title: IL-4 alpha chain receptor (IL-4Ralpha) polymorphisms in allergic bronchopulmonary sspergillosis.
abstract: BACKGROUND
  Allergic bronchopulmonary aspergillosis occurs in 7-10% of cystic fibrosis (CF) and 1-2% of asthmatic patients. HLA-DR restriction and increased sensitivity to IL-4 stimulation have been proposed as risk factors in these populations.
  
  
  OBJECTIVE
  We examined for the presence of IL-4 receptor alpha chain (IL-4Ralpha) single nucleotide polymorphisms (SNPs) in ABPA and whether these accounted for increased sensitivity to IL-4 stimulation.
  
  
  METHODS
  One extracellular (ile75val) and four cytoplasmic IL-4Ralpha SNPs were analyzed in 40 CF and 22 asthmatic patients and in 56 non-ABPA CF and asthmatic patients. Sensitivity to IL-4 stimulation was measured by induction of CD23 expression on B cells.
  
  
  RESULTS
  IL-4Ralpha SNPs were observed in 95% of ABPA patients. The predominant IL-4Ralpha SNP was the extracellular IL-4Ralpha SNP, ile75val, observed in 80% of ABPA patients.
  
  
  CONCLUSIONS
  The presence of IL-4Ralpha SNPs, principally ile75val, appears to be a genetic risk for the development of ABPA.
authors.affiliation: Division of Allergy/Immunology, Saint Louis University Health Sciences Center and St, Louis, Missouri, USA. knutsenm@slu.edu
authors.forename: Alan P
authors.initials: AP
authors.lastname: Knutsen
authors.forename: Barbara
authors.initials: B
authors.lastname: Kariuki
authors.forename: Judy D
authors.initials: JD
authors.lastname: Consolino
authors.forename: Manoj R
authors.initials: MR
authors.lastname: Warrier