Quantitation of IgE Binding to the Chitinase and Chitinase-Like House Dust Mite Allergens Der p 15 and Der p 18 Compared to the Major and Mid-Range Allergens

• Published in: International archives of allergy and immunology Vol. 160; no. 3; pp. 233 - 240
• Main Authors: Hales, Belinda J., Elliot, Claire E., Chai, Lee Ying, Pearce, Leigh J., Tipayanon, Thitinun, Hazell, Lee, Stone, Shane, Piboonpocanun, Surapon, Thomas, Wayne R., Smith, Wendy-Anne
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.01.2013
• Subjects: Adult; Allergies; Animals; Antigens, Dermatophagoides - immunology; Arthropod Proteins - immunology; Australia; Chitinase; Chitinases - immunology; Dogs; Female; Humans; Hypersensitivity - immunology; Hypersensitivity - veterinary; Immunoglobulin E - immunology; Immunoglobulins; Insects; Male; Middle Aged; Original Paper; Pichia - genetics; Protein Binding; Protein Conformation; Pyroglyphidae - immunology; Recombinant Proteins - immunology; Chitinase; House dust mite; Recombinant allergens; IgE
• ISSN: 1018-2438; 1423-0097
• DOI: 10.1159/000339760

Background: The prevalence of IgE binding to the group 15 and 18 house dust mite (HDM) allergens of the Dermatophagoides species is reported to be >50% and they are the major allergens of HDM-sensitised dogs. The objective was to quantitate the IgE titres to Der p 15 and Der p 18 and evaluate their importance in human HDM sensitisation compared to the known major and mid-tier allergens. Methods: Der p 15 and Der p 18 were produced in Pichia pastoris, and their structure validated by circular dichroism. IgE binding was measured in 37 Australian HDM-allergic adults using a quantitative DELFIA™ assay. Results: The prevalence of IgE titres to Der p 15 and Der p 18 >0.1 ng/ml was low (38%) and only one subject had a titre >10 ng/ml to either allergen. The mean anti-Der p 15 and Der p 18 titres were 1.2 and 2.6 ng/ml, respectively, i.e. approximately 10- to 20-fold lower than the response to the major Der p 1 and Der p 2 allergens (p < 0.001). The IgE responses to Der p 15 and Der p 18 were lower than the mid-tier allergens Der p 5 and Der p 7 and although they correlated with each other, they did not correlate with titres to either the major or mid-tier allergens. Conclusions: Sensitisation to Der p 15 and Der p 18 makes a minor contribution to anti-HDM IgE titres, and the titres do not correlate with the size of the response to the major allergens.