High frequency of cerebrospinal fluid autoantibodies in COVID-19 patients with neurological symptoms

BACKGROUND

COVID-19 intensive care patients can present with neurological syndromes, usually in the absence of SARS-CoV-2 in cerebrospinal fluid (CSF). The recent finding of some virus-neutralizing antibodies cross-reacting with brain tissue suggests the possible involvement of specific autoimmunity.

DESIGN

Blood and CSF samples from eleven critically ill COVID-19 patients presenting with unexplained neurological symptoms including myoclonus, oculomotor disturbance, delirium, dystonia and epileptic seizures, were analyzed for anti-neuronal and anti-glial autoantibodies.

RESULTS

Using cell-based assays and indirect immunofluorescence on unfixed murine brain sections, all patients showed anti-neuronal autoantibodies in serum or CSF. Antigens included intracellular and neuronal surface proteins, such as Yo or NMDA receptor, but also various specific undetermined epitopes, reminiscent of the brain tissue binding observed with certain human monoclonal SARS-CoV-2 antibodies. These included vessel endothelium, astrocytic proteins and neuropil of basal ganglia, hippocampus or olfactory bulb.

CONCLUSION

The high frequency of autoantibodies targeting the brain in the absence of other explanations suggests a causal relationship to clinical symptoms, in particular to hyperexcitability (myoclonus, seizures). Several underlying autoantigens and their potential molecular mimicry with SARS-CoV-2 still await identification. However, autoantibodies may already now explain some aspects of multi-organ disease in COVID-19 and can guide immunotherapy in selected cases.

Neurological Manifestations of COVID-19 Feature T Cell Exhaustion and Dedifferentiated Monocytes in Cerebrospinal Fluid

Patients suffering from Coronavirus disease 2019 (COVID-19) can develop neurological sequelae, such as headache and neuroinflammatory or cerebrovascular disease. These conditions—termed here as Neuro-COVID—are more frequent in patients with severe COVID-19. To understand the etiology of these neurological sequelae, we utilized single-cell sequencing and examined the immune cell profiles from the cerebrospinal fluid (CSF) of Neuro-COVID patients compared with patients with non-inflammatory and autoimmune neurological diseases or with viral encephalitis. The CSF of Neuro-COVID patients exhibited an expansion of dedifferentiated monocytes and of exhausted CD4⁺ T cells. Neuro-COVID CSF leukocytes featured an enriched interferon signature; however, this was less pronounced than in viral encephalitis. Repertoire analysis revealed broad clonal T cell expansion and curtailed interferon response in severe compared with mild Neuro-COVID patients. Collectively, our findings document the CSF immune compartment in Neuro-COVID patients and suggest compromised antiviral responses in this setting.

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Single-cell atlas of cerebrospinal fluid in Neuro-COVID and controls

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Expansion of dedifferentiated monocytes and exhausted CD4⁺ T cells in Neuro-COVID

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Less pronounced interferon signature in Neuro-COVID than in viral encephalitis

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Curtailed interferon-response in severe Neuro-COVID

Cerebrospinal fluid in COVID-19: A systematic review of the literature

OBJECTIVE

We sought to review the literature on cerebrospinal fluid (CSF) testing in patients with COVID-19 for evidence of viral neuroinvasion by SARS-CoV-2.

METHODS

We performed a systematic review of Medline and Embase between December 1, 2019 and November 18, 2020 to identify case reports or series of patients who had COVID-19 diagnosed based on positive SARS-CoV-2 polymerase chain reaction (PCR) or serologic testing and had CSF testing due to a neurologic symptom.

RESULTS

We identified 242 relevant documents which included 430 patients with COVID-19 who had acute neurological symptoms prompting CSF testing. Of those, 321 (75%) patients had symptoms that localized to the central nervous system (CNS). Of 304 patients whose CSF was tested for SARS-CoV-2 PCR, there were 17 (6%) whose test was positive, all of whom had symptoms that localized to the central nervous system (CNS). The majority (13/17, 76%) of these patients were admitted to the hospital because of neurological symptoms. Of 58 patients whose CSF was tested for SARS-CoV-2 antibody, 7 (12%) had positive antibodies with evidence of intrathecal synthesis, all of whom had symptoms that localized to the CNS. Of 132 patients who had oligoclonal bands evaluated, 3 (2%) had evidence of intrathecal antibody synthesis. Of 77 patients tested for autoimmune antibodies in the CSF, 4 (5%) had positive findings.

CONCLUSION

Detection of SARS-CoV-2 in CSF via PCR or evaluation for intrathecal antibody synthesis appears to be rare. Most neurological complications associated with SARS- CoV-2 are unlikely to be related to direct viral neuroinvasion.

COVID-19 and chronic fatigue syndrome: Is the worst yet to come?

There has been concern about possible long-term sequelae resembling myalgic encephalomyelitis/chronic fatigue syndrome in COVID-19 patients. Clarifying the mechanisms underlying such a "post-COVID-19 fatigue syndrome" is essential for the development of preventive and early treatment methods for this syndrome. In the present paper, by integrating insights pertaining to the glymphatic system and the nasal cerebrospinal fluid outflow pathway with findings in patients with chronic fatigue syndrome, idiopathic intracranial hypertension, and COVID-19, I provide a coherent conceptual framework for understanding the pathophysiology of post-COVID-19 fatigue syndrome. According to this hypothesis, this syndrome may result from damage to olfactory sensory neurons, causing reduced outflow of cerebrospinal fluid through the cribriform plate, and further leading to congestion of the glymphatic system with subsequent toxic build-up within the central nervous system. I further postulate that patients with post-COVID-19 fatigue syndrome may benefit from cerebrospinal fluid drainage by restoring glymphatic transport and waste removal from the brain. Obviously, further research is required to provide further evidence for the presence of this post-viral syndrome, and to provide additional insight regarding the relative contribution of the glymphatic-lymphatic system to it. Other mechanisms may also be involved. If confirmed, the glymphatic-lymphatic system could represent a target in combating post-COVID-19 fatigue syndrome. Moreover, further research in this area could also provide new insights into the understanding of chronic fatigue syndrome.

Cerebrospinal fluid findings in COVID-19: a multicenter study of 150 lumbar punctures in 127 patients

BACKGROUND

Comprehensive data on the cerebrospinal fluid (CSF) profile in patients with COVID-19 and neurological involvement from large-scale multicenter studies are missing so far.

OBJECTIVE

To analyze systematically the CSF profile in COVID-19.

METHODS

Retrospective analysis of 150 lumbar punctures in 127 patients with PCR-proven COVID-19 and neurological symptoms seen at 17 European university centers RESULTS: The most frequent pathological finding was blood-CSF barrier (BCB) dysfunction (median QAlb 11.4 [6.72-50.8]), which was present in 58/116 (50%) samples from patients without pre-/coexisting CNS diseases (group I). QAlb remained elevated > 14d (47.6%) and even > 30d (55.6%) after neurological onset. CSF total protein was elevated in 54/118 (45.8%) samples (median 65.35 mg/dl [45.3-240.4]) and strongly correlated with QAlb. The CSF white cell count (WCC) was increased in 14/128 (11%) samples (mostly lympho-monocytic; median 10 cells/µl, > 100 in only 4). An albuminocytological dissociation (ACD) was found in 43/115 (37.4%) samples. CSF L-lactate was increased in 26/109 (24%; median 3.04 mmol/l [2.2-4]). CSF-IgG was elevated in 50/100 (50%), but was of peripheral origin, since QIgG was normal in almost all cases, as were QIgA and QIgM. In 58/103 samples (56%) pattern 4 oligoclonal bands (OCB) compatible with systemic inflammation were present, while CSF-restricted OCB were found in only 2/103 (1.9%). SARS-CoV-2-CSF-PCR was negative in 76/76 samples. Routine CSF findings were normal in 35%. Cytokine levels were frequently elevated in the CSF (often associated with BCB dysfunction) and serum, partly remaining positive at high levels for weeks/months (939 tests). Of note, a positive SARS-CoV-2-IgG-antibody index (AI) was found in 2/19 (10.5%) patients which was associated with unusually high WCC in both of them and a strongly increased interleukin-6 (IL-6) index in one (not tested in the other). Anti-neuronal/anti-glial autoantibodies were mostly absent in the CSF and serum (1509 tests). In samples from patients with pre-/coexisting CNS disorders (group II [N = 19]; including multiple sclerosis, JC-virus-associated immune reconstitution inflammatory syndrome, HSV/VZV encephalitis/meningitis, CNS lymphoma, anti-Yo syndrome, subarachnoid hemorrhage), CSF findings were mostly representative of the respective disease.

CONCLUSIONS

The CSF profile in COVID-19 with neurological symptoms is mainly characterized by BCB disruption in the absence of intrathecal inflammation, compatible with cerebrospinal endotheliopathy. Persistent BCB dysfunction and elevated cytokine levels may contribute to both acute symptoms and 'long COVID'. Direct infection of the CNS with SARS-CoV-2, if occurring at all, seems to be rare. Broad differential diagnostic considerations are recommended to avoid misinterpretation of treatable coexisting neurological disorders as complications of COVID-19.

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.

Central and peripheral nervous system involvement by COVID-19: a systematic review of the pathophysiology, clinical manifestations, neuropathology, neuroimaging, electrophysiology, and cerebrospinal fluid findings

BACKGROUND

SARS-CoV-2 can affect the human brain and other neurological structures. An increasing number of publications report neurological manifestations in patients with COVID-19. However, no studies have comprehensively reviewed the clinical and paraclinical characteristics of the central and peripheral nervous system's involvement in these patients. This study aimed to describe the features of the central and peripheral nervous system involvement by COVID-19 in terms of pathophysiology, clinical manifestations, neuropathology, neuroimaging, electrophysiology, and cerebrospinal fluid findings.

METHODS

We conducted a comprehensive systematic review of all the original studies reporting patients with neurological involvement by COVID-19, from December 2019 to June 2020, without language restriction. We excluded studies with animal subjects, studies not related to the nervous system, and opinion articles. Data analysis combined descriptive measures, frequency measures, central tendency measures, and dispersion measures for all studies reporting neurological conditions and abnormal ancillary tests in patients with confirmed COVID-19.

RESULTS

A total of 143 observational and descriptive studies reported central and peripheral nervous system involvement by COVID-19 in 10,723 patients. Fifty-one studies described pathophysiologic mechanisms of neurological involvement by COVID-19, 119 focused on clinical manifestations, 4 described neuropathology findings, 62 described neuroimaging findings, 28 electrophysiology findings, and 60 studies reported cerebrospinal fluid results. The reviewed studies reflect a significant prevalence of the nervous system's involvement in patients with COVID-19, ranging from 22.5 to 36.4% among different studies, without mortality rates explicitly associated with neurological involvement by SARS-CoV-2. We thoroughly describe the clinical and paraclinical characteristics of neurological involvement in these patients.

CONCLUSIONS

Our evidence synthesis led to a categorical analysis of the central and peripheral neurological involvement by COVID-19 and provided a comprehensive explanation of the reported pathophysiological mechanisms by which SARS-CoV-2 infection may cause neurological impairment. International collaborative efforts and exhaustive neurological registries will enhance the translational knowledge of COVID-19's central and peripheral neurological involvement and generate therapeutic decision-making strategies.

REGISTRATION

This review was registered in PROSPERO 2020 CRD42020193140 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020193140.

First Report of SARS-CoV-2 Detection in Cerebrospinal Fluid in a Child With Guillain-Barré Syndrome

Underlying mechanisms on the association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and neurologic complications are still poorly understood. Cases of Guillain-Barré Syndrome (GBS) have been linked to the SARS-CoV-2 infection as the result of dysregulated immune response with damage in neuronal tissues. In the current report, we present the first pediatric case of GBS with detection of SARS-CoV-2 in the cerebrospinal fluid (CFS). This unique case of COVID-19-associated GBS with detection of SARS-CoV-2 RNA in the CSF indicates direct viral involvement inducing peripheral nerve inflammation.

A Comprehensive Systematic Review of CSF analysis that defines Neurological Manifestations of COVID-19

BACKGROUND

Limited literature exists on Cerebrospinal fluid (CSF) findings in COVID-19 patients with neurological symptoms. In this review, we conducted a descriptive analysis of CSF findings in patients with COVID-19 to understand prognosis and explore therapeutic options.

METHODS

We searched PubMed, Google Scholar, and Scopus databases using the keywords "SARS-CoV-2 in cerebrospinal fluid" and "SARS-CoV-2 and CNS Complications"" for reports of CSF findings in COVID-19 related neurological manifestations. Descriptive analyses were conducted to observe the CSF protein and cell counts based on age, gender, severity, fatality of COVID-19, and whether central (CNS) or peripheral nervous system (PNS) was associated.

RESULTS

A total of 113 patients were identified from 67 studies. Of these, 7 patients (6.2%) were fatal COVID-19 cases and 35 patients (31%) were considered severe COVID-19 cases. CSF protein was elevated in 100% (7/7) of the fatal cases with an average of 61.28 mg/dl and in 65.0% (52/80) in non-fatal cases with an average 56.73 mg/dl. CSF protein levels were elevated in 74.5% (38/51) patients with non-severe COVID-19 and 68.6% (24/35) in those with a severe COVID-19 infection. CSF cell count was increased in 43% of fatal cases, 25.7% severe cases, and 29.4% of non-severe cases.

CONCLUSION

Our analysis showed that the most common CSF findings situation in COVID-19 infection is elevated protein with, very occasionally, mild lymphocyte predominant pleocytosis. Further studies to elucidate the pathophysiology of neurological complications in COVID-19 are recommended.

Monoclonal antibodies protect aged rhesus macaques from SARS-CoV-2-induced immune activation and neuroinflammation

Anti-viral monoclonal antibody (mAb) treatments may provide immediate but short-term immunity from coronavirus disease 2019 (COVID-19) in high-risk populations, such as people with diabetes and the elderly; however, data on their efficacy in these populations are limited. We demonstrate that prophylactic mAb treatment blocks viral replication in both the upper and lower respiratory tracts in aged, type 2 diabetic rhesus macaques. mAb infusion dramatically curtails severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-mediated stimulation of interferon-induced chemokines and T cell activation, significantly reducing development of interstitial pneumonia. Furthermore, mAb infusion significantly dampens the greater than 3-fold increase in SARS-CoV-2-induced effector CD4 T cell influx into the cerebrospinal fluid. Our data show that neutralizing mAbs administered preventatively to high-risk populations may mitigate the adverse inflammatory consequences of SARS-CoV-2 exposure.

Cerebrospinal fluid cytokines in COVID-19: a review and meta-analysis

INTRODUCTION

Neurological involvement can occur in patients with SARS-CoV-2 infections, resulting in coronavirus disease 2019 (COVID-19). Cytokine alterations are associated with neurological symptoms in COVID-19. We performed a review of cytokines in the cerebrospinal fluid (CSF) of patients with COVID-19.

METHODS

Two reviewers independently searched PubMed for all relevant articles published prior to November 11, 2022. Active SARS-CoV-2 infection and CSF cytokine analyses were required for inclusion.

RESULTS

Three-hundred forty-six patients with COVID-19 and 356 controls from 28 studies were included. SARS-CoV-2 PCR was positive in the CSF of 0.9% (3/337) of patients with COVID-19. Thirty-seven different cytokines were elevated in the CSF of patients with COVID-19 when compared to controls and the standards set forth by individual assays used in each study. Of the 37 cytokines, IL-6 and IL-8 were most commonly elevated. CSF IL-6 is elevated in 60%, and CSF IL-8 is elevated in 51% of patients with COVID-19.

CONCLUSION

Levels of several inflammatory cytokines are elevated in the CSF of patients with COVID-19, and SARS-CoV-2 PCR is often not isolated in the CSF of patients with COVID-19. Many patients with COVID-19 have neurological symptoms and given the cytokine elevations in the absence of detectable viral RNA in cerebrospinal fluid; further study of the CSF cytokine profiles and pathogenesis of neurological symptoms in COVID-19 is needed.

The Significance of COVID-19 Immunological Status in Severe Neurological Complications and Multiple Sclerosis-A Literature Review

SARS-CoV-2/Coronavirus 2019 (COVID-19) is responsible for the pandemic, which started in December 2019. In addition to the typical respiratory symptoms, this virus also causes other severe complications, including neurological ones. In diagnostics, serological and polymerase chain reaction tests are useful not only in detecting past infections but can also predict the response to vaccination. It is now believed that an immune mechanism rather than direct viral neuroinvasion is responsible for neurological symptoms. For this reason, it is important to assess the presence of antibodies not only in the serum but also in the cerebrospinal fluid (CSF), especially in the case of neuro-COVID. A particular group of patients are people with multiple sclerosis (MS) whose disease-modifying drugs weaken the immune system and lead to an unpredictable serological response to SARS-CoV-2 infection. Based on available data, the article summarizes the current serological information concerning COVID-19 in CSF in patients with severe neurological complications and in those with MS.

In-vitro and in-vivo assessment of nirmatrelvir penetration into CSF, central nervous system cells, tissues, and peripheral blood mononuclear cells

Three years after SARS-CoV-2 emerged as a global infectious threat, the virus has become endemic. The neurological complications such as depression, anxiety, and other CNS complications after COVID-19 disease are increasing. The brain, and CSF have been shown as viral reservoirs for SARS-CoV-2, yielding a potential hypothesis for CNS effects. Thus, we investigated the CNS pharmacology of orally dosed nirmatrelvir/ritonavir (NMR/RTV). Using both an in vitro and an in vivo rodent model, we investigated CNS penetration and potential pharmacodynamic activity of NMR. Through pharmacokinetic modeling, we estimated the median CSF penetration of NMR to be low at 18.11% of plasma with very low accumulation in rodent brain tissue. Based on the multiples of the 90% maximal effective concentration (EC90) for SARS-CoV-2, NMR concentrations in the CSF and brain do not achieve an exposure level similar to that of plasma. A median of only 16% of all the predicted CSF concentrations in rats were > 3xEC90 (unadjusted for protein binding). This may have implications for viral persistence and neurologic post-acute sequelae of COVID-19 if increased NMR penetration in the CNS leads to decreased CNS viral loads and decreased CNS inflammation.

Targeted metabolomics identifies accurate CSF metabolite biomarkers for the differentiation between COVID-19 with neurological involvement and CNS infections with neurotropic viral pathogens

BACKGROUND

COVID-19 is primarily considered a respiratory tract infection, but it can also affect the central nervous system (CNS), which can result in long-term sequelae. In contrast to CNS infections by classic neurotropic viruses, SARS-CoV-2 is usually not detected in cerebrospinal fluid (CSF) from patients with COVID-19 with neurological involvement (neuro-COVID), suggesting fundamental differences in pathogenesis.

METHODS

To assess differences in CNS metabolism in neuro-COVID compared to CNS infections with classic neurotropic viruses, we applied a targeted metabolomic analysis of 630 metabolites to CSF from patients with (i) COVID-19 with neurological involvement [n = 16, comprising acute (n = 13) and post-COVID-19 (n = 3)], (ii) viral meningitis, encephalitis, or myelitis (n = 10) due to herpes simplex virus (n = 2), varicella zoster virus (n = 6), enterovirus (n = 1) and tick-borne encephalitis virus (n = 1), and (iii) aseptic neuroinflammation (meningitis, encephalitis, or myelitis) of unknown etiology (n = 21) as additional disease controls.

RESULTS

Standard CSF parameters indicated absent or low neuroinflammation in neuro-COVID. Indeed, CSF cell count was low in neuro-COVID (median 1 cell/µL, range 0-12) and discriminated it accurately from viral CNS infections (AUC = 0.99) and aseptic neuroinflammation (AUC = 0.98). 32 CSF metabolites passed quality assessment and were included in the analysis. Concentrations of differentially abundant (fold change ≥|1.5|, FDR ≤ 0.05) metabolites were both higher (9 and 5 metabolites) and lower (2 metabolites) in neuro-COVID than in the other two groups. Concentrations of citrulline, ceramide (d18:1/18:0), and methionine were most significantly elevated in neuro-COVID. Remarkably, triglyceride TG(20:1_32:3) was much lower (mean fold change = 0.09 and 0.11) in neuro-COVID than in all viral CNS infections and most aseptic neuroinflammation samples, identifying it as highly accurate biomarker with AUC = 1 and 0.93, respectively. Across all samples, TG(20:1_32:3) concentration correlated only moderately with CSF cell count (ρ = 0.65), protein concentration (ρ = 0.64), and Q-albumin (ρ = 0.48), suggesting that its low levels in neuro-COVID CSF are only partially explained by less pronounced neuroinflammation.

CONCLUSIONS

The results suggest that CNS metabolite responses in neuro-COVID differ fundamentally from viral CNS infections and aseptic neuroinflammation and may be used to discover accurate diagnostic biomarkers in CSF and to gain insights into differences in pathophysiology between neuro-COVID, viral CNS infections and aseptic neuroinflammation.

Clinical and CSF single-cell profiling of post-COVID-19 cognitive impairment

Natural history and mechanisms for persistent cognitive symptoms ("brain fog") following acute and often mild COVID-19 are unknown. In a large prospective cohort of people who underwent testing a median of 9 months after acute COVID-19 in the New York City/New Jersey area, we found that cognitive dysfunction is common; is not influenced by mood, fatigue, or sleepiness; and is correlated with MRI changes in very few people. In a subgroup that underwent cerebrospinal fluid analysis, there are no changes related to Alzheimer's disease or neurodegeneration. Single-cell gene expression analysis in the cerebrospinal fluid shows findings consistent with monocyte recruitment, chemokine signaling, cellular stress, and suppressed interferon response-especially in myeloid cells. Longitudinal analysis shows slow recovery accompanied by key alterations in inflammatory genes and increased protein levels of CXCL8, CCL3L1, and sTREM2. These findings suggest that the prognosis for brain fog following COVID-19 correlates with myeloid-related chemokine and interferon-responsive genes.

Impact of COVID-19 on the Prevalence and Drug Resistance of Bacteria Isolated From Bacterial Meningitis Cerebrospinal Fluid in Shandong Province: A Multicenter Retrospective Study

Our objective was to evaluate the ramifications of the 2019 coronavirus disease (COVID-19) pandemic on the microbial profile and antimicrobial resistance patterns of bacteria isolated from cerebrospinal fluid (CSF) specimens of patients with bacterial meningitis. We conducted a retrospective analysis of laboratory results and clinical records about positive CSF cultures reported by the SPARSS network from 2017 to 2023. The study covered three distinct periods: January 2017 to December 2019 (before the COVID-19 pandemic), January 2020 to December 2022 (during the COVID-19 pandemic), and January 2023 to December 2023 (after the COVID-19 pandemic), with a total of 5793 CSF isolates collected. Notably, the proportion of male patients (61.3%) was higher than that of females. After COVID-19, we observed a notable shift in the seasonal peak of CSF pathogens, with a delay of approximately 3 months. Remarkable alterations were evident in both pediatric and adult CSF isolate profiles. In children, the predominant pathogens included coagulase-negative Staphylococcus (CoNS), Streptococcus pneumonia, and Escherichia coli. Notably. After COVID-19, there was a significant decrease in the proportion of CoNS (p = 0.0039) and a notable increase in E. coli (p = 0.0067). In adults, the top three pathogens were CoNS, Acinetobacter baumannii, and Klebsiella pneumoniae. After the pandemic, we observed a significant reduction in the prevalence of A. baumannii (p = 0.0059), while the proportions of K. pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis increased significantly (p < 0.05). Additionally, among multidrug-resistant bacteria, the detection rate of carbapenem-resistant E. coli escalated (p = 0.0375). Antimicrobial susceptibility analysis indicated a declining trend in resistance rates for CoNS and A. baumannii to certain antibiotics following the pandemic. Conversely, resistance to imipenem in A. baumannii increased. In conclusion, the COVID-19 pandemic has significantly influenced the composition, antimicrobial resistance patterns, and epidemiological dynamics of CSF-isolated bacteria in Shandong province. To effectively address these changes, ongoing and dynamic surveillance of pathogen trends and antimicrobial resistance rate is essential.

A Comparison between Demyelinating and Omicron Variant Infection-Associated Optic Neuritis

BACKGROUND

The connection between viral infection and the onset of demyelination has garnered considerable attention. Omicron, the most recent prevalent strain of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised concerns. Optic neuritis (ON) associated with Omicron infection and spontaneous demyelinating ON may manifest distinct disease progressions. This study aims to contrast the features of these two distinct etiologies of ON.

METHODS

This case-control study comprised fifteen patients (21 eyes) diagnosed with Omicron infection-related ON and fifteen patients (24 eyes) with demyelinating ON serving as the control group. Clinical characteristics, cerebrospinal fluid (CSF) analysis, treatment protocols, and outcomes were compared between the two groups.

RESULTS

The Omicron-infected group exhibited a higher incidence of pain upon ocular movement (p = 0.023) and peripapillary hemorrhages (p = 0.046). In CSF analysis, there was an elevation in white cell counts (WCCs) (p = 0.004), with lymphocytes being the predominant cell type in the Omicron-related ON group. However, oligoclonal bands (OCBs), indicative of intrathecal synthesis, were significantly lower and lagged behind those of the demyelinating ON group (p = 0.021). SARS-CoV-2 RNA was not directly detected in the CSF of the Omicron-related ON group, and the degree of WCC elevation was closely linked with peripapillary hemorrhages (odds ratio = 0.029, p = 0.02). Additionally, the Omicron-related ON group displayed more pronounced ganglion cell loss following 3-month treatment (p = 0.02).

CONCLUSION

Omicron-related ON is distinguished by more pronounced clinical symptoms and distinct CSF characteristics compared to spontaneous demyelinating ON. The absence of viral RNA sequence in the CSF of Omicron-associated ON supports the use of steroid monotherapy; however, varying treatment options and prognoses should be considered for these two types of ON.

Elucidating SARS-CoV-2 neurotropism: a comprehensive Mendelian randomization study on cerebrospinal fluid biomarkers and their relevance to COVID-19 neurological manifestations

A mendelian randomization (MR) analysis was conducted to investigate whether SARS-CoV-2 invaded the human nervous system. This was confirmed by an increase in biomarkers found in the cerebrospinal fluid (CSF) and plasma of COVID-19 patients. To confirm the neuroinvasive properties of SARS-CoV-2, a series of analyses were conducted utilizing accessible datasets by MR. In addition, external validation was conducted by testing specific proteins in a retrospective cohort study, which included 40 COVID-19 patients with neurological complications and 15 disease controls (DC). Our investigation revealed the hospitalization, severity of COVID-19 increased the area and volume of certain brain regions, but no other significant causal effects were found of brain imaging-derived phenotypes (IDPs) on COVID-19. Notably, the COVID-19 hospitalization significantly increased the area and volume of the left caudal middle frontal gyrus (p_fdr = 0.012; p_fdr = 0.012, respectively). Additionally, COVID-19 severity was linked to the area, volume of the right caudal anterior-cingulate cortex and the volume of the right cuneus cortex (p_fdr = 0.023; p_fdr = 0.025; p_fdr = 0.026, respectively). In the CSF of COVID-19 patients, the median level of CHI3L1 was significantly higher (13677 pg/mL) compared to the DC group (8421 pg/mL, p < 1.00E-04). Similar trends were also found in CSF KLK6 and NGF-β. Additionally, the median NRGN level in plasma was significantly higher in the COVID-19 group (1013.00 pg/mL) compared to the control group (360.00 pg/mL, p = 6.50E-03). A subgroup analysis demonstrated that COVID-19 patients experiencing moderate to critical symptoms exhibited higher levels of GFAP in their CSF compared to those without. Elevated CSF levels of GFAP and S100B were also found in COVID-19 patients with decreased consciousness and comorbidities. This MR analysis provided evidence that SARS-CoV-2 may invade the human nervous system, as indicated by the increased levels of CSF biomarkers CHI3L1, NGF-β, and KLK6 in COVID-19 patients. These findings suggested that neuroinflammation could be a potential mechanism underlying the neurological complications seen in COVID-19 patients.

Challenges in the Diagnosis of SARS-CoV-2 Infection in the Nervous System

Neurological involvement has been widely reported in SARS-CoV-2 infection. However, viral identification in the cerebrospinal fluid (CSF) is rarely found. The aim of this study is to evaluate the accuracy of virological and immunological biomarkers in CSF for the diagnosis of neuroCOVID-19. We analyzed 69 CSF samples from patients with neurological manifestations: 14 with suspected/confirmed COVID-19, with 5 additional serial CSF samples (group A), and as a control, 50 non-COVID-19 cases (group B-26 with other neuroinflammatory diseases; group C-24 with non-inflammatory diseases). Real-time reverse-transcription polymerase chain reaction (real-time RT-PCR) was used to determine SARS-CoV-2, and specific IgG, IgM, neopterin, and protein 10 induced by gamma interferon (CXCL-10) were evaluated in the CSF samples. No samples were amplified for SARS-CoV-2 by real-time RT-PCR. The sensitivity levels of anti-SARS-CoV-2 IgG and IgM were 50% and 14.28%, respectively, with 100% specificity for both tests. CXCL-10 showed high sensitivity (95.83%) and specificity (95.83%) for detection of neuroinflammation. Serial CSF analysis showed an association between the neuroinflammatory biomarkers and outcome (death and hospital discharge) in two cases (meningoencephalitis and rhombencephalitis). The detection of SARS-CoV-2 RNA and specific immunoglobulins in the CSF can be used for neuroCOVID-19 confirmation. Additionally, CXCL-10 in the CSF may contribute to the diagnosis and monitoring of neuroCOVID-19.

Systematic review on molecular detection of congenital and neonatal infections caused by TORCH and SARS-CoV-2 in newborns' cerebrospinal fluid

OBJECTIVE

To verify the use and identify advantages of molecular methods for congenital infections diagnosis in cerebrospinal fluid of neonates.

DATA SOURCE

The review was registered in the International Prospective Register of Systematic Reviews (PROSPERO), under CRD42021274210. The literature search was performed in databases: PubMed, Virtual Health Library/ Latin American and Caribbean Center on Health Sciences Information (VHL/BIREME), Scopus, Web of Science, Excerpta Medica database (EMBASE), Cochrane, ProQuest, and EBSCOhost. The search was carried out from August to October 2021 and updated in December 2022, respecting the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The selection sequence was: 1) Duplicate title removal; 2) Examination of titles and abstracts; 3) Full-text retrieval of potentially relevant reports; and 4) Evaluation of the full text according to eligibility criteria by two independent authors. Inclusion criteria considered randomized and non-randomized control trials, longitudinal, cross-sectional, and peer-reviewed studies in humans, published in English, Spanish, Italian, and Portuguese, with newborns up to 28 days old who had congenital neuroinfections by toxoplasmosis, rubella, cytomegalovirus, herpes simplex (TORCH), and others such as Treponema pallidum, Zika, parvovirus B-19, varicella zoster, Epstein-Barr, and SARS-CoV2, diagnosed by polymerase chain reaction (PCR). Two evaluators extracted the following information: author, year of publication, nationality, subjects, study type, methods, results, and conclusion.

DATA SYNTHESIS

The most studied pathogen was herpes simplex. Several articles reported only nonspecific initial symptoms, motivating the collection of cerebrospinal fluid and performing PCR for etiological investigation.

CONCLUSIONS

Molecular methods are effective to detect pathogen genomes in cerebrospinal fluid, which can impact clinical evolution and neurological prognosis.

Systemic and cerebrospinal fluid immune mediators coordinate a dichotomic microenvironment in parturients with acute or convalescent phases of COVID-19

The present study intended to characterize the profile of soluble immune mediators in serum samples and in the cerebrospinal fluid (CSF) microenvironment from parturients with acute and convalescent COVID-19 as compared to healthy controls (HC), during the circulation of B.1.1.28 and B.1.1.33 SARS-CoV-2 strains, which were identified during the initial spread of COVID-19 in Brazil. Data demonstrated increased levels of immune mediators in serum at acute infection with a clear waning during convalescent COVID-19. Conversely, a progressive increase of immune mediators was observed in CSF from acute infection towards convalescent COVID-19. Immune mediator signatures and integrative correlation circuits further confirmed these findings and supported the existence of dichotomic microenvironments in the serum and CSF compartments. While a waning of correlations involving pro-inflammatory cytokines with increased connectivity of regulatory cytokines was observed in serum samples from acute towards convalescent COVID-19, an increasing frequency of correlations mediated by pro-inflammatory cytokines with decreased connectivity of regulatory cytokine was the hallmark of CSF. Correlations analysis identified a set of molecules associated with the dichotomic crosstalk between serum and CSF compartments, including chemokines (CXCL8, CCL5, CXCL10) and regulatory cytokines (IL-4 and IL-9). These immune biomarkers may represent potential targets for therapeutic strategies in parturients with COVID-19. Together, these findings demonstrated the existence of a divergent landscape of soluble immune mediators in serum and CSF, emphasizing the relevance of understanding the systemic and compartmentalized immune response elicited by SARS-CoV-2 infection during pregnancy.

Antibodies against SARS-CoV-2 spike protein in the cerebrospinal fluid of COVID-19 patients and vaccinated controls: a multicentre study

INTRODUCTION

SARS-CoV-2 antibodies in the cerebrospinal fluid (CSF) of COVID-19 patients possibly reflect blood-cerebrospinal fluid barrier (BCB) disruption due to systemic inflammation. However, some studies indicate that CSF antibodies signal a neurotropic infection. Currently, larger studies are needed to clarify this, and it is unknown if CSF antibodies appear solely after infection or also after COVID-19 vaccination. Therefore, we aimed to investigate the CSF dynamics of SARS-CoV-2 antibodies in a multicenter study of COVID-19 patients and vaccinated controls.

METHODS

A cohort study of Danish and Norwegian COVID-19 patients and controls investigated with a lumbar puncture (April 2020-December 2022). Serum and CSF were analysed locally for routine investigations, and centrally at Statens Serum Institut (Danish governmental public health institute) for SARS-CoV-2 IgG antibodies against the spike protein using the Euroimmun (quantitative) and Wantai (qualitative) assays. Primary outcome was the quantity of CSF SARS-CoV-2 antibodies post-COVID versus post-vaccination. Secondary outcomes included regression models examining the relationship between CSF antibodies and serum levels, albumin ratio, CSF pleocytosis, COVID-19 severity, and temporal antibody dynamics.

RESULTS

We included 124 individuals (Mean [SD] age 47.2 [16.6]; 59.7% males surviving COVID-19 and controls. Of these, 86 had paired CSF-serum testing. Antibody-index calculations did not support a SARS-CoV-2 brain infection. Multi-variate regression revealed that CSF SARS-CoV-2 antibodies were most strongly influenced by serum antibody levels and BCB permeability, as measured by increasing albumin ratio. CSF antibody levels displayed a dose-response relationship (p < 0.0001) influenced by preceding vaccinations or infections. CSF antibody levels (median [IQR]) were highest among those both previously infected and vaccinated, 100.0 [25.0-174.0], and those vaccinated without prior infection, 85.0 [12.0-142.0], and lowest among previously infected individuals without preceding vaccination, 5.9 [2.7-55.1], (p = 0.003). SARS-CoV-2 antibodies in CSF were also detected via qualitative assays in the COVID-19 (46.8%) and vaccinated (78.6%) groups, p = 0.03.

CONCLUSION

SARS-CoV-2 antibodies detected in CSF can be derived following both infection and vaccination for COVID-19. CSF antibody levels increase in a dose-response relationship with the number of prior infections and vaccinations and are most strongly influenced by serum antibody levels and BCB permeability. These findings stress the importance of carefully interpreting CSF antibody results when assessing neurological complications following infections not categorized as neurotropic.

Central and peripheral kynurenine pathway metabolites in COVID-19: Implications for neurological and immunological responses

Long-term symptoms such as pain, fatigue, and cognitive impairments are commonly observed in individuals affected by coronavirus disease 2019 (COVID-19). Metabolites of the kynurenine pathway have been proposed to account for cognitive impairment in COVID-19 patients. Here, cerebrospinal fluid (CSF) and plasma levels of kynurenine pathway metabolites in 53 COVID-19 patients and 12 non-inflammatory neurological disease controls in Sweden were measured with an ultra-performance liquid chromatography-tandem mass spectrometry system (UPLC-MS/MS) and correlated with immunological markers and neurological markers. Single cell transcriptomic data from a previous study of 130 COVID-19 patients was used to investigate the expression of key genes in the kynurenine pathway. The present study reveals that the neuroactive kynurenine pathway metabolites quinolinic acid (QUIN) and kynurenic acid (KYNA) are increased in CSF in patients with acute COVID-19. In addition, CSF levels of kynurenine, ratio of kynurenine/tryptophan (rKT) and QUIN correlate with neurodegenerative markers. Furthermore, tryptophan is significantly decreased in plasma but not in the CSF. In addition, the kynurenine pathway is strongly activated in the plasma and correlates with the peripheral immunological marker neopterin. Single-cell transcriptomics revealed upregulated gene expressions of the rate-limiting enzyme indoleamine 2,3- dioxygenase1 (IDO1) in CD14+ and CD16+ monocytes that correlated with type II-interferon response exclusively in COVID-19 patients. In summary, our study confirms significant activation of the peripheral kynurenine pathway in patients with acute COVID-19 and, notably, this is the first study to identify elevated levels of kynurenine metabolites in the central nervous system associated with the disease. Our findings suggest that peripheral inflammation, potentially linked to overexpression of IDO1 in monocytes, activates the kynurenine pathway. Increased plasma kynurenine, crossing the blood-brain barrier, serves as a source for elevated brain KYNA and neurotoxic QUIN. We conclude that blocking peripheral-to-central kynurenine transport could be a promising strategy to protect against neurotoxic effects of QUIN in COVID-19 patients.

Comparing clinical and biochemical characteristics of febrile seizures in children with and without COVID-19: a retrospective study

BACKGROUND

Transmission of COVID-19 is now normalized. There is an association between it and increased incidence of febrile seizures in children. Exploring whether COVID-19 has a specific effect on the clinical and biochemical features of febrile seizures is critical for the development of clinical treatment and prevention strategies. This study is to compare the differences in clinical features, hematological features, and cerebrospinal fluid characteristics between COVID-19 and non-COVID-19 children with febrile seizures and to provide a new perspective for further exploring the impact of COVID-19 on the nervous system of children.

METHODS

This was a retrospective case-control study. The cases included children with COVID-19 and non-COVID-19 febrile seizures admitted to Xiamen Children's Hospital from December 2022 to December 2023. The age, gender, length of hospital stay, peak body temperature, presence or absence of other viral infections, hematological characteristics, and cerebrospinal fluid characteristics were compared between children with COVID-19 febrile seizures and non-COVID-19 febrile seizures.

RESULTS

A total of 50 COVID-19 children with febrile seizures and 192 non-COVID-19 children with febrile seizures were enrolled in this study. Multivariate analysis showed that age (OR = 0.715, P = 0.031), blood urea nitrogen (OR = 0.454, P = 0.029), platelet count (OR = 0.987, P = 0.009) and magnesium ion concentration (OR = 0.109, P < 0.001) were negatively correlated with COVID-19 febrile seizures. Albumin (OR = 1.840, P < 0.001) was positively correlated. The concentration of potassium ion in cerebrospinal fluid (OR = 0.334, P = 0.012) was negatively correlated with COVID-19 febrile seizures, and the concentration of sodium ion (OR = 4.383, P = 0.022) was positively correlated with COVID-19 febrile seizures.

CONCLUSION

There were differences in age, blood urea nitrogen, platelet count, magnesium ion concentration, albumin, potassium ion concentration in cerebrospinal fluid, and sodium ion concentration in the cerebrospinal fluid between children with COVID-19 febrile seizures and non-COVID-19 febrile seizures. This study may provide valuable insights into the potential mechanisms of COVID-19 damage to the nervous system in children, and the long-term neurological prognosis of these children requires long-term follow-up.