Assessing Sensitization to Der p 23 and Inhibition of Specific IgE Using Commercial Extracts in House Dust...

House dust mite (HDM) allergy is a leading cause of allergic rhinoconjunctivitis and asthma. Among the major HDM allergens, Der p 23 has been recognized as clinically relevant. However, allergen immunotherapy (AIT) extracts often lack defined amounts of Der p 23, which may compromise treatment in patients sensitized exclusively to this component. Objective: To determine the prevalence of monosensitization to Der p 23 among HDM-allergic patients and to assess the capacity of commercial HDM skin prick test (SPT) extracts to inhibit IgE binding.

A retrospective analysis on 1700 HDM-allergic patients was carried out between 2019 and 2023. Specific IgE to Der p 1, 2, and 23 was measured using ImmunoCAP. Monosensitization to Der p 23 was defined as sIgE >0.35 kUA/L to Der p 23 and <0.10 kUA/L to Der p 1 and 2. Additional molecular profiling (ALEX microarray) was performed to confirm exclusive sensitization. sIgE inhibition assays were used to evaluate 5 commercial HDM extracts.

Almost two-thirds of patients (62.3%) were sensitized to Der p 23, and 3.47% (n=59) were monosensitized. Of these, 72.7% (16/22) were confirmed by ALEX. SPT extracts inhibited IgE binding in between 42% and 77% of cases depending on the manufacturer.

The findings indicate that monosensitization to Der p 23, though relatively infrequent, affects a clinically relevant subset of patients. Commercial extracts vary in their ability to inhibit sIgE to Der p 23, underscoring the need for improved extract formulations and further research into the efficacy of AIT in this subgroup.