Molecular diagnosis in house dust mite allergic patients suggests clinical relevance of Der p 23 in asthmatic children.

BACKGROUND: Sensitization patterns to dust mites depend on the geographic area and are important in clinical practice. However, the role of molecular diagnosis is not currently defined. We sought to characterize a pediatric population focusing on sensitization to different mite species and major mite components, to assess the clinical relevance of sensitization to allergenic components in our practice.

METHODS: Consecutive children with respiratory allergy sensitized to house dust mites by skin prick test were recruited. Specific IgE to nDer p 1, rDer p 2, rDer p 23 by ImmunoCAP, and sIgE by ImmunoCAP-ISAC microarray was determined. Subjects were followed-up for three years.

RESULTS: A total of 276 children were recruited. Sensitization was 86.6% to nDer p 1, 79.3% to rDer p 2 and 75.8% to rDer p 23. Lepidoglyphus was the most common storage mite detected by SPT. Twenty-six patients (9.4%) were not sensitized to Der p 1 and Der p 2; noteworthy, 14 of them (53.8%) had positive IgE binding to Der p 23. Asthmatic patients, and especially those with a persistent moderate and severe phenotype, recognized more often the three major allergens.

CONCLUSIONS: Most of our population with mite allergy is sensitized to Der p 1, Der p 2 and Der p 23 major allergens; however, 5% were sensitized only to Der p 23 of the allergens evaluated. Sensitization to Der p 23 should be considered in the diagnosis and treatment of mite allergy, especially in patients with moderate and severe asthma because it may worsen the clinical phenotype.