Predominant expression of 950delCAG of IL-18R alpha chain cDNA is associated with reduced IFN-gamma production and high serum IgE levels in atopic Japanese children

J Allergy Clin Immunol. 2002 Apr;109(4):669-75. doi: 10.1067/mai.2002.122158.


Background: We previously reported that serum IgE levels were negatively correlated with the amount of IFN-gamma produced by phytohemagglutinin-stimulated or IL-12-stimulated PBMCs and that one of the mechanisms of the pathogenesis of atopy was the reduced IFN-gamma production, which led to upregulated IgE production.

Objective: IL-18 is also known to be a strong inducer of IFN-gamma production. However, it has not yet been determined whether IL-18 is associated with atopic disease.

Methods: We investigated the response to IL-18 or IL-12 stimulation and the sequence of IL-18 receptor (IL-18R) alpha chain cDNA in 41 nonatopic controls and 39 atopic patients.

Results: Serum IgE level was negatively correlated with IFN-gamma production by PBMCs stimulated with IL-18. The IL-18R alpha chain cDNA of atopic patients was sequenced. We identified a 3-base deletion of the IL-18R alpha chain cDNA (950delCAG ), which was generated by alternative splicing, as determined on the basis of genomic sequence data for the IL-18R alpha chain gene. PBMCs with the predominant expression of 950delCAG significantly showed the reduced IFN-gamma production after IL-18 stimulation. There was a significant difference in the expression pattern of the IL-18R alpha chain transcript between the atopic patients and the nonatopic controls.

Conclusion: According to these results, the dominant expression of the 950delCAG transcript of IL-18R alpha chain cDNA, which was associated with reduced IFN-gamma production by IL-18 stimulation and high serum IgE levels, is predisposition to some atopic diseases.

MeSH terms

  • Adolescent
  • Cells, Cultured
  • Child
  • Child, Preschool
  • DNA, Complementary / analysis*
  • Gene Deletion*
  • Humans
  • Hypersensitivity / genetics
  • Hypersensitivity / immunology*
  • Immunoglobulin E / blood*
  • Infant
  • Interferon-gamma / biosynthesis*
  • Interleukin-18 / pharmacology
  • Interleukin-18 Receptor alpha Subunit
  • Phytohemagglutinins / pharmacology
  • RNA, Messenger / analysis
  • Receptors, Interleukin / genetics*
  • Receptors, Interleukin-18


  • DNA, Complementary
  • IL18R1 protein, human
  • Interleukin-18
  • Interleukin-18 Receptor alpha Subunit
  • Phytohemagglutinins
  • RNA, Messenger
  • Receptors, Interleukin
  • Receptors, Interleukin-18
  • Immunoglobulin E
  • Interferon-gamma