Cerebrospinal fluid biomarkers and cognitive trajectories in patients with Alzheimer's disease and a history of traumatic brain injury.

Traumatic brain injury (TBI) and Alzheimer's disease (AD) have overlapping mechanisms but it remains unknown if pathophysiological characteristics and cognitive trajectories in AD patients are influenced by TBI history. Here, we studied AD patients (stage MCI or dementia) with TBI history (ADTBI+, n=110), or without (ADTBI-, n=110) and compared baseline CSF concentrations of amyloid beta 1-42 (Aß42), phosphorylated tau181 (pTau181), total tau, neurofilament light chain (NfL), synaptosomal associated protein-25kDa (SNAP25), neurogranin (Ng), neuronal pentraxin-2 (NPTX2) and glutamate receptor-4 (GluR4), as well as differences in cognitive trajectories using linear mixed models. Explorative, analyses were repeated within stratified TBI groups by TBI characteristics (timing, severity, number). We found no differences in baseline CSF biomarker concentrations nor in cognitive trajectories between ADTBI+ and ADTBI- patients. TBI >5 years ago was associated with higher NPTX2 and a tendency for higher SNAP25 concentrations compared to TBI ≤ 5 years ago, suggesting that TBI may be associated with long-term synaptic dysfunction only when occurring before onset or in a pre-clinical disease stage of AD.

Study of the Role of Cerebrospinal Fluid C-reactive Protein and Adenosine Deaminase to differentiate Various Types of Meningitis.

OBJECTIVE: (1) To study cerebrospinal fluid (CSF) adenosine deaminase (ADA) and CSF C-reactive protein (CRP) levels in the differentiation of viral, pyogenic, and tuberculous meningitis (TBM). (2) To estimate the borderline levels of CRP in CSF in viral, pyogenic, and TBM. METHODS: A prospective and cross-sectional study was conducted at the Department of Medicine, SRN Hospital, Prayagraj, Uttar Pradesh, India, between August 2016 and September 2018. In this study, a total of 100 patients with meningitis were included applying specific inclusion and exclusion criteria after proper ethical approval. RESULTS: Out of 100 patients, 61 were TBM, 31 were pyogenic meningitis, and eight were viral meningitis (VM). CSF CRP level was significantly increased in pyogenic meningitis (1.05 ± 0.36 mg/dL) compared to nonpyogenic meningitis [TBM (0.42 ± 0.13 mg/dL) and VM (0.37 ± 0.09 mg/dL)]. At the cut-off level of CRP in CSF > 0.6 mg/dL, its diagnostic sensitivity in pyogenic meningitis was 93.55% and specificity 94.20%. While CSF ADA levels were higher in the TBM group (13.32 ± 3.21 U/L) compared to the other two groups [pyogenic meningitis (6.15 ± 1.27 U/L) and VM (4.86 ± 0.88 U/L)]. At a cut-off, CSF ADA level of >10 U/L, its diagnostic sensitivity for TBM was 91.67% and specificity 90%. CONCLUSION: Cerebrospinal fluid (CSF) CRP levels were found to be raised in pyogenic meningitis, and CSF ADA was found to be elevated in TBM. While both ADA level and CRP level in CSF are found low in VM.

Accuracy of Cerebrospinal Fluid C-Reactive Protein and Multiplex Polymerase Chain Reaction and Serum Procalcitonin in Diagnosis of Bacterial and Viral Meningitis in Children.

BACKGROUND: Meningitis is one of the most dangerous infection affecting children. The need for rapid and accurate diagnosis is mandatory for improving the outcome. AIM OF THE WORK: to evaluate the role of multiplex polymerase chain reaction (PCR), cerebrospinal fluid (CSF)-C-reactive protein (CRP) and serum procalcitonin (PCT) in diagnosis of meningitis and to detect its accuracy. PATIENTS AND METHODS: A cross-sectional study was carried out in University Children hospital, Faculty of Medicine, between November 2019 and September 2020. The study was approved by the Ethics Review Board of Faculty of Medicine, Assiut University, and informed written consent was obtained. The committee's reference number is 17200161. CLINICALTRIALS: gov ID: NCT03387969. 48 Children aged 2 to 18 years with meningitis were included. Detailed history and examination. Blood glucose level at time of admission prior to lumbar puncture, serum CRP level, serum PCT, CSF-CRP level and Multiplex PCR were evaluated. FUNDING: The study was supported by Grant Office of Faculty of Medicine, Assiut University with grant NO. 2018-01-04-006-R2. RESULTS: The mean age of children was 3.27 plus or minus 1.27 years. 35 (72.9%) cases were bacterial meningitis, while 13 (27.1%) cases were viral meningitis. Patients with bacterial meningitis had significantly higher serum CRP, serum PCT and higher CSF-CRP and significantly lower CSF/blood glucose compared to viral meningitis. Multiplex PCR had 94% sensitivity and 100% specificity for diagnosis of bacterial and viral meningitis. CONCLUSION: CSF-CRP, CSF/blood glucose, PCT and Multiplex-PCR may help in diagnosis and differentiation of bacterial and viral meningitis.

Ability of Procalcitonin and C-Reactive Protein for Discriminating between Bacterial and Enteroviral Meningitis in Children Using Decision Tree.

Bacterial meningitis (BM) is a public health burden in developing countries, including Central Asia. This disease is characterized by a high mortality rate and serious neurological complications. Delay with the start of adequate therapy is associated with an increase in mortality for patients with acute bacterial meningitis. Cerebrospinal fluid culture, as a gold standard in bacterial meningitis diagnosis, is time-consuming with modest sensitivity, and this is unsuitable for timely decision-making. It has been shown that bacterial meningitis differentiation from viral meningitis could be done through different parameters such as clinical signs and symptoms, laboratory values, such as PCR, including blood and cerebrospinal fluid (CSF) analysis. In this study, we proposed the method for distinguishing the bacterial form of meningitis from enteroviral one. The method is based on the machine learning process deriving making decision rules. The proposed fast-and-frugal trees (FFTree) decision tree approach showed an ability to determine procalcitonin and C-reactive protein (CRP) with cut-off values for distinguishing between bacterial and enteroviral meningitis (EVM) in children. Such a method demonstrated 100% sensitivity, 96% specificity, and 98% accuracy in the differentiation of all cases of bacterial meningitis in this study. These findings and proposed method may be useful for clinicians to facilitate the decision-making process and optimize the diagnostics of meningitis.

Changes in Cerebrospinal Fluid Balance of TNF and TNF Receptors in Naïve Multiple Sclerosis Patients: Early Involvement in Compartmentalised Intrathecal Inflammation.

An imbalance of TNF signalling in the inflammatory milieu generated by meningeal immune cell infiltrates in the subarachnoid space in multiple sclerosis (MS), and its animal model may lead to increased cortical pathology. In order to explore whether this feature may be present from the early stages of MS and may be associated with the clinical outcome, the protein levels of TNF, sTNF-R1 and sTNF-R2 were assayed in CSF collected from 122 treatment-naïve MS patients and 36 subjects with other neurological conditions at diagnosis. Potential correlations with other CSF cytokines/chemokines and with clinical and imaging parameters at diagnosis (T0) and after 2 years of follow-up (T24) were evaluated. Significantly increased levels of TNF (fold change: 7.739; p < 0.001), sTNF-R1 (fold change: 1.693; p < 0.001) and sTNF-R2 (fold change: 2.189; p < 0.001) were detected in CSF of MS patients compared to the control group at T0. Increased TNF levels in CSF were significantly (p < 0.01) associated with increased EDSS change (r = 0.43), relapses (r = 0.48) and the appearance of white matter lesions (r = 0.49). CSF levels of TNFR1 were associated with cortical lesion volume (r = 0.41) at T0, as well as with new cortical lesions (r = 0.56), whilst no correlation could be found between TNFR2 levels in CSF and clinical or MRI features. Combined correlation and pathway analysis (ingenuity) of the CSF protein pattern associated with TNF expression (encompassing elevated levels of BAFF, IFN-γ, IL-1ß, IL-10, IL-8, IL-16, CCL21, haptoglobin and fibrinogen) showed a particular relationship to the interaction between innate and adaptive immune response. The CSF sTNF-R1-associated pattern (encompassing high levels of CXCL13, TWEAK, LIGHT, IL-35, osteopontin, pentraxin-3, sCD163 and chitinase-3-L1) was mainly related to altered T cell and B cell signalling. Finally, the CSF TNFR2-associated pattern (encompassing high CSF levels of IFN-ß, IFN-λ2, sIL-6Rα) was linked to Th cell differentiation and regulatory cytokine signalling. In conclusion, dysregulation of TNF and TNF-R1/2 pathways associates with specific clinical/MRI profiles and can be identified at a very early stage in MS patients, at the time of diagnosis, contributing to the prediction of the disease outcome.

Preterm Intraventricular Hemorrhage-Induced Inflammatory Response in Human Choroid Plexus Epithelial Cells.

Following an intraventricular hemorrhage (IVH), red blood cell lysis and hemoglobin (Hb) oxidation with the release of heme can cause sterile neuroinflammation. In this study, we measured Hb derivates and cellular adhesion molecules ICAM-1 and VCAM-1 with cell-free miRNAs in cerebrospinal fluid (CSF) samples obtained from Grade-III and Grade-IV preterm IVH infants (IVH-III and IVH-IV, respectively) at multiple time points between days 0-60 after the onset of IVH. Furthermore, human choroid plexus epithelial cells (HCPEpiCs) were incubated with IVH and non-IVH CSF (10 v/v %) for 24 h in vitro to investigate the IVH-induced inflammatory response that was investigated via: (i) HMOX1, IL8, VCAM1, and ICAM1 mRNAs as well as miR-155, miR-223, and miR-181b levels by RT-qPCR; (ii) nuclear translocation of the NF-κB p65 subunit by fluorescence microscopy; and (iii) reactive oxygen species (ROS) measurement. We found a time-dependent alteration of heme, IL-8, and adhesion molecules which revealed a prolonged elevation in IVH-IV vs. IVH-III with higher miR-155 and miR-181b expression at days 41-60. Exposure of HCPEpiCs to IVH CSF samples induced HMOX1, IL8, and ICAM1 mRNA levels along with increased ROS production via the NF-κB pathway activation but without cell death, as confirmed by the cell viability assay. Additionally, the enhanced intracellular miR-155 level was accompanied by lower miR-223 and miR-181b expression in HCPEpiCs after CSF treatment. Overall, choroid plexus epithelial cells exhibit an abnormal cell phenotype after interaction with pro-inflammatory CSF of IVH origin which may contribute to the development of later clinical complications in preterm IVH.

Longitudinal CSF proteomics identifies NPTX2 as a prognostic biomarker of Alzheimer's disease.

INTRODUCTION: Biomarkers that reflect pathologic processes affecting neuronal function during preclinical and early stages of Alzheimer's disease (AD) are needed to aid drug development. METHODS: A targeted, stable isotope, quantitative mass spectrometry-based investigation of longitudinal changes in concentrations of previously identified candidate biomarkers was performed in cerebrospinal fluid (CSF) of Alzheimer's Disease Neuroimaging Initiative participants who were classified as cognitively normal (CN; n = 76) or with mild cognitive impairment (MCI; n = 111) at baseline. RESULTS: Of the candidate biomarkers, the CSF concentration of neuronal pentraxin 2 (NPTX2), a protein involved in synaptic function, exhibited rates of change that were significantly different between three comparison groups (i.e., CN vs. MCI participants; AD pathology positive vs. negative defined by phosphorylated tau181/amyloid beta1-42 ratio; and clinical progressors vs. non-progressors). The rate of change of NPTX2 also significantly correlated with declining cognition. DISCUSSION: CSF NPTX2 concentration is a strong prognostic biomarker candidate of accelerated cognitive decline with potential use as a therapeutic target.

Inflammatory Depression-Mechanisms and Non-Pharmacological Interventions.

Treatment of depression is hampered by the failure to identify distinct symptom profiles with distinct pathophysiologies that differentially respond to distinct treatments. We posit that inflammatory depression is a meaningful depression subtype associated with specific symptoms and biological abnormalities. We review several upstream, potentially causative, mechanisms driving low-grade inflammation in this subtype of depression. We also discuss downstream mechanisms mediating the link between inflammation and symptoms of depression, including alterations in dopaminergic neurotransmission and tryptophan metabolism. Finally, we review evidence for several non-pharmacological interventions for inflammatory depression, including probiotics, omega-3 fatty acids, and physical exercise interventions. While some evidence suggests that these interventions may be efficacious in inflammatory depression, future clinical trials should consider enriching patient populations for inflammatory markers, or stratify patients by inflammatory status, to confirm or refute this hypothesis.

Role of cerebrospinal fluid C-reactive protein in tuberculous meningitis.

Background: Tuberculosis (TB) is still a significant health problem worldwide. Central nervous system TB amounts to 10% of all cases of TB. Despite advances in the pharmacological management of TB, the overall outcomes remain poor with significant mortality and morbidity. There are no predictors for neurological outcomes in tuberculosis meningitis (TBM). In this study, we aimed to evaluate the role of cerebrospinal fluid (CSF) C-reactive protein (CRP) in predicting mortality and neurological outcome in TBM. Method: In this observational study, all patients with TBM were recruited prospectively over a 12-month duration. Baseline demographic data, laboratory parameters, and Imaging findings were collected. CSF CRP was obtained on the CSF sample collected at the time of diagnosis. Patients were followed up at 3 months to assess neurological status and mortality. Results: Seventy-one patients with TBM were recruited in this study. The overall mortality in this study was 22.5% of patients. The primary composite outcome of mortality and adverse neurological outcome occurred in 40.8%. The CSF CRP levels ranged between 0.1 and 4.8 mg/dl, and the mean CSF CRP level was 1.11 mg/dl. The Relative risk for a patient with high CSF CRP to develop adverse outcome was 1.84 (P = 0.038). CSF CRP was a good predictor of mortality with a relative risk of 2.92 (P = 0.027). Stroke in TBM had a high incidence of 47.9% and a relative risk of 3.42 for an adverse neurological outcome. CSF CRP did not predict the occurrence of stroke. Hydrocephalus and elevated intracranial pressure were good predictors of stroke. Conclusion: TBM is a disease with significant mortality and morbidity. CRP level in the CSF can be measured, but a highly sensitive scale may be needed as the mean values were much lower compared to the serum values. CSF CRP Levels showed significant associations with adverse outcomes and mortality.

Cerebrospinal fluid profile of NPTX2 supports role of Alzheimer's disease-related inhibitory circuit dysfunction in adults with Down syndrome.

BACKGROUND: Alzheimer's disease (AD) is the major cause of death in adults with Down syndrome (DS). There is an urgent need for objective markers of AD in the DS population to improve early diagnosis and monitor disease progression. NPTX2 has recently emerged as a promising cerebrospinal fluid (CSF) biomarker of Alzheimer-related inhibitory circuit dysfunction in sporadic AD patients. The objective of this study was to evaluate NPTX2 in the CSF of adults with DS and to explore the relationship of NPTX2 to CSF levels of the PV interneuron receptor, GluA4, and existing AD biomarkers (CSF and neuroimaging). METHODS: This is a cross-sectional, retrospective study of adults with DS with asymptomatic AD (aDS, n = 49), prodromal AD (pDS, n = 18) and AD dementia (dDS, n = 27). Non-trisomic controls (n = 34) and patients with sporadic AD dementia (sAD, n = 40) were included for comparison. We compared group differences in CSF NPTX2 according to clinical diagnosis and degree of intellectual disability. We determined the relationship of CSF NPTX2 levels to age, cognitive performance (CAMCOG, free and cued selective reminding, semantic verbal fluency), CSF levels of a PV-interneuron marker (GluA4) and core AD biomarkers; CSF Aß1-42, CSF t-tau, cortical atrophy (magnetic resonance imaging) and glucose metabolism ([18F]-fluorodeoxyglucose positron emission tomography). RESULTS: Compared to controls, mean CSF NPTX2 levels were lower in DS at all AD stages; aDS (0.6-fold, adj.p < 0.0001), pDS (0.5-fold, adj.p < 0.0001) and dDS (0.3-fold, adj.p < 0.0001). This reduction was similar to that observed in sporadic AD (0.5-fold, adj.p < 0.0001). CSF NPTX2 levels were not associated with age (p = 0.6), intellectual disability (p = 0.7) or cognitive performance (all p > 0.07). Low CSF NPTX2 levels were associated with low GluA4 in all clinical groups; controls (r2 = 0.2, p = 0.003), adults with DS (r2 = 0.4, p < 0.0001) and sporadic AD (r2 = 0.4, p < 0.0001). In adults with DS, low CSF NPTX2 levels were associated with low CSF Aß1-42 (r2 > 0.3, p < 0.006), low CSF t-tau (r2 > 0.3, p < 0.001), increased cortical atrophy (p < 0.05) and reduced glucose metabolism (p < 0.05). CONCLUSIONS: Low levels of CSF NPTX2, a protein implicated in inhibitory circuit function, is common to sporadic and genetic forms of AD. CSF NPTX2 represents a promising CSF surrogate marker of early AD-related changes in adults with DS.

Cerebrospinal fluid neuronal pentraxin receptor as a biomarker of long-term progression of Alzheimer's disease: a 24-month follow-up study.

Lower cerebrospinal fluid (CSF) levels of neuronal pentraxin receptor (NPTXR) are associated with Alzheimer's disease (AD), but few studies show longitudinal changes in CSF NPTXR. In the present study, CSF NPTXR was measured at 0, 12, and 24 months using an enzyme-linked immunosorbent assay. The study groups included 28 patients with mild cognitive impairment (MCI) (MCI-MCI), 27 MCI patients who progressed to AD (MCI-AD) during the study, and 28 AD patients (AD-AD). Baseline levels were assessed for 46 control individuals. AD patients had lower baseline CSF NPTXR than controls (p = 0.023). Linear mixed models estimated a 6.7% annualized decrease in CSF NPTXR in the AD-AD group, significantly different from MCI-MCI (p = 0.03) and MCI-AD groups (p = 0.048). CSF NPTXR did not correlate with CSF Aß42 and weakly correlated with CSF Aß40, T-tau, P-tau (all R2 < 0.22, p < 0.06). These trends suggest CSF NPTXR may be a candidate biomarker of AD progression but not sufficiently sensitive to resolve when patients convert from MCI to dementia.

Neuronal pentraxin 2: a synapse-derived CSF biomarker in genetic frontotemporal dementia.

INTRODUCTION: Synapse dysfunction is emerging as an early pathological event in frontotemporal dementia (FTD), however biomarkers are lacking. We aimed to investigate the value of cerebrospinal fluid (CSF) neuronal pentraxins (NPTXs), a family of proteins involved in homeostatic synapse plasticity, as novel biomarkers in genetic FTD. METHODS: We included 106 presymptomatic and 54 symptomatic carriers of a pathogenic mutation in GRN, C9orf72 or MAPT, and 70 healthy non-carriers participating in the Genetic Frontotemporal dementia Initiative (GENFI), all of whom had at least one CSF sample. We measured CSF concentrations of NPTX2 using an in-house ELISA, and NPTX1 and NPTX receptor (NPTXR) by Western blot. We correlated NPTX2 with corresponding clinical and neuroimaging datasets as well as with CSF neurofilament light chain (NfL) using linear regression analyses. RESULTS: Symptomatic mutation carriers had lower NPTX2 concentrations (median 643 pg/mL, IQR (301-872)) than presymptomatic carriers (1003 pg/mL (624-1358), p<0.001) and non-carriers (990 pg/mL (597-1373), p<0.001) (corrected for age). Similar results were found for NPTX1 and NPTXR. Among mutation carriers, NPTX2 concentration correlated with several clinical disease severity measures, NfL and grey matter volume of the frontal, temporal and parietal lobes, insula and whole brain. NPTX2 predicted subsequent decline in phonemic verbal fluency and Clinical Dementia Rating scale plus FTD modules. In longitudinal CSF samples, available in 13 subjects, NPTX2 decreased around symptom onset and in the symptomatic stage. DISCUSSION: We conclude that NPTX2 is a promising synapse-derived disease progression biomarker in genetic FTD.

Post-Stroke Cognitive Impairment: A Review Focusing on Molecular Biomarkers.

Post-stroke cognitive impairment (PSCI), as one of the major complications after stroke, refers to a series of syndromes from mild cognitive impairment to dementia caused by stroke. Stroke has been reported to increase the risk of cognitive impairment by at least five to eight times. The assessment of PSCI usually relies on neuropsychological tests, but the results of these tests are subjective and inaccurate, and can be insufficient for the diagnosis and prognosis of PSCI. In recent years, an increasing number studies have indicated that changes in the expression of biomarkers such as C-reactive protein (CRP), interleukin 6 (IL-6) and IL-10 in blood, urine and other body fluids are associated with cognitive decline after stroke. Therefore, the detection of biomarkers in circulating blood serum, plasma and cerebrospinal fluid (CSF) may improve the accuracy of diagnosis and prognosis in PSCI. This review aims to summarize the studies on potential molecular biomarkers of PSCI.

Local and Systemic Humoral Response to Autologous Lineage-Negative Cells Intrathecal Administration in ALS Patients.

Amyotrophic lateral sclerosis (ALS) remains a fatal disease with limited therapeutic options. Signaling via neurotrophins (NTs), neuroinflammation, and certain micro-RNAs are believed to play essential role in ALS pathogenesis. Lineage-negative stem/progenitor cells (Lin-) were obtained from bone marrow of 18 ALS patients and administered intrathecally. Clinical assessment was performed using ALS Functional Rating Scale (FRSr) and Norris scale. Protein concentrations were measured in plasma and cerebrospinal fluid (CSF) by multiplex fluorescent bead-based immunoassay. Gene expression in nucleated blood cells was assessed using gene microarray technique. Finally, miRNA expression was analyzed using qPCR in CSF and plasma samples. We observed a significant decrease of C-reactive protein (CRP) concentration in plasma on the seventh day from the application of cells. Gene array results revealed decreased expression of gene sets responsible for neutrophil activation. Further analysis revealed moderate negative correlation between CRP level in CSF and clinical outcome. Brain-derived neurotrophic factor (BDNF) concentrations in both plasma and CSF significantly correlated with the favorable clinical outcome. On a micro-RNA level, we observed significant increase of miR-16-5p expression one week after transplantation in both body fluids and significant increase of miR-206 expression in plasma. Administration of Lin- cells may decrease inflammatory response and prevent neurodegeneration. However, these issues require further investigations.

Pathologically Decreased CSF Levels of Synaptic Marker NPTX2 in DLB Are Correlated with Levels of Alpha-Synuclein and VGF.

Background: Dementia with Lewy bodies (DLB) is a neurodegenerative disease where synaptic loss and reduced synaptic integrity are important neuropathological substrates. Neuronal Pentraxin 2(NPTX2) is a synaptic protein that drives the GABAergic inhibitory circuit. Our aim was to examine if NPTX2 cerebral spinal fluid (CSF) levels in DLB patients were altered and how these levels related to other synaptic protein levels and to cognitive function and decline. Methods: NPTX2, VGF, and α-synuclein levels were determined in CSF of cognitive healthy (n = 27), DLB (n = 48), and AD (n = 20) subjects. Multiple cognitive domains were tested, and data were compared using linear models. Results: Decreased NPTX2 levels were observed in DLB (median = 474) and AD (median = 453) compared to cognitive healthy subjects (median = 773). Strong correlations between NPTX2, VGF, and α-synuclein were observed dependent on diagnosis. Combined, these markers had a high differentiating power between DLB and cognitive healthy subjects (AUC = 0.944). Clinically, NPTX2 levels related to global cognitive function and cognitive decline in the visual spatial domain. Conclusion: NPTX2 CSF levels were reduced in DLB and closely correlated to decreased VGF and α-synuclein CSF levels. CSF NPTX2 levels in DLB related to decreased functioning in the visual spatial domain.

Determination of pentraxin 3 levels in cerebrospinal fluid during central nervous system infections.

Pentraxin 3 (PTX3) is an acute phase protein; its plasmatic levels significantly rise during severe infections. Data on PTX3 levels in cerebrospinal fluid (CSF) of patients with central nervous system (CNS) infections are lacking. We aimed (a) to assess the diagnostic potential of measuring CSF PTX3 levels in patients with CNS infections and (b) to establish CSF PTX3 cutoffs to distinguish between bacterial and aseptic meningoencephalitis (ROC curve). PTX3 levels were measured in CSF from 19 patients admitted to Trieste Hospital, Italy, with CNS infection. A diagnosis of bacterial infection and aseptic meningoencephalitis was made in 7 (37%) and 12 (63%) patients, respectively. Subjects with bacterial infections showed significantly higher PTX3 levels (13.5 vs 1.27 ng/mL in aseptic meningoencephalitis, p = 0.010). We identified two different CSF PTX3 levels cutoffs. (1) The best cutoff to maximise Youden's J was 9.6 ng/mL with a sensitivity, specificity, positive predictive value and negative predictive value (NPV) of 71.4%, 91.4%, 83.3%, 84.6%, respectively. (2) The cutoff with higher NPV (100%) was 3.6 ng/mL; a diagnosis of bacterial infections was obtained in 0% patients with CSF PTX3 levels < 3.6 ng/mL vs 58% of those with CSF PTX3 levels ≥ 3.6 ng/mL (p = 0.017). CSF PTX3 levels are higher in bacterial meningitis than aseptic meningoencephalitis. A cutoff of 3.6 ng/mL of CSF PTX3 has a high NPV and can be used to exclude bacterial CNS infections.

Liquid biopsy of cerebrospinal fluid identifies neuronal pentraxin receptor (NPTXR) as a biomarker of progression of Alzheimer's disease.

Background Alzheimer's disease (AD) is the most prevalent form of dementia. Currently, the most studied biomarkers of AD are cerebrospinal fluid (CSF) amyloid ß 1-42, total tau and phosphorylated tau. However, misdiagnosis can exceed 20%. Recently, we found that CSF amyloid ß precursor-like protein-1 (APLP1) and neuronal pentraxin receptor (NPTXR) are promising biomarkers of AD. The aim of the present study is to validate CSF APLP1 and NPTXR as biomarkers of AD severity. Methods APLP1 and NPTXR concentrations were measured in the CSF of patients with mild cognitive impairment (MCI) (n = 14), mild AD (n = 21), moderate AD (n = 43) and severe AD (n = 30) using enzyme-linked immunosorbent assays (ELISAs). Results CSF APLP1 and NPTXR were not associated with age or sex. CSF APLP1 was not different between any of the AD severity groups (p = 0.31). CSF NPTXR was significantly different between MCI and mild AD (p = 0.006), mild and moderate AD (p = 0.016), but not between moderate and severe AD (p = 0.36). NPTXR concentration progressively declined from MCI to mild, to moderate and to severe AD patients (p < 0.0001, Kruskal-Wallis test). CSF NPTXR positively correlated with the Mini-Mental Status Examination (MMSE) score (p < 0.001). Conclusions NPTXR concentration in CSF is a promising biomarker of AD severity and could inform treatment success and disease progression in clinical settings.

CSF chitinase proteins in amyotrophic lateral sclerosis.

OBJECTIVE: To evaluate the classifier performance, clinical and biochemical correlations of cerebrospinal fluid (CSF) levels of the chitinase proteins Chitotriosidase-1 (CHIT1), Chitinase-3-like protein 1 (CHI3L1) and Chitinase-3-like protein 2 (CHI3L2) in amyotrophic lateral sclerosis (ALS). METHODS: CSF levels of CHIT1, CHI3L1, CHI3L2, phosphorylated neurofilament heavy chain (pNFH) and C-reactive protein were measured by ELISA in a longitudinal cohort of patients with ALS (n=82), primary lateral sclerosis (PLS, n=10), ALS-mimic conditions (n=12), healthy controls (n=25) and asymptomatic carriers of ALS-causing genetic mutations (AGC; n=5). RESULTS: CSF CHIT1, CHI3L1 and CHI3L2 were elevated in patients with ALS compared with healthy controls (p<0.001) and ALS-mimics (CHIT1, p<0.001; CHI3L1, p=0.017; CHI3L2, p<0.001). CHIT1 and CHI3L2 were elevated in ALS compared with PLS (CHIT1, p=0.021; CHI3L1, p=0.417; CHI3L2, p<0.001). Chitinase levels were similar in AGCs and healthy controls. Chitinase proteins distinguished ALS from healthy controls (area under the curve (AUC): CHIT1 0.92; CHI3L1 0.80; CHI3L2 0.90), mimics (AUC: CHIT1 0.84; CHI3L1 0.73; CHI3L2 0.88) and, to a lesser extent, PLS (AUC: CHIT 0.73; CHI3L1 0.51; CHI3L2 0.82) but did not outperform pNFH. CHIT1 and CHI3L2 correlated with disease progression rate (Pearson's r=0.49, p<0.001; r=0.42, p<0.001, respectively). CHI3L1 correlated with degree of cognitive dysfunction (r=-0.25, p=0.038). All chitinases correlated with pNFH. CHIT1 levels were associated with survival in multivariate models. Chitinase levels were longitudinally stable. CONCLUSIONS: CSF chitinase proteins may have limited value as independent diagnostic and stratification biomarkers in ALS, but offer a window into non-autonomous mechanisms of motor neuronal loss in ALS, specifically in assessing response to therapies targeting neuroinflammatory pathways.

CSF inflammatory markers differ in gram-positive versus gram-negative shunt infections.

BACKGROUND: Cerebrospinal fluid (CSF) shunt placement is frequently complicated by bacterial infection. Shunt infection diagnosis relies on bacterial culture of CSF which can often produce false-negative results. Negative cultures present a conundrum for physicians as they are left to rely on other CSF indices, which can be unremarkable. New methods are needed to swiftly and accurately diagnose shunt infections. CSF chemokines and cytokines may prove useful as diagnostic biomarkers. The objective of this study was to evaluate the potential of systemic and CSF biomarkers for identification of CSF shunt infection. METHODS: We conducted a retrospective chart review of children with culture-confirmed CSF shunt infection at Children's Hospital and Medical Center from July 2013 to December 2015. CSF cytokine analysis was performed for those patients with CSF in frozen storage from the same sample that was used for diagnostic culture. RESULTS: A total of 12 infections were included in this study. Patients with shunt infection had a median C-reactive protein (CRP) of 18.25 mg/dL. Median peripheral white blood cell count was 15.53 × 103 cells/mL. Those with shunt infection had a median CSF WBC of 332 cells/mL, median CSF protein level of 406 mg/dL, and median CSF glucose of 35.5 mg/dL. An interesting trend was observed with gram-positive infections having higher levels of the anti-inflammatory cytokine interleukin (IL)-10 as well as IL-17A and vascular endothelial growth factor (VEGF) compared to gram-negative infections, although these differences did not reach statistical significance. Conversely, gram-negative infections displayed higher levels of the pro-inflammatory cytokines IL-1ß, fractalkine (CX3CL1), chemokine ligand 2 (CCL2), and chemokine ligand 3 (CCL3), although again these were not significantly different. CSF from gram-positive and gram-negative shunt infections had similar levels of interferon gamma (INF-γ), tumor necrosis factor alpha (TNF-α), IL-6, and IL-8. CONCLUSIONS: This pilot study is the first to characterize the CSF cytokine profile in patients with CSF shunt infection and supports the distinction of chemokine and cytokine profiles between gram-negative and gram-positive infections. Additionally, it demonstrates the potential of CSF chemokines and cytokines as biomarkers for the diagnosis of shunt infection.

Effect of Dexmedetomidine on Cerebral Vasospasm and Associated Biomarkers in a Rat Subarachnoid Hemorrhage Model.

BACKGROUND: The α2 adrenergic agonist dexmedetomidine (DEX) has huge potential for protecting against cerebral vasospasm, a leading cause of death and disability after subarachnoid hemorrhage (SAH). Biomarker assays for SAH have recently emerged as tools for predicting vasospasm and outcomes. We investigated the effects of DEX on vasospasm and assessed relevant biomarkers in a rat SAH model. METHODS: Male Wistar rats were randomly assigned to sham (n=10), vehicle (n=10), SAH (n=10), or SAH+ DEX (n=10) groups. The SAH and SAH+DEX groups received 0.3 mL injections of autologous blood into the cisterna magna, followed by intraperitoneal injections of normal saline or 10 µg/kg DEX. Forty-eight hours later, neurological deficits as well as the basilar artery (BA) wall thickness and cross-sectional area were measured. Cerebrospinal fluid (CSF) and blood samples were obtained to assess concentrations of interleukin (IL)-6, C-reactive protein (CRP), endothelin-1, and S100-ß using enzyme-linked immunosorbent assays. RESULTS: The SAH and SAH+DEX groups exhibited deteriorated neurological function as well as structural and morphological BA vasospasm. The SAH+DEX group showed an improved neurological function score (ie, a 52% decrease), a 10% reduction in wall thickness, and a BA cross-sectional area enlarged by 157%. Compared with the sham group, CSF levels of IL-6 and CRP in the SAH and SAH+DEX groups, as well as serum IL-6 and CRP levels in the SAH group, were significantly elevated. The SAH+DEX group showed significantly lower CSF IL-6 levels than the SAH group. Serum and CSF levels of endothelin-1 and S100-ß were similar across all groups. CONCLUSIONS: DEX administration reduced the severity of cerebral vasospasm and improved neurological function in SAH rats; this may be closely linked to reduced CSF IL-6 levels.