NO CSF BIOMARKER EVIDENCE OF PERSISTING CNS INFECTION AFTER SARS-CoV-2 INFECTION

Background: Neurocognitive symptoms are common in acute as well as convalescent (post-acute sequelae of COVID-19 [PASC]) COVID-19, but mechanisms of CNS pathogenesis are unclear. The aim of this study was to investigate cerebrospinal fluid (CSF) biomarker evidence of CNS infection, immune activation and neuronal injury in convalescent compared with acute infection. Method(s): We included 68 (35% female) patients >=18 years with CSF sampled during acute (46), 3-6 months after (22) SARS-CoV-2 infection or both (17), and 20 (70% female) healthy controls from longitudinal studies. The 22 patients sampled only at 3-6 months were recruited in a PASC protocol. CSF N-Ag was analyzed using an ultrasensitive antigen capture immunoassay platform (S-PLEX SARS-CoV-2 N Kit, Meso Scale Diagnostics, LLC. Rockville, MD). Additional analyses included CSF beta2-microglobulin (beta2M)], IFN-gamma, IL-6, TNF-alpha neurofilament light (NfL), and total and phosphorylated tau. Log-transformed CSF biomarkers were compared using ANOVA (Tukey post-hoc test). Result(s): Patients sampled during acute infection had moderate (27) or severe (19) COVID-19. In patients sampled at 3-6 months, corresponding initial severity was 10 (mild), 14 (moderate), and 15 (severe). At 3-6 months, 31/39 patients reported neurocognitive symptoms;8/17 patients also sampled during acute infection reported full recovery after 3-6 months. CSF biomarker results are shown in Figure 1. SARS-CoV-2 RNA was universally undetectable. N-Ag was detectable only during acute infection (32/35) but was undetectable in all follow up and control samples. Significantly higher CSF concentrations of beta2M (p< 0.0001), IFN-gamma (p=0.02), IL-6 (p< 0.0001) and NfL (p=0.04) were seen in acute compared to post-infection. Compared to controls, beta2M (p< .0001), IL-6 (p< 0.0001) and NfL (p=0.005) were significantly higher in acute infection. No biomarker differences were seen post-infection compared with controls. No differences were seen in CSF GFAp, t-tau or p-tau. Conclusion(s): We found no evidence of residual infection (RNA, N-Ag), inflammation (beta2M, IL-6, IFN-gamma, TNF-alpha), astrocyte activity (GFAp) or neuronal injury (NfL, tau) 3-6 months after initial COVID-19, while significantly higher concentrations of several markers were found during acute infection, suggesting that PASC may be a consequence of earlier injury rather than active CNS damage. CSF beta2M, IL-6, IFN-gamma and NfL were significantly lower after 3-6 months than during acute COVID-19 and not different from healthy controls. (Figure Presented).

Nanopore single-molecule analysis of biomarkers: Providing possible clues to disease diagnosis

Biomarker detection has attracted increasing interest in recent years due to the minimally or non-invasive sampling process. Single entity analysis of biomarkers is expected to provide real-time and accurate biological information for early disease diagnosis and prognosis, which is critical to the effective disease treatment and is also important in personalized medicine. As an innovative single entity analysis method, nanopore sensing is a pioneering single-molecule detection technique that is widely used in analytical bioanalytical fields. In this review, we overview the recent progress of nanopore biomarker detection as new approaches to disease diagnosis. In highlighted studies, nanopore was focusing on detecting biomarkers of different categories of communicable and noncommunicable diseases, such as pandemic COVID-19, AIDS, cancers, neurologic diseases, etc. Various sensitive and selective nanopore detecting strategies for different types of biomarkers are summarized. In addition, the challenges, opportunities, and direction for future development of nanopore-based biomarker sensors are also discussed.Copyright © 2023 Elsevier B.V.

The Risk of COVID-19 in Patients of Chronic Kidney Disease with Cognitive Dysfunction Like Alzheimer Disease: A Perspective on Erythropoietin as a Potential Adjuvant Therapy

Background: The universal risk to mankind, coronavirus disease 2019 (COVID-19), shares etiological cofactors with a variety of diseases, including anemic chronic kidney disease patients (CKD) with cognitive dysfunction like Alzheimer disease (AD). Understanding the shared links between COVID-19 and CKD, as well as cognitive impairment such as AD, might aid in designing therapeutic ways to combat both. Given the need of developing COVID-19 medicine, the connection and symptoms of CKD with cognitive impairment have been reviewed here, with a focus on memory and learning disturbance. Objective(s): COVID-19 and CKD with cognitive dysfunction share angiotensin-converting enzyme 2 receptors, and AD indicators include amyloid, tau protein, and glycogen synthase kinase-3beta. Anemia in patients with CKD and pulmonary fibrosis is frequently treated with recombinant human erythropoietin (rHuEPO). Through nitric oxide stimulation, neuroprotection, and various organ hypoxias, rHuEPO promotes red blood cells (RBC) growth while also assisting oxygen delivery. Results and Conclusion(s): In COVID-19, rHuEPO may be advantageous. The common etiological variables and manifestations outlined in this review could aid in the development of therapeutic options for COVID-19 and CKD with cognitive impairment, such as AD, and so help to eliminate the ongoing universal risk. Copyright © 2022 Wolters Kluwer Medknow Publications. All rights reserved.

New Insights into the Molecular Interplay between Human Herpesviruses and Alzheimer's Disease-A Narrative Review.

Human herpesviruses (HHVs) have been implicated as possible risk factors in Alzheimer's disease (AD) pathogenesis. Persistent lifelong HHVs infections may directly or indirectly contribute to the generation of AD hallmarks: amyloid beta (Aß) plaques, neurofibrillary tangles composed of hyperphosphorylated tau proteins, and synaptic loss. The present review focuses on summarizing current knowledge on the molecular mechanistic links between HHVs and AD that include processes involved in Aß accumulation, tau protein hyperphosphorylation, autophagy, oxidative stress, and neuroinflammation. A PubMed search was performed to collect all the available research data regarding the above mentioned mechanistic links between HHVs and AD pathology. The vast majority of research articles referred to the different pathways exploited by Herpes Simplex Virus 1 that could lead to AD pathology, while a few studies highlighted the emerging role of HHV 6, cytomegalovirus, and Epstein-Barr Virus. The elucidation of such potential links may guide the development of novel diagnostics and therapeutics to counter this devastating neurological disorder that until now remains incurable.

Portable Vertical Graphene@Au-Based Electrochemical Aptasensing Platform for Point-of-Care Testing of Tau Protein in the Blood.

Alzheimer's disease (AD) is a long-term neurodegenerative disease that poses a serious threat to human life and health. It is very important to develop a portable quantitative device for AD diagnosis and personal healthcare. Herein, we develop a portable electrochemical sensing platform for the point-of-care detection of AD biomarkers in the blood. Such a portable platform integrates nanoAu-modified vertical graphene (VG@Au) into a working electrode, which can significantly improve sensitivity and reduce detection limit due to the large specific surface, excellent electrical conductivity, high stability, and good biocompatibility. The tau protein, as an important factor in the course of AD, is selected as a key AD biomarker. The results show that the linear range of this sensing platform is 0.1 pg/mL to 1 ng/mL, with a detection limit of 0.034 pg/mL (S/N = 3), indicating that this portable sensing platform meets the demand for the detection of the tau protein in the blood. This work offers great potential for AD diagnosis and personal healthcare.

A CLASSIC CASE OF CREUTZFELDT-JAKOB DISEASE (CJD)

CASE: A 64-year-old woman was brought in by husband for inability to care for patient. Previously active, she developed gait instability, slurred speech, and memory lapse to the point of selective mutism and being bed-bound within three months. Her medical history was notable for hypertension and Covid four months prior. She had had mild upper respiratory symptoms and recovered in ten days. Examination revealed general encephalopathy, dysarthria, limited ability to follow commands. She had decreased strength but increased tone and rigidity in all extremities. She had rhythmic jaw movement and bradykinesia with scatter myoclonic movements. Cerebellar exam was notable for ataxia, but she had normal cranial nerve and sensory exams and normal reflexes. MRI of the brain revealed restricted diffusion and T2/Flair signal abnormality involving bilateral basal ganglia, ventral medial thalami, hippocampi, and cerebral cortices. Toxic metabolic workup was unrevealing. CSF was positive for 14-3-3 protein and elevated total tau protein, confirming Creutzfeldt-Jakob disease. IMPACT/DISCUSSION: Creutzfeldt-Jakob Disease (CJD) is a prion disease with one in a million prevalence. Patients present with rapidly progressing dementia, myoclonus, and signs of cerebellar, corticospinal and extrapyramidal involvement including nystagmus, ataxia, hyperreflexia, spasticity, hypokinesia, bradykinesia, dystonia, and rigidity. CJD is fatal within months to two years. Patients with end stage disease may have akinetic mutism. Magnetic resonance imaging (MRI), electroencephalogram (EEG), and cerebrospinal fluid (CSF) analysis are important for evaluation of CJD. Most sensitive in early stages, MRI Brain commonly shows hyperintense signal involving the cerebral cortex, corpus striatum, caudate, and putamen. EEG may capture pattern of periodic bi-or triphasic period sharp wave complexes. CSF might detect 14-3-3 protein with elevation of tau protein but real-time quaking-induced conversion (RT-QuIC) has the highest specificity for diagnosis for CJD. Though brain biopsy is the sole method of definitive diagnosis, results of MRI, EEG, and CSF analysis along with presenting signs and symptoms are sufficient for clinical diagnosis of CJD. Our patient's dementia, myoclonus, ataxia, hypokinesia, bradykinesia, dystonia, and rigidity all progressing to akinetic mutism within three months are classic presentation of CJD. EEG was normal, but MRI with hyperintensity of basal ganglia and cerebral cortices and CSF analysis with positive 14-3-3 and elevated tau proteins are all lead to diagnosis of CJD. CONCLUSION: This case illustrates a classic case of a Creutzfeldt-Jakob Disease, a rare prion disease marked by rapidly progressive dementia with neuropsychiatric features.

18fluorodeoxyglucose (FDG) brain PET/CT as the only diagnostic tool able to identify early cognitive impairment in a covid-19 patient: a case-report

Background-Aim: Cognitive impairment may represent a long lasting symptom after COVID-19 resolution and FDG brain PET is useful to evaluate if brain metabolic changes are transient or long lasting. Hypometabolism was shown in many brain areas, i.e. cingulate cortex, bilateral gyrus rectus, prefrontal and orbitofrontal cortex and cerebellar vermis. Methods: We report the case of a 62 years old man with type 2 diabetes, affected by COVID-19 infection in October 2020. After resolution, the patient had short-term memory loss and speech deficit affecting daily living and working activities and referred to the Gerontology and Geriatrics Institute (Univ. of Perugia). Neurological examination and neuropsychological tests were carried out and no alterations were found. In October 2021, the neurological examination was still normal, as well as neuropsychological tests. Brain MRI showed only two small chronic ischemic foci without bi-hemispheric white matter clinically significant abnormalities. In November 2021, the patient underwent FDG brain PET/CT (discovery ST, G.E.) according to standard protocols and images were evaluated both qualitatively and semiquantitatively. Results: An area of moderate significant hypometabolism was identified in the precuneus (predominant on the right side) and others multiple small and mild hypometabolic regions were localized in bilateral pre-frontal cortex, sensorimotor and parietal cortex both on left hemisphere. PET and MRI fusion images (Syngo.via VB10B image processing software, Siemens) showed that hypometabolic areas corresponded to structurally intact parenchyma at MRI. In January 2022 clinical and neuropsychological follow up did not evidence cognitive impairment, although the patient still felt depressed and impaired in memory, attention and daily living activities. Conclusions: In this case, FDG brain PET/CT was the only diagnostic procedure showing findings consistent with patient symptoms. In particular, precuneus hypometabolism may represent in this patient an early hallmark of dementia (i.e. Alzheimer's disease-AD), although other characteristic brain areas are not significantly impaired (i.e. cingulate cortex). In this case, FDG brain PET use, during follow up, could be crucial to evaluate if the metabolic changes may evolve into a chronic state, thus supporting mild cognitive impairment clinical suspect due to AD or confirming a stable COVID related neuronal damage. Furthermore, a second normal FDG brain PET/CT scan may suggest a post-acute infection transient phase, preluding to normal functional status. In conclusion, FDG brain PET/CT may represent an important diagnostic tool in modifying subsequent diagnostic assessment suggesting or routinely clinical follow up or other investigations for dementia (i.e. amyloid PET, amyloid and Tau protein liquor measurement). In our study, fused PET and MRI images were used, although hybrid PET/MRI system could be the choice option if available.

Alzheimer's Disease and Toxins Produced by Marine Dinoflagellates: An Issue to Explore.

This paper examined the toxins naturally produced by marine dinoflagellates and their effects on increases in ß-amyloid plaques along with tau protein hyperphosphorylation, both major drivers of Alzheimer's disease (AD). This approach is in line with the demand for certain natural compounds, namely those produced by marine invertebrates that have the potential to be used in the treatment of AD. Current advances in AD treatment are discussed as well as the main factors that potentially affect the puzzling global AD pattern. This study focused on yessotoxins (YTXs), gymnodimine (GYM), spirolides (SPXs), and gambierol, all toxins that have been shown to reduce ß-amyloid plaques and tau hyperphosphorylation, thus preventing the neuronal or synaptic dysfunction that ultimately causes the cell death associated with AD (or other neurodegenerative diseases). Another group of toxins described, okadaic acid (OA) and its derivatives, inhibit protein phosphatase activity, which facilitates the presence of phosphorylated tau proteins. A few studies have used OA to trigger AD in zebrafish, providing an opportunity to test in vivo the effectiveness of new drugs in treating or attenuating AD. Constraints on the production of marine toxins for use in these tests have been considered. Different lines of research are anticipated regarding the action of the two groups of toxins.

Longitudinal changes of neurospecific serum proteins in COVID-19 patients

INTRODUCTION/HYPOTHESIS: COVID-19 has been associated with distinct types of neuronal damage. We hypothesize that the progression of neurological damage will be related to an imbalance between neurodegeneration, neuroinflammatory, and neuroprotective markers, therefore suggesting a potential mechanism for the emergence of adverse, chronic outcomes. METHODS: 105 patients admitted to an urban, academic hospital with a diagnosis of COVID-19 were enrolled. Serum neuroprotective (clusterin, fetuin), neurodegenerative (τ, phosphorylated τ, amyloids, TDP43, NRGN, NCAM-1, and KLK6), and neuroinflammatory (CCL23, YKL40, MIF) markers were collected. These were analyzed longitudinally in conjunction with immune system activators (RAGE, IL-34) using the multiplex platform. Electronic medical records were used to collect demographic and clinical data. RESULTS: Of the 105 patients, 5 were diagnosed with stroke within 28 days of admission, followed by an additional 6 strokes occurring by 6 months, or a 9.5% occurrence of stroke overall. Serum levels of Amyloid β42 declined significantly for the general population 7 days after admission when compared to initial collections (p< 0.001), while Amyloid β40, KLK6, and MIF declined and recovered within the same 7 days (p< 0.001, p< 0.001, p=0.003). The neuroprotective markers fetuin and clusterin were particularly dynamic with fetuin decreasing and restoring in less than 7 days (p=0.02) and clusterin remaining low after admission (p< 0.001). Most patients had persistently elevated CCL23 levels, with the stroke patient cohort having the highest values (p=0.018). The IL-6 levels of stroke patients were significantly higher compared to their non-stroke counterparts one week after admission (p=0.001), while IL-8 levels fluctuated before declining (p< 0.001). CONCLUSIONS: Our data reveals elevations in neuronal damage in the 7 days following hospital admission for COVID-19 patients. The down-regulation of fetuin and clusterin is particularly compelling as their declines may be linked to the elevated neuronal injury seen with increased neuroinflammatory markers, specifically CCL23 and IL-6. Serum levels of neurodegeneration markers proved complex, therefore possibly suggesting a more dynamic relationship to the neural abnormalities seen in COVID-19 patients.

Cross-Sectional Exploration of Plasma Biomarkers of Alzheimer's Disease in Down Syndrome: Early Data from the Longitudinal Investigation for Enhancing Down Syndrome Research (LIFE-DSR) Study.

With improved healthcare, the Down syndrome (DS) population is both growing and aging rapidly. However, with longevity comes a very high risk of Alzheimer's disease (AD). The LIFE-DSR study (NCT04149197) is a longitudinal natural history study recruiting 270 adults with DS over the age of 25. The study is designed to characterize trajectories of change in DS-associated AD (DS-AD). The current study reports its cross-sectional analysis of the first 90 subjects enrolled. Plasma biomarkers phosphorylated tau protein (p-tau), neurofilament light chain (NfL), amyloid ß peptides (Aß1-40, Aß1-42), and glial fibrillary acidic protein (GFAP) were undertaken with previously published methods. The clinical data from the baseline visit include demographics as well as the cognitive measures under the Severe Impairment Battery (SIB) and Down Syndrome Mental Status Examination (DS-MSE). Biomarker distributions are described with strong statistical associations observed with participant age. The biomarker data contributes to understanding DS-AD across the spectrum of disease. Collectively, the biomarker data show evidence of DS-AD progression beginning at approximately 40 years of age. Exploring these data across the full LIFE-DSR longitudinal study population will be an important resource in understanding the onset, progression, and clinical profiles of DS-AD pathophysiology.

Cerebrospinal fluid findings in neurological diseases associated with COVID-19 and insights into mechanisms of disease development.

OBJECTIVES: To analyze the cerebrospinal fluid (CSF) of patients with SARS-CoV-2 infection and neurological manifestations to provide evidence for the understanding of mechanisms associated with central nervous system (CNS) involvement in COVID-19. METHODS: Patients (n = 58) were grouped according to their main neurological presentation: headache (n = 14); encephalopathy (n = 24); inflammatory neurological diseases, including meningoencephalitis (n = 4), acute myelitis (n = 3), meningitis (n = 2), acute disseminated encephalomyelitis (ADEM) (n = 2), encephalitis (n = 2), and neuromyelitis optica (n = 1); and Guillain-Barré syndrome (n = 6). Data regarding age, sex, cerebrovascular disease, and intracranial pressure were evaluated in combination with CSF profiles defined by cell counts, total protein and glucose levels, concentration of total Tau and neurofilament light chain (NfL) proteins, oligoclonal band patterns, and detection of SARS-CoV-2 RNA. RESULTS: CSF of patients with inflammatory neurological diseases was characterized by pleocytosis and elevated total protein and NfL levels. Patients with encephalopathy were mostly older men (mean age of 61.0 ± 17.6 years) with evidence of cerebrovascular disease. SARS-CoV-2 RNA in CSF was detected in 2 of 58 cases: a patient with refractory headache, and another patient who developed ADEM four days after onset of COVID-19 symptoms. Three patients presented intrathecal IgG synthesis, and four had identical oligoclonal bands in CSF and serum, indicating systemic inflammation. CONCLUSION: Patients with neurological manifestations associated with COVID-19 had diverse CSF profiles, even within the same clinical condition. Our findings indicate a possible contribution of viral replication on triggering CNS infiltration by immune cells and the subsequent inflammation promoting neuronal injury.