D3.228 - One-Year Changes in Molecular sIgE Profiles During House Dust Mite Immunotherapy: A Pilot Study

House dust mite (HDM) is a major perennial aeroallergen and a leading cause of allergic rhinitis. Allergen-specific immunotherapy (ASIT) is the only treatment that can change the natural course of allergic diseases. Data on longitudinal changes in patients’ molecular sensitization profiles during ASIT are still limited. This study aimed to assess changes in patients’ quality of life and molecular allergen-specific IgE (sIgE) levels one year after initiation of HDM ASIT. 

5 patients completed Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). Serum sIgE levels were measured at baseline and after 12 months of ASIT using a multiplex assay (ALEX², Macro Array Diagnostics GmbH, Vienna, Austria).

Although the reduction in sIgE concentration to HDM did not reach statistical significance (Wilcoxon signed-rank test, exact p=0.063), a trend toward a consistent decrease in sIgE median was observed for Der f 2, Der p 2 and Der p 21 (from 5.03 (1.63–8.29) to 2.5 (1.6–6.14) kUA/L, 4.4 (2.28–9.26) to 3.41 (2.18–7.55) kUA/L and 1.8 (1.46-5.09) to 1.2 (1.10–3.05) kUA/L, respectively). In contrast, median Der p 23 sIgE levels increased in four of five patients, from 0.28 (0.15–0.60) to 0.73 (0.39–0.94) kUA/L. Additionally, two patients developed new sensitization to this component. Four out of five patients demonstrated improvement in daily activities, non-nasal/eye symptoms and reduction of practical problems. Although the reduction in overall RQLQ scores were not statistically significance (Wilcoxon signed-rank test, exact p=0.063), a consistent trend toward clinical improvement was observed. 

After one year of HDM ASIT, improvements in selected quality-of-life domains and reductions in sIgE levels to Der f 2 and Der p 2 were observed. However, increased Der p 23 sIgE levels and new sensitization were detected. Larger studies are needed to clarify the clinical relevance of molecular sensitization dynamics during ASIT.