Significance of immunoglobulins synthesis with central nervous system involvement in Neuro-Behçet's disease.

OBJECTIVES: Demyelination and immunocyte-infiltrated lesions have been found in neuro-Behçet's disease (NBD) pathology. Lacking satisfying laboratory biomarkers in NBD impedes standard clinical diagnostics. We aim to explore the ancillary indicators for NBD diagnosis unveiling its potential etiology. METHODS: 28 NBD with defined diagnosis, 29 patients with neuropsychiatric lupus erythematosus, 30 central nervous system idiopathic inflammatory demyelination diseases (CNS-IIDD), 30 CNS infections, 30 cerebrovascular diseases, and 30 noninflammatory neurological diseases (NIND) were retrospectively enrolled. Immunoglobulins (Ig) in serum and cerebral spinal fluid (CSF) were detected by immunonephelometry and myelin basic protein (MBP) by quantitative enzyme-linked immunosorbent assay. RESULTS: IgA index is almost twice enhanced in NBD than NIND with an accuracy of 0.8488 in differential diagnosis, the sensitivity and specificity of which were 75.00 % and 90.00 % when the cutoff was > 0.6814. The accuracy of CSF Ig and quotient of Ig all exceed 0.90 in discerning NBD with damaged and intact blood-brain barrier (BBB). Clustering analyses divided NBD into two different phenotypes: one with BBB damage has lower Ig synthesis, the other with extra-synthesis in parenchymal sites but with intact BBB. MBP index is significantly correlated with kappa (KAP) index and lambda (LAM) index (r = 0.358, 0.575, P < 0.001), hinting the NBD pathogenesis of CNS demyelination in triggering excessive intrathecal Ig productions and humoral responses. CONCLUSIONS: IgA index acts as a potential diagnostic indicator in differentiating NBD from NIND and CNS-IIDD. Excessive immunoglobulin production induced by CNS inflammation and demyelination might be latent immunopathogenesis of NBD.

A novel chronic dural port platform for continuous collection of cerebrospinal fluid and intrathecal drug delivery in free-moving mice.

BACKGROUND: Cerebrospinal fluid (CSF) provides a close representation of pathophysiological changes occurring in the central nervous system (CNS); therefore, it has been employed in pathogenesis research and biomarker development for CNS disorders. CSF obtained from valid mouse models relevant to CNS disorders can be an important resource for successful biomarker and drug development. However, the limited volume of CSF that can be collected from tiny intrathecal spaces and the technical difficulties involved in CSF sampling has been a bottleneck that has hindered the detailed analysis of CSF in mouse models. METHODS: We developed a novel chronic dural port (CDP) method without cannulation for CSF collection of mice. This method enables easy and repeated access to the intrathecal space in a free-moving, unanesthetized mouse, thereby enabling continuous long-term CSF collection with minimal tissue damage and providing a large volume of high-quality CSF from a single mouse. When combined with chemical biosensors, the CDP method allows for real-time monitoring of the dynamic changes in neurochemicals in the CSF at a one-second temporal resolution in free-moving mice. Moreover, the CDP can serve as a direct access point for the intrathecal injection of CSF tracers and drugs. RESULTS: We established a CDP implantation and continuous CSF collection protocol. The CSF collected using CDP was not contaminated with blood and maintained physiological concentrations of basic electrolytes and proteins. The CDP method did not affect mouse's physiological behavior or induce tissue damage, thereby enabling a stable CSF collection for up to four weeks. The spatio-temporal distribution of CSF tracers delivered using CDP revealed that CSF metabolism in different brain areas is dynamic. The direct intrathecal delivery of centrally acting drugs using CDP enabled real-time behavioral assessments in free-moving mice. CONCLUSIONS: The CDP method enables the collection of a large volume of high-quality CSF and direct intrathecal drug administration with real-time behavioral assessment in free-moving mice. Combined with animal models relevant to CNS disorders, this method provides a unique and valuable platform for biomarker and therapeutic drug research.

Inflammatory profiles in plasma and cerebrospinal fluid of patients with neurosarcoidosis.

METHODS: Cerebrospinal fluid (CSF) and plasma levels of 38 biomarkers from 20 neurosarcoidosis (NS) patients were compared to healthy controls (HC). RESULTS: In CSF, 25 biomarkers were significantly elevated compared to HC: IFNγ, TNFα, TNFß, IL-2, IL-6, IL-10, IL-12B, IL-15, IL-16, CCL2, CCL3, CCL4, CCL11, CCL13, CCL17, CCL22, CCL26, CXCL8, CXCL10, TNFR2, VEGF-A, PIGF, SAA, VCAM1, and ICAM1. In plasma, 12 biomarkers were significantly elevated compared to HC: IFNγ, TNFα, CCL2, CCL3, CCL4, CCL17, CXCL10, VEGFR1, PIGF, SAA, VCAM1, and ICAM1. CONCLUSION: NS patients have profoundly elevated cytokines, chemokines, vascular angiogenesis, and vascular injury biomarkers in CSF and plasma.

The CSF in neurosarcoidosis contains consistent clonal expansion of CD8 T cells, but not CD4 T cells.

The tissue-specific drivers of neurosarcoidosis remain poorly defined. To identify cerebrospinal fluid (CSF) specific, antigen-driven T and B cell responses, we performed single-cell RNA sequencing of CSF and blood cells from neurosarcoid participants coupled to T and B cell receptor sequencing. In contrast to pulmonary sarcoidosis, which is driven by CD4 T cells, we found CD8 T cell clonal expansion enriched in the neurosarcoid CSF. These CSF-enriched CD8 T cells were composed of two subsets with differential expression of EBI2, CXCR3, and CXCR4. Lastly, our data suggest that IFNγ signaling may distinguish neurosarcoidosis from other neurological disorders.

Metabolic Profiling and Quantitative Analysis of Cerebrospinal Fluid Using Gas Chromatography-Mass Spectrometry: Current Methods and Future Perspectives.

Cerebrospinal fluid is a key biological fluid for the investigation of new potential biomarkers of central nervous system diseases. Gas chromatography coupled to mass-selective detectors can be used for this investigation at the stages of metabolic profiling and method development. Different sample preparation conditions, including extraction and derivatization, can be applied for the analysis of the most of low-molecular-weight compounds of the cerebrospinal fluid, including metabolites of tryptophan, arachidonic acid, glucose; amino, polyunsaturated fatty and other organic acids; neuroactive steroids; drugs; and toxic metabolites. The literature data analysis revealed the absence of fully validated methods for cerebrospinal fluid analysis, and it presents opportunities for scientists to develop and validate analytical protocols using modern sample preparation techniques, such as microextraction by packed sorbent, dispersive liquid-liquid microextraction, and other potentially applicable techniques.

Characteristics of Central Nervous System (CNS) Involvement in Children With Non-Hodgkin's Lymphoma (NHL) and the Diagnostic Value of CSF Flow Cytometry in CNS Positive Disease.

OBJECTIVE: To investigate the characteristics of central nervous system (CNS) involvement in children with non-Hodgkin's lymphoma (NHL) and the value of flow cytometry (FC) in the diagnosis of CNS disease in pediatric NHL. METHODS: The data of 56 newly diagnosed pediatric NHL patients with CNS involvement (CNS+/mass, CNS+/palsy, CNS+/CSF) were analyzed. The proportions and formats of CNS disease in different pathological types were compared. In addition, FC and conventional cytology (CC) of cerebrospinal fluid (CSF) were carried out in 383 newly diagnosed NHL cases. RESULTS: A total of 383 children with NHL were enrolled. Among these patients, 56 (14.6%) were diagnosed with positive CNS involvement (CNS+), 33 had bulky disease (tumor diameter >10 cm), 32 had bone marrow invasion, 32 had lactate dehydrogenase levels >1000 U/L, and 25 had invasion of more than 4 organs at the time of diagnosis. There were 14 patients with T lymphoblastic lymphoma (T-LBL), 9 with B lymphoblastic lymphoma (B-LBL), 26 with Burkitt's lymphoma (BL), and 2 with Epstein-Barr virus-positive diffuse large B cell lymphoma (EBV + DLBCL). Among the 56 CNS+ patients, 35 were CSF-positive (CSF+); there were 2 patients who were CSF+ via CC detection and 35 who were CSF+ via FC detection. The difference between CC and FC was statistically significant (P < 0.01). In the T-LBL group, 14 patients were CNS+/CSF, and in the B-LBL group, 8 were CNS+/mass. In the BL group, 22 patients were CNS+/mass and 15 were CNS+/CSF. In the anaplastic large-cell lymphoma group, 5 patients were CNS+/mass. Nine of the 56 CNS+ patients had events. The 2-year overall survival rate was 87% ± 0.046%, and the 2-year event-free survival rate was 76.2% ± 0.07%. CONCLUSION: CNS+ diagnoses were more common in pediatric NHL patients with bulky disease and/or bone marrow involvement and/or involvement of more than 4 organs at the time of diagnosis, and they were also common in the EBV + DLBCL and BL groups. FC of CSF showed important clinical significance in the diagnosis of CNS disease in pediatric NHL patients, and it can be used to significantly improve the CNS+ detection rate.

COVID-19 and neuroinflammation: a literature review of relevant neuroimaging and CSF markers in central nervous system inflammatory disorders from SARS-COV2.

BACKGROUND: The literature on neurological manifestations in COVID-19 patients has been rapidly increasing with the pandemic. However, data on CNS inflammatory disorders in COVID-19 are still evolving. We performed a literature review of CNS inflammatory disorders associated with coronavirus disease-2019 (COVID-19). METHODS: We screened all articles resulting from a search of PubMed, Google Scholar and Scopus, using the keywords; "SARS-CoV-2 and neurological complication", "SARS-CoV-2 and CNS Complication" looking for reports of transverse myelitis, longitudinally extensive transverse myelitis, neuromyelitis optica, myelitis, Myelin Oligodendrocyte Glycoprotein Antibody Disorder (MOGAD), Acute Disseminated Encephalomyelitis (ADEM), Acute Hemorrhagic Necrotizing Encephalitis/Acute Hemorrhagic Leukoencephalitis (AHNE/AHLE), Cytotoxic lesion of the Corpus Callosum/Mild Encephalopathy Reversible Splenium Lesion(CLOCC/MERS) and Optic neuritis published between December 01, 2019 and March 15, 2021. RESULTS: Our literature search revealed 43 patients meeting the diagnosis of myelitis, including Transverse Myelitis, ADEM, AHNE/AHLE or CLOCC/MERS and Optic neuritis. Acute myelitis was most commonly associated with non-severe COVID-19 and all reported cases of AHNE/AHLE had severe COVID-19 infection. Based on IDSA/ATS criteria of either requiring vasopressor for septic shock or mechanical ventilation, 49% (n = 18) patients were considered to have a severe COVID infection. There were 7 (n = 19%) fatalities. CONCLUSION: To our knowledge, this is among the first reviews that includes the clinical features, neuroimaging, CSF findings and outcomes in COVID-19-associated CNS inflammatory disorders. Our observational review study reveals that although rare, myelitis, ADEM, AHNE and CLOCC can be associated with COVID-19 infection. Further studies using MRI imaging and CSF analysis in early diagnosis and intervention of these disorders are warranted.

Direction and magnitude of cerebrospinal fluid flow vary substantially across central nervous system diseases.

BACKGROUND: Several central nervous system diseases are associated with disturbed cerebrospinal fluid (CSF) flow patterns and have typically been characterized in vivo by phase-contrast magnetic resonance imaging (MRI). This technique is, however, limited by its applicability in space and time. Phase-contrast MRI has yet to be compared directly with CSF tracer enhanced imaging, which can be considered gold standard for assessing long-term CSF flow dynamics within the intracranial compartment. METHODS: Here, we studied patients with various CSF disorders and compared MRI biomarkers of CSF space anatomy and phase-contrast MRI at level of the aqueduct and cranio-cervical junction with dynamic intrathecal contrast-enhanced MRI using the contrast agent gadobutrol as CSF tracer. Tracer enrichment of cerebral ventricles was graded 0-4 by visual assessment. An intracranial pressure (ICP) score was used as surrogate marker of intracranial compliance. RESULTS: The study included 94 patients and disclosed marked variation of CSF flow measures across disease categories. The grade of supra-aqueductal reflux of tracer varied, with strong reflux (grades 3-4) in half of patients. Ventricular tracer reflux correlated with stroke volume and aqueductal CSF pressure gradient. CSF flow in the cerebral aqueduct was retrograde (from 4th to 3rd ventricle) in one third of patients, with estimated CSF net flow volume about 1.0 L/24 h. In the cranio-cervical junction, net flow was cranially directed in 78% patients, with estimated CSF net flow volume about 4.7 L/24 h. CONCLUSIONS: The present observations provide in vivo quantitative evidence for substantial variation in direction and magnitude of CSF flow, with re-direction of aqueductal flow in communicating hydrocephalus, and significant extra-cranial CSF production. The grading of ventricular reflux of tracer shows promise as a clinical useful method to assess CSF flow pattern disturbances in patients.

Cerebrospinal Fluid Pterins, Pterin-Dependent Neurotransmitters, and Mortality in Pediatric Cerebral Malaria.

BACKGROUND: Cerebral malaria (CM) pathogenesis remains incompletely understood. Having shown low systemic levels of tetrahydrobiopterin (BH4), an enzymatic cofactor for neurotransmitter synthesis, we hypothesized that BH4 and BH4-dependent neurotransmitters would likewise be low in cerebrospinal fluid (CSF) in CM. METHODS: We prospectively enrolled Tanzanian children with CM and children with nonmalaria central nervous system conditions (NMCs). We measured CSF levels of BH4, neopterin, and BH4-dependent neurotransmitter metabolites, 3-O-methyldopa, homovanillic acid, and 5-hydroxyindoleacetate, and we derived age-adjusted z-scores using published reference ranges. RESULTS: Cerebrospinal fluid BH4 was elevated in CM (n = 49) compared with NMC (n = 51) (z-score 0.75 vs -0.08; P < .001). Neopterin was increased in CM (z-score 4.05 vs 0.09; P < .001), and a cutoff at the upper limit of normal (60 nmol/L) was 100% sensitive for CM. Neurotransmitter metabolite levels were overall preserved. A higher CSF BH4/BH2 ratio was associated with increased odds of survival (odds ratio, 2.94; 95% confidence interval, 1.03-8.33; P = .043). CONCLUSION: Despite low systemic BH4, CSF BH4 was elevated and associated with increased odds of survival in CM. Coma in malaria is not explained by deficiency of BH4-dependent neurotransmitters. Elevated CSF neopterin was 100% sensitive for CM diagnosis and warrants further assessment of its clinical utility for ruling out CM in malaria-endemic areas.

Analysis of Cerebrospinal Fluid Extracellular Vesicles by Proximity Extension Assay: A Comparative Study of Four Isolation Kits.

There is a lack of reliable biomarkers for disorders of the central nervous system (CNS), and diagnostics still heavily rely on symptoms that are both subjective and difficult to quantify. The cerebrospinal fluid (CSF) is a promising source of biomarkers due to its close connection to the CNS. Extracellular vesicles are actively secreted by cells, and proteomic analysis of CSF extracellular vesicles (EVs) and their molecular composition likely reflects changes in the CNS to a higher extent compared with total CSF, especially in the case of neuroinflammation, which could increase blood-brain barrier permeability and cause an influx of plasma proteins into the CSF. We used proximity extension assay for proteomic analysis due to its high sensitivity. We believe that this methodology could be useful for de novo biomarker discovery for several CNS diseases. We compared four commercially available kits for EV isolation: MagCapture and ExoIntact (based on magnetic beads), EVSecond L70 (size-exclusion chromatography), and exoEasy (membrane affinity). The isolated EVs were characterized by nanoparticle tracking analysis, ELISA (CD63, CD81 and albumin), and proximity extension assay (PEA) using two different panels, each consisting of 92 markers. The exoEasy samples did not pass the built-in quality controls and were excluded from downstream analysis. The number of detectable proteins in the ExoIntact samples was considerably higher (~150% for the cardiovascular III panel and ~320% for the cell regulation panel) compared with other groups. ExoIntact also showed the highest intersample correlation with an average Pearson's correlation coefficient of 0.991 compared with 0.985 and 0.927 for MagCapture and EVSecond, respectively. The median coefficient of variation was 5%, 8%, and 22% for ExoIntact, MagCapture, and EVSecond, respectively. Comparing total CSF and ExoIntact samples revealed 70 differentially expressed proteins in the cardiovascular III panel and 17 in the cell regulation panel. To our knowledge, this is the first time that CSF EVs were analyzed by PEA. In conclusion, analysis of CSF EVs by PEA is feasible, and different isolation kits give distinct results, with ExoIntact showing the highest number of identified proteins with the lowest variability.

Presence of anti-neuronal antibodies in children with neurological disorders beyond encephalitis.

BACKGROUND: Anti-neuronal autoantibodies have been reported as the cause of several neurologic disorders other than encephalitis. Unfortunately, data are mostly based on serum analysis. Predictions about pathogenicity are thus limited. To determine the presence of so far unidentified autoantibody-derived neuroreactivity we analyzed cerebrospinal fluid (CSF) of children with neurological disorders other than encephalitis. PATIENTS AND METHODS: We did a retrospective analysis of CSF from 254 children with various neurologic diseases other than encephalitis and searched for reactivity against neuronal surface antigens by immunofluorescence on unfixed murine brain sections (tissue-based assay, TBA) and by commercial cell-based assays (CBA). A semi-quantitative fluorescence score classified our results and we described the clinical course of all positive patients with strong neuroreactivity. RESULTS: Strong anti-neuronal IgG immunoreactivity of unknown antigen specificity was detected in CSF samples of 10 pediatric patients (4%, n = 10/254) with unsolved neurological disorders. CSF inflammatory markers were elevated. Most patients did not or only partly recover. Five screening-positive patients presented with a combination of headache and visual impairment due to optic nerve atrophy. Our data suggest to consider inflammatory, autoantibody-related etiologies, especially in cases without definite diagnoses. CONCLUSIONS: We present an overview of CSF neuroreactivity in children with neurological disorders other than encephalitis, indicating the presence of unidentified anti-neuronal autoantibodies. As TBA enables screening for unknown autoantibodies, we suggest this method as a second step if commercial CBAs do not yield a result. Further studies are necessary to characterize such antibodies, evaluate pathogenicity, and answer the question whether positive CSF neuroreactivity should prompt an immunotherapeutic approach.

The Burden of Neurosarcoidosis: Essential Approaches to Early Diagnosis and Treatment.

Neurosarcoidosis (NS) is an often severe, destructive manifestation with a likely under-reported prevalence of 5 to 15% of sarcoidosis cases, and in its active phase demands timely treatment intervention. Clinical signs and symptoms of NS are variable and wide-ranging, depending on anatomical involvement. Cranial nerve dysfunction, cerebrospinal parenchymal disease, aseptic meningitis, and leptomeningeal disease are the most commonly recognized manifestations. However, non-organ-specific potentially neurologically driven symptoms, such as fatigue, cognitive dysfunction, and small fiber neuropathy, appear frequently.Heterogeneous clinical presentations and absence of any single conclusive test or biomarker render NS, and sarcoidosis itself, a challenging definitive diagnosis. Clinical suspicion of NS warrants a thorough systemic and neurologic evaluation hopefully resulting in supportive extraneural physical exam and/or tissue findings. Treatment targets the severity of the manifestation, with careful discernment of whether NS reflects active potentially reversible inflammatory granulomatous disease versus inactive postinflammatory damage whereby functional impairment is unlikely to be pharmacologically responsive. Non-organ-specific symptoms are poorly understood, challenging in deciphering reversibility and often identified too late to respond to conventional immunosuppressive/pharmacological treatment. Physical therapy, coping strategies, and stress reduction may benefit patients with all disease activity levels of NS.This publication provides an approach to screening, diagnosis, disease activity discernment, and pharmacological as well as nonpharmacological treatment interventions to reduce disability and protect health-related quality of life in NS.

Cerebrospinal fluid CD4+ /CD8+ ratio in diagnosing neurosarcoidosis.

OBJECTIVE: Neurosarcoidosis affects 5%-10% of patients with sarcoidosis. CD4+ /CD8+ ratio in bronchoalveolar lavage is included in diagnostic routine for pulmonary sarcoidosis. Previously, it has been suggested that a cerebrospinal fluid CD4+ /CD8+ ratio ≥5 can be an aid in diagnosing neurosarcoidosis. MATERIALS AND METHODS: This study included 66 cases where neurosarcoidosis was a differential diagnosis and hence subjected to the analysis of CSF CD4+ /CD8+ ratio by flow cytometry. RESULTS: Eleven cases of neurosarcoidosis, had a significantly higher median CSF CD4+ /CD8+ ratio than the other group, P = .024. The median CSF CD4+ /CD8+ ratio was 4.2, hence not reaching the suggested level of ≥5 for diagnosing neurosarcoidosis. When combined, the elevated CSF CD4+ /CD8+ ratio ≥5 and an elevated CSF lymphocyte count (>3 lymphocytes/uL) gave a positive predictive value of 57% and a high negative predictive value of 88%, with a specificity of 95% for neurosarcoidosis. CONCLUSION: The study confirms that increased CSF CD4+ /CD8+ ratio is associated with neurosarcoidosis but cannot alone distinguish the conditions from other neurological diagnoses. However, a ratio below <5 combined with an absence of pleocytosis in CSF yields a negative predictive value (NPV) of 88% suggesting a role for the analysis in differential diagnosing neuroinflammatory conditions.

Distinguishing neurosarcoidosis from multiple sclerosis based on CSF analysis: A retrospective study.

OBJECTIVE: To characterize a cohort of patients with neurosarcoidosis with particular focus on CSF analysis and to investigate whether CSF values could help in distinguishing it from multiple sclerosis (MS). METHODS: This retrospective cohort study enrolled 85 patients with a diagnosis of neurosarcoidosis (possible, probable, or definite). CSF total protein, white cell count, and angiotensin-converting enzyme levels were measured. CSF and serum oligoclonal immunoglobulin G (IgG) patterns were analyzed with the use of odds ratios and binary logistic regression. RESULTS: Eighty patients had a probable (nonneural positive histology) or definite (neural positive histology) diagnosis of neurosarcoidosis. Most frequent findings on MRI were leptomeningeal enhancement (35%) and white matter and spinal cord involvement (30% and 23%). PET scan showed avid areas in 74% of cases. CSF analysis frequently showed lymphocytosis (63%) and elevated protein (62%), but CSF-selective oligoclonal bands were rare (3%). Serum ACE levels were elevated in 51% of patients but in only 14% of those with isolated neurosarcoidosis. Elevated CSF ACE was not found in any patient. CONCLUSIONS: Large elevations in total protein, white cell count, and serum ACE occur in neurosarcoidosis but are rare in MS. The diagnostic use of these tests is, however, limited because minimal changes may occur in both. MS clinical mimics in neurosarcoidosis are not common, and intrathecal synthesis of oligoclonal IgG is a powerful discriminator because it is rare in neurosarcoidosis but occurs in 95% to 98% cases of MS. We suggest caution in making a diagnosis of neurosarcoidosis when intrathecal oligoclonal IgG synthesis is found.

Analysis of soluble interleukin-2 receptor as CSF biomarker for neurosarcoidosis.

OBJECTIVE: To systematically analyze soluble interleukin-2 receptor (sIL-2R) in CSF as a diagnostic and disease activity biomarker in patients with sarcoidosis involving the CNS (neurosarcoidosis). METHODS: sIL-2R was determined by chemiluminescent immunoassays in CSF/serum samples from patients with neurosarcoidosis (n = 23), MS (n = 19), neurotuberculosis (n = 8), viral (n = 18) and bacterial (n = 9) meningitis, cerebral lymphoma (n = 15), Guillain-Barré syndrome (n = 8), and 115 patients with noninflammatory neurologic diseases (NINDs) as controls. The sIL-2R index was calculated by dividing the CSF/serum sIL-2R quotient (QsIL-2R) through the CSF/serum albumin quotient (QAlb). sIL-2R quotient diagrams were established by plotting QsIL-2R against QAlb. sIL-2R levels were correlated with clinical, MRI, and CSF disease activity markers of neurosarcoidosis. RESULTS: Patients with neurosarcoidosis had higher CSF sIL-2R, QsIL-2R, and sIL-2R index values than patients with NINDs (p < 0.0001 for all pairwise group comparisons). sIL-2R quotient diagrams demonstrated an intrathecal sIL-2R synthesis in >50% of neurosarcoidosis samples. Similar findings were observed in viral/bacterial meningitis, CNS lymphoma, and, most pronounced, in neurotuberculosis, but not in patients with MS. CSF sIL-2R parameters were associated with clinical disease activity, leptomeningeal gadolinium enhancement, and the CSF white cell count in patients with neurosarcoidosis. CONCLUSIONS: CSF sIL-2R parameters are elevated in patients with neurosarcoidosis, but this finding is not specific for neurosarcoidosis. Nevertheless, CSF sIL-2R parameters may help distinguishing neurosarcoidosis from MS and are associated with clinical, radiologic, and CSF disease activity markers of neurosarcoidosis. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that CSF sIL-2R parameters distinguish neurosarcoidosis from NINDs and MS.

Clinical and MRI phenotypes of sarcoidosis-associated myelopathy.

OBJECTIVE: To determine the characteristic clinical and spinal MRI phenotypes of sarcoidosis-associated myelopathy (SAM), we analyzed a large cohort of patients with this disorder. METHODS: Patients diagnosed with SAM at a single center between 2000 and 2018 who met the established criteria for definite and probable neurosarcoidosis were included in a retrospective analysis to identify clinical profiles, CSF characteristics, and MRI lesion morphology. RESULTS: Of 62 included patients, 33 (53%) were male, and 30 (48%) were African American. SAM was the first clinical presentation of sarcoidosis in 49 patients (79%). Temporal profile of symptom evolution was chronic in 81%, with sensory symptoms most frequently reported (87%). CSF studies showed pleocytosis in 79% and CSF-restricted oligoclonal bands in 23% of samples tested. Four discrete patterns of lesion morphology were identified on spine MRI: longitudinally extensive myelitis (n = 28, 45%), short tumefactive myelitis (n = 14, 23%), spinal meningitis/meningoradiculitis (n = 14, 23%), and anterior myelitis associated with areas of disc degeneration (n = 6, 10%). Postgadolinium enhancement was seen in all but 1 patient during the acute phase. The most frequent enhancement pattern was dorsal subpial enhancement (n = 40), followed by meningeal/radicular enhancement (n = 23) and ventral subpial enhancement (n = 12). In 26 cases (42%), enhancement occurred at locations with coexisting structural changes (e.g., spondylosis). CONCLUSIONS: Recognition of the clinical features (chronically evolving myelopathy) and distinct MRI phenotypes (with enhancement in a subpial and/or meningeal pattern) seen in SAM can aid diagnosis of this disorder. Enhancement patterns suggest that SAM may have a predilection for areas of the spinal cord susceptible to mechanical stress.

Chemokine CXCL13 in serum, CSF and blood-CSF barrier function: evidence of compartment restriction.

BACKGROUND AND PURPOSE: Elevation of the chemokine CXCL13 in CSF frequently occurs during active and acute CNS inflammatory processes and presumably is associated with B cell-related immune activation. Elevation levels, however, vary a lot and "leaking" of CXCL13 from blood across dysfunctional brain barriers is a possible source. The aim was to clarify the relation between CXCL13 concentrations in CSF, CXCL13 concentrations in serum and blood-CSF barrier (BCSFB) function for a correct interpretation of the intrathecal origin of CXCL13. METHODS: We retrospectively analyzed CXCL13 of banked CSF/serum samples (n = 69) selected from patient records and categorized the CSF CXCL13 elevations as CXCL13 negative (< 30 pg/ml), low (30-100 pg/ml), medium (101-250 pg/ml), or high (> 250 pg/ml). CXCL13 concentrations in CSF and serum and the corresponding CSF/serum CXCL13 quotients (Qcxcl13) were compared to CSF/serum albumin quotients (QAlb) as a measure for BCSFB function. The CXCL13 negative category included two subgroups with normal and dysfunctional BCSFB. RESULTS: Serum CXCL13 concentrations were similar across categories with median levels around 100 pg/ml but differed between individuals (29 to > 505 pg/ml). Despite clear evidence in serum, CXCL13 was detectable only at trace amounts (medians 3.5 and 7.5 pg/ml) in CSF of the two CXCL13 negative subgroups irrespective of a normal or pathological QAlb. Moreover, we found no association between CSF and serum CXCL13 levels or between QAlb and CSF CXCL13 levels in any of the CSF CXCL13-delineated categories. CXCL13 apparently does not "leak" from blood into CSF. This implies an intrathecal origin also for low CSF CXCL13 levels and a caveat for analyzing the Qcxcl13, because higher serum than CSF concentrations arithmetically depress the Qcxcl13 resulting in misleadingly low CSF/serum quotients. CONCLUSION: We demonstrated that CXCL13 does not cross from blood into CSF, not even during severe BCSFB dysfunction. CSF CXCL13 elevations therefore most likely always are CNS-derived, which highlights their relevance as indicator of inflammatory CNS processes. We recommend data should not be corrected for BCSFB permeability (QAlb) and not to calculate CSF/serum quotients for CXCL13 as these may introduce error.

Leukocyte profiles in blood and CSF distinguish neurosarcoidosis from multiple sclerosis.

Distinguishing neurosarcoidosis (NS) from multiple sclerosis (MS) remains challenging and available parameters lack discriminatory power. Comprehensive flow cytometry data of blood and CSF leukocytes of patients with NS (n = 24), MS (n = 49) and idiopathic intracranial hypertension (IIH, n = 52) were analyzed by machine learning algorithms. NS featured a specific immune cell pattern with increased activated CD4+ T cells in CSF and increased plasma cells in blood. Combining blood and CSF parameters improved the differentiation. We thereby identify and independently validate a multi-dimensional model of blood and CSF supporting the difficult differential diagnosis between NS and MS.

Differentiation between neurosarcoidosis and primary central nervous system vasculitis based on demographic, cerebrospinal and imaging features.

OBJECTIVES: Neurosarcoidosis (NS) and primary angiitis of central nervous system (PACNS) are inflammatory diseases affecting central nervous system, with overlapping clinical and pathological characteristics. Distinguishing these diseases is important given distinct therapeutic implications. In this study, we aimed to compare demographic, CSF and MRI characteristics between these two conditions. METHODS: All the clinical, CSF and laboratory characteristics at the time of presentation were retrieved from electronic medical records. Brain and/or spinal cord MRI performed near the time of presentation were blindly evaluated by two neuroradiologists. Data regarding involvement of pachy- and leptomeninges, basal meninges, cranial nerves, cerebral grey and white matter, and spinal cord were recorded for each patient. RESULTS: 78 patients with PACNS and 25 patients with NS were included in the study. Mean age of patients was 43.7 (±16.7) and 43.6 (±12.5) in PACNS and NS, respectively. African-American race was found to be associated with the diagnosis of NS rather than PACNS. Patients with PACNS had higher frequency of cerebral involvement, while patients with NS demonstrated more frequent spinal cord, basal meningeal and cranial nerve involvements. CONCLUSIONS: These findings suggest that MRI can be an efficient tool in distinguishing PACNS from NS. A follow-up study with a larger sample size would be required to validate our results.

Soluble CD146, a cerebrospinal fluid marker for neuroinflammation, promotes blood-brain barrier dysfunction.

The blood-brain barrier (BBB) dysfunction is an initial event of various neuroinflammatory diseases. However, the absence of reliable markers and mechanisms for BBB damage greatly limits the diagnosis and treatment of neuroinflammatory diseases. Soluble CD146 (sCD146) is mainly derived from vascular endothelial cells (ECs) and highly elevated in inflammatory settings. Based on a small cohort, our previous study showed that sCD146 is elevated in the cerebrospinal fluid (CSF) of multiple sclerosis (MS), which is accompanied with BBB damage. Nevertheless, whether sCD146 monitors and regulates the BBB dysfunction remains unknown. Methods: Coupled serum and CSF samples from patients with or without neuroinflammatory diseases were collected via multicenter collaborations. sCD146 was measured by sandwich ELISA using anti-CD146 antibodies AA1 and AA98, both of which were generated in our laboratory. The correlations between sCD146 and other clinical parameters or inflammatory factors were analyzed by Spearman's correlation coefficient analysis. The role of sCD146 on BBB function was examined in an in vitro BBB model. Results: Between July 20, 2011, and February 31, 2017, we collected coupled serum and CSF samples from 823 patients, of which 562 (68.3%) had neuroinflammatory diseases, 44 (5.3%) had remitting MS, and 217 (26.4%) had non-inflammatory neurological diseases (NIND). We found that sCD146 in CSF, but not in serum, is abnormally elevated in neuroinflammatory diseases (37.3 ± 13.3 ng/mL) compared with NIND (4.7 ± 2.9 ng/mL) and remitting MS (4.6 ± 3.5 ng/mL). Abnormally elevated CSF sCD146 is significantly correlated with the hyperpermeability-related clinical parameters of BBB and neuroinflammation-related factors. Moreover, CSF sCD146 shows higher sensitivity and specificity for evaluating BBB damage. Using an in vitro BBB model, we found that sCD146 impairs BBB function by promoting BBB permeability via an association with integrin αvß1. Blocking integrin αvß1 significantly attenuates sCD146-induced hyperpermeability of the BBB. Conclusion: Our study provides convincing evidence that CSF sCD146 is a sensitive marker of BBB damage and neuroinflammation. Furthermore, sCD146 is actively involved in BBB dysfunction.