title: Evidence of a role for B cell-activating factor of the TNF family in the pathogenesis of chronic rhinosinusitis with nasal polyps.
abstract: BACKGROUND
  The polypoid form of chronic rhinosinusitis (chronic rhinosinusitis with nasal polyps [CRSwNP]) is a highly prevalent disease that often requires surgical intervention for treatment. Nasal polyps contain large quantities of B lymphocytes and immunoglobulin as well as eosinophils.
  
  
  OBJECTIVE
  The objective of this study was to investigate the expression of B cell-activating factor of the TNF family (BAFF), an important regulator of class-switch recombination and immunoglobulin production, in patients with chronic rhinosinusitis (CRS).
  
  
  METHODS
  We collected nasal tissue and nasal lavage fluid from patients with CRS and control subjects. We assayed mRNA for BAFF and B-lymphocyte markers, CD20 and transmembrane activator and calcium-modulator and cyclophilin ligand interactor, by using real-time PCR, and assayed BAFF protein by using ELISA and immunohistochemistry.
  
  
  RESULTS
  BAFF mRNA was significantly increased in nasal polyps from patients with CRSwNP (P < .001) compared with inferior turbinate tissue from patients with CRS or healthy subjects. BAFF protein was also elevated in polypoid tissue and nasal lavage from patients with CRSwNP. Immunohistochemistry showed considerable BAFF staining in mucosal epithelial cells in nasal polyps along with unidentified cells in the lamina propria. Expression of mRNA for BAFF in sinonasal tissue was significantly correlated with CD20 and transmembrane activator and CAML interactor in sinus tissue. IgA, an immunoglobulin isotype known to activate eosinophils, was also significantly elevated in the polypoid tissue.
  
  
  CONCLUSIONS
  Overproduction of BAFF in nasal polyps may contribute to the pathogenesis of CRSwNP via the local induction of IgA and activation of eosinophils.
authors.affiliation: Division of Allergy and Immunology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Ill 60611, USA.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kato
authors.forename: Anju
authors.initials: A
authors.lastname: Peters
authors.forename: Lydia
authors.initials: L
authors.lastname: Suh
authors.forename: Roderick
authors.initials: R
authors.lastname: Carter
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Harris
authors.forename: Rakesh
authors.initials: R
authors.lastname: Chandra
authors.forename: David
authors.initials: D
authors.lastname: Conley
authors.forename: Leslie C
authors.initials: LC
authors.lastname: Grammer
authors.forename: Robert
authors.initials: R
authors.lastname: Kern
authors.forename: Robert P
authors.initials: RP
authors.lastname: Schleimer
mesh_terms: D000328:Adult; D000368:Aged; D053264:B-Cell Activating Factor / Q000096:biosynthesis*; D002908:Chronic Disease; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology / Q000378:metabolism; D007150:Immunohistochemistry; D008875:Middle Aged; D017817:Nasal Lavage Fluid / Q000737:chemistry / Q000276:immunology; D009298:Nasal Polyps / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012220:Rhinitis / Q000276:immunology / Q000378:metabolism*; D012852:Sinusitis / Q000276:immunology / Q000378:metabolism*; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13 / Q000096:biosynthesis
chemical_list: D053264:B-Cell Activating Factor; D007070:Immunoglobulin A; D012333:RNA, Messenger; C505719:TNFSF13B protein, human; D053300:Tumor Necrosis Factor Ligand Superfamily Member 13