Aim of this study was to verify, in subjects with mild/moderate allergic bronchial asthma due to house dust mite (HDM), the efficacy of the sublingual immunotherapy (SLIT) performed with a monomeric allergoid (Lais, Lofarma, Italy).

Forty seven patients were enrolled. Twenty four were randomized to the standard therapy according to the international guidelines (group 1) while 23 received, in addition to this therapy, the allergoid SLIT (group 2). At baseline and every six months, for 3 years, all the patients carried out a bronchial provocation test (BPT) specific for HDM and an aspecific BPT with methacholine, to investigate bronchial hyperreactivity (BHR). Before every visit, the patients filled in, for 2 weeks, a diary card to register the symptom score and the morning and evening peak expiratory flow (PEF). The patients with a symptom score less than 12 and/or needing a dose of budesonide greater than 400 μg/day for more than 2 weeks were excluded.

Nineteen patients out of 24 in group 1 (79%) and 21 out of 23 in group 2 (91%) completed the study (p<0.05). The symptom score, the on demand use of bronchodilator drugs and PEF measurements were statistically better in group 2, already after the first year of therapy. Specific and aspecific BPT improved to a greater extent in the patients treated with the allergoid SLIT too (p<0.05).

These results show that, in patients with allergic bronchial asthma to HDM, allergoid SLIT, in addition to the standard therapy, significantly improves symptoms control, specific and aspecific BHR.