Serum-specific IgE and allergen immunotherapy in allergic children.

Aim: Allergen immunotherapy (AIT) is indicated in IgE-mediated respiratory allergy. Recently, it has been reported that serum-specific IgE (sIgE) levels >10 kU/l may predict AIT efficacy in adults with allergic rhinitis. The aim of the present preliminary study was to investigate whether this cut-off could also be associated with perception of effective AIT in children with allergic asthma and/or rhinitis due to house dust mites (HDM).

Methods: A total of 31 allergic children (17 males; mean age of 12.5 years) with levels of serum sIgE to HDM >10 kU/l were evaluated. Eight allergic children (five males; mean age of 13.4 years) with levels of serum sIgE to HDM <10 kU/l were considered as control. All patients were treated with sublingual immunotherapy for 3 years with HDM allergen extract. Children's perception of AIT efficacy was assessed by visual analog scale (VAS), considering both symptom severity and drug use. Responder patients were defined with >6 VAS. Severity of nasal symptoms was assessed by nasal VAS, and asthma control was evaluated by asthma control test; both were considered before and after AIT.

Results: All children (but one) with sIgE >10 kU/l perceived AIT efficacy, whereas only one child with sIgE <10 kU/l perceived AIT benefit (p < 0.001). There was a strong relationship between perception of AIT efficacy by VAS and serum sIgE levels (r = 0.615; p < 0.001). Also, nasal VAS and asthma control tests significantly improved only in children with sIgE >10 kU/l (p < 0.001 for both).

Conclusion: Allergen-sIgE assessment before AIT prescription might represent a useful tool to individuate potential responders.