Dust Mite Allergen Components in Children from Costa Rica, Ghana, and Ecuador: More Evidence that Der p 23 is a Major Allergen

Abstract

Dust mites (DM) are a major source of indoor allergens and IgE to DM are strongly associated with allergic asthma. Der p 23 is a recently described major DM allergen but investigations to date have been limited to small cohorts and/or microchip assays. Using ImmunoCAP, we assessed specific-IgE (sIgE) to DM components (Der p 1, 2, 10 and 23) in sera of asthmatic and non-asthmatic children from Costa Rica (CR), Ghana and Ecuador who previously tested positive for sIgE to Dermatophagoides pteronyssinus. IgE to Der p 1, 2, 10 and 23 were common in asthmatics from CR (73%, 76%, 21% and 70%), Ghana (55%, 53%, 26% and 39%) and Ecuador (43%, 48%, 14%, and 36%). Correlations between sIgE to Der p 23 and Der p 1/2 were moderate-strong and using a cut-off of 0.1 IU/mL poly-sensitization to each of Der p 1, 2 and 23 was common (CR 57%, Ghana 65%, and Ecuador 48%) in all three cohorts. Among children in these countries who lived in rural areas with pre-hygiene conditions, sIgE titers to DM components were lower. Der p 23 represents a peritrophin-like-protein of DM that is present in mites at lower levels than Der p1/2, but is nonetheless a major target of IgE. The high frequency of poly-sensitization to these three proteins provides further evidence that DM are potent agents of IgE sensitization. Differences in IgE titers to DM components between pre-hygiene and post-hygiene environments parallel differences in asthma prevalence and provide additional evidence for the hygiene hypothesis.