A PREVENTIVE approach to allergen immunotherapy may help alter the course of allergy development in young children. Researchers reported that house dust mite sublingual immunotherapy (HDM-SLIT) induced protective immune responses in sensitised preschool children before the onset of allergy symptoms.
The randomised trial enrolled children aged 3–5 years who were sensitised to house dust mite allergens but had not yet developed clinical allergic disease. Conducted between 2017 and 2022, the study compared daily HDM-SLIT treatment with placebo over a two-year period. Children who received more than four months of therapy were included in the final analysis.
Dust Mite SLIT Boosts Blocking Antibodies
Investigators primarily assessed changes in allergen-specific IgG antibodies against Der p 1, a major house dust mite allergen. Eighteen children received HDM-SLIT and 15 received placebo. By the end of treatment, children treated with HDM-SLIT showed significantly increased Der p 1-specific IgG levels compared with placebo, suggesting a strong immunomodulatory effect.
The treatment also increased levels of HDM-specific IgG1 and IgG4 antibodies, which are thought to play a role in blocking allergic reactions. Importantly, researchers found no sustained increase in allergen-specific IgE levels, indicating that treatment did not worsen allergic sensitisation over time.
Additional analyses demonstrated reduced skin and basophil reactivity to house dust mite allergens among children receiving SLIT. The therapy also appeared to limit the development of new sensitisations during the study period. Functional testing further showed that serum from treated participants could inhibit basophil activation, providing evidence that the induced antibodies had biologically relevant blocking activity.
Dust Mite Immunotherapy May Delay Allergy
The authors concluded that preventive HDM-SLIT can induce early immune changes associated with allergy protection, even before symptoms arise. They suggest that early intervention in sensitised, high-risk children could potentially interrupt progression to allergic disease, although larger studies will be needed to determine whether these immunological effects translate into long-term clinical prevention.
Reference
Dwivendi V et al. Preventive application of house dust mite-sublingual immunotherapy induces blocking antibodies in sensitized preschool children. Allergy. 2026; DOI: 10.1111/all.70387.
Featured image: penyushkin on Adobe Stock
