Sublingual-swallow immunotherapy (SLIT) in patients with asthma due to house-dust mites: a double-blind, placebo-controlled study (original) (raw)

Sublingual-swallow immunotherapy (SLIT) in patients with asthma due to house-dust mites: a doubleblind, placebo-controlled study Key words: asthma; house-dust mite; respiratory function; sublingual immunotherapy. A double-blind, placebo-controlled study was carried out in 85 patients with a well-documented history of perennial asthma caused by house-dust mites. Patients received either placebo or sublingual immunotherapy (SLIT) with a standardized Dermatophagoides pteronyssinus (DP)±D. farinae (DF) 50/50 extract. After a run-in period, patients received increasing doses up to 300 IR every day for 4 weeks and then three times a week for the following 24 months. The cumulative dose was about 104 000 IR, equivalent to 4.2 mg Der p 1 and 7.3 mg Der f 1. Symptom and medication scores and respiratory function were assessed throughout the trial. Serum speci®c IgE and IgG4 were determined before SLIT (t 0 ) and after 6 (t 1 ), 11 (t 2 ), 17 (t 3 ), and 25 months (t 4 ) of SLIT. Mite exposure was evaluated at t 0 , t 2 , and t 4 by semiquantitative guanine determinations. Patients aged 15 years and older were asked to assess their quality of life (QoL) by completing the SF20 (Short Form Health Status Survey) plus two items at t 0 , t 2 , and t 4 . Use of inhaled corticosteroids and b 2 -agonists was signi®cantly decreased after 25 months of treatment in both groups (P,0.03). SLIT patients showed signi®cant improvements in respiratory function at t 4 (% predicted FEV 1 (P=0.01), VC (P=0.002), morning (P=0.01) and evening (P=0.03) PEFR), and reduction in daytime asthma score (P=0.02). In the SLIT group, the post-treatment PD 20 was 1.75 times higher than the baseline value. There was no change in PD 20 in the placebo group. Compared to the placebo group, the SLIT group showed a signi®cant increase in speci®c IgE DP(P=0.05), IgE DF(P=0.02), IgG4 DP(P=0.001), and IgG4 DF