Can the Dermatophagoides Pteronyssinus Molecular Allergen Sensitization Profile, assessed with a Skin Prick Test, Be Useful in Evaluating Clinically Relevant House Dust Mite Allergy?
Ana Vitória Soares (Porto, Portugal), José Luís Plácido (Porto, Portugal), Diana Silva (Porto, Portugal)
Background

Molecular allergen diagnosis is crucial for identifying major allergens and relevant sensitizations. However, its clinical relevance compared to allergen challenges remains unclear. This study assessed the diagnostic value of skin prick tests (SPT) with molecular allergens for D. pteronyssinus (Der p 1, Der p 2, and Der p 23) using conjunctival allergen provocation tests (CPT) as the gold standard in patients with suspected D. pteronyssinus allergy.

Method

This cross-sectional study included immunotherapy-naive patients with rhinitis, conjunctivitis, and/or asthma referred for CPT in 2024. All patients were sensitized to D. pteronyssinus, based on SPT, specific IgE, and/or component-resolved diagnosis (CRD). CPTs were performed using D. pteronyssinus extract (Leti®), and SPTs with Der p 1, Der p 2,and Der p 23 extracts (Diater®).

Results

Thirty-two individuals (59.3% female, 32% children) were included. Seven had asthma, and 53.1% were polysensitized. CPT was positive in 27 patients (84.4%) and negative in 5. Among positive CPTs, one patient showed no sensitization to tested major allergens, 3 were monosensitized to Der p 23, and 87.5% were polysensitized to Der p 1, 2, and 23. One patient with a negative CPT had mild sensitization to Der p 23. All asthma patients had positive CPT results, with 28.6% monosensitized to Der p 23. Sensitivity and specificity values are in table 1. The AUC was higher for Der p 23 0.896 95% CI [0.756; 1.00] versus Der p 1 and Der p 2 0.852 95% CI [0.719;0.985]. CPT cumulative allergen dose negatively correlated with mean wheal sizes for Der p 1 (r=-0.493; p=0.004), Der p 2 (r=-0.586, p<0.001), and Der p 23 (r=-0.326, p=0.068). 

Conclusion

Sensitization to Der p 1, 2, and 23 was significantly associated with more positive CPT results and lower allergen reactivity. Der p 23 showed a better diagnostic accuracy than Der p 1 and Der p 2. However, molecular SPT cannot replace CPT, as evidenced by one patient sensitized to Der p 23 who had a negative CPT. Further studies with larger samples are needed to assess the clinical relevance of major allergen sensitization.