title: Beyond anti-microbial properties: The role of cathelicidin in allergic rhinitis.
abstract: BACKGROUND
  Cathelicidin, an anti-microbial peptide, is a component of the innate immune system. Cathelicidin has anti-microbial, anti-inflammatory and immunoregulatory functions. Knowledge about the role of the innate immune system in the pathogenesis of allergic diseases has expanded in recent years. We measured levels of the LL-37 peptide in the nasal fluids of children with allergic rhinitis (AR) and investigated the possible role of this peptide in the pathogenesis of AR.
  
  
  METHODS
  The study population included 46 children who were newly diagnosed with AR and not taking any medication. Thirty-three healthy control subjects were also enrolled. Nasal secretions were collected from the study and control groups using a polyurethane sponge nasal secretion collector, and nasal fluid LL-37 levels were determined using the ELISA method.
  
  
  RESULTS
  The levels of LL-37 in the nasal fluid of the AR patients were lower than those of the control group (median of 2.3ng/ml [minimum-maximum, 2.1-3.2] vs. 2.6ng/ml [2.1-5.4], respectively; p<0.001), and they were significantly reduced in patients with moderate/severe AR compared with those of patients with mild AR (2.2ng/ml [2.1-2.4] vs. 2.5ng/ml [2.1-3.1], respectively; p<0.001).
  
  
  CONCLUSIONS
  Our results show that children with AR have reduced nasal fluid LL-37 levels compared with healthy controls. Additionally, children with moderate/severe AR have decreased nasal fluid LL-37 levels compared with children with mild AR. These findings highlight the role of cathelicidin in the pathogenesis of AR.
authors.affiliation: Department of Pediatric Allergy and Immunology, Bezmialem Vakif University Medical Faculty, Adnan Menderes Bulvari, Vatan Caddesi, 34093 Fatih, Istanbul, Turkey. Electronic address: drfatihdilek@yahoo.com.
authors.forename: F
authors.initials: F
authors.lastname: Dilek
authors.affiliation: Department of Clinical Microbiology, Bezmialem Vakif University Medical Faculty, Adnan Menderes Bulvari, Vatan Caddesi, 34093 Fatih, Istanbul, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Gultepe
authors.affiliation: Department of Pediatric Allergy and Immunology, Bezmialem Vakif University Medical Faculty, Adnan Menderes Bulvari, Vatan Caddesi, 34093 Fatih, Istanbul, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Ozkaya
authors.affiliation: Department of Pediatric Allergy and Immunology, Bezmialem Vakif University Medical Faculty, Adnan Menderes Bulvari, Vatan Caddesi, 34093 Fatih, Istanbul, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Yazici
authors.affiliation: Department of Pediatric Pulmonology, Bezmialem Vakif University Medical Faculty, Adnan Menderes Bulvari, Vatan Caddesi, 34093 Fatih, Istanbul, Turkey.
authors.forename: A H
authors.initials: AH
authors.lastname: Gedik
authors.affiliation: Department of Pediatric Pulmonology, Bezmialem Vakif University Medical Faculty, Adnan Menderes Bulvari, Vatan Caddesi, 34093 Fatih, Istanbul, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Cakir
mesh_terms: D000293:Adolescent; D023181:Antimicrobial Cationic Peptides / Q000032:analysis / Q000276:immunology*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D017817:Nasal Lavage Fluid / Q000276:immunology*; D009297:Nasal Mucosa / Q000276:immunology; D065631:Rhinitis, Allergic / Q000276:immunology*; D012882:Skin Tests; D054804:Cathelicidins
chemical_list: D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins
keywords: Allergic rhinitis; Cathelicidin; Disease severity; LL-37; Nasal fluid