Cerebrospinal fluid B-cell activating factor levels as a novel biomarker in patients with neurosarcoidosis.

OBJECTIVES: Neurosarcoidosis (NS) is a severe complication of sarcoidosis. Patients with NS often have poor outcomes. To improve both the quality of life and prognosis in patients with NS, accurate and reliable methods for early diagnosis and determining the efficacy of treatment are needed. This study aims to investigate B-cell-activating factor of the tumor necrosis factor family (BAFF) in cerebrospinal fluid (CSF) and elucidate the relationship between CSF BAFF levels and various parameters of NS. METHODS: We studied 20 patients with NS and 14 control subjects. We measured CSF BAFF levels in all subjects and investigated the relationship with clinical findings, serum and CSF measures, and magnetic resonance imaging (MRI) findings. RESULTS: CSF BAFF levels were significantly increased in patients with NS compared with controls (median 0.089 vs 0.04 ng/mL, p = 0.0005). CSF BAFF values were correlated with CSF findings-cell count, protein, angiotensin-converting enzyme, lysozyme, soluble interleukin-2 receptor, and immunoglobulin G-but not with serum parameters. CSF BAFF levels were especially higher in patients with abnormal intraparenchymal lesions of the brain and abnormal spinal MRI findings. CSF BAFF levels decreased significantly after immunosuppressive therapy. CONCLUSION: CSF BAFF may aid the quantitative evaluation of NS and may serve as a biomarker for this disease.

Cerebrospinal fluid and serum protein markers in autism: A co-twin study.

No robust biomarkers have yet been identified for autism spectrum disorder (ASD) or autistic traits. Familial factors likely influence biomarkers such as protein concentrations. Comparing twins with ASD or high autistic traits to the less affected co-twin allows estimating the impact of familial confounding. We measured 203 proteins in cerebrospinal fluid (n = 86) and serum (n = 127) in twins (mean age 14.2 years, 44.9% females) enriched for ASD and other neurodevelopmental conditions. Autistic traits were assessed by using the parent-report version of the Social Responsiveness Scale-2. In cerebrospinal fluid, autistic traits correlated negatively with three proteins and positively with one. In serum, autistic traits correlated positively with 15 and negatively with one. Also in serum, six were positively-and one negatively-associated with ASD. A pathway analysis of these proteins revealed immune system enrichment. In within twin pair analyses, autistic traits were associated with serum B-cell activating factor (BAFF) only, whereas Cystatin B (CSTB) remained significantly associated with ASD. These associations did not remain significant when only considering monozygotic twins. For the remainder, the within-pair analysis indicated familial confounding, including shared environment and genes, influencing both autism and protein levels. Our findings indicate proteins involved in immunity as putative biomarkers of autistic traits and ASD with partial genetic confounding. Although some results are in line with previous studies in general, further studies are needed for replication.

Mass Cytometry of CSF Identifies an MS-Associated B-cell Population.

OBJECTIVE: To identify an MS-specific immune cell population by deep immune phenotyping and relate it to soluble signaling molecules in CSF. METHODS: We analyzed surface expression of 22 markers in paired blood/CSF samples from 39 patients using mass cytometry (cytometry by time of flight). We also measured the concentrations of 296 signaling molecules in CSF using proximity extension assay. Results were analyzed using highly automated unsupervised algorithmic informatics. RESULTS: Mass cytometry objectively identified a B-cell population characterized by the expression of CD49d, CD69, CD27, CXCR3, and human leukocyte antigen (HLA)-DR as clearly associated with MS. Concentrations of the B cell-related factors, notably FCRL2, were increased in MS CSF, especially in early stages of the disease. The B-cell trophic factor B cell activating factor (BAFF) was decreased in MS. Proteins involved in neural plasticity were also reduced in MS. CONCLUSION: When analyzed without a priori assumptions, both the soluble and the cellular compartments of the CSF in MS were characterized by markers related to B cells, and the strongest candidate for an MS-specific cell type has a B-cell phenotype.

BAFF serum and CSF levels in patients with multiple sclerosis and infectious nervous system diseases.

PURPOSE: Multiple sclerosis (MS) is the most common immune-mediated CNS disease, characterised by demyelination and progressive neurological disability. The B-cell activating factor BAFF has been described as one important factor in the pathophysiology of different autoimmune diseases. METHODS: We measured BAFF levels in the serum and cerebrospinal fluid (CSF) in 50 consecutive patients with MS and 35 patients with infectious CNS disease (ID). 52 patients with other, non-inflammatory disorders (OND), served as controls. RESULTS: BAFF-serum levels in ID patients were higher than in patients diagnosed with MS (ID 0.55 ± 0.24 ng/ml, MS 0.43 ± 0.14 ng/ml, OND 0.45 ± 0.24 ng/ml; p = 0.09). Interestingly, MS patients had lower BAFF CSF levels compared to the controls and ID patients, and the CSF levels in the latter were elevated compared to those of the controls (MS 0.17 ± 0.11 ng/ml, OND 0.25 ± 0.14 ng/ml, ID 0.97 ± 0.78 ng/ml; p < 0.001). CONCLUSIONS: The ID patients' having higher absolute BAFF levels in the CSF than in the serum indicates that the increased BAFF CSF levels were caused by intrathecal synthesis rather than passive transfer via a disturbed blood-brain-barrier. The significantly decreased BAFF CSF levels in MS patients were a surprising result of our study. Although it has been reported that astrocytes in active MS lesions can express BAFF, the soluble form was not increased in the CSF of MS patients. It remains unclear whether the inflammatory features of active MS plaques are truly represented by the CSF compartment.

Alteration of BAFF and APRIL in the cerebrospinal fluid based on the therapeutic response in primary central nervous system B-cell lymphoma.

We evaluated the cerebrospinal fluid (CSF) levels of the B-cell activating factor of the tumor necrosis factor family (BAFF) and A proliferation-inducing ligand (APRIL) in two cases of primary central nervous system B-cell lymphoma (PCNSBL) before and after treatment. One patient achieved clinical remission, and demonstrated decrease in the CSF levels of both BAFF and APRIL after treatment. Meanwhile, the other patient with insufficient therapeutic response showed increase in the BAFF levels despite decrease in APRIL levels. This report suggests that the combination of BAFF and APRIL levels could be useful in estimating the therapeutic efficacy in treating PCNSBL as reliable CSF markers.

Cerebrospinal fluid biomarkers implicated in the pathogenesis of anti-neutrophil cytoplasmic antibody-related hypertrophic pachymeningitis.

OBJECTIVE: Hypertrophic pachymeningitis (HP) related to anti-neutrophil cytoplasmic antibody (ANCA) is the most frequently seen immune-mediated HP. We investigated cerebrospinal fluid (CSF) biomarkers related to the pathogenesis of ANCA-related HP (ANCA-HP). METHODS: The levels of B cell activation factor of the tumor necrosis factor family (BAFF), a proliferation-inducing ligand (APRIL), and transforming growth factor beta 1 (TGF-ß1) in the CSF were compared between patients with ANCA-HP (n = 12), other types of immune-mediated HP (other HP; n = 12), multiple sclerosis (MS; n = 14), and non-inflammatory neurological disorders (NIND; n = 10). In addition, we evaluated whether ANCA would be detected in CSF. RESULTS: CSF levels of BAFF, APRIL, and TGF-ß1 were significantly increased in ANCA-HP and other HP. In particular, BAFF and APRIL levels were significantly correlated with the IgG index in ANCA-HP. In other HP, BAFF and APRIL levels were significantly correlated with cell counts and protein levels in CSF. Of 12 patients with ANCA-HP, the CSF of 7 patients (58%) tested positive for myeloperoxidase (MPO)- or proteinase 3 (PR3)-ANCA, while none of the CSF samples from other HP, MS, or NIND patients tested positive. CONCLUSION: The levels of BAFF, APRIL, and TGF-ß1 may serve as useful CSF biomarkers for assessing the disease activity of immune-mediated HP. Moreover, BAFF and APRIL in the CSF may be implicated in the pathogenesis of ANCA-HP via promoting autoreactive B cells, while detecting MPO- or PR3-ANCA in the CSF may be found in some patients with ANCA-HP.Key Points• CSF BAFF, APRIL, and TGF-ß1 levels increase significantly in immune-mediated HP.• CSF BAFF and APRIL levels are significantly correlated with IgG index in ANCA-HP.• Detection of MPO- or PR3-ANCA in the CSF is found in some patients with ANCA-HP.• BAFF, APRIL, and ANCA in the CSF may be implicated in the pathogenesis of ANCA-HP.

The predictive value of CSF multiple assay in multiple sclerosis: A single center experience.

BACKGROUND: Multiple sclerosis (MS) is a chronic, immune-mediated, inflammatory, neurodegenerative disorder. Many studies are investigating the potential role of body fluid biomarkers as prognostic factors for early identification of patients presenting with clinical isolated syndrome (CIS) at high risk for conversion to MS or to recognize RRMS patients at high risk for progression. OBJECTIVES: To evaluate the correlation between levels of BAFF, chitinase 3-like 1 (CHI3L1), sCD163, Osteopontin (OPN), both on serum and cerebral spinal fluid (CSF), and the disease activity and progression. We also want to explore a possible relationship between serological and CSF biomarker's levels. PATIENTS AND METHODS: We enrolled 82 patients between June 2014 and June 2016. Seventy-one received a diagnosis of demyelinating disease of CNS (46 RRMS and 25 CIS), while 11 were affected by other neurological diseases. All patients underwent a neural axis MRI, lumbar puncture and blood samples. Levels of BAFF, CHI3L1, sCD163, OPN on serum and CSF were analyzed by Luminex xMAP system, with a kit 11-plex ad hoc. RESULTS: The CSF CHI3L1, sCD163 and OPN levels were significantly higher in MS patients than in controls. We did not find significant differences in serum CHI3L1, sCD163 and OPN levels, nor CSF or serum BAFF levels between patient and control groups. We found significantly higher CSF level of sCD163 and CHI3L1 in all patients' subgroups compared with controls, while OPN was higher in CIS and RR subgroups. We did not find significant differences for serum and CSF levels of all the markers between patients with or without clinical or radiological disease activity. CSF sCD163 and CHI3L1 levels was significant higher in CIS patients who converted to MS (p < 0.05). Using ROC curve analysis, CSF sCD163 resulted the best predictive factor. CSF CHI3L1 and OPN levels resulted useful independent predictors too. Combined ROCs of those three analytes demonstrated a better predictive value, with sCD163 and CHI3L1 resulting as the best combination. CONCLUSIONS: CSF sCD163 CHI3L1 and OPN levels were higher in MS patients whereas serum CHI3L1, sCD163 and OPN levels did not show differences compared with controls. This finding confirms the high CSF specificity with regards to the analysis of processes, inflammatory and non-inflammatory, that occur within the CNS.

Increased BAFF and APRIL levels in the cerebrospinal fluid of patients with anti-neutrophil cytoplasmic antibody-related hypertrophic pachymeningitis.

Hypertrophic pachymeningitis (HP) is an inflammatory disorder involving intracranial or spinal thickened dura mater. It has been recognized that anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis may lead to HP; however, the immune-mediated pathogenesis of ANCA-related HP (ANCA-HP) remains elusive. In the present study, we analyzed B-cell activation factor of the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) expression in the cerebrospinal fluid (CSF) and serum of patients with ANCA-HP, multiple sclerosis (MS), and non-inflammatory neurological disorders (NIND). BAFF and APRIL levels in the CSF were significantly higher in patients with ANCA-HP than in those with MS and NIND. In addition, a positive correlation between BAFF levels in the CSF and IgG-index was found in patients with ANCA-HP. On the other hand, no correlation was detected between CSF and serum levels of BAFF or APRIL. The results suggest that increased levels of BAFF and APRIL produced in the central nervous system may influence the development of ANCA-HP.

Raised cerebrospinal fluid BAFF and APRIL levels in anti-N-methyl-d-aspartate receptor encephalitis: Correlation with clinical outcome.

In this study, we aimed to assess the levels of B cell activating factor from the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL) in cerebrospinal fluid (CSF) of patients with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis and determine their correlation with clinical outcome. BAFF and APRIL concentrations in CSF and serum from 40 patients with anti-NMDAR encephalitis and 20 controls were measured by enzyme-linked immunosorbent assay (ELISA). Compared with controls, the levels of both BAFF and APRIL in CSF were significantly increased in patients with anti-NMDAR encephalitis (p<0.001 and p<0.001). Patients with unfavorable outcome had higher levels of BAFF and APRIL in CSF than those who had favorable outcome (p<0.05 and p<0.05). BAFF and APRIL levels in CSF were elevated and associated with clinical outcome in patients with anti-NMDAR encephalitis, indicating that they may be valuable biomarkers to this disease.

BAFF Index and CXCL13 levels in the cerebrospinal fluid associate respectively with intrathecal IgG synthesis and cortical atrophy in multiple sclerosis at clinical onset.

BACKGROUND: B lymphocytes are thought to play a relevant role in multiple sclerosis (MS) pathology. The in vivo analysis of intrathecally produced B cell-related cytokines may help to clarify the mechanisms of B cell recruitment and immunoglobulin production within the central nervous system (CNS) in MS. METHODS: Paired cerebrospinal fluid (CSF) and serum specimens from 40 clinically isolated syndrome suggestive of MS or early-onset relapsing-remitting MS patients (CIS/eRRMS) and 17 healthy controls (HC) were analyzed for the intrathecal synthesis of IgG (quantitative formulae and IgG oligoclonal bands, IgGOB), CXCL13, BAFF, and IL-21. 3D-FLAIR, 3D-DIR, and 3D-T1 MRI sequences were applied to evaluate white matter (WM) and gray matter (GM) lesions and global cortical thickness (gCTh). RESULTS: Compared to HC, CIS/eRRMS having IgGOB (IgGOB+, 26 patients) had higher intrathecal IgG indexes (p < 0.01), lower values of BAFF Index (11.9 ± 6.1 vs 17.5 ± 5.2, p < 0.01), and higher CSF CXCL13 levels (27.7 ± 33.5 vs 0.9 ± 1.5, p < 0.005). In these patients, BAFF Index but not CSF CXCL13 levels inversely correlated with the intrathecal IgG synthesis (r > 0.5 and p < 0.05 for all correlations). CSF leukocyte counts were significantly higher in IgGOB+ compared to IgGOB- (p < 0.05) and HC (p < 0.01), and correlated to CSF CXCL13 concentrations (r 0.77, p < 0.001). The gCTh was significantly lower in patients with higher CSF CXCL13 levels (2.41 ± 0.1 vs 2.49 ± 0.1 mm, p < 0.05), while no difference in MRI parameters of WM and GM pathology was observed between IgGOB+ and IgGOB-. CONCLUSIONS: The intrathecal IgG synthesis inversely correlated with BAFF Index and showed no correlation with CSF CXCL13. These findings seem to indicate that intrathecally synthesized IgG are produced by long-term PCs that have entered the CNS from the peripheral blood, rather than produced by PCs developed in the meningeal follicle-like structures (FLS). In this study, CXCL13 identifies a subgroup of MS patients characterized by higher leukocyte counts in the CSF and early evidence of cortical thinning, further suggesting a role for this chemokine as a possible marker of disease severity.

BAFF is decreased in the cerebrospinal fluid of multiple sclerosis at clinical onset.

B-cells are thought to play a relevant role in multiple sclerosis (MS) pathology. BAFF (B cell activating factor of the TNF family) is a B-cell survival factor constitutively produced inside the CNS by astrocytes. We studied the intrathecal synthesis of BAFF in MS at clinical onset. Paired serum and cerebrospinal fluid (CSF) specimens from 40 clinically isolated syndromes (CIS) suggestive of MS or early relapse-onset MS (eRRMS) and from 18 healthy controls (HC) were analysed. Patients were classified based on the detection of oligoclonal IgG bands in the CSF (IgGOB+ and IgGOB-). BAFF was detected by highly sensitive ELISA and its ratio (CSF-BAFF/serum-BAFF, QBAFF) and Index (QBAFF/QAlb, BAFF-Index) were calculated. IgGOB+ presented lower CSF concentrations of BAFF compared to both HC and IgGOB- (p<0.05). BAFF Index was significantly lower in IgGOB+ compared to both HC and IgGOB- (p<0.01). A significant inverse correlation between QIgG and QBAFF (r: -0.4, p<0.05) and between BAFF index and IgGIF (r: -0.4, p<0.05) or IgG Index (r: -0.4, p=0.05) was found in IgGOB+. The decreased CSF levels of BAFF in IgGOB+ at clinical onset suggest the absorption of this factor by intrathecally recruited B cells since the early disease phases.

The effects of intrathecal rituximab on biomarkers in multiple sclerosis.

OBJECTIVES: Clinical trials of IV-rituximab have proved successful. It is unclear whether intrathecal (IT)-rituximab is more efficacious at lower doses. We examine its effects on B-cell biomarkers. METHODS: MS patients received IT-rituximab at 3 time-points. CSF and serum samples were obtained at up to 5 time-points (days 0, 7, 14, 56 and 112). Serum and CSF BAFF and CXCL13, and CSF kappa and lambda free light chains (FLC) were measured. Flow cytometry was performed, examining effects on lymphocytes, CD3-19+ and CD3-20+ cells. RESULTS: CSF BAFF fell following rituximab (p=0.0091 absolute values, p=0.0284 change from baseline) whilst serum BAFF increased across time-points 1-4 (p=0.0005 absolute values, p=0.0017 change from baseline). There were significant reductions in CD20+ and CD19+ cells in blood from baseline (p<0.0001) but not in CSF. CSF kappa FLC levels significantly increased (p=0.0480). CONCLUSIONS: BAFF levels fall in CSF but increase in serum following IT-rituximab. Rituximab appears to act peripherally with dramatic decreases in peripheral CD20+ and CD19+ cells. It is likely that CSF B-cell counts were too low to enable differences to be seen. The rapid reduction in B-cells suggests rituximab has immediate effects. The profound depletion of B-cells, despite low doses of rituximab, underlines rituximab's efficacy.

Anti-N-methyl-D-aspartate receptor encephalitis: the clinical course in light of the chemokine and cytokine levels in cerebrospinal fluid.

BACKGROUND: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder of the central nervous system (CNS). Its immunopathogenesis has been proposed to include early cerebrospinal fluid (CSF) lymphocytosis, subsequent CNS disease restriction and B cell mechanism predominance. There are limited data regarding T cell involvement in the disease. To contribute to the current knowledge, we investigated the complex system of chemokines and cytokines related to B and T cell functions in CSF and sera samples from anti-NMDAR encephalitis patients at different time-points of the disease. One patient in our study group had a long-persisting coma and underwent extraordinary immunosuppressive therapy. METHODS: Twenty-seven paired CSF/serum samples were collected from nine patients during the follow-up period (median 12 months, range 1-26 months). The patient samples were stratified into three periods after the onset of the first disease symptom and compared with the controls. Modified Rankin score (mRS) defined the clinical status. The concentrations of the chemokines (C-X-C motif ligand (CXCL)10, CXCL8 and C-C motif ligand 2 (CCL2)) and the cytokines (interferon (IFN)γ, interleukin (IL)4, IL7, IL15, IL17A and tumour necrosis factor (TNF)α) were measured with Luminex multiple bead technology. The B cell-activating factor (BAFF) and CXCL13 concentrations were determined via enzyme-linked immunosorbent assay. We correlated the disease period with the mRS, pleocytosis and the levels of all of the investigated chemokines and cytokines. Non-parametric tests were used, a P value <0.05 was considered to be significant. RESULTS: The increased CXCL10 and CXCL13 CSF levels accompanied early-stage disease progression and pleocytosis. The CSF CXCL10 and CXCL13 levels were the highest in the most complicated patient. The CSF BAFF levels remained unchanged through the periods. In contrast, the CSF levels of T cell-related cytokines (INFγ, TNFα and IL17A) and IL15 were slightly increased at all of the periods examined. No dynamic changes in chemokine and cytokine levels were observed in the peripheral blood. CONCLUSIONS: Our data support the hypothesis that anti-NMDAR encephalitis is restricted to the CNS and that chemoattraction of immune cells dominates at its early stage. Furthermore, our findings raise the question of whether T cells are involved in this disease.

CSF cytokines/chemokines as biomarkers in neuroinflammatory CNS disorders: A systematic review.

Despite improved understanding of the pathogenesis of neuroinflammatory disorders of the brain and development of new diagnostic markers, our biomarker repertoire to demonstrate and monitor inflammation remains limited. Using PubMed database, we reviewed 83 studies on CSF cytokines and chemokines and describe the pattern of elevation and possible role of cytokines/chemokines as biomarkers in viral and autoimmune inflammatory neurological disorders of the CNS. Despite inconsistencies and overlap of cytokines and chemokines in different neuroinflammation syndromes, there are some trends regarding the pattern of cytokines/chemokine elevation. Namely B cell markers, such as CXCL13 and BAFF are predominantly investigated and found to be elevated in autoantibody-associated disorders, whereas interferon gamma (IFN-γ) is elevated mainly in viral encephalitis. Th2 and Th17 cytokines are frequently elevated in acute disseminated encephalomyelitis (ADEM) and neuromyelitis optica (NMO), whereas Th1 and Th17 cytokines are more commonly elevated in multiple sclerosis (MS). Cytokine/chemokine profiling might provide new insights into disease pathogenesis, and improve our ability to monitor inflammation and response to treatment.

[Investigation of B-cell activating factor in serum and cerebrospinal fluid of patients with neuromyelitis optical].

OBJECTIVE: To study the expression of B-cell activating factor (BAFF) in the serum and cerebrospinal fluid of patients with neuromyelitis optical (NMO). METHODS: Clinical data were collected from 44 patients with NMO and 38 patients with multiple sclerosis (MS). Thirty healthy controls and 15 controls with noninflammatory neurological diseases were also recruited. The concentration of BAFF in the serum and cerebrospinal fluid were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean serum BAFF level was 250.2 ± 126.9 pg/ml in NMO patients, 249.6 ± 130.7 pg/ml in MS patients, and 222.9 ± 126.1 pg/ml in the control subjects, showing no significant difference among the 3 groups (P>0.05). The mean BAFF level in the CSF was significantly higher in NMO patients than in MS patients (525.8 ± 230.0 pg/ml vs 298.4 ± 141.9 pg/ml, P<0.05), and higher in MS patients than in the control subjects (141.4 ± 76.2 pg/ml, P<0.05). Both NMO and MS group showed a positive correlation between EDSS scores and CSF BAFF level. But in NMO patients, CSF BAFF level was not associated with AQP4-antibody titer. CONCLUSION: BAFF in the CSF may be a useful biomarker for a differential diagnosis of NMO from MS and has an important value in evaluating the disease severity.

CCR7 signaling in pediatric opsoclonus-myoclonus: upregulated serum CCL21 expression is steroid-responsive.

Identifying and blocking chemokine inflammatory mediators in pediatric opsoclonus-myoclonus syndrome (OMS) is critical to the treatment of this autoimmune, paraneoplastic, neurological disorder. In a prospective, case-control, clinico-scientific study of children with OMS compared to non-inflammatory neurological controls and other inflammatory neurological disorders, CCL19 (n=369) and CCL21 (n=312) were quantified in CSF and serum, respectively, by ELISA. Both cross-sectional and longitudinal effects of OMS and various immunotherapies were evaluated. Significant upregulation of CCL21 concentration (mean ± SD) (+32%) was found in serum of untreated OMS (630 ± 133 pg/mL), compared to controls (478 ± 168 pg/mL), (p<0.0001). Both corticosteroids and ACTH (corticotropin) significantly lowered CCL21 to control levels, as they did in combination with IVIg, rituximab, cyclophosphamide or other treatments, without additional reduction attributable to the other agents. In a pilot longitudinal study of ACTH-based triple therapy, the mean serum CCL21 concentration fell 59% from elevated to less than 1 SD below controls 1 week after high-dose ACTH, gradually returning to the control mean with ACTH tapering by 3 weeks and out to 12 weeks (p<0.0001). In contrast, CCL19, detectable in CSF, was not significantly altered by OMS or various immunotherapies. In the "high" CCL21 subgroup, higher serum concentrations of CCL22 (+57%) and CXCL13 (+40%), as well as the CSF concentration of BAFF (+64%), also were found. Elevated serum CCL21, not CSF CCL19, correlates with OMS severity and duration in pediatric OMS. Corticosteroids and ACTH were the only immunotherapies evaluated that down-regulated CCL21 production. Validation studies are needed to assess treatment biomarker status.

Expression of CXCR3 and its ligands CXCL9, -10 and -11 in paediatric opsoclonus-myoclonus syndrome.

Opsoclonus-myoclonus syndrome (OMS) is a neuroinflammatory disorder associated with remote cancer. To understand more clearly the role of inflammatory mediators, the concentration of CXCR3 ligands CXCL10, CXCL9 and CXCL11 was measured in 245 children with OMS and 81 paediatric controls using enzyme-linked immunosorbent assay (ELISA), and CXCR3 expression on CD4(+) T cells was measured by flow cytometry. Mean cerebrospinal fluid (CSF) CXCL10 was 2·7-fold higher in untreated OMS than controls. Intrathecal production was demonstrated by significantly different CXCL10 CSF : serum ratios. The dichotomized 'high' CSF CXCL10 group had higher CSF leucocyte count (P = 0·0007) and B cell activating factor (BAFF) and CXCL13 concentrations (P < 0·0001). CSF CXCL10 did not correlate with clinical severity or relapse using grouped data, although it did in some patients. Among seven types of immunotherapy, including rituximab or chemotherapy, only adrenocorticotrophic hormone (ACTH) monotherapy showed reduced CSF CXCL10, but prospective longitudinal studies of ACTH combination therapies indicated no reduction in CXCL10 despite clinical improvement (P < 0·0001). CXCL10 concentrations were 11-fold higher in CSF and twofold higher in serum by multiplexed fluorescent bead-based immunoassay than enzyme-linked immunosorbent assay, but the two correlated (r = 0·7 and 0·83). In serum, no group differences for CXCL9 or CXCL11 were found. CXCR3 expression on CD4(+) T cells was fivefold higher in those from CSF than blood, but was not increased in OMS or altered by conventional immunotherapy. These data suggest alternative roles for CXCL10 in OMS. Over-expression of CXCL10 was not reduced by clinical immunotherapies as a whole, indicating the need for better therapeutic approaches.

BAFF/APRIL system in pediatric OMS: relation to severity, neuroinflammation, and immunotherapy.

BACKGROUND: B-cell dysregulation has been implicated but not fully characterized in pediatric opsoclonus-myoclonus syndrome (OMS), a neuroblastoma-associated neuroinflammatory disorder. OBJECTIVE: To assess the role of B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL), two critical B cell-modulating cytokines, as potential biomarkers of disease activity and treatment biomarkers in OMS. METHODS: Soluble BAFF and APRIL were measured in cerebrospinal fluid (CSF) and serum by ELISA in 433 children (296 OMS, 109 controls, 28 other inflammatory neurological disorders (OIND)). BAFF-R receptors on circulating CD19+ B cells were measured by flow cytometry. A blinded scorer rated motor severity on the OMS Evaluation Scale. Immunotherapies were evaluated cross-sectionally and longitudinally. RESULTS: The mean CSF BAFF concentration, which was elevated in untreated OMS and OIND, correlated with OMS severity category (P = 0.006), and reduction by adrenocorticotropic hormone or corticotropin (ACTH) (-61%) or corticosteroids (-38%) was seen at each level of severity. In contrast, CSF APRIL was normal in OMS and OIND and unaffected by immunotherapy. When the entire OMS dataset was dichotomized into 'high' versus 'normal' CSF BAFF concentration, the phenotype of the high group included greater motor severity and number of CSF oligoclonal bands, and a higher concentration of inflammatory chemokines CXCL13 and CXCL10 in CSF and CXCL9 and CCL21 in serum. Serum APRIL was 6.7-fold higher in the intravenous immunoglobulins (IVIg) group, whereas serum BAFF was 2.6-fold higher in the rituximab group. The frequency of B cell BAFF-R expression was similar in untreated and treated OMS. Longitudinal studies of CSF BAFF revealed a significant decline in ACTH-treated patients (with or without rituximab) (P < 0.0001). Longitudinal studies of serum APRIL showed a 2.9-fold increase after 1 to 2 g/kg IVIg monotherapy (P = 0.0003). CONCLUSIONS: Striking distinctions in BAFF/APRIL signaling were found. OMS displayed heterogeneity in CSF BAFF expression, which met many but not all criteria as a potential biomarker of disease activity. We speculate that CSF BAFF may have more utility in a biomarker panel than as a stand-alone biomarker, and that the selective upregulation of both serum APRIL by IVIg and BAFF by rituximab, as well as downregulation of CSF BAFF by ACTH/steroids, may have utility as treatment biomarkers.

Cerebrospinal fluid BAFF and APRIL levels in neuromyelitis optica and multiple sclerosis patients during relapse.

BACKGROUND: BAFF (B-cell activating factor of the tumor necrosis factor family) and APRIL (a proliferation-inducing ligand) are two of the major survival factors for B cells. Many studies have shown that BAFF levels were elevated in MS patients. However, whether the levels of CSF BAFF/APRIL increased in NMO patients was still unclear. OBJECTIVE: To measure the CSF BAFF and APRIL concentration of in NMO patients, and explore their relationship with disease activity in NMO. METHODS: CSF BAFF and APRIL was measured by an enzyme-linked immunosorbent assay (ELISA) in NMO (n = 22), MS (n = 18) patients and controls (n = 14). RESULTS: Concentration of BAFF and APRIL in NMO patients were significantly higher than MS and controls. CSF BAFF and APRIL levels in controls were also lower than MS. Both NMO and MS revealed an increased disease disability with increased CSF BAFF. CSF APRIL was associated with EDSS scores in NMO, but not found in MS. CONCLUSIONS: BAFF/APRIL system considered important for aggressive B cells and T-cell responses, and may stimulates B cells and T cell activation in acute relapse of NMO and MS. In NMO patients, CSF BAFF and APRIL may be key factors of B cell immune response and reflect disease severity.