In vitro assessment of house dust mite sensitization: No need for multiple Dermatophagoides tests

Background. - House dust mites (HDM) are one of the major causes of allergic asthma and rhinitis in France. Under temperate climate, the two main species involved are Dermatophagoides pteronyssinus (Dp) and D. farinae (Df). Determination of immunoglobulin (Ig) E to whole Df and Dp extracts is widely used for perennial respiratory allergy diagnosis Few studies have addressed the compared analytical and clinical performance of the two extracts, and the advantage of testing both extracts rather than a single one. Our purpose is to identify whether only one IgE sensitization is enough.Methods. - We collected and analysed 3809 results of specific IgE to Dp and Df, from 4 distinct laboratories. Results were obtained from 2011 to 2021 using ImmunoCAP platform (Thermo Fisher Scientific, Uppsala, Sweden).Results. - The overall sex-ratio M/F was 0.85. IgE to Dp and Df were concordant in 95.7% of cases, with 39.4% and 56.3% with negative and positive agreement, respectively. Sensitization to Dp (but not Df) were observed in 108 cases (2.8%) whereas sensitization to Df (but not Dp) were in 56 cases (1.5%). IgE to Dp and Df were positivity class agreement in 67.2%, and there was one IgE class-level difference in 30.2% (in those, IgE to Dp were higher than Df in 70.8%). Specific IgE to Df and Dp were highly correlated (r = 0.98; p = < 10-4).Conclusion. - Assessing specific IgE to both Dp and Df in routine in vitro diagnosis procedures does not bring advantage over assessing a single extract. Data presented here suggest that measuring IgE to Dp alone is sufficient as a first step for in vitro investigation of HDM sensitization.(c) 2022 Elsevier Masson SAS. All rights reserved.