in treating long COVID and/or ME/CFS. Conclusion This study demonstrates the power of combinatorial analytics for stratifying heterogeneous populations in complex diseases that do not have simple monogenic etiologies. These results build upon the genetic findings from combinatorial analyses of severe acute COVID-19 patients and an ME/CFS population and we expect that access to additional independent, larger patient datasets will further improve the disease insights and validate potential treatment options in long COVID.

A Systematic Review of Diffusion Microstructure Imaging (Dmi): Current and Future Applications in Neurology Research (preprint)

Background: Diffusion microstructure imaging (DMI) is a novel diffusion magnetic resonance imaging (MRI) technique that provides rich estimates of microscopic tissue properties, such as axon morphologies and fiber configurations. DMI has potential applications in neurology, where various diseases and disorders affect the brain tissue's microstructure and connectivity.Objectives: To investigate the current and future applications of DMI in neurology, covering various diseases and disorders such as brain tumors and metastases, Parkinson's syndromes, COVID-19-related neurological symptoms, temporal lobe epilepsy, and acute ischemic stroke.Methods: The PRISMA 2020 statement was followed. Four electronic databases were searched from inception to May the 5th 2023. Two reviewers independently screened, selected, and extracted data from the eligible studies.Results: Seven studies were included in the review. The studies showed that DMI can differentiate between various neurological diseases or disorders based on alterations in brain tissue microstructure and connectivity. The studies also showed that DMI can be superior to conventional diffusion imaging techniques, such as diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI), in detecting subtle differences between pathological conditions.Conclusions: DMI is a powerful diffusion imaging technique that can provide rich estimates of microscopic tissue properties and differentiate between various neurological diseases or disorders. However, more research is needed to compare DMI with other imaging modalities or clinical measures and to evaluate longitudinal changes or treatment effects using DMI in neurological diseases or disorders.

Long-term outcomes of hospitalized SARS-CoV-2/COVID-19 patients with and without neurological involvement: 3-year follow-up assessment (preprint)

Background and ObjectivesAcute neurological manifestations are a common complication of acute COVID-19 disease. This study investigated the 3-year outcomes of patients with and without significant neurological manifestations during initial COVID-19 hospitalization. MethodsPatients infected by SARS-CoV-2 between March 1 and April 16, 2020 and hospitalized in the Montefiore Health System in the Bronx, an epicenter of the early pandemic, were included. Follow-up data was captured up to January 23, 2023 (3 years post COVID-19). This cohort consisted of 414 COVID-19 patients with significant neurological manifestations and 1199 propensity-matched COVID- 19 patients without neurological manifestations. Primary outcomes were mortality, stroke, heart attack, major adverse cardiovascular events (MACE), reinfection, and hospital readmission post-discharge. Secondary outcomes were clinical neuroimaging findings (hemorrhage, active stroke, prior stroke, mass effect, and microhemorrhage, white-matter changes, microvascular disease, and volume loss). Predictive models were used to identify risk factors of mortality post-discharge. ResultsMore patients in the neurological cohort were discharged to acute rehabilitation (10.54% vs 3.68%, p<0.0001), skilled nursing facilities (30.67% vs 20.78%, p=0.0002) and fewer to home (55.27% vs 70.21%, p<0.0001) compared to the matched controls. Incidence of readmission for any medical reason (65.70% vs 60.72%, p=0.036), stroke (6.28% vs 2.34%, p<0.0001), and MACE (20.53% vs 16.51%, p=0.032) was higher in the neurological cohort post-discharge. Neurological patients were more likely to die post-discharge (58 (14.01%) vs 94 (7.84%), p=0.0001) compared to controls (HR=2.346, 95% CI=(1.586, 3.470), p<0.0001). The major causes of death post-discharge were heart disease (14.47%), sepsis (13.82%), influenza and pneumonia (11.18%), COVID-19 (8.55%) and acute respiratory distress syndrome (7.89%). Factors associated with mortality after leaving the hospital were belonging to the neurological cohort (OR=1.802 (1.237, 2.608), p=0.002), discharge disposition (OR=1.508, 95% CI=(1.276, 1.775), p<0.0001), congestive heart failure (OR=2.281 (1.429, 3.593), p=0.0004), higher COVID-19 severity score (OR=1.177 (1.062, 1.304), p=0.002), and older age (OR=1.027 (1.010, 1.044), p=0.002). There were no group differences in gross radiological findings, except the neurological cohort showed significantly more age-adjusted brain volume loss (p<0.05) compared to controls. DiscussionCOVID-19 patients with neurological manifestations have worse long-term outcomes compared to matched controls. These findings raise awareness and the need for closer monitoring and timely interventions for COVID-19 patients with neurological manifestations.

Neurologic manifestations associated with COVID-19: a multicentre registry.

OBJECTIVES: To provide an overview of the spectrum, characteristics and outcomes of neurologic manifestations associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: We conducted a single-centre retrospective study during the French coronavirus disease 2019 (COVID-19) epidemic in March-April 2020. All COVID-19 patients with de novo neurologic manifestations were eligible. RESULTS: We included 222 COVID-19 patients with neurologic manifestations from 46 centres in France. Median (interquartile range, IQR) age was 65 (53-72) years and 136 patients (61.3%) were male. COVID-19 was severe or critical in 102 patients (45.2%). The most common neurologic diseases were COVID-19-associated encephalopathy (67/222, 30.2%), acute ischaemic cerebrovascular syndrome (57/222, 25.7%), encephalitis (21/222, 9.5%) and Guillain-Barré syndrome (15/222, 6.8%). Neurologic manifestations appeared after the first COVID-19 symptoms with a median (IQR) delay of 6 (3-8) days in COVID-19-associated encephalopathy, 7 (5-10) days in encephalitis, 12 (7-18) days in acute ischaemic cerebrovascular syndrome and 18 (15-28) days in Guillain-Barré syndrome. Brain imaging was performed in 192 patients (86.5%), including 157 magnetic resonance imaging (70.7%). Among patients with acute ischaemic cerebrovascular syndrome, 13 (22.8%) of 57 had multiterritory ischaemic strokes, with large vessel thrombosis in 16 (28.1%) of 57. Brain magnetic resonance imaging of encephalitis patients showed heterogeneous acute nonvascular lesions in 14 (66.7%) of 21. Cerebrospinal fluid of 97 patients (43.7%) was analysed, with pleocytosis found in 18 patients (18.6%) and a positive SARS-CoV-2 PCR result in two patients with encephalitis. The median (IQR) follow-up was 24 (17-34) days with a high short-term mortality rate (28/222, 12.6%). CONCLUSIONS: Clinical spectrum and outcomes of neurologic manifestations associated with SARS-CoV-2 infection were broad and heterogeneous, suggesting different underlying pathogenic processes.