Advancements in Cerebrospinal Fluid Biosensors: Bridging the Gap from Early Diagnosis to the Detection of Rare Diseases.

Cerebrospinal fluid (CSF) is a body fluid that can be used for the diagnosis of various diseases. However, CSF collection requires an invasive and painful procedure called a lumbar puncture (LP). This procedure is applied to any patient with a known risk of central nervous system (CNS) damage or neurodegenerative disease, regardless of their age range. Hence, this can be a very painful procedure, especially in infants and elderly patients. On the other hand, the detection of disease biomarkers in CSF makes diagnoses as accurate as possible. This review aims to explore novel electrochemical biosensing platforms that have impacted biomedical science. Biosensors have emerged as techniques to accelerate the detection of known biomarkers in body fluids such as CSF. Biosensors can be designed and modified in various ways and shapes according to their ultimate applications to detect and quantify biomarkers of interest. This process can also significantly influence the detection and diagnosis of CSF. Hence, it is important to understand the role of this technology in the rapidly progressing field of biomedical science.

Association between tight junction proteins and cognitive performance in untreated persons with HIV.

BACKGROUND: HIV-associated neurocognitive disorders (HAND) still affects persons with HIV (PWH) and their pathogenesis is not completely understood. We aimed to explore the association between plasma and cerebrospinal fluid (CSF) markers of blood-brain barrier (BBB) impairment and HAND in untreated PWH. DESIGN: Cross-sectional study. METHODS: We enrolled untreated PWH, who underwent blood examinations and lumbar puncture to measure inflammation (IL-15, TNF-α), BBB damage (zonulin and tight junction proteins, tight junction proteins: occludin, claudin-5) and endothelial adhesion molecules (VCAM-1, ICAM-1). A comprehensive neurocognitive battery was used to diagnose HAND (Frascati criteria). RESULTS: Twenty-one patients (21/78, 26.9%) patients presented HAND (100% ANI). HAND patients displayed more frequently non-CNS AIDS-defining conditions, lower nadir CD4 + T cells and increased CD4 + T-cell exhaustion (lower CD4 + CD127 + and CD4 + CD45RA + T-cell percentages), in comparison to individuals without cognitive impairment. Furthermore, HAND was characterized by higher plasma inflammation (IL-15) but lower CSF levels of biomarkers of BBB impairment (zonulin and occludin). The association between BBB damage with HAND was confirmed by fitting a multivariable logistic regression. CSF/plasma endothelial adhesion molecules were not associated with HAND but with a poor performance in different cognitive domains. CONCLUSION: By showing heightened inflammation and BBB impairment, our study suggests loss of BBB integrity as a possible factor contributing to the development of HAND in untreated PWH.

NIR-II nanoprobes for investigating the glymphatic system function under anesthesia and stroke injury.

The glymphatic system plays an important role in the transportation of cerebrospinal fluid (CSF) and the clearance of metabolite waste in brain. However, current imaging modalities for studying the glymphatic system are limited. Herein, we apply NIR-II nanoprobes with non-invasive and high-contrast advantages to comprehensively explore the function of glymphatic system in mice under anesthesia and cerebral ischemia-reperfusion injury conditions. Our results show that the supplement drug dexmedetomidine (Dex) enhances CSF influx in the brain, decreases its outflow to mandibular lymph nodes, and leads to significant differences in CSF accumulation pattern in the spine compared to isoflurane (ISO) alone, while both ISO and Dex do not affect the clearance of tracer-filled CSF into blood circulation. Notably, we confirm the compromised glymphatic function after cerebral ischemia-reperfusion injury, leading to impaired glymphatic influx and reduced glymphatic efflux. This technique has great potential to elucidate the underlying mechanisms between the glymphatic system and central nervous system diseases.

Continuous evaluation of single-dose moxifloxacin concentrations in brain extracellular fluid, cerebrospinal fluid, and plasma: a novel porcine model.

BACKGROUND: Knowledge regarding CNS pharmacokinetics of moxifloxacin is limited, with unknown consequences for patients with meningitis caused by bacteria resistant to beta-lactams or caused by TB. OBJECTIVE: (i) To develop a novel porcine model for continuous investigation of moxifloxacin concentrations within brain extracellular fluid (ECF), CSF and plasma using microdialysis, and (ii) to compare these findings to the pharmacokinetic/pharmacodynamic (PK/PD) target against TB. METHODS: Six female pigs received an intravenous single dose of moxifloxacin (6 mg/kg) similar to the current oral treatment against TB. Subsequently, moxifloxacin concentrations were determined by microdialysis within five compartments: brain ECF (cortical and subcortical) and CSF (ventricular, cisternal and lumbar) for the following 8 hours. Data were compared to simultaneously obtained plasma samples. Chemical analysis was performed by high pressure liquid chromatography with mass spectrometry. The applied PK/PD target was defined as a maximum drug concentration (Cmax):MIC ratio >8. RESULTS: We present a novel porcine model for continuous in vivo CNS pharmacokinetics for moxifloxacin. Cmax and AUC0-8h within brain ECF were significantly lower compared to plasma and lumbar CSF, but insignificantly different compared to ventricular and cisternal CSF. Unbound Cmax:MIC ratio across all investigated compartments ranged from 1.9 to 4.3. CONCLUSION: A single dose of weight-adjusted moxifloxacin administered intravenously did not achieve adequate target site concentrations within the uninflamed porcine brain ECF and CSF to reach the applied TB CNS target.

Granulocytes in cerebrospinal fluid of adults suspected of a central nervous system infection: a prospective study of diagnostic accuracy.

PURPOSE: Cerebrospinal fluid (CSF) granulocytes are associated with bacterial meningitis, but information on its diagnostic value is limited and primarily based on retrospective studies. Therefore, we assessed the diagnostic accuracy of CSF granulocytes. METHODS: We analyzed CSF granulocytes (index test) from all consecutive patients in two prospective cohort studies in the Netherlands. Both studies included patients ≥ 16 years, suspected of a central nervous system (CNS) infection, who underwent a diagnostic lumbar puncture. All episodes with elevated CSF leukocytes (≥ 5 cells per mm3) were selected and categorized by clinical diagnosis (reference standard). RESULTS: Of 1261 episodes, 625 (50%) had elevated CSF leukocytes and 541 (87%) were included. 117 of 541 (22%) were diagnosed with bacterial meningitis, 144 (27%) with viral meningoencephalitis, 49 (9%) with other CNS infections, 76 (14%) with CNS autoimmune disorders, 93 (17%) with other neurological diseases and 62 (11%) with systemic diseases. The area under the curve to discriminate bacterial meningitis from other diagnoses was 0.97 (95% confidence interval [CI] 0.95-0.98) for CSF granulocyte count and 0.93 (95% CI 0.91-0.96) for CSF granulocyte percentage. CSF granulocyte predominance occurred in all diagnostic categories. A cutoff at 50% CSF granulocytes gave a sensitivity of 94% (95% CI 90-98), specificity of 80% (95% CI 76-84), negative predictive value of 98% (95% CI 97-99) and positive predictive value of 57% (95% CI 52-62). CONCLUSION: CSF granulocytes have a high diagnostic accuracy for bacterial meningitis in patients suspected of a CNS infection. CSF granulocyte predominance occurred in all diagnostic categories, limiting its value in clinical practice.

Quantitative proteomics of cerebrospinal fluid from African Americans and Caucasians reveals shared and divergent changes in Alzheimer's disease.

BACKGROUND: Despite being twice as likely to get Alzheimer's disease (AD), African Americans have been grossly underrepresented in AD research. While emerging evidence indicates that African Americans with AD have lower cerebrospinal fluid (CSF) levels of Tau compared to Caucasians, other differences in AD CSF biomarkers have not been fully elucidated. Here, we performed unbiased proteomic profiling of CSF from African Americans and Caucasians with and without AD to identify both common and divergent AD CSF biomarkers. METHODS: Multiplex tandem mass tag-based mass spectrometry (TMT-MS) quantified 1,840 proteins from 105 control and 98 AD patients of which 100 identified as Caucasian while 103 identified as African American. We used differential protein expression and co-expression approaches to assess how changes in the CSF proteome are related to race and AD. Co-expression network analysis organized the CSF proteome into 14 modules associated with brain cell-types and biological pathways. A targeted mass spectrometry method, selected reaction monitoring (SRM), with heavy labeled internal standards was used to measure a panel of CSF module proteins across a subset of African Americans and Caucasians with or without AD. A receiver operating characteristic (ROC) curve analysis assessed the performance of each protein biomarker in differentiating controls and AD by race. RESULTS: Consistent with previous findings, the increase of Tau levels in AD was greater in Caucasians than in African Americans by both immunoassay and TMT-MS measurements. CSF modules which included 14-3-3 proteins (YWHAZ and YWHAG) demonstrated equivalent disease-related elevations in both African Americans and Caucasians with AD, whereas other modules demonstrated more profound disease changes within race. Modules enriched with proteins involved with glycolysis and neuronal/cytoskeletal proteins, including Tau, were more increased in Caucasians than in African Americans with AD. In contrast, a module enriched with synaptic proteins including VGF, SCG2, and NPTX2 was significantly lower in African Americans than Caucasians with AD. Following SRM and ROC analysis, VGF, SCG2, and NPTX2 were significantly better at classifying African Americans than Caucasians with AD. CONCLUSIONS: Our findings provide insight into additional protein biomarkers and pathways reflecting underlying brain pathology that are shared or differ by race.

A single-cell map of antisense oligonucleotide activity in the brain.

Antisense oligonucleotides (ASOs) dosed into cerebrospinal fluid (CSF) distribute broadly throughout the central nervous system (CNS). By modulating RNA, they hold the promise of targeting root molecular causes of disease and hold potential to treat myriad CNS disorders. Realization of this potential requires that ASOs must be active in the disease-relevant cells, and ideally, that monitorable biomarkers also reflect ASO activity in these cells. The biodistribution and activity of such centrally delivered ASOs have been deeply characterized in rodent and non-human primate (NHP) models, but usually only in bulk tissue, limiting our understanding of the distribution of ASO activity across individual cells and across diverse CNS cell types. Moreover, in human clinical trials, target engagement is usually monitorable only in a single compartment, CSF. We sought a deeper understanding of how individual cells and cell types contribute to bulk tissue signal in the CNS, and how these are linked to CSF biomarker outcomes. We employed single nucleus transcriptomics on tissue from mice treated with RNase H1 ASOs against Prnp and Malat1 and NHPs treated with an ASO against PRNP. Pharmacologic activity was observed in every cell type, though sometimes with substantial differences in magnitude. Single cell RNA count distributions implied target RNA suppression in every single sequenced cell, rather than intense knockdown in only some cells. Duration of action up to 12 weeks post-dose differed across cell types, being shorter in microglia than in neurons. Suppression in neurons was generally similar to, or more robust than, the bulk tissue. In macaques, PrP in CSF was lowered 40% in conjunction with PRNP knockdown across all cell types including neurons, arguing that a CSF biomarker readout is likely to reflect ASO pharmacodynamic effect in disease-relevant cells in a neuronal disorder. Our results provide a reference dataset for ASO activity distribution in the CNS and establish single nucleus sequencing as a method for evaluating cell type specificity of oligonucleotide therapeutics and other modalities.

Antisense oligonucleotide (ASO) drugs are a type of chemically modified DNA that can be injected into cerebrospinal fluid in order to enter brain cells and reduce the amount of RNA from a specific gene. The brain is a complex mixture of hundreds of billions of cells. When an ASO lowers a target gene's RNA by 50%, is that a 50% reduction in 100% of cells, or a 100% reduction in 50% of cells? Are the many different cell types of the brain affected equally? This new study uses single cell RNA sequencing to answer these questions, finding that ASOs are broadly active across cell types and individual cells, and linking reduction of target protein in cerebrospinal fluid to disease-relevant cells.

La citometría de flujo aumenta la proporción de muestras valorables en líquido cefalorraquídeo con recuento celular normal en hemopatías malignas / Flow cytometry increases the proportion of valuable samples in cerebrospinal fluid with normal cell count in malignant blood diseases

INTRODUCCIÓN: El compromiso del líquido cefalorraquídeo (LCR) en hemopatías malignas es un marcador de mal pronóstico y es habitualmente estudiado por citometría de flujo o citología. Ocasionalmente, las muestras de LCR oligocelulares (≤ 5 céls/dL) pueden ser consideradas como no aptas para diagnóstico por la baja cantidad de eventos. Objetivo: Evaluar la proporción de muestras reportadas como valorables para diagnóstico obtenidas por citometría y citología en muestras de LCR oligocelular. Material y Métodos: Se seleccionaron 169 muestras de LCR oligocelular correspondientes a 115 pacientes con hemopatías malignas. Las muestras fueron obtenidas mediante punción lumbar en tubos acondicionados con EDTA y preservante celular (Transfix®). El inmunofenotipo se realizó con panel de 8 colores, 55 (32%) de las cuales se hizo con panel para pequeñas muestras (SST). En todos los casos se incluyó CD14 para identificación de monocitos y CD3 para linfocitos T. La adquisición se realizó en citómetro FACSCantoII® y el análisis en software Infinicyt®. Resultados: La proporción de muestras valorables fue mayor en citometría en comparación con la citología (98% vs 61%, p < 0,000). En la mayoría se identificaron linfocitos T (98%) y/o monocitos (90%). En las muestras con SST, la cantidad de eventos obtenida fue menor en muestras con < de 1 mL (140 vs 556, p < 0,001) y se logró identificar una mediana de 3 poblaciones celulares. Conclusión: La citometría proporciona una mayor cantidad de muestras valorables en los LCR paucicelulares en relación con la citología en muestras de LCR enviadas para estudio de compromiso de LCR por hemopatías malignas.

BACKGROUND: The alteration of cerebrospinal fluid (CSF) in hematologic neoplasms is a poor prognostic marker. The characteristics of CSF are usually analyzed by flow cytometry or cytology. However, paucicellular CSF samples (≤5 cells/dL) can sometimes be considered unsuitable for analysis due to the low number of events. Objective: To evaluate the proportion of samples reported as suitable for analysis obtained by cytometry (FCM) and cytology in paucicellular CSF samples. Material and Methods: 169 samples ofpaucicellular CSF corresponding to 115 patients with hematologic neoplasms were selected. The samples were obtained by lumbar puncture in tubes conditioned with EDTA and Transfix®. We characterized the immunophenotype ofCSF samples with an 8-color panel, and 55 samples (32%) were in a small sample tube (SST). In all cases, monocytes were identified by CD14 labeling and T lymphocytes by CD3 labeling. The acquisition was carried out in a FACSCantoII® cytometer, and the analysis was performed using Infinicyt® software. Results: The proportion of samples suitable for analysis was higher in FCM compared to cytology (98% vs 61%, p < 0.000). We identified the presence of T lymphocytes and/or monocytes in most samples (98% and 90%, respectively). In the SST samples, the number of events recorded in low-volume samples (< 1 mL) was lower than in samples with higher volume (140 vs 556, p < 0.001), with a median of identification of 3 cell populations. Conclusion: FCM allows the analysis of a higher proportion ofpaucicellular CSF samples than cytology in hematologic neoplasms study.

Liquid chromatography-tandem mass spectrometry analysis of delamanid and its metabolite in human cerebrospinal fluid using protein precipitation and on-line solid-phase extraction.

The penetration of the antituberculosis drug delamanid into the central nervous system is not established. The distribution of delamanid and its major metabolite, DM-6705, into the cerebrospinal fluid requires investigation. A liquid chromatography-tandem mass spectrometry method for the quantification of delamanid and DM-6705 in human cerebrospinal fluid was developed and validated. The calibration range for both analytes was 0.300 - 30.0 ng/mL. The deuterium-labelled analogue of delamanid (delamanid-d4) and OPC-14714 were used as internal standards for delamanid and DM-6705, respectively. Samples were processed by protein precipitation followed by on-line solid-phase extraction and high-performance liquid chromatography on an Agilent 1260 HPLC system. A Phenomenex Gemini-NX C18 (5.0 µm, 50 mm × 2.0 mm) analytical column was used for on-line solid-phase extraction, and a Waters Xterra MS C18 (5.0 µm, 100 mm × 2.1 mm) analytical column for chromatographic separation using gradient elution, at a flow rate of 300 µL/min. The total run time was 7.5 min. Analytes were detected by multiple reaction monitoring on an AB Sciex 5500 triple quadrupole mass spectrometer at unit mass resolution, with electrospray ionization in the positive mode. Accuracy and precision were assessed over three independent validation batches. Extraction recoveries were more than 98% and were consistent across the analytical range. Both analytes in CSF exhibited non-specific adsorption to polypropylene tubes. The method was used to analyse cerebrospinal fluid samples from patients with pulmonary tuberculosis in an exploratory pharmacokinetic study.

Use of cerebrospinal fluid CXCL13 concentration for diagnosis and monitoring of neurosyphilis: a three-case report

Introduction: Previous retrospective studies have demonstrated that the concentration of chemokine ligand CXCL13 in cerebrospinal fluid (CSF-CXCL13) is a promising biomarker in the diagnosis of neurosyphilis and, additionally, in the monitoring of therapeutic efficacy. Objective: To describe three cases of patients with neurosyphilis (NS) treated at Hospital Universitário Gaffrée e Guinle, in Rio de Janeiro, Brazil, with suspected active syphilis with neurological symptoms. Case report: Three patients from Rio de Janeiro, Brazil, were investigated for symptomatic NS. The concentration of CSF-CXCL13 was prospectively performed by enzyme-linked immunosorbent assay (ELISA) in all participants at baseline and in follow-up visits at 3 months after therapy. CSF-CXCL13 concentrations were significantly higher in all three patients with established NS. The CSF-CXCL13 concentrations decreased after 3 months of therapy compared to baseline in all cases reported. The added high concentration of CSF-CXCL13 plus CSF-TPHA reactivity above 1:40 titer agreed with the diagnosis of NS in 100% of the cases. Conclusion: In this case series, we present three cases of NS diagnosed using CXCL13 in CSF as a complementary test. These case series suggest that the clinical use of CSF-CXCL13 is useful as a supplementary biomarker for NS and for monitoring the effectiveness of NS therapy, especially in patients with nonreactive CSF-VDRL, excluding other neurologic diseases

Neurodegeneration Markers in the Cerebrospinal Fluid of 100 Patients with Schizophrenia Spectrum Disorder.

BACKGROUND: Schizophrenia spectrum disorders (SSD) can be associated with neurodegenerative processes causing disruption of neuronal, synaptic, or axonal integrity. Some previous studies have reported alterations of neurodegenerative markers (such as amyloid beta [Aß], tau, or neurofilaments) in patients with SSD. However, the current state of research remains inconclusive. Therefore, the rationale of this study was to investigate established neurodegenerative markers in the cerebrospinal fluid (CSF) of a large group of patients with SSD. STUDY DESIGN: Measurements of Aß1-40, Aß1-42, phospho- and total-tau in addition to neurofilament light (NFL), medium (NFM), and heavy (NFH) chains were performed in the CSF of 100 patients with SSD (60 F, 40 M; age 33.7 ± 12.0) and 39 controls with idiopathic intracranial hypertension (33 F, 6 M; age 34.6 ± 12.0) using enzyme-linked immunoassays. STUDY RESULTS: The NFM levels were significantly increased in SSD patients (P = .009), whereas phospho-tau levels were lower in comparison to the control group (P = .018). No other significant differences in total-tau, beta-amyloid-quotient (Aß1-42/Aß1-40), NFL, and NFH were identified. CONCLUSIONS: The findings argue against a general tauopathy or amyloid pathology in patients with SSD. However, high levels of NFM, which has been linked to regulatory functions in dopaminergic neurotransmission, were associated with SSD. Therefore, NFM could be a promising candidate for further research on SSD.

[Flow cytometry increases the proportion of valuable samples in cerebrospinal fluid with normal cell count in malignant blood diseases]. / La citometría de flujo aumenta la proporción de muestras valorables en líquido cefalorraquídeo con recuento celular normal en hemopatías malignas.

BACKGROUND: The alteration of cerebrospinal fluid (CSF) in hematologic neoplasms is a poor prognostic marker. The characteristics of CSF are usually analyzed by flow cytometry or cytology. However, paucicellular CSF samples (≤5 cells/dL) can sometimes be considered unsuitable for analysis due to the low number of events. OBJECTIVE: To evaluate the proportion of samples reported as suitable for analysis obtained by cytometry (FCM) and cytology in paucicellular CSF samples. MATERIAL AND METHODS: 169 samples ofpaucicellular CSF corresponding to 115 patients with hematologic neoplasms were selected. The samples were obtained by lumbar puncture in tubes conditioned with EDTA and Transfix®. We characterized the immunophenotype ofCSF samples with an 8-color panel, and 55 samples (32%) were in a small sample tube (SST). In all cases, monocytes were identified by CD14 labeling and T lymphocytes by CD3 labeling. The acquisition was carried out in a FACSCantoII® cytometer, and the analysis was performed using Infinicyt® software. RESULTS: The proportion of samples suitable for analysis was higher in FCM compared to cytology (98% vs 61%, p < 0.000). We identified the presence of T lymphocytes and/or monocytes in most samples (98% and 90%, respectively). In the SST samples, the number of events recorded in low-volume samples (< 1 mL) was lower than in samples with higher volume (140 vs 556, p < 0.001), with a median of identification of 3 cell populations. CONCLUSION: FCM allows the analysis of a higher proportion ofpaucicellular CSF samples than cytology in hematologic neoplasms study.

SOBA: Development and testing of a soluble oligomer binding assay for detection of amyloidogenic toxic oligomers.

The formation of toxic Amyloid ß-peptide (Aß) oligomers is one of the earliest events in the molecular pathology of Alzheimer's Disease (AD). These oligomers lead to a variety of downstream effects, including impaired neuronal signaling, neuroinflammation, tau phosphorylation, and neurodegeneration, and it is estimated that these events begin 10 to 20 y before the presentation of symptoms. Toxic Aß oligomers contain a nonstandard protein structure, termed α-sheet, and designed α-sheet peptides target this main-chain structure in toxic oligomers independent of sequence. Here we show that a designed α-sheet peptide inhibits the deleterious effects on neuronal signaling and also serves as a capture agent in our soluble oligomer binding assay (SOBA). Pre-incubated synthetic α-sheet-containing Aß oligomers produce strong SOBA signals, while monomeric and ß-sheet protofibrillar Aß do not. α-sheet containing oligomers were also present in cerebrospinal fluid (CSF) from an AD patient versus a noncognitively impaired control. For the detection of toxic oligomers in plasma, we developed a plate coating to increase the density of the capture peptide. The proof of concept was achieved by testing 379 banked human plasma samples. SOBA detected Aß oligomers in patients on the AD continuum, including controls who later progressed to mild cognitive impairment. In addition, SOBA discriminated AD from other forms of dementia, yielding sensitivity and specificity of 99% relative to clinical and neuropathological diagnoses. To explore the broader potential of SOBA, we adapted the assay for a-synuclein oligomers and confirmed their presence in CSF from patients with Parkinson's disease and Lewy body dementia.

SWATH Mass Spectrometry-Based CSF Proteome Profile of GBA-Linked Parkinson's Disease Patients.

ß-glucocerebrosidase (GBA)-associated mutations are a significant risk factor for Parkinson's disease (PD) that aggravate the disease pathology by upregulating the deposition of α-Synuclein (α-Syn). The resultant clinical profile varies for PD patients without GBA mutations. The current study aimed to identify the proteomic targets involved in the pathogenic pathways leading to the differential clinical presentation of GBA-associated PD. CSF samples (n = 32) were obtained from PD patients with GBA mutations (n = 22), PD patients without GBA mutations (n = 7), and healthy controls that were carriers of GBA mutations (n = 3). All samples were subjected to in-gel tryptic digestion followed by the construction of the spectral library and quantitative SWATH-based analysis. CSF α-Syn levels were reduced in both PDIdiopathic and PDGBA cases. Our SWATH-based mass spectrometric analysis detected 363 proteins involved in immune response, stress response, and cell signaling in various groups. Intergroup analysis showed that 52 proteins were significantly up- or downregulated in various groups. Of these 52 targets, 20 proteins were significantly altered in PDGBA cases only while 2 showed different levels in PDIdiopathic patients. Our results show that the levels of several pathologically relevant proteins, including Contactin-1, Selenium-binding protein 1, Adhesion G Protein-Coupled Receptor, and Apolipoprotein E are significantly different among the sporadic and genetic variants of PD and hint at aggravated synaptic damage, oxidative stress, neuronal loss, and aggregation of α-Syn in PDGBA cases.

Cerebrospinal Fluid and Blood Biomarkers of Neuroinflammation and Blood-Brain Barrier in Psychotic Disorders and Individually Matched Healthy Controls.

BACKGROUND AND HYPOTHESIS: Neuroinflammation and blood-brain barrier (BBB) dysfunction have been observed in patients with psychotic disorders. However, previous studies have mainly focused on selected patients and broad screenings of cerebrospinal fluid (CSF) of patients with recent onset psychosis compared to healthy controls are lacking. STUDY DESIGN: We included 104 patients with recent onset psychotic disorder and 104 individually matched healthy controls. CSF and blood were analyzed for readily available markers assessing neuroinflammation and BBB dysfunction. Primary outcomes were CSF white blood cell count (WBC), total protein, IgG Index, and CSF/serum albumin ratio. Secondary outcomes included additional markers of inflammation and BBB, and analyses of association with clinical variables. STUDY RESULTS: CSF/serum albumin ratio (Relative Mean Difference (MD): 1.11; 95%CI: 1.00-1.23; P = .044) and CSF/serum IgG ratio (MD: 1.17; 95%CI: 1.01-1.36; P = .036) was increased in patients compared to controls. A higher number of patients than controls had CSF WBC >3 cells/µl (seven vs. one, OR: 7.73, 95%CI: 1.33-146.49, P = .020), while WBC>5 cells/µl was found in two patients (1.9%) and no controls. Inpatients had higher serum WBC and neutrophil/lymphocyte ratio (all p-values for effect heterogeneity < .011). Mean CSF WBC (MD: 1.10; 95%CI: 0.97-1.26), protein (MD: 1.06; 95%CI: 0.98-1.15) and IgG index (MD: 1.05; 95%CI: 0.96-1.15) were not significantly elevated. CONCLUSIONS: When comparing a broad group of patients with psychotic disorders with healthy controls, patients had increased BBB permeability, more patients had high CSF WBC levels, and inpatients had increased peripheral inflammation, consistent with the hypothesis of a subgroup of patients with increased activation of the immune system.

Impact of Cerebrospinal Fluid Sample Handling on Cytokine Detection Results.

OBJECTIVE: To investigate the impact of different treatment methods on cerebrospinal fluid (CSF) cytokine detection. METHODS: CSF samples were collected from 25 patients. The levels of IL-6, IL-10, IFN-γ, and IL-2 were measured after CSF was stored at room temperature (25°C) or 4°C for 6, 12, and 24 hrs. The CSF was frozen at -80°C, thawed at room temperature for 1 hr every 8 hrs and then frozen. This process was repeated three times in a row, and then cytokine levels in CSF were detected again. RESULTS: The four cytokines were stable when the CSF was kept at room temperature for 6 hrs. After 12 hrs of storage, the levels of the four cytokines decreased, and the changes in IL-6 and IL-10 levels were statistically significant. After 24 hrs of storage, the levels of the four cytokines were further reduced, and the changes were statistically significant. Cytokines were stable when CSF was stored at 4°C, and only IL-10 exhibited statistically significant changes when stored for 24 hrs. IL-6, IL-10 IFN-γ, and IL-2 were stable in CSF samples after three freeze-thaw cycles. CONCLUSION: The stability of CSF cytokines is poor after storage at room temperature and good after storage at 4°C. Therefore, cytokine detection should be carried out after CSF collection as often as possible. If the detection cannot be done quickly enough, the specimens should be stored in cold storage for no more than 24 hrs.