D3.466 - Quantitative assessment of environmental exposure to Der p1, Der p 2 and Der p 23 in European and South African house dust samples

Der p 23 is a major dust mite allergen and sensitization to Der p 23 is positively associated with asthma (Platts-Mills, eBioMed 2025). There is little data on environmental exposure to Der p 23. Our aim was to compare environmental exposure to Der p 1, Der p 2 and Der p 23 across multiple locations in Europe and South Africa. 

Household dust samples were collected from Germany, The Netherlands, Italy, Spain, Lithuania, Latvia and South Africa between 2015 and 2017. Dust samples were initially analysed for mite allergens by quantitative multiplex array and kept at-80°C for long-term storge (8+ years). Extracts (n=146) with an initial result of >2µg/g Der p 1 were thawed and Der p 1, Der p 2 and Der p 23 were quantified simultaneously by multiplex array. Results were compared between countries and correlation analysis between the dust mite allergens was performed.

Der p 1 results exhibited high correlation with the original Der p 1 values (R²=0.9090, p<0.0001). Der p 1, Der p 2 and Der p 23 were found in every sample analysed, with means of 5.2µg/g, 3.6µg/g and 0.4µg/g, respectively. Highest correlation between the dust mite allergens was observed between Der p 1 and Der p 23 (R²=0.7806, p<0.0001). Der p 23 levels from each country were analysed. No significant differences were observed between countries, with mean Der p 23 levels measuring 0.5µg/g for Germany (n=23), 0.3µg/g for The Netherlands (n=5), 0.9µg/g for Italy (n=2), and 0.4µg/g for the other countries; Spain (n=53), Lithuania (n=9), Latvia (n=11) and South Africa (n=43). 

The results demonstrate a high prevalence of Der p 23 in dust samples from Europe and South Africa. Notably, levels of Der p 23 were 8-12-fold lower than Der p 1 or Der p 2, which may explain why Der p 23 does not induce high levels of IgG4 antibodies. These data will enable the correlation between Der p 23 exposure and IgE/IgG antibody responses to be further investigated, together with the clinical relevance of these exposures in the development of asthma.