Increased IL-22 in cerebrospinal fluid of neuro-behçet's disease patients.

Remitting-Relapsing Multiple Sclerosis (RRMS) and Neuro-Behçet Disease (NBD) are two chronic neuro-inflammatory disorders leading to brain damage and disability in young adults. Herein, we investigated in these patients the cytokine response by beads-based multiplex assays during the early stages of these disorders. Cytokine investigations were carried out on treatment-naive patients suffering from RRMS and NBD recruited at the first episode of clinical relapse. Our findings demonstrate that Cerebrospinal Fluid (CSF) cells from NBD patients, but not RRMS, secrete significant high levels of IL-22 which is associated with elevated IL-22 mRNA expression. We also observed an increase in IL-22 levels in the definite NBD subgroup as compared to the probable NBD one, indicating a clear relationship between elevated IL-22 levels and diagnostic certainty. Interestingly, we found no correlation of IL-22 secretion between CSF and serum arguing about intrathecal release of IL-22 in the CNS of NBD patients. Moreover, we showed by correlogram analysis that this cytokine doesn't correlate with IL-17A, IL-17F and IL-21 suggesting that this cytokine is secreted by Th22 cells and not by Th17 cells in the CSF of NBD patients. Finally, we found elevated levels of IL-6 and a positive correlation between IL and 6 and IL-22 in the CSF of NBD. In conclusion, these results suggest that IL-6 contributes to the production of IL-22 by T cells leading to the exacerbation of inflammation and damage within the CNS of NBD patients.

Detection and significance of exosomal mRNA expression profiles in the cerebrospinal fluid of patients with meningeal carcinomatosis.

Exosomes are cell-derived membrane vesicles with cargo that can be transported into receiver cells to exert their biological roles. Exosomal RNA signature profiles and exosome-derived proteomics are often used to explore the molecular regulation of diseases, and can mirror the conditional state of their tissue of origin, thus serving as biomarkers. The onset of meningeal carcinomatosis (MC) is concealed, and early diagnosis is difficult. To enable early diagnosis of MC, it is essential to identify new biomarkers. Few studies have investigated the function of exosomes in MC. In this study, high-throughput sequencing was used to examine the mRNA profiles of exosomes in the cerebrospinal fluid (CSF) of patients with MC. We further analyzed the functions and signaling pathways associated with the differentially expressed genes in exosomes to reveal the putative mechanisms by which the exosomal mRNAs function in MC. In summary, this study identified biomarker candidates for MC, and provided new insights into the significant role of exosomal mRNA regulation in MC.

Liquid biopsies for diagnosing and monitoring primary tumors of the central nervous system.

Obtaining diagnostic specimens, notably to monitor disease course in cancer patients undergoing therapy, is an emerging area of research, however, with few clinical implications so far in the field of Neuro-oncology. Specifically for patients with primary brain tumors where repeat biosampling from the tumor and clinical decision making based on neuroimaging alone remain challenging, this area may assume a central role. In principle, sampling could focus on blood, cerebrospinal fluid or urine with differential sensitivities and specificities of findings that differ between specific parameters and target molecules. These include protein, mRNA, miRNA, cell-free DNA, either freely circulating or as cargo of extracellular vesicles, as well circulating tumor cells. The most solid biomarkers are those directly reflecting neoplastic disease, e.g., in the case of primary brain tumors isocitrate dehydrogenase mutation or epidermal growth factor receptor variant III. Importantly, the main goals of liquid biopsy marker development are to better understand response to therapy, natural evolution and emergence of resistant clones, rather than obviating the need for surgical interventions which remain to be a mainstay of therapy for the vast majority of primary brain tumors.

Identification of biomarkers for amyotrophic lateral sclerosis by comprehensive analysis of exosomal mRNAs in human cerebrospinal fluid.

BACKGROUND: Exosomes are a subset of extracellular vesicles 30-200 nm in diameter secreted from cells, which contain functional mRNAs and microRNAs. Cerebrospinal fluid (CSF) is the primary source for liquid biopsy to examine diseases in central nervous system. To date, there is no available method to analyze exosomal mRNAs comprehensively in human CSF. METHODS: The main purpose of this study is to established the methodology of comprehensive analysis of exosomal mRNAs in CSF by a highly sensitive next-generation sequencing. The signatures of CSF exosomal mRNAs were then compared between four normal healthy donors and four sporadic amyotrophic lateral sclerosis patients to identify disease-related biomarkers. Differentially expressed genes were identified by DESeq2. RESULTS: RNA sequencing from CSF exosomes was successfully performed, that was demonstrated by the high pearson's product-moment correlation coefficient (r = 0.993) in the technical replicates. Also, position coverage analysis revealed that most detected mRNAs retained their integrity throughout their full-length in CSF exosomes. In CSF exosomes from normal healthy donors, an average of 14,807 genes were detected, of which 4580 genes were commonly detected among four individuals, including neuron-enriched genes such as TUBB3 and CAMK2A. In comparison with exosomal mRNAs in CSF from four patients with amyotrophic lateral sclerosis, 543 genes were significantly changed, as represented by CUEDC2. Gene Ontology analysis and pathway analysis with these genes revealed functional enrichment of ubiquitin-proteasome pathway, oxidative stress response, and unfolded protein response. These pathways are related to pathomechanisms of amyotrophic lateral sclerosis. CONCLUSION: We successfully established the methodology of comprehensive analysis of exosomal mRNAs in human CSF. It was shown to be useful to identify disease biomarkers for central nervous system. Several genes, such as CUEDC2, in CSF exosomes were suggested to be candidate disease biomarkers for amyotrophic lateral sclerosis.

Dose-Dependent Lowering of Mutant Huntingtin Using Antisense Oligonucleotides in Huntington Disease Patients.

On December 11 of 2017, Ionis Pharmaceuticals published a press release announcing dose-dependent reductions of mutant huntingtin protein in their HTTRx Phase 1/2a study in Huntington disease (HD) patients. The results from this Ionis trial have gained much attention from the patient community and the oligonucleotide therapeutics field, since it is the first trial targeting the cause of HD, namely the mutant huntingtin protein, using antisense oligonucleotides (ASOs). The press release also states that the primary endpoints of the study (safety and tolerability) were met, but does not contain data. This news follows the approval of another therapeutic ASO nusinersen (trade name Spinraza) for a neurological disease, spinal muscular atrophy, by the U.S. Food and Drug Administration and European Medicines Agency, in 2016 and 2017, respectively. Combined, this offers hope for the development of the HTTRx therapy for HD patients.

Altered Expression of MicroRNA-15a and Kruppel-Like Factor 4 in Cerebrospinal Fluid and Plasma After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Cerebral vasospasm (CVS) is a major determinant of prognosis in patients with subarachnoid hemorrhage (SAH). Alteration in the vascular phenotype contributes to development of CVS. However, little is known about the role of microRNAs (miRNAs) in the phenotypic alteration after SAH. We investigated the expression profile of miRNAs and the chronologic changes in the expression of microRNA-15a (miR-15a) and Kruppel-like factor 4 (KLF4), a potent regulator of vascular phenotype modulation that modulates the expression of miR-15a, in the plasma and cerebrospinal fluid (CSF) of patients with SAH. METHODS: Peripheral blood and CSF samples were collected from 8 patients with aneurysmal SAH treated with endovascular obliteration. Samples obtained from 3 patients without SAH were used as controls in the analysis. Exosomal miRNAs were isolated and subjected to microarray analysis with the three-dimensional-gene miRNA microarray kit. The time course of the expression of miR-15a and KLF4 was analyzed using quantitative real-time polymerase chain reaction. RESULTS: Microarray analysis showed that 12 miRNAs including miR-15a were upregulated or downregulated both in the CSF and in plasma after SAH within 3 days. Quantitative real-time polymerase chain reaction showed that miR-15a expression was significantly increased in both the CSF and plasma, with a peak around 3-5 days after SAH, whereas the expression of KLF4 was significantly decreased around 1-3 days after SAH and remained lower than in controls. CONCLUSIONS: Our results suggest that an early and persistent decrease in KLF4 followed by an increase in miR-15a may contribute to the altered vascular phenotype, resulting in development of CVS.

Increased interleukin-1ß and basic fibroblast growth factor levels in the cerebrospinal fluid during human herpesvirus-6B (HHV-6B) encephalitis.

Human herpesvirus 6B (HHV-6B) causes exanthema subitum in infants and is known to be mildly pathogenic. However, HHV-6B infection can induce febrile seizures in a high percentage of patients, and in rare cases, result in encephalitis. We detected higher levels of interleukin (IL)-1ß and basic fibroblast growth factor (bFGF) in the cerebrospinal fluid (CFS) of patients with HHV-6B encephalitis when compared to those in patients with non-HHV-6B-induced febrile seizures. In vitro, IL-1ß and bFGF enhanced HHV-6B gene expression in infected U373 astrocytes during the initial and maintenance phases of infection, respectively. These findings indicated that IL-1ß and bFGF contribute to HHV-6B growth and the onset of encephalitis.

The immune response in the CNS in Theiler's virus induced demyelinating disease switches from an early adaptive response to a chronic innate-like response.

Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) is an important model of the progressive disability caused by irreversible CNS tissue injury, and provides an example of how a CNS pathogen can cause inflammation, demyelination, and neuronal damage. We were interested in which molecules, especially inflammatory mediators, might be upregulated in the CNS throughout TMEV-IDD. We quantitated by a real-time RT-PCR multi-gene system the expression of a pathway-focused panel of genes at 30 and 165 days post infection, characterizing both the early inflammatory and the late neurodegenerative stages of TMEV-IDD. Also, we measured 32 cytokines/chemokines by multiplex Luminex analysis in CSF specimens from early and late TMEV-IDD as well as sham-treated mice. Results indicate that, in the later stage of TMEV-IDD, activation of the innate immune response is most prominent: TLRs, type I IFN response genes, and innate immunity-associated cytokines were highly expressed in late TMEV-IDD compared to sham (p ≤ 0.0001) and early TMEV-IDD (p < 0.05). Conversely, several molecular mediators of adaptive immune response were highly expressed in early TMEV-IDD (all p ≤ 0.001). Protein detection in the CSF was broadly concordant with mRNA abundance of the corresponding gene measured by real-time RT-PCR in the spinal cord, since several cytokines/chemokines were increased in the CSF of TMEV-IDD mice. Results show a clear shift from adaptive to innate immunity from early to late TMEV-IDD, indicating that adaptive and innate immune pathways are likely involved in the development and progression of the disease to different extents. CSF provides an optimal source of biomarkers of CNS neuroinflammation.

Differential Expression of microRNA in Cerebrospinal Fluid as a Potential Novel Biomarker for Alzheimer's Disease.

BACKGROUND AND OBJECTIVE: The need to find a better reflection of Alzheimer's disease (AD) pathophysiology led us to investigate differential expression of microRNA (miRNA) in cerebrospinal fluid (CSF) of AD patients compared to matched controls, using a genome-wide data-driven approach. METHODS: From the Amsterdam Dementia Cohort, we selected 19 AD patients with CSF indicative of AD pathophysiology and 19 age and gender-matched controls without CSF evidence of AD (67 ± 6 years old, 20 [53%] female). We measured 754 miRNA in CSF using qRT-PCR (Taqman Array MicroRNA cards A and B, v3.0) according to the Megaplex Taqman protocol. Hierarchical cluster analysis was performed and groups were compared using Linear Models for Microarray Data, a modified t-test. We performed validation analysis using qRT-PCR single assays. RESULTS: 144 ± 66 miRNA could be detected using Megaplex array analysis (19% ). Mean Ct (average 32.4 ± 0.5) was correlated to age (r = 0.52, p = 0.001). Five miRNA were differentially expressed in CSF of AD patients. None of these could be replicated. After stratification by age, seven miRNA showed differential expression in late-onset AD, of which lower abundance of let-7a was replicated (log10RQ -1.46, p <  0.05). In early-onset AD, twelve miRNA were differentially expressed of which lower abundance of miRNA-532-3p remained borderline significant (log10RQ -1.27, p = 0.05). CONCLUSION: Although we could not consistently separate AD patients and controls in the whole group, we have found indications miRNA in CSF are able to reflect aging and perhaps also heterogeneity in AD. Further investigation requires optimizing RNA input, while maintaining strict age matching.

Intrathecal BCR transcriptome in multiple sclerosis versus other neuroinflammation: Equally diverse and compartmentalized, but more mutated, biased and overlapping with the proteome.

The mechanisms driving the intrathecal synthesis of IgG in multiple sclerosis (MS) are unknown. We combined high-throughput sequencing of transcribed immunoglobulin heavy-chain variable (IGHV) genes and mass spectrometry to chart the diversity and compartmentalization of IgG-producing B cells in the cerebrospinal fluid (CSF) of MS patients and controls with other neuroinflammatory diseases. In both groups, a few clones dominated the intrathecal IGHV transcriptome. In most MS patients and some controls, dominant transcripts matched the CSF IgG. The IGHV transcripts in CSF of MS patients frequently carried IGHV4 genes and had more replacement mutations compared to controls. In both groups, dominant IGHV transcripts were identified within clusters of clonally related B cells that had identical or related IGHV transcripts in the blood. These findings suggest more pronounced affinity maturation, but an equal degree of diversity and compartmentalization of the intrathecal B-cell response in MS compared to other neuroinflammatory diseases.

Dominance of chemokine ligand 2 and matrix metalloproteinase-2 and -9 and suppression of pro-inflammatory cytokines in the epidural compartment after intervertebral disc extrusion in a canine model.

BACKGROUND CONTEXT: In canine intervertebral disc (IVD) disease, a useful animal model, only little is known about the inflammatory response in the epidural space. PURPOSE: To determine messenger RNA (mRNA) expressions of selected cytokines, chemokines, and matrix metalloproteinases (MMPs) qualitatively and semiquantitatively over the course of the disease and to correlate results to neurologic status and outcome. STUDY DESIGN/SETTING: Prospective study using extruded IVD material of dogs with thoracolumbar IVD extrusion. PATIENT SAMPLE: Seventy affected and 13 control (24 samples) dogs. OUTCOME MEASURES: Duration of neurologic signs, pretreatment, neurologic grade, severity of pain, and outcome were recorded. After diagnostic imaging, decompressive surgery was performed. METHODS: Messenger RNA expressions of interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor (TNF), interferon (IFN)γ, MMP-2, MMP-9, chemokine ligand (CCL)2, CCL3, and three housekeeping genes was determined in the collected epidural material by Panomics 2.0 QuantiGene Plex technology. Relative mRNA expression and fold changes were calculated. Relative mRNA expression was correlated statistically to clinical parameters. RESULTS: Fold changes of TNF, IL-1ß, IL-2, IL-4, IL-6, IL-10, IFNγ, and CCL3 were clearly downregulated in all stages of the disease. MMP-9 was downregulated in the acute stage and upregulated in the subacute and chronic phase. Interleukin-8 was upregulated in acute cases. MMP-2 showed mild and CCL2 strong upregulation over the whole course of the disease. In dogs with severe pain, CCL3 and IFNγ were significantly higher compared with dogs without pain (p=.017/.020). Dogs pretreated with nonsteroidal anti-inflammatory drugs revealed significantly lower mRNA expression of IL-8 (p=.017). CONCLUSIONS: The high CCL2 levels and upregulated MMPs combined with downregulated T-cell cytokines and suppressed pro-inflammatory genes in extruded canine disc material indicate that the epidural reaction is dominated by infiltrating monocytes differentiating into macrophages with tissue remodeling functions. These results will help to understand the pathogenic processes representing the basis for novel therapeutic approaches. The canine IVD disease model will be rewarding in this process.

The detection of surfactant proteins A, B, C and D in the human brain and their regulation in cerebral infarction, autoimmune conditions and infections of the CNS.

Surfactant proteins (SP) have been studied intensively in the respiratory system. Surfactant protein A and surfactant protein D are proteins belonging to the family of collectins each playing a major role in the innate immune system. The ability of surfactant protein A and surfactant protein D to bind various pathogens and facilitate their elimination has been described in a vast number of studies. Surfactant proteins are very important in modulating the host's inflammatory response and participate in the clearance of apoptotic cells. Surfactant protein B and surfactant protein C are proteins responsible for lowering the surface tension in the lungs. The aim of this study was an investigation of expression of surfactant proteins in the central nervous system to assess their specific distribution patterns. The second aim was to quantify surfactant proteins in cerebrospinal fluid of healthy subjects compared to patients suffering from different neuropathologies. The expression of mRNA for the surfactant proteins was analyzed with RT-PCR done with samples from different parts of the human brain. The production of the surfactant proteins in the brain was verified using immunohistochemistry and Western blot. The concentrations of the surfactant proteins in cerebrospinal fluid from healthy subjects and patients suffering from neuropathologic conditions were quantified using ELISA. Our results revealed that surfactant proteins are present in the central nervous system and that the concentrations of one or more surfactant proteins in healthy subjects differed significantly from those of patients affected by central autoimmune processes, CNS infections or cerebral infarction. Based on the localization of the surfactant proteins in the brain, their different levels in normal versus pathologic samples of cerebrospinal fluid and their well-known functions in the lungs, it appears that the surfactant proteins may play roles in host defense of the brain, facilitation of cerebrospinal fluid secretion and maintenance of the latter's rheological properties.

Detection of minimally disseminated disease in the cerebrospinal fluid of children with high-risk retinoblastoma by reverse transcriptase-polymerase chain reaction for GD2 synthase mRNA.

AIM: To evaluate minimally disseminated disease (MDD) in cytologically negative cerebrospinal fluid (CSF) specimens of patients with high-risk retinoblastoma by the detection of the synthase of ganglioside GD2 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR). METHODS: The CSF was evaluated in 26 patients with high risk for CSF relapse: 14 with postlaminar optic nerve invasion, five of them with tumour at the resection margin, five with massive choroidal invasion, three with overt orbital extension and four patients with systemic metastasis. Serial CSF examinations were repeated at different time intervals according to stage and in the event of suspected relapse. GD2 synthase mRNA was evaluated by RT and nested PCR at each procedure. RESULTS: MDD was present at diagnosis in six cases (23%) and it was significantly associated to massive optic nerve involvement or history of glaucoma (p<0.05). Three of the children with positive MDD had a CSF relapse. Thirteen patients had negative MDD at diagnosis and one had a CSF relapse. In seven children no ARN could be obtained for PCR analysis and two subsequently relapsed. The probability of CSF relapse was 0.50 (95% confidence interval (CI) 0.13-0.88) for children with MDD and 0.08 (95% CI 0.02-0.46) for those with negative RT-PCR examination of the CSF at diagnosis (p=0.03). CONCLUSIONS: MDD in the CSF detected by RT-PCR for GD2-synthase mRNA occurred in 31.7% of evaluable high-risk children with retinoblastoma with no initial central nervous system (CNS) involvement. It was significantly associated to optic nerve involvement and glaucoma and increased risk of CSF relapse.

MicroRNAs in cerebrospinal fluid as biomarker for disease course monitoring in primary central nervous system lymphoma.

Diagnosis of primary lymphomas of the central nervous system (PCNSL) largely depends on histopathology of tumor biopsies. Recently, we identified miRNAs detected in the CSF of PCNSL patients as novel non-invasive biomarkers for this disease. In combined analyses of miR-21, miR-19b, and miR-92 CSF levels, it was possible to differentiate PCNSL from other neurological disorders. In the current study, we first confirmed our previous findings in an enlarged PCNSL cohort (n = 39; sensitivity 97.4 %). Also, we sought to establish the potential role of CSF miRNAs as biomarkers for disease course monitoring. In sequential miRNA measurements in CSF derived from nine patients with different disease courses, an intriguing correlation of miRNA levels and PCNSL status during treatment and/or disease follow-up was demonstrated. Finally, we demonstrated that miRNA levels in serum of PCNSL patients (n = 14) were not elevated as compared to controls. In summary, this study provides the first evidence that CSF miRNAs have the potential as biomarkers for treatment monitoring and disease follow-up of patients with PCNSL.

Interleukin 18 receptor 1 expression distinguishes patients with multiple sclerosis.

Definition of dysregulated immune components in multiple sclerosis may help in the identification of new therapeutic targets. Deviation of the interleukin 18 receptor 1 (IL18R1) is of particular interest since the receptor is critical for experimental neuroinflammation. The objective of this study was to determine whether expression of IL18R1 varies between multiple sclerosis patients and controls, and to test genetic association of IL18R1 with multiple sclerosis. We used quantitative real-time PCR to assess mRNA levels of IL18R1 in cerebrospinal fluid and peripheral blood mononuclear cells of 191 patients with multiple sclerosis, 61 patients with clinically isolated syndrome and 168 controls having other neurological disorders. Association was tested in 2153 patients with multiple sclerosis and 1733 controls using 13 tagging single nucleotide polymorphisms within the IL18R1 gene. We found that patients with multiple sclerosis had increased IL18R1 mRNA expression in both cerebrospinal fluid cells (p < 0.05) and peripheral blood mononuclear cells (p < 0.05) compared with controls. Patients with clinically isolated syndrome had elevated levels compared with controls in cerebrospinal fluid cells (p < 0.001) but not in peripheral blood mononuclear cells. The gene was not associated to multiple sclerosis. We conclude that the increased expression of IL18R1 may contribute pathogenically to disease and is therefore a potential therapeutic target. The absence of a genetic association in the IL18R1 gene itself suggests regulation from other parts of the genome, or as part of the inflammatory cascade in multiple sclerosis without a prime genetic cause.

Gene expression profiling in multiple sclerosis: a disease of the central nervous system, but with relapses triggered in the periphery?

The aetiology of multiple sclerosis (MS), an autoimmune demyelinating disease of the central nervous system (CNS), includes both genetic and environmental factors, but the pathogenesis is still incompletely known. We performed gene expression profiling on paired cerebrospinal fluid (CSF) and peripheral blood mononuclear cells (PBMCs) samples from 26 MS patients without immunomodulatory treatment, sampled in relapse or remission, and 18 controls using Human Genome U133 plus 2.0 arrays (Affymetrix). In the CSF, 939 probe sets detected differential expression in MS patients compared to controls, but none in PBMCs, confirming that CSF cells might mirror the disease processes. The regulation of selected transcripts in CSF of MS patients was confirmed by quantitative PCR. Unexpectedly however, when comparing MS patients in relapse to those in remission, 266 probe sets detected differential expression in PBMCs, but not in CSF cells, indicating the importance of events outside of the CNS in the triggering of relapse.

VEGF and mRNA VEGF expression in CSF from Behçet's disease with neurological involvement.

Vascular endothelial growth factor (VEGF) stimulates angiogenesis, but is also pro-inflammatory and plays an important role in the development of neurological disease, where it can have both attenuating and exacerbating effects. Several studies have indicated that VEGF-A (VEGF) may play a role in the pathogenesis of neurological inflammatory diseases. To assess the role of VEGF in patients with Behçet's disease with neurological involvement, VEGF was measured in the cerebrospinal fluid (CSF) of 32 patients compared to a group of 12 patients with noninflammatory neurological diseases (NIND) and 14 patients with multiple sclerosis (MS). We have also studied the expression of mRNA-VEGF (VEGF-A) in CSF and in peripheral blood mononuclear cells. The mean VEGF(CSF) was significantly increased in neuro-BD and MS patients compared to NIND patients. There was an association between neuro-BD-VEGF(CSF), and leukocyte count. A significant correlation was also observed between neuro-BD-VEGF(CSF) and CSF(%CD4) cells. As a measure of the integrity of the blood-brain barrier Q(albumin) was found correlated to VEGF(CSF). VEGF mRNA was significantly increased in neuro-BD patients compared to NIND patients. These results indicate that, VEGF may be associated with the increased percentages of CD4 cell subpopulation. The role of VEGF is within the inflammatory cascade in the mediation of blood-brain barrier disruption and not specific to Behçet's.

Chlamydophila pneumoniae DNA and mRNA transcript levels in peripheral blood mononuclear cells and cerebrospinal fluid of patients with multiple sclerosis.

Chlamydophila pneumoniae DNA and mRNA transcripts were investigated by PCR and RT-PCR in fresh CSF and PBMC specimens co-cultured in Hep-2 cell lines and collected from 14 patients with definite RR MS and 19 patients with other inflammatory (OIND) and non-inflammatory (NIND) neurological controls. A positivity for C. pneumoniae DNA and mRNA was detected in CSF and PBMCs of 9 RR MS patients (64.2%) with evidence of disease activity, whereas only 3 controls were positive for Chlamydial DNA. These preliminary findings suggest that C. pneumoniae may occur in a persistent and metabolically active state at both peripheral and intrathecal levels in MS, but not in OIND and NIND.

Dual infections of the central nervous system with Epstein-Barr virus.

We describe clinical and laboratory characteristics of 16 patients with central nervous system (CNS) infection caused by Epstein-Barr virus (EBV) and another pathogen. Seven of 10 immunocompromised patients had coinfection with viruses (3 with cytomegalovirus, 2 with JC virus, and 2 with varicella zoster virus) and 3 with nonviral pathogens (2 with pneumococcus and 1 with Cryptococcus species). Three of 6 immunocompetent patients had coinfections with viruses (1 each with herpes simplex virus, varicella zoster virus, and West Nile virus), and 3 had coinfections with nonviral pathogens (2 with Ehrlichia chaffeensis and 1 with Mycoplasma pneumoniae). The EBV load was similar in immunocompromised and immunocompetent patients and in patients with viral and nonviral coinfections. EBV lytic-cycle mRNA was detected in the cerebrospinal fluid of 5 of 6 tested samples, indicating EBV replication in the CNS during coinfection.