Efficacy of specific sublingual immunotherapy on quality of life in asthmatic children with house dust mite respiratory allergy: prospective, multicenter case-controls 36-month study

Rationale: Specific immunotherapy (SIT) is considered as the only causal treatment of respiratory allergies. It is also known that SIT could have a positive impact on Quality of Life (QOL) of the allergic patients. However the are few data evaluating the impact of SIT or symptomatic drug treatment only in children with allergic rhinitis and asthma induced by perennial allergens. Study aim: To investigate the impact of sublingual SIT on Quality of Life and the clinical efficacy in paediatric patients with house dust mite (HDM) respiratory allergy (rhinitis and mild to moderate asthma) in comparison with pharmacological treatment only. Patients and Methods: In a multicentre, prospective 36-month case-control study 76 consecutive paediatric patients with rhinoconjunctivitis and asthma due to HDM (mean [SD] age 11(3); 50 male) were enrolled. A total of 41 patients (cases) started a SIT (SLITone, ALK-Abello’) one vial daily for 12 months as an add-one therapy and 35 matched subjects treated with symptomatic drugs only the controlsgroup. All patients had a confirmed diagnosis of HDM induced respiratory allergy. QOL was evaluated at baseline, after 12, 24 and 36 months by the means of two validated specific questionnaires (EQ-5D, italian version) (PAQLQ(S), italian version) Clinical efficacy was evaluated with symptom and medication score at baseline and after 12 month (intention-to-treat analysis). A Visual Analogic Scale (VAS) was also used to evaluate the subjective health status at the same times. Results: PAQLQ score improved significantly (P = 0.02) after 12 (+14%), 24 (+21%) and 36 (+36%) months of the observation period in case group in comparison with control group. Significant improvement was observed in the symptom and activity domains (10%). PAQLQ score in controls was slight reduced at the end of the observation period in comparison with baseline (P = 0.6). VAS score improves significantly (P = 0.001) in cases but not in the control subjects. Conclusion: Our study confirms that in comparison with symptomatic drug treatment only, SIT improves significantlyQuality of Life and the clinical course of the disease in children with HDM allergic asthma.