Immune Response In Cerebrospinal Fluid Research Articles

Profile of Cytokines and T Cell Subsets Transcription Factors in Cerebrospinal Fluid of Patients with Viral Encephalitis.

This study investigates the demographic, clinical characteristics, virological profiles, and immunological responses of patients with viral encephalitis (VE) compared with a control group. The VE group displayed a wide range of neurological symptoms. Virological analysis revealed the predominance of Herpesviridae family viruses. Immune responses in cerebrospinal fluid (CSF) from patients with VE were examined, highlighting an immunological shift toward T helper 1 (Th1) cells dominance, altered T helper 17 cells/regulatory T cells (Th17/Tregs) balance, and high interleukin-6 expression. These findings provide insights into the complex immunological landscape of VE, highlighting the role of specific cytokines and T cell subsets in its pathogenesis and potentially guiding targeted therapeutic strategies.

495. Enterovirus Genotype Specific Immune Response in Cerebrospinal Fluid of Infected Infants

Abstract Background Non-polio Enteroviruses (EV) are important neonatal CNS pathogens. Multiple EV genotypes have been detected in pediatric CSF, e.g. Echovirus (E) 6 and E30. CSF innate immune responses to EV genotypes remain poorly defined. Most data are from EV-A71 or E30 CNS infections and do not compare responses between these or other EV types. We sought to better define innate immune responses to EV genotypes in CSF. Methods Salvaged standard of care CSF samples from ≤6 month olds (real time EV PCR(+) or EV PCR(-) controls) from Jan 2010 - Dec 2020 were tested in duplicate on a 21- cytokine bead panel (MilliporeSigma). EV positive samples were previously genotyped by sequencing the viral capsid gene. Cytokine levels calculated from the standard curve were compared by Kruskal-Wallis and post-hoc analysis (GraphPad Prism 8.4.3). Natural partitioning of participants was explored using principal component analysis and cluster analysis (IBM SPSS v27). The utility of cytokine signatures in predicting EV status was explored using discriminant analysis and ROC analysis (IBM SPSS v27). Results Data from 72 CSF with E6 (N=16), E9 (N= 9), E18 (N=9), and E30 (N=21) showed significant differences among EV genotypes vs. controls for 20 cytokines (IL-17 was excluded). Significant differences in cytokine levels in EV CSF vs controls were seen: E6 for all 20 cytokines; E9 for Fractalkine, IP10, and MCP1; E18 for Fractalkine and MCP1; E30 19 cytokines (not GM-CSF). PCA revealed only minor overlap of controls and EV positives; EV types overlapped, except E30, differing most from E9 and E18 but overlapping E6. The most important type-differentiating cytokines by PCA were MCP1, Fractalkine, IL-8, and IL-10. Patterns in DA resembled PCA; controls clearly separated from EV CSF, E30 being the most distinct. Overall, the discriminant model correctly classified EV type or controls at a 63% rate - highest for controls (94.1%) and E30 (74.1%). In the DA model, the most important cytokines were IP-10, IL-2, IL-1Ra, and Fractalkine. Discriminant scores had the largest area under the curve (AUC), 0.990. Among cytokines, IFNa2 had the largest AUC, 0.987. Conclusion Preliminary data show significant EV-genotype differences in innate immune response to CNS infections. Cytokine patterns may serve as a key predictor for discerning EV genotypes. Disclosures Brian R. Lee, PhD, MPH, CDC: Grant/Research Support|Merck: Grant/Research Support Christopher J Harrison, MD, Astellas: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|Pediatric news: Honoraria|Pfizer: Grant/Research Support Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, F(AAM), BioFire: Grant/Research Support|Luminex: Grant/Research Support.

Comparison of laboratory and immune characteristics of the initial and second phase of tick-borne encephalitis

ABSTRACT Tick-borne encephalitis (TBE) usually has a biphasic course which begins with unspecific febrile illness, followed by central nervous system involvement. Because TBE is not yet suspected during the initial phase, knowledge of early TBE pathogenesis is incomplete. Herein we evaluated laboratory and immune findings in the initial and second (meningoencephalitic) phase of TBE in 88 well-defined adult patients. Comparison of nine laboratory blood parameters in both phases of TBE revealed that laboratory abnormalities, consisting of low leukocyte and platelet counts and increased liver enzymes levels, were predominately associated with the initial phase of TBE and resolved thereafter. Assessment of 29 immune mediators in serum during the initial phase, and in serum and cerebrospinal fluid (CSF) during the second phase of TBE revealed highly distinct clustering patterns among the three groups. In the initial phase of TBE, the primary finding in serum was a rather heterogeneous immune response involving innate (CXCL11), B cell (CXCL13, BAFF), and T cell mediators (IL-27 and IL-4). During the second phase of TBE, growth factors associated with angiogenesis (GRO-α and VEGF-A) were the predominant characteristic in serum, whereas innate and Th1 mediators were the defining feature of immune responses in CSF. These findings imply that distinct immune processes play a role in the pathophysiology of different phases of TBE and in different compartments.

A preliminary study on the characteristics of Th1/Th2 immune response in cerebrospinal fluid of AIDS patients with cryptococcal meningitis

BackgroundCryptococcal Meningitis (CM) is a common opportunistic infection in the late stage of acquired immunodeficiency syndrome (AIDS). Despite the wide use of effective antiretroviral and antifungal therapy in AIDS patients, CM is still a major morbidity and mortality cause. Understanding the immune response in cryptococcal infection may help to improve the treatment strategies.MethodsWe established a prospective cohort of twelve AIDS patients with CM (HIV + CM+) admitted to the hospital from 2019 to 2020. All patients were examined at the baseline, 2 weeks, and 4 weeks thereafter. The level of 19 cytokines in cerebrospinal fluid (CSF) were recorded to analyze the characteristics and dynamic changes of Th1/Th2 immune response. Meanwhile, six AIDS patients without CM (HIV + CM-) and seventeen healthy subjects (HIV-CM-) were included as control groups for CSF assessment.ResultsThe HIV+ CM+ group had higher CSF IFN-γ, TNF-α, IL-6, IL-7, IL-8, IL-10, IL-12 (P40), IL-15, IL-18, CCL2 levels but lower IL-4 when compared with the HIV-CM- group at baseline. And they also had a higher level of IL-12 (P40) and IL-17A compared with HIV + CM- patients. Except one patient dropped out of the study, eleven HIV + CM+ patients received induction antifungal therapy and regular CSF testing, and the mortality rate was 9.1% (1/11) and 18.2% (2/11) respectively at week 2 and week 4. Compared with baseline CSF cytokines, IL-2, IL-13, IL-17A, and VEGF-A decreased in week 2, and the VEGF-A levels further decreased in week 4. But there was no difference in the levels of all cytokines between survivors and the dead.ConclusionNo evidence of Th1/Th2 imbalance was found in AIDS patients with CM. However, the CSF cytokine network may provide new clues for the treatment of AIDS patients with CM.Trial registrationThis trial was prospectively registered in 2019.7.16. The registered number is ChiCTR1900024565.

The Innate Immune Response Characterizes Posterior Reversible Encephalopathy Syndrome

While posterior reversible encephalopathy syndrome (PRES) is often characterized by an inflammatory cerebrospinal-fluid (CSF) profile, knowledge of immune cell patterns in PRES is lacking. Thus, we retrospectively characterized CSF and peripheral blood (PB) from 15 PRES patients, which we analyzed by multidimensional flow cytometry (FC). Results were compared to 72 controls, as well as to 9 patients with progressive multifocal leukoencephalopathy (PML, as a relevant differential diagnosis) and 15 multiple sclerosis patients (MS, as a classical neuroinflammatory disorder), respectively. Total protein level in CSF from PRES patients was elevated compared to that in controls, but not to MS and PML. In-depth FC analysis revealed no differences for adaptive immune cells (B cells, plasma cells, CD4+, and CD8+ T cells) in PB or CSF of PRES compared to controls. In contrast, we observed alterations of the adaptive immune response in CSF of PML and MS compared to PRES, indicating that the adaptive immune response is not a driver of disease in PRES. Indeed, PRES was characterized by an innate immune response with CD14++/CD16+ (intermediate) monocytes elevated in PB and CSF, while CD14++/CD16− (classical) monocytes were decreased in PB from PRES patients as compared to controls. Levels of CD14++/CD16+ monocytes correlated with the duration of hospital stay as a surrogate marker for disease severity in PRES patients. Our findings argue for a role of innate rather than adaptive immunity in the pathophysiology of PRES. The observed shift in monocyte subsets might provide valuable diagnostic clues for the clinical management of these patients.

2853. Innate Immune Response in Serum and Cerebrospinal Fluid of Neonates and Infants Infected with Parechovirus-A3 and Enteroviruses

BackgroundParechovirus-A3 (PeV-A3) and enteroviruses (EVs) are the most common viral causes of neonatal and infantile sepsis. We previously reported that the clinical manifestations of PeV-A3 infection—e.g., high body temperature, tachycardia, and poor peripheral circulation, but not cerebrospinal fluid (CSF) pleocytosis—tend be more severe than those of EV infection. We tested the hypothesis that innate immune responses to PeV-A3 and EVs are distinct.MethodsUsing serum and CSF samples, we investigated immune responses of febrile neonates and infants <4 months in Niigata, Japan, from 2015 through 2018. PeV-A and EV infections were diagnosed with real-time PCR. PeV-A3 infection was diagnosed by sequence analysis of the VP1 region. The control was clinically well patients without serum and CSF findings suggestive of bacterial or viral etiology. The Milliplex MAP human cytokine/chemokine magnetic bead panel (Merck Millipore, Germany) was used to analyze 22 cytokines/chemokines related to innate immunity in serum and CSF.ResultsWe evaluated 14 PeV-A3-infected and 15 EV-infected patients and 8 controls. Serum levels of proinflammatory cytokines/chemokines (fractalkine, interferon-α2, interleukin [IL]-1 receptor α, IL-6, IL-8, and IL-15) were significantly higher in PeV-A3-infected patients than in EV-infected patients (P < 0.005). Serum cytokine/chemokine profiles of EV-infected patients did not differ from those of controls. However, while most pro- and anti-inflammatory cytokines/chemokines in CSF were elevated in EV-infected patients, levels were low or undetectable in PeV-A3-infected patients and controls (P < 0.005).ConclusionPeV-A3-infected patients had high serum levels of proinflammatory cytokines/chemokines, which may explain why clinical manifestations were more severe in this patient group than in EV-infected patients. Conversely, the limited or nonexistent innate immune response in CSF from PeV-A3-infected patients might explain the absence of CSF pleocytosis. These findings improve our understanding of the differing pathophysiological characteristics of PeV-A3 and EV infection in neonates and young infants.Disclosures All Authors: No reported Disclosures.

Markedly increased CSF interleukin-6 levels in neuromyelitis optica, but not in multiple sclerosis

To investigate differences in helper T cell immune responses in cerebrospinal fluid (CSF) between neuromyelitis optica (NMO) and multiple sclerosis (MS), we measured CSF levels of interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor-a and interferon-c at the time of relapse in 17 NMO patients and 21 MS patients using fluorescence-activated cell sorting. CSF IL-6 levels were significantly higher in NMO patients than in patients with MS (P = 0.001) and other neurological diseases (P = 0.001). The other cytokines tested were undetectable. Elevated CSF levels of IL-6 in only NMO supports the view of different pathophysiologies of NMO and MS. CSF IL-6 levels may be useful in the differential diagnosis of the two disorders.

Distinct heterogeneity of IgG immune response in cerebrospinal fluid (CSF) detected by isoelectric focusing (IEF) with extended immunofixation

An optimized automated IEF procedure in polyacrylamide micro gels and immunofixation with 10 monospecific antibodies against some fragments of the IgG molecule and against the whole IgG isotypes IgG 1, IgG 2, IgG 3, IgG 4, respectively, detected oligoclonal bands (OBs) within acid, neutral, and alkaline ranges of the gels. Accuracy and reliability of the OB assay for detection of an intrathecal IgG synthesis proved to be higher with immunofixation than with silver staining of bands precipitated by trichloroacetic acid. CSF OBs were specified as lambda or kappa IgG subfractions, respectively, duplex IgGs precipitated with anti-lambda, anti-kappa, and anti-Fc antibodies at the same p I. Most of OBs were classified as belonging to either IgG 1, IgG 2, IgG 3, or IgG 4 isotypes in CSF. The IEF procedure additionally allowed the discrimination of both free light chains and possible “free” heavy gamma chain fragments in CSF, when immunofixation was done with monospecific antibodies against both light chains and gamma chain fragments (e.g. anti-F(ab′) 2, anti-Fd, anti-Fc, anti-C H2). The results pointed out a distinct heterogeneity of the IgG immune response in human CSF. The IEF procedure with extended immunofixation is recommended for completion of the basic laboratory procedures used in neuroimmunology in order to discriminate inflammatory processes in human CNS.

Molecular Immunologic Strategies to Identify Antigens and B-Cell Responses Unique to Multiple Sclerosis

Identification of the causative agent of multiple sclerosis (MS) has long eluded investigators and has become the "Holy Grail" of researchers in the field. The immune response in cerebrospinal fluid of patients with MS, indicated by an increased IgG level and the presence of specific oligoclonal bands after electrophoresis, strongly parallels that found in various infectious diseases of the central nervous system. To understand the nature of B-lymphocyte activation in MS, 4 laboratories studied the antigen-binding regions of antibodies found in MS brain demyelinative plaques and cerebrospinal fluid. Each analysis revealed (1) limited germline expression, results not expected for a random bystander response; (2) features consistent with a specific antigen-targeted process; and (3) the clonal expansion of populations of B lymphocytes in MS. The screening of libraries expressing protein products derived from chronic MS plaque messenger RNA with antibodies purified from plaques, cerebrospinal fluid, or serum of patients with MS has thus far not revealed the antigenic target(s) of the MS antibody response. Because putative MS antigens could be in low abundance, the screening of large libraries of random peptides expressed on phage surfaces might offer an alternative approach to identify peptide sequences recognized by MS antibodies. New sophisticated molecular immunologic techniques described herein should enhance our ability to identify putative antigen(s) targets in MS.

Heterogeneous humoral immune responses in cerebrospinal fluid arising from inflammatory diseases of the human central nervous system. Detection of oligoclonal immunoglobulin bands after isoelectric focusing

Automated isoelectric focusing (IEF) with polyacrylamide micro gels (PAGs) and immune fixation in the modified PhastSystem ™ proved to be more sensitive and accurate for detecting oligoclonal immunoglobulin (Ig) bands (OBs) in cerebrospinal fluid (CSF) than IEF with non-specific silver staining of bands or the calculation of intrathecal IgG production by two formulae comparing both routine OB assays and the formulae during inflammatory processes of the human central nervous system (CNS). Immune specific detection of OBs on parts of the gamma chain (Fc, C H2; Fab; Fd) and on the light chains lambda, kappa yielded different numbers of OBs of which most indicated IgG kappa and/or IgG lambda subfractions in CSF differing in pI besides a varying ground pattern of Ig in CSF and blood serum samples. In some cases more OBs on lambda (or kappa) chains than found on the gamma chain indicate other Ig subfractions and/or free light chains. Heterogeneous IgG subfractions were found in acid, neutral and alkaline regions of the PAG gel with the OB assay with immune-specific band detection; they varied with different inflammations of the CNS and during the inflammatory process. Identical OBs in CSF and serum samples were detected during chronic degradation processes of the CNS; they indicate additional heterogeneous IgG subfractions in the CSF and blood compartment, probably involved with autoimmune processes.

HAM/TSP: Immune response in cerebrospinal fluid

HAM/TSP: Immune response in cerebrospinal fluid

Relation between benign course of multiple sclerosis and low-grade humoral immune response in cerebrospinal fluid.

The prognosis in multiple sclerosis (MS) is related to the presence of an abnorma humoral immune response within the central nervous system: 14/17 MS patients (82%) without oligoclonal CSF IgG displayed no or slight disability after a mean duration of MS of 17 years, while 53% of 88 patients with oligoclonal CSF IgG had a benign course after a mean duration of 13 years (p less than 0.05). A benign course also was more often accompanied by a normal CSF IgG index. MS patients without oligoclonal CSF IgG had elevated CSF/serum ratios of albumin in 6%, and of the complement factors C3 in 0% and C4 in 6%, as against 20%, 27% and 37%, respectively, in MS patients with oligoclonal CSF IgG.

Unique Aspects of Central Nervous System Immunology

In this review the authors discuss three immunologically unique aspects of the central nervous system (CNS). The first relates to whether the CNS is really an immunologically privileged site. Although still somewhat controversial, the answer to that question is that the CNS is, to a large extent, an immunologically privileged site. The second unique aspect of the CNS is the origin and significance of the microglial cell. Some microglial cells seem to originate from the systemic circulation, whereas other microglial cells seem to have a primary CNS origin. The function of the microglial cell is that of a macrophage. In addition it may play an important role in the immune response of the CNS. Present evidence suggests that the microglial cell can be classified as a lymphoreticular cell and as such is the only member of this cell type present in the CNS under normal circumstances. The final unique aspect of the central nervous system is the cerebrospinal fluid (CSF). Under normal circumstances this fluid is essentially acellular, and the only immunoglobulins present are those that are passively derived by diffusion from the systemic circulation. However, in pathological situations (i.e., demyelinating diseases, infections, and possibly even tumors) a local immune response occurs within the CNS and can result in the production of immunoglobulins. At present the detection of such local immune responses in CSF is predominately of diagnostic value only. However, these local CNS immune responses almost certainly play an important role in the pathogenesis of the diseases in which they occur.