title: Utility of CSF Cytokine/Chemokines as Markers of Active Intrathecal Inflammation: Comparison of Demyelinating, Anti-NMDAR and Enteroviral Encephalitis.
abstract: BACKGROUND
  Despite the discovery of CSF and serum diagnostic autoantibodies in autoimmune encephalitis, there are still very limited CSF biomarkers for diagnostic and monitoring purposes in children with inflammatory or autoimmune brain disease. The cause of encephalitis is unknown in up to a third of encephalitis cohorts, and it is important to differentiate infective from autoimmune encephalitis given the therapeutic implications.
  
  
  OBJECTIVE
  To study CSF cytokines and chemokines as diagnostic biomarkers of active neuroinflammation, and assess their role in differentiating demyelinating, autoimmune, and viral encephalitis.
  
  
  METHODS
  We measured and compared 32 cytokine/chemokines using multiplex immunoassay and APRIL and BAFF using ELISA in CSF collected prior to commencing treatment from paediatric patients with confirmed acute disseminated encephalomyelitis (ADEM, n = 16), anti-NMDAR encephalitis (anti-NMDAR E, n = 11), and enteroviral encephalitis (EVE, n = 16). We generated normative data using CSF from 20 non-inflammatory neurological controls. The sensitivity of CSF cytokine/chemokines to diagnose encephalitis cases was calculated using 95th centile of control values as cut off. We correlated CSF cytokine/chemokines with disease severity and follow up outcome based on modified Rankin scale. One-way hierarchical correlational cluster analysis of molecules was performed in different encephalitis and outcome groups.
  
  
  RESULTS
  In descending order, CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 had the best sensitivity (>79.1%) when all encephalitis patients were included. The combination of IL-6 and IFN-α was most predictive of inflammation on multiple logistic regression with area under the ROC curve 0.99 (CI 0.97-1.00). There were no differences in CSF cytokine concentrations between EVE and anti-NMDAR E, whereas ADEM showed more pronounced elevation of Th17 related (IL-17, IL-21) and Th2 (IL-4, CCL17) related cytokine/chemokines. Unlike EVE, heat map analysis showed similar clustering of cytokine/chemokine molecules in immune mediated encephalitis (ADEM and anti-NMDAR E). Th1 and B cell (CXCL13 and CXCL10) molecules clustered together in patients with severe encephalopathy at admission and worse disability at follow up in all encephalitis. There was no correlation between CSF neopterin and IFN-γ or IFN-α.
  
  
  CONCLUSIONS
  A combination panel of cytokine/chemokines consisting of CSF TNF-α, IL-10, IFN-α, IL-6, CXCL13 and CXCL10 measured using multiplex immunoassay may be used to diagnose and monitor intrathecal inflammation in the brain. Given their association with worse outcome, certain key chemokines (CXCL13, CXCL10) could represent potential therapeutic targets in encephalitis.
authors: Brain Autoimmunity group, Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, NSW, Australia.
authors: Kavitha
authors: K
authors: Kothur
authors: Department of Clinical Immunology, Royal Prince Alfred Hospital, Sydney, NSW, Australia.
authors: Louise
authors: L
authors: Wienholt
authors: Brain Autoimmunity group, Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, NSW, Australia.
authors: Shekeeb S
authors: SS
authors: Mohammad
authors: Brain Autoimmunity group, Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, NSW, Australia.
authors: Esther M
authors: EM
authors: Tantsis
authors: Brain Autoimmunity group, Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, NSW, Australia.
authors: Sekhar
authors: S
authors: Pillai
authors: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, and The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors: Philip N
authors: PN
authors: Britton
authors: Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, and The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors: Cheryl A
authors: CA
authors: Jones
authors: Department of Neonatology, Nepean Hospital, University of Sydney, Sydney, NSW, Australia.
authors: Rajeshwar R
authors: RR
authors: Angiti
authors: NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia.
authors: Elizabeth H
authors: EH
authors: Barnes
authors: Sydney School of Public Health, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors: Timothy
authors: T
authors: Schlub
authors: Department of Biochemistry, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors: Sushil
authors: S
authors: Bandodkar
authors: Brain Autoimmunity group, Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, NSW, Australia.
authors: Fabienne
authors: F
authors: Brilot
authors: Brain Autoimmunity group, Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, University of Sydney, Sydney, NSW, Australia.
authors: Russell C
authors: RC
authors: Dale
mesh_terms: D000293:Adolescent; D060426:Anti-N-Methyl-D-Aspartate Receptor Encephalitis / Q000175:diagnosis / Q000276:immunology*; D015415:Biomarkers / Q000134:cerebrospinal fluid; D018925:Chemokines / Q000134:cerebrospinal fluid*; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000134:cerebrospinal fluid*; D004268:DNA-Binding Proteins / Q000134:cerebrospinal fluid / Q000378:metabolism; D003937:Diagnosis, Differential; D018792:Encephalitis, Viral / Q000175:diagnosis / Q000276:immunology*; D004673:Encephalomyelitis, Acute Disseminated / Q000175:diagnosis / Q000276:immunology*; D004769:Enterovirus Infections / Q000175:diagnosis / Q000276:immunology*; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D048493:Proto-Oncogene Proteins B-raf / Q000134:cerebrospinal fluid / Q000378:metabolism; D012372:ROC Curve; D014157:Transcription Factors / Q000134:cerebrospinal fluid / Q000378:metabolism
chemical_list: D015415:Biomarkers; D018925:Chemokines; D016207:Cytokines; D004268:DNA-Binding Proteins; C118660:PDS5B protein, human; D014157:Transcription Factors; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf