Cerebrospinal Fluid Of Patients Research Articles

Evaluation and Limitations of the Novel Chemiluminescent Enzyme Immunoassay Technique for Measuring Total Tau Protein in the Cerebrospinal Fluid of Patients with Human Prion Disease: A 10-Year Prospective Study (2011–2020)

Background: Recently, the investigation of cerebrospinal fluid (CSF) biomarkers for diagnosing human prion diseases (HPD) has garnered significant attention. Reproducibility and accuracy are paramount in biomarker research, particularly in the measurement of total tau (T-tau) protein, which is a crucial diagnostic marker. Given the global impact of the coronavirus disease pandemic, the frequency of measuring this protein using one of the world’s fully automated assays, chemiluminescent enzyme immunoassay (CLEA), has increased. At present, the diagnosis and monitoring of neurological diseases mainly rely on traditional methods, but their accuracy and responsiveness are limited. There is limited knowledge of the accuracy of CLEA in tau measurements. We aimed to measure T-tau protein using CLEA and to elucidate its merits and limitations. Methods: We randomly selected 60 patients with rapidly progressive dementia, using ELISA and CLEA analysis of cerebrospinal fluid specimens. Additionally, we used Western blotting to detect the presence of 14-3-3 protein and employed real-time quaking-induced conversion (RT-QuIC) assays to analyze the same set of samples. Furthermore, we examined the correlation coefficient between ELISA and CLEA results in a subset of 60 samples. Moreover, using CLEA, we evaluated the diurnal reproducibility, storage stability, dilutability, and freeze–thaw effects in three selected samples. Results: In 172 patients, 172 samples were extracted, with each patient providing only one sample, and a total of 88 (35 men and 53 women) tested positive for HPD in the RT-QuIC assay. In contrast, all CSF samples from the remaining 84 patients without HPD (50 men and 34 women) tested negative in the RT-QuIC assay. Both ELISA and CLEA showed perfect sensitivity and specificity (100%) in measuring T-tau protein levels. In addition, ELISA and CLEA are similar in terms of measurement sensitivity and marginal effect of detection extrema. CLEA analysis exhibited instability for certain samples with T-tau protein levels exceeding 2000 pg/mL, leading to low reproducibility during dilution analysis. Conclusions: Our findings indicate that CLEA outperforms ELISA in terms of diurnal reproducibility, storage stability, and freeze–thaw effects. However, ELISA demonstrated superior performance in the dilution assay. Therefore, it is imperative to develop innovative approaches for the dilution of biomarker samples for CLEA measurements during clinical trials.

Clinical Metagenomic Next-Generation Sequencing for Diagnosis of Central Nervous System Infections: Advances and Challenges.

Central nervous system (CNS) infections carry a substantial burden of morbidity and mortality worldwide, and accurate and timely diagnosis is required to optimize management. Metagenomic next-generation sequencing (mNGS) has proven to be a valuable tool in detecting pathogens in patients with suspected CNS infection. By sequencing microbial nucleic acids present in a patient's cerebrospinal fluid, brain tissue, or samples collected outside of the CNS, such as plasma, mNGS can detect a wide range of pathogens, including rare, unexpected, and/or fastidious organisms. Furthermore, its target-agnostic approach allows for the identification of both known and novel pathogens. This is particularly useful in cases where conventional diagnostic methods fail to provide an answer. In addition, mNGS can detect multiple microorganisms simultaneously, which is crucial in cases of mixed infections without a clear predominant pathogen. Overall, clinical mNGS testing can help expedite the diagnostic process for CNS infections, guide appropriate management decisions, and ultimately improve clinical outcomes. However, there are key challenges surrounding its use that need to be considered to fully leverage its clinical impact. For example, only a few specialized laboratories offer clinical mNGS due to the complexity of both the laboratory methods and analysis pipelines. Clinicians interpreting mNGS results must be aware of both false negatives-as mNGS is a direct detection modality and requires a sufficient amount of microbial nucleic acid to be present in the sample tested-and false positives-as mNGS detects environmental microbes and their nucleic acids, despite best practices to minimize contamination. Additionally, current costs and turnaround times limit broader implementation of clinical mNGS. Finally, there is uncertainty regarding the best practices for clinical utilization of mNGS, and further work is needed to define the optimal patient population(s), syndrome(s), and time of testing to implement clinical mNGS.

Cytokine Profiling in Cerebrospinal Fluid of Patients with Newly Diagnosed Relapsing-Remitting Multiple Sclerosis (RRMS): Associations between Inflammatory Biomarkers and Disease Activity

Cytokines regulate immune responses and are crucial to MS pathogenesis. This study evaluated pro-inflammatory and anti-inflammatory cytokine concentrations in the CSF of de novo diagnosed RRMS patients compared to healthy controls. We assessed cytokine levels in the CSF of 118 de novo diagnosed RRMS patients and 112 controls, analyzing relationships with time from symptom onset to diagnosis, MRI lesions, and serum vitamin D levels. Elevated levels of IL-2, IL-4, IL-6, IL-13, FGF-basic, and GM-CSF, and lower levels of IL-1β, IL-1RA, IL-5, IL-7, IL-9, IL-10, IL-12p70, IL-15, G-CSF, PDGF-bb, and VEGF were observed in RRMS patients compared to controls. IL-2, IL-4, IL-12p70, PDGF, G-CSF, GM-CSF, and FGF-basic levels increased over time, while IL-10 decreased. IL-1β, IL-1RA, IL-6, TNF-α, and PDGF-bb levels negatively correlated with serum vitamin D. TNF-α levels positively correlated with post-contrast-enhancing brain lesions. IL-15 levels negatively correlated with T2 and Gd(+) lesions in C-spine MRI, while TNF-α, PDGF-bb, and FGF-basic correlated positively with T2 lesions in C-spine MRI. IL-6 levels positively correlated with post-contrast-enhancing lesions in Th-spine MRI. Distinct cytokine profiles in the CSF of de novo diagnosed MS patients provide insights into MS pathogenesis and guide immunomodulatory therapy strategies.

Cytokine Profiling in Cerebrospinal Fluid of Patients with Newly Diagnosed Relapsing-Remitting Multiple Sclerosis (RRMS): Associations between Inflammatory Biomarkers and Disease Activity.

Cytokines regulate immune responses and are crucial to MS pathogenesis. This study evaluated pro-inflammatory and anti-inflammatory cytokine concentrations in the CSF of de novo diagnosed RRMS patients compared to healthy controls. We assessed cytokine levels in the CSF of 118 de novo diagnosed RRMS patients and 112 controls, analyzing relationships with time from symptom onset to diagnosis, MRI lesions, and serum vitamin D levels. Elevated levels of IL-2, IL-4, IL-6, IL-13, FGF-basic, and GM-CSF, and lower levels of IL-1β, IL-1RA, IL-5, IL-7, IL-9, IL-10, IL-12p70, IL-15, G-CSF, PDGF-bb, and VEGF were observed in RRMS patients compared to controls. IL-2, IL-4, IL-12p70, PDGF, G-CSF, GM-CSF, and FGF-basic levels increased over time, while IL-10 decreased. IL-1β, IL-1RA, IL-6, TNF-α, and PDGF-bb levels negatively correlated with serum vitamin D. TNF-α levels positively correlated with post-contrast-enhancing brain lesions. IL-15 levels negatively correlated with T2 and Gd(+) lesions in C-spine MRI, while TNF-α, PDGF-bb, and FGF-basic correlated positively with T2 lesions in C-spine MRI. IL-6 levels positively correlated with post-contrast-enhancing lesions in Th-spine MRI. Distinct cytokine profiles in the CSF of de novo diagnosed MS patients provide insights into MS pathogenesis and guide immunomodulatory therapy strategies.

ATF2/BAP1 Axis Mediates Neuronal Apoptosis After Subarachnoid Hemorrhage via P53 Pathway.

Neuronal apoptosis plays an essential role in the pathogenesis of brain injury after subarachnoid hemorrhage (SAH). BAP1 (BRCA1-associated protein 1) is considered to exert pro-apoptotic effects in multiple diseases. However, evidence supporting the effect of BAP1 on the apoptotic response to SAH is lacking. Therefore, we aimed to confirm the role of BAP1 in SAH-induced apoptosis. Enzyme-linked immunosorbent assay (ELISA) was used to detect BAP1 expression in the cerebrospinal fluid. Endovascular perforation was performed in mice to induce SAH. Lentiviral short hairpin RNA targeting BAP1 mRNA was transduced into the ipsilateral cortex of mice with SAH to investigate the role of BAP1 in neuronal damage. Luciferase and coimmunoprecipitation assays were performed to investigate the mechanism through which BAP1 participates in hemin-induced SAH. First, BAP1 expression was upregulated in the cerebrospinal fluid of patients with SAH and positively associated with unfavorable outcomes. ATF2 (activating transcription factor-2) then regulated BAP1 expression by binding to the BAP1 promoter. In addition, BAP1 overexpression enhanced P53 activity and stability by reducing P53 proteasome-mediated degradation. Subsequently, elevated P53 promoted neuronal apoptosis via the P53 pathway. Inhibition of the neuronal BAP1/P53 axis significantly reduced neurological deficits and neuronal apoptosis and improved neurological dysfunction in mice after SAH. Our results suggest that the neuronal ATF2/BAP1 axis exerts a brain-damaging effect by modulating P53 activity and stability and may be a novel therapeutic target for SAH.

The immune response behind peptide vaccination in diffuse midline glioma.

A first-in-human trial demonstrated that a vaccine targeting the histone mutation H3K27M can induce an immune response, in a mutation-specific manner, in patients with diffuse midline glioma. In a recent study by Boschert etal., the same group now dissects the functional immune response triggered after effective vaccination of one of the patients, who has been in remission for over 3 years. The H3K27M peptide vaccine, named H3-vac, induces a CD4+ T-cell-specific immune response in this patient and expands the repertoire of polyclonal H3K27M-specific T-cell receptors. A clonal H3K27M-reactive B-cell population was also detected in the patient's cerebrospinal fluid. Importantly, the immune response is induced across various human leukocyte antigen alleleotypes, indicating the potential efficacy of the vaccine in diverse populations. By exploring in detail the immune response linked to this patient's long-term survival, the authors prove peptide vaccinations as a viable therapeutic approach. This paves the way for personalised therapies harnessing immunogenic T- and B-cell responses against different tumour types.

Tumor reactive T cells from the cerebrospinal fluid of patients with leptomeningeal disease from melanoma.

2027 Background: Leptomeningeal disease (LMD) is a devastating complication from cancer, with a median survival of 6-8 weeks. The incidence of LMD is highest in melanoma (5-25%) carrying the worst prognosis. Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) showed complete and durable responses in patients with advanced metastatic melanoma. CSF-derived T cell populations in LMD shift to more exhausted phenotypes compared to extracranial and brain metastases. Ex vivo large T cell expansion can overcome this shortfall, with adoptive T cell transfer representing a novel therapeutic approach to treat melanoma LMD (M-LMD). The goal of this study is to optimize rapid CSF-derived tumor reactive T cell expansion in M-LMD, and evaluate the immune microenvironment in CSF compared to peripheral immunity and anti-tumoral response. Methods: CSF was collected from M-LMD patients (n=6) via lumbar puncture or Ommaya. Cells were plated following established TIL culture protocols to determine optimal expansion conditions i.e.: 1) 6000 IU/mL IL-2, 2) IL-2+OKT3, 3) IL-2+anti-4-1BB agonistic antibody, 4) IL-2+IL-7+IL-15+IL-21, 5) IL-2+anti-CD3/CD28 human dynabeads, & 6) IL-2+anti-CD3/CD28/CD137 human dynabeads. After 4 weeks, T cells were propagated via rapid expansion protocol (REP) and phenotyped for CD4+ and CD8+ T cells with flow cytometry. T cells were co-cultured for 18-24 hours with HLA-matched melanoma cell lines to assess functionality, and IFN-y levels evaluated in supernatant. Ongoing studies are evaluating other biomarkers i.e., chemokines via Luminex. To examine the expanded TCR clonotypes, TCR beta seq was done in CSF-derived T cells at different times point of expansion and peripheral T cells. Results: Collected CSF yielded an average 8.12e4 viable cells for expansion (range 5e2-2.43e6). After initial culture in IL-2, 61.9% of samples showed increased cell yield with an average 101.68-fold expansion (range 2.35-1054). PreREP T cells were predominantly CD4+ (45.7%). REP was completed with a 100% success rate (mean 187.47-fold expansion). Post-REP flow cytometry analysis revealed similar results with further expansion of T cells. Additional culture supplements (Methods #2-6) produced similar expansion with a reduced T cell input requirement and demonstrated the potential to enrich for CD8+ T cells. M-LMD T cells were highly functional, producing substantial levels of IFN-y in response to HLA-matched melanoma cell lines. Anti-CD3/CD28 produced a larger expansion of T cells with higher levels of IFN-y. Preliminary TCR beta sequencing data revealed a distinct clonal distribution between peripheral and CSF-derived T cells. Conclusions: Therapies for LMD patients are desperately needed. Results demonstrate successful expansion of T cells ex vivo from CSF in M-LMD. Results raise potential to use autologous CSF-derived T cells as therapeutic strategy for patients with LMD.

A Microfluidic, Multi-Antibody Cell Capture Method to Evaluate Tumor Cells in Cerebrospinal Fluid in Patients With Suspected Leptomeningeal Metastases.

Leptomeningeal disease (LMD) is a clinical sequela of central nervous system metastasis involving the cerebrospinal fluid (CSF), often seen in late-stage solid tumors. It has a grave prognosis without urgent treatment. Standard of care methodologies to diagnose LMD include CSF cytology, magnetic resonance imaging, and clinical evaluation. These methods offer limited sensitivity and specificity for the evaluation of LMD. Here, we describe the analytic performance characteristics of a microfluidic-based tumor cell enrichment and detection assay optimized to detect epithelial cells in CSF using both contrived samples as well as CSF from patients having suspected or confirmed LMD from carcinomas. To demonstrate the feasibility of using a microfluidic, multi-antibody cell capture assay to identify and quantify tumor cells in CSF. An artificial CSF solution was spiked with 34 different human carcinoma cell lines at different concentrations and assayed for the ability to detect tumor cells to assess analytic accuracy. Two cell lines were selected to assess linearity, intra-assay precision, interinstrument precision, and sample stability. Clinical verification was performed on 65 CSF specimens from patients. Parameters assessed included the number of tumor cells, coefficient of variation percentage, and percentage of tumor cell capture (TCC). Among contrived samples, average tumor cell capture ranged from 50% to 82% (261 of 522; 436 of 531), and coefficients of variation ranged from 7% to 67%. The cell capture assay demonstrated a sensitivity of 92% and a specificity of 95% among clinical samples. This assay demonstrated the ability to detect and enumerate epithelial cells in contrived and clinical specimens in an accurate and reproducible fashion. The use of cell capture assays in CSF may be useful as a sensitive test for the diagnosis and longitudinal monitoring of LMD from solid tumors.

Bone morphogenetic protein 4 derived from the cerebrospinal fluid in patients with postherpetic neuralgia induces allodynia via the crosstalk between microglia and astrocyte

IntroductionDuring postherpetic neuralgia (PHN), the cerebral spinal fluid (CSF) possesses the capability to trigger glial activation and inflammation, yet the specific changes in its composition remain unclear. Recent findings from our research indicate elevations of central bone morphogenetic protein 4 (BMP4) during neuropathic pain (NP), serving as an independent modulator of glial cells. Herein, the aim of the present study is to test the CSF-BMP4 expressions and its role in the glial modulation in the process of PHN. MethodsCSF samples were collected from both PHN patients and non-painful individuals (Control) to assess BMP4 and its antagonist Noggin levels. Besides, intrathecal administration of both CSF types was conducted in normal rats to evaluate the impact on pain behavior, glial activity, and inflammation.; Additionally, both Noggin and STAT3 antagonist-Stattic were employed to treat the PHN-CSF or exogenous BMP4 challenged cultured astrocytes to explore downstream signals. Finally, microglial depletion was performed prior to the PHN-CSF intervention so as to elucidate the microglia-astrocyte crosstalk. ResultsBMP4 levels were significantly higher in PHN-CSF compared to Control-CSF (P < 0.001), with a positive correlation with pain duration (P < 0.05, r = 0.502). Comparing with the Control-CSF producing moderate paw withdrawal threshold (PWT) decline and microglial activation, PHN-CSF further exacerbated allodynia and triggered both microglial and astrocytic activation (P < 0.05). Moreover, PHN-CSF rather than Control-CSF evoked microglial proliferation and pro-inflammatory transformation, reinforced iron storage, and activated astrocytes possibly through both SMAD159 and STAT3 signaling, which were all mitigated by the Noggin application (P < 0.05). Next, both Noggin and Stattic effectively attenuated BMP4-induced GFAP and IL-6 upregulation, as well as SMAD159 and STAT3 phosphorylation in the cultured astrocytes (P < 0.05). Finally, microglial depletion diminished PHN-CSF induced astrogliosis, inflammation and endogenous BMP4 expression (P < 0.05). ConclusionOur study highlights the role of CSF-BMP4 elevation in glial activation and allodynia during PHN, suggesting a potential therapeutic avenue for future exploration.

Moxifloxacin treatment for Mycoplasma hominis meningitis in an extremely preterm infant

The patient, a male newborn, was admitted to the hospital 2 hours after birth due to prematurity (gestational age 27+5 weeks) and respiratory distress occurring 2 hours postnatally. After admission, the infant developed fever and elevated C-reactive protein levels. On the fourth day after birth, metagenomic next-generation sequencing of cerebrospinal fluid indicated a positive result for Mycoplasma hominis (9 898 reads). On the eighth day, a retest of cerebrospinal fluid metagenomics confirmed Mycoplasma hominis (56 806 reads). The diagnosis of purulent meningitis caused by Mycoplasma hominis was established, and the antibiotic treatment was switched to moxifloxacin [5 mg/(kg·day)] administered intravenously for a total of 4 weeks. After treatment, the patient's cerebrospinal fluid tests returned to normal, and he was discharged as cured on the 76th day after birth. This article focuses on the diagnosis and treatment of neonatal Mycoplasma hominis purulent meningitis, introducing the multidisciplinary diagnosis and treatment of the condition in extremely preterm infants.

Long-term elevation of complement factors in cerebrospinal fluid of patients with Borna disease virus 1 (BoDV-1) encephalitis.

Borna disease virus 1 (BoDV-1) causes rare but severe zoonotic infections in humans, presenting as severe encephalitis. The case-fatality risk is very high and no effective countermeasures have been established so far. An immunopathology is presumed, while data on immune responses in humans are limited. Evidence of a role of the complement system in various neurological disorders and central nervous viral infections is increasing and specific inhibitors are available as therapeutic options. In this study, we investigated factors of the complement system in the cerebrospinal fluid (CSF) of patients with BoDV-1 infections (n = 17) in comparison to non-inflammatory control CSF samples (n = 11), using a bead-based multiplex assay. In addition, immunohistochemistry was performed using post-mortem brain tissue samples. We found an intrathecal elevation of complement factors of all complement pathways and an active cascade during human BoDV-1 infections. The increase of certain complement factors such as C1q was persistent and C3 complement deposits were detected in post-mortem brain sections. Intrathecal complement levels were negatively correlated with survival. Further investigations are warranted to clarify, whether targeting the complement cascade by specific inhibitors might be beneficial for patients suffering from severe BoDV-1 encephalitis.

New knowledge on anti-IgLON5 disease.

Anti-IgLON5 disease is characterized by a distinctive sleep disorder, associated with a heterogeneous spectrum of neurological symptoms. Initial autopsies showed a novel neuronal tauopathy predominantly located in the tegmentum of the brainstem. Recently, new diagnostic red flags, biomarkers predictors of response to immunotherapy, and novel insights into the autoimmune pathogenesis of the disease have been reported. Patients with diagnosis of neurodegenerative dementia, progressive supranuclear palsy (PSP) or with motor-neuron disease (MND)-like syndrome have been reported to have IgLON5 antibodies, which are the hallmark of anti-IgLON5 disease. Second, low levels of neurofilament light chain in serum and cerebrospinal fluid of patients at disease onset could be a predictor of immunotherapy response. Recent neuropathological studies indicate that the neuronal tau deposits occur late in the course of the disease. Moreover, IgLON5 antibodies induce cytoskeletal changes in cultured hippocampal neurons suggesting that the tauopathy could be secondary of the IgLON5 antibody effects. Anti-IgLON5 disease can mimic and should be considered in atypical presentations of MND, neurodegenerative dementia and PSP. Neurofilament light chain levels seem promising biomarker for disease prognosis. Finally, the neuropathological and in vitro experimental studies strengthen the autoimmune hypothesis of the disease.

VEGFA, VEGFR1, VEGFR2 serum and cerebrospinal fluid concentration in patients with acute leukemia

Background. Vascular endothelial growth factor A (VEGFA) is one of the most important factors for regulation of hematopoietic stem cells differentiation. It is involved in leukemogenesis and central nervous system (CNS) damage in acute leukemia. According to the literature, the VEGFA production by blast cells is increased, but the values of serum concentration and the associations with CNS involvement are contradictory.Aim. evaluate the VEGFA, VEGFR1, VEGFR2 concentration in serum and cerebrospinal fluid of patient with different types of acute leukemia in disease onset and during treatment.Materials and methods. The concentration of VEGFA in serum and cerebrospinal fluid was studied in 74 primary patients with acute leukemia. The comparison group consisted of 67 healthy donors. VEGFR1, VEGFR2 were studied in serum and cerebrospinal fluid in 34 patients at the onset of the disease. The comparison group consisted of 10 healthy donors. For the analysis, an enzyme immunoassay was used on a semi-automatic Personal Lab analyzer (Adaltis) and Affymetrix eBioscience human VEGF-A Platinum ELISA reagents.Results. Serum VEGFA concentration was statistically significantly lower in acute leukemia patients than that of donors (median 149.78 and 432.19 pg/ml respectively; p &lt;0.0001). Factor deficiency was significantly more pronounced in patients with blastemia (p &lt;0.015). During antitumor therapy, there was a tendency to increase the amount of the factor in the blood serum. Serum concentration of soluble VEGFR2 was also lower in patients than that of donors (6949.9 and 8795.9 pg/ml respectively; p = 0.0026). For concentration of VEGFR1 such deviations were not found. The concentrations of VEGFR1 and VEGFR2 in serum were higher than in cerebrospinal fluid (p &lt;0.0001), while VEGFR1 showed a positive correlation between serum and cerebrospinal fluid concentrations. the concentration of VEGFR1 in the cerebrospinal fluid was significantly lower in patients with B-lymphoblastic leukemia/lymphoma compared to other types of leukemia.Conclusion. the concentration of VEGFA in serum decreases in patients with blastemia, this may indicate a lack of secretion and excessive consumption of the factor by blast cells with a decrease in the proportion of leukocytes that normally secrete the factor. In the cerebrospinal fluid, the concentrations of VEGFR1 and VEGFR2 are lower than in serum, with the lowest values being found in patients with B-lymphoblastic leukemia/lymphoma, but no relationship with the development of CNS involvement was found.

Abstract 2057: Monitoring cGAMP Biochemically and in cell using homogenous HTS formatted bioluminescent assay

Abstract The STimulator of INterferon Genes (STING) is a transmembrane protein located at the endoplasmic reticulum, which serves as a molecular hub in response to cytoplasmic cyclic dinucleotide (CDN) second messengers such as cyclic GMP-AMP (cGAMP). Upon its generation via cyclic GMP-AMP synthase (cGAS) by a wide array of pathogens that provide extracellular microbial DNA and by intracellular (nuclear and mitochondrial) DNA, it binds directly to the STING protein resulting in the activation of the STING pathway. This activation by cytosolic DNA initiates a cascade of events, cGAS-STING-TBK1-IRF3 signaling, that induces type 1 IFN response, and eventually the signaling is terminated by degradation of pathway components and clearance of stimulatory DNA. Given its significant role as an adaptor for DNA sensors to pathogens and its involvement in immune sensing, tumor growth control, and control of autoinflammatory and autoimmune disorders, the STING pathway has become a very important drug target. Credible evidence suggests that the cGAS–cGAMP–STING pathway makes fundamental contributions to at least three major cancer therapies: radiation therapy, chemotherapy, and immunotherapy, and it thus represents a promising drug target. Therefore, there is a need to identify lead compounds that effectively modulate human STING for further drug development. Towards this goal, we have developed a bioluminescent assay to monitor the concentration of cGAMP in intracellular as well as extracellular compartments. The assay relies on the new concept of Protein Complementation Assay (PCA) using nanoluciferase (nanoluc) complementation technology where a small peptide (SmBiT) derived from nanoluc linked to cGAMP through a linker (cGAMP tracer) can be recognized by an anti cGAMP antibody that is linked to a nanoluc complementary fragment (LgBiT) resulting in bioluminescence upon the addition of nanoluc substrate. The presence of free cGAMP that is generated in the reaction competes with cGAMP tracer and decreases bioluminescence. We have optimized the assay for higher sensitivity down to less than 10 nM cGAMP and less than one ng of cGAS and thus, and it is suitable for testing compounds that modulate cGAS activity. We also improved cell lysis condition to increase recovery of cGAMP that is generated intracellularly using several cGAS activators and correlating its concentration with cytokine release. We envision using this assay to monitor cGAMP presence in sera and spinal fluids of patients who have ALS and Alzheimer diseases. The assay is homogenous, with minimal or no false hits using LOPAC screening and HTS formatted and can be completed in less than one hour. Thus, this assay provides valuable contribution for investigating modulators of the STING pathway and facilitates the search for novel therapeutics. Citation Format: Said A. Goueli, kevin Hsiao, Nate Murray, dareen Mikheil, Matt Larsen, Hui Wang. Monitoring cGAMP Biochemically and in cell using homogenous HTS formatted bioluminescent assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2057.

Mitochondrial DNA deletions in the cerebrospinal fluid of patients with idiopathic REM sleep behaviour disorder

Idiopathic rapid eye movement (REM) sleep behaviour disorder (IRBD) represents the prodromal stage of Lewy body disorders (Parkinson's disease (PD) and dementia with Lewy bodies (DLB)) which are linked to variations in circulating cell-free mitochondrial DNA (cf-mtDNA). Here, we assessed whether altered cf-mtDNA release and integrity are already present in IRBD. We used multiplex digital PCR (dPCR) to quantify cf-mtDNA copies and deletion ratio in cerebrospinal fluid (CSF) and serum in a cohort of 71 participants, including 1) 17 patients with IRBD who remained disease-free (non-converters), 2) 34 patients initially diagnosed with IRBD who later developed either PD or DLB (converters), and 3) 20 age-matched controls without IRBD or Parkinsonism. In addition, we investigated whether CD9-positive extracellular vesicles (CD9-EVs) from CSF and serum samples contained cf-mtDNA. Patients with IRBD, both converters and non-converters, exhibited more cf-mtDNA with deletions in the CSF than controls. This finding was confirmed in CD9-EVs. The high levels of deleted cf-mtDNA in CSF corresponded to a significant decrease in cf-mtDNA copies in CD9-EVs in both IRBD non-converters and converters. Conversely, a significant increase in cf-mtDNA copies was found in serum and CD9-EVs from the serum of patients with IRBD who later converted to a Lewy body disorder. Alterations in cf-mtDNA copy number and deletion ratio known to occur in Lewy body disorders are already present in IRBD and are not a consequence of Lewy body disease conversion. This suggests that mtDNA dysfunction is a primary molecular mechanism of the pathophysiological cascade that precedes the full clinical motor and cognitive manifestation of Lewy body disorders. Funded by Michael J. Fox Foundation research grant MJFF-001111. Funded by MICIU/AEI/10.13039/501100011033 "ERDF A way of making Europe", grants PID2020-115091RB-I00 (RT) and PID2022-143279OB-I00 (ACo). Funded by Instituto de Salud Carlos III and European Union NextGenerationEU/PRTR, grant PMP22/00100 (RT and ACo). Funded by AGAUR/Generalitat de Catalunya, grant SGR00490 (RT and ACo). MP has an FPI fellowship, PRE2018-083297, funded by MICIU/AEI/10.13039/501100011033 "ESF Investing in your future".

Study of Bitespiramycin Distribution in Rats and Cerebrospinal Fluid of Patients by a Sensitive LC-MS/MS Method with Rapid Sample Preparation.

Bitespiramycin, has been shown to have a therapeutic effect against respiratory tract inflammation, including a potential effect against COVID-19. A current clinical trial in China showed that bitespiramycin was an effective treatment for severe pneumonia and intracranial infection. However, there is lack of an analytical method to elucidate the distribution of bitespiramycin. In this study, a highly sensitive, rapid and reliable UPLC-MS/MS method was developed to comprehensively characterize the bitespiramycin distribution in various bio-samples, which is significantly improved upon the published work. A rapid sample preparation method was developed by using n-butanol as the solvent to extract bitespiramycin from different bio-samples. The extract was then directly analyzed by UPLC-MS/MS coupled with an alkaline-resistant column after centrifugation which avoids the time-consuming concentration process under nitrogen and redissolution. The method was employed to accurately quantify bitespiramycin and its metabolites in rat plasma, tissues, and human cerebrospinal fluid. Notably, the presence of bitespiramycin and its metabolites was identified for the first time in various rat organs including brain, testis, bladder and prostate as well as in human cerebrospinal fluid. This newly developed approach shows great promise for drug distribution assays including other antibiotics and can help elucidate the ADME of bitespiramycin.

Balanced transformer: efficient classification of glioblastoma and primary central nervous system lymphoma

Objective. Primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) are malignant primary brain tumors with different biological characteristics. Great differences exist between the treatment strategies of PCNSL and GBM. Thus, accurately distinguishing between PCNSL and GBM before surgery is very important for guiding neurosurgery. At present, the spinal fluid of patients is commonly extracted to find tumor markers for diagnosis. However, this method not only causes secondary injury to patients, but also easily delays treatment. Although diagnosis using radiology images is non-invasive, the morphological features and texture features of the two in magnetic resonance imaging (MRI) are quite similar, making distinction with human eyes and image diagnosis very difficult. In order to solve the problem of insufficient number of samples and sample imbalance, we used data augmentation and balanced sample sampling methods. Conventional Transformer networks use patch segmentation operations to divide images into small patches, but the lack of communication between patches leads to unbalanced data layers. Approach. To address this problem, we propose a balanced patch embedding approach that extracts high-level semantic information by reducing the feature dimensionality and maintaining the geometric variation invariance of the features. This approach balances the interactions between the information and improves the representativeness of the data. To further address the imbalance problem, the balanced patch partition method is proposed to increase the receptive field by sampling the four corners of the sliding window and introducing a linear encoding component without increasing the computational effort, and designed a new balanced loss function. Main results. Benefiting from the overall balance design, we conducted an experiment using Balanced Transformer and obtained an accuracy of 99.89%, sensitivity of 99.74%, specificity of 99.73% and AUC of 99.19%, which is far higher than the previous results (accuracy of 89.6% ∼ 96.8%, sensitivity of 74.3% ∼ 91.3%, specificity of 88.9% ∼ 96.02% and AUC of 87.8% ∼ 94.9%). Significance. This study can accurately distinguish PCNSL and GBM before surgery. Because GBM is a common type of malignant tumor, the 1% improvement in accuracy has saved many patients and reduced treatment times considerably. Thus, it can provide doctors with a good basis for auxiliary diagnosis.

Misfolded alpha-synuclein in amyotrophic lateral sclerosis: Implications for diagnosis and treatment.

Alpha-synuclein (α-Syn) oligomers and fibrils have been shown to augment the aggregation of TAR DNA-binding Protein 43 (TDP-43) monomers invitro, supporting the idea that TDP-43 proteinopathies such as ALS may be modulated by the presence of toxic forms of α-Syn. Recently, parkinsonian features were reported in a study of European patients and Lewy bodies have been demonstrated pathologically in a similar series of patients. Based on these and other considerations, we sought to determine whether seed-competent α-Syn can be identified in spinal fluid of patients with ALS including familial, sporadic, and Guamanian forms of the disease. Based on the finding that α-Syn has been found to be a prion-like protein, we have utilized a validated α-Synuclein seed amplification assay to determine if seed-competent α-Syn could be detected in the spinal fluid of patients with ALS. Toxic species of α-Syn were detected in CSF in 18 of 127 ALS patients, 5 of whom were from Guam. Two out of twenty six samples from patients with C9orf72 variant ALS had positive seed-amplification assays (SAAs). No positive tests were noted in superoxide dismutase type 1 ALS subjects (n = 14). The SAA was negative in 31 control subjects. Our findings suggest that a sub-group of ALS occurs in which self-replicating α-Syn is detectable and likely contributes to its pathogenesis. This finding may have implications for the diagnosis and treatment of this disorder.

Don't rash it! The clinical significance of positive Varicella zoster virus PCR in cerebrospinal fluid of patients with neurological symptoms

BackgroundVaricella zoster virus (VZV) is among the leading pathogens causing meningitis and encephalitis. While VZV-PCR-positive CSF is considered a gold-standard for diagnosis, it is not-uncommon to detect VZV-DNA in CSF of patients with other acute or chronic illness. Our goal was to determine the clinical relevance of VZV-PCR-positive CSF when investigating patients with neurological symptoms. MethodsIn this retrospective cohort from the largest hospital in Israel, we collected demographic, clinical and laboratory data of patients with VZV-PCR-positive CSF, analyzing the significance of various parameters. ResultsDuring a 5-years study, 125 patient-unique VZV-PCR-positive CSFs were recorded, in which only 9 alternative diagnoses were noted. The commonest symptoms were headache (N = 104, 83 %) and rash (N = 96, 76 %). PCR-cycle-threshold (Ct), a surrogate of viral burden, did not significantly vary across the clinical manifestations; however, patients with rash and Ct<35 were prone to develop stroke in the following year (N = 6, 7 %). Empiric nucleoside-analogue treatment was not associated with a better outcome compared to treatment administered upon a positive-PCR result. DiscussionOur findings suggest that in patients with neurological symptoms, detection of VZV-DNA in CSF renders VZV the probable culprit. Nevertheless, a systematic evaluation of treatment and follow-up algorithms of patients with suspected or proved VZV meningitis and encephalitis is needed. The benefits of a prompt treatment should be weighed against the potential complications of nucleoside-analogue. Conversely, the propensity for stroke in patients with higher viral-burden, necessitates further studies assessing VZV causal role, directing additional workup, treatment and monitoring policy.

Age-Dependent and Aβ-Induced Dynamic Changes in the Subcellular Localization of HMGB1 in Neurons and Microglia in the Brains of an Animal Model of Alzheimer's Disease.

HMGB1 is a prototypical danger-associated molecular pattern (DAMP) molecule that co-localizes with amyloid beta (Aβ) in the brains of patients with Alzheimer's disease. HMGB1 levels are significantly higher in the cerebrospinal fluid of patients. However, the cellular and subcellular distribution of HMGB1 in relation to the pathology of Alzheimer's disease has not yet been studied in detail. Here, we investigated whether HMGB1 protein levels in brain tissue homogenates (frontal cortex and striatum) and sera from Tg-APP/PS1 mice, along with its cellular and subcellular localization in those regions, differed. Total HMGB1 levels were increased in the frontal cortices of aged wildtype (7.5 M) mice compared to young (3.5 M) mice, whereas total HMGB1 levels in the frontal cortices of Tg-APP/PS1 mice (7.5 M) were significantly lower than those in age-matched wildtype mice. In contrast, total serum HMGB1 levels were enhanced in aged wildtype (7.5 M) mice and Tg-APP/PS1 mice (7.5 M). Further analysis indicated that nuclear HMGB1 levels in the frontal cortices of Tg-APP/PS1 mice were significantly reduced compared to those in age-matched wildtype controls, and cytosolic HMGB1 levels were also significantly decreased. Triple-fluorescence immunohistochemical analysis indicated that HMGB1 appeared as a ring shape in the cytoplasm of most neurons and microglia in the frontal cortices of 9.5 M Tg-APP/PS1 mice, indicating that nuclear HMGB1 is reduced by aging and in Tg-APP/PS1 mice. Consistent with these observations, Aβ treatment of both primary cortical neuron and primary microglial cultures increased HMGB1 secretion in the media, in an Aβ-dose-dependent manner. Our results indicate that nuclear HMGB1 might be translocated from the nucleus to the cytoplasm in both neurons and microglia in the brains of Tg-APP/PS1 mice, and that it may subsequently be secreted extracellularly.