title: Nasal Levels of Antimicrobial Peptides in Allergic Asthma Patients and Healthy Controls: Differences and Effect of a Short 1,25(OH)2 Vitamin D3 Treatment.
abstract: BACKGROUND
  Allergy is often accompanied by infections and lower levels of antimicrobial peptides (AMPs). Vitamin D has been shown to increase expression of selected AMPs. In this study we investigated whether antimicrobial peptide levels in nasal secretions of allergic asthma patients are lower than in healthy controls, and whether administration of the active form of vitamin D (1,25(OH)2D3) affects these antimicrobial peptide levels.
  
  
  METHODS
  The levels of antimicrobial peptides in nasal secretions were compared between 19 allergic asthma patients and 23 healthy controls. The effect of seven days daily oral treatment with 2 μg 1,25(OH)2D3 on antimicrobial peptides in nasal secretions was assessed in a placebo-controlled cross-over clinical study.
  
  
  RESULTS
  Levels of neutrophil α-defensins (human neutrophil peptides 1-3; HNP1-3) and lipocalin 2 (LCN2; also known as NGAL) were significantly lower in asthmatics, but no differences in LL-37 and SLPI were detected. Treatment with a short-term 1,25(OH)2D3 caused a small increase in HNP1-3, but not when the asthma and control groups were analyzed separately. LL-37, LCN2 and SLPI did not change after treatment with 1,25(OH)2D3.
  
  
  CONCLUSIONS
  Levels of the antimicrobial peptides HNP1-3 and LCN2 are lower in nasal secretions in asthmatics and are not substantially affected by a short-term treatment with active vitamin D.
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.|Department of Pulmonology, Spaarne Hospital, Hoofddorp, The Netherlands.
authors.forename: Willemien
authors.initials: W
authors.lastname: Thijs
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Janssen
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Annemarie M
authors.initials: AM
authors.lastname: van Schadewijk
authors.affiliation: Department of Endocrinology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Socrates E
authors.initials: SE
authors.lastname: Papapoulos
authors.affiliation: Department of Clinical Epidemiology and Department of Medical Statistics, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Saskia
authors.initials: S
authors.lastname: le Cessie
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Saskia
authors.initials: S
authors.lastname: Middeldorp
authors.affiliation: Department of Pulmonology, Spaarne Hospital, Hoofddorp, The Netherlands.
authors.forename: Christian F
authors.initials: CF
authors.lastname: Melissant
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.|Department of Pulmonology and Thoracic Surgery, Lungen Clinic Grosshansdorf, Grosshansdorf, Germany.
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Rabe
authors.affiliation: Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Pieter S
authors.initials: PS
authors.lastname: Hiemstra
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000890:Anti-Infective Agents / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism*; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D002762:Cholecalciferol / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D018479:Early Intervention, Educational; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D050071:Bone Density Conservation Agents; D002762:Cholecalciferol; D009569:Nitric Oxide; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase