title: Diagnostic value of IgG4 Indices in IgG4-related hypertrophic pachymeningitis.
abstract: Diagnosis of IgG4-Related Hypertrophic Pachymeningitis (IgG4-HP) relies on meningeal biopsies, because cerebrospinal fluid (CSF) diagnostic biomarkers are lacking. Here, we determined whether IgG4 intrathecal production could distinguish IgG4-HP from other disorders presenting with HP (OHP). In patients with IgG4-HP, the median CSF IgG4 concentration, IgG4 Index and IgG4Loc were significantly higher than in both controls and OHP. CSF IgG4 levels higher than 2.27mg/dL identified 100% of IgG4-HP and 5% of OHP. An IgG4Loc cut-off of 0.47 identified 100% of IgG4-HP and no cases of OHP. Our results support CSF IgG4 quantification and IgG4 Indices as alternatives to meningeal biopsy for the diagnosis of IgG4-HP when this procedure is contraindicated or uninformative.
authors.affiliation: Università Vita-Salute San Raffaele, School of Medicine, San Raffaele Scientific Institute, via Olgettina 58, 20132, Milan, Italy; Unit of Medicine and Clinical Immunology, San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy. Electronic address: dellatorre.emanuel@hsr.it.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Della-Torre
authors.affiliation: Infectious Diseases Department, San Raffaele Scientific Institute, Via Stamira d'Ancona 20, 20100, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Galli
authors.affiliation: Laboratory of Neuroimmunology, National Neurological Institute C. Mondino, Pavia, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Franciotta
authors.affiliation: Unit of Medicine and Clinical Immunology, San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
authors.forename: Enrica Paola
authors.initials: EP
authors.lastname: Bozzolo
authors.affiliation: Department of Neurosciences, University of Padova, Via Giustiniani 5, 35128, Padova, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Briani
authors.affiliation: Clinical Neuroimmunology Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, via Olgettina 58, 20132, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Furlan
authors.affiliation: Department of Neurology, San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Roveri
authors.affiliation: Department of Neurology, San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Sessa
authors.affiliation: Diagnostica e ricerca, San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Passerini
authors.affiliation: Università Vita-Salute San Raffaele, School of Medicine, San Raffaele Scientific Institute, via Olgettina 58, 20132, Milan, Italy; Unit of Medicine and Clinical Immunology, San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Sabbadini
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006984:Hypertrophy; D007074:Immunoglobulin G / Q000097:blood* / Q000134:cerebrospinal fluid*; D008297:Male; D008581:Meningitis / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000276:immunology*; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D007074:Immunoglobulin G
keywords: Cerebrospinal fluid; Hypertrophic pachymeningitis; IgG4; IgG4-related disease; IgG4-related pachymeningitis; Pachymeningitis