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

Abstract

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 104000 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 specific IgE and IgG4 were determined before SLIT (t0) and after 6 (t1), 11 (t2), 17 (t3), and 25 months (t4) of SLIT. Mite exposure was evaluated at t0, t2, and t4 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 t0, t2, and t4. Use of inhaled corticosteroids and beta2-agonists was significantly decreased after 25 months of treatment in both groups (P<0.03). SLIT patients showed significant improvements in respiratory function at t4 (% predicted FEV1 (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 PD20 was 1.75 times higher than the baseline value. There was no change in PD20 in the placebo group. Compared to the placebo group, the SLIT group showed a significant increase in specific IgE DP(P = 0.05), IgE DF(P = 0.02), IgG4 DP(P = 0.001), and IgG4 DF (P = 0.001) levels after SLIT. QoL scores were similar in both groups at t0 and t2. At t4, all scores were better in the SLIT group than in the placebo group, with the differences being most marked for the general perception of health (P = 0.01) and physical pain (P = 0.02). Adverse events were similar in the two groups. This study shows that SLIT in house-dust-mite-related asthma has a good safety profile and improves respiratory function, bronchial hyperreactivity, and QoL.

Lack of Detectable Alterations in Immune Responses during Sublingual Immunotherapy in Children with Seasonal Allergic Rhinoconjunctivitis to Grass Pollen

“…Studies on SLIT treatment are contradictory. In adults with house dust mite allergy [35, 36] or pollen allergy [26, 30, 37, 38,] significant increases in IgG4 concomitant with significant symptom relief have been reported. However, other studies in adults have seen neither changes in specific IgE nor in IgG4 levels despite symptom relief [32].…”

Current Issues on Immunotherapy in Children

“…One of them is Ciprandi et al study [102] that has showed the improvement of QOL in polysensitized patients with AR and/or asthma treated with SLIT. Bousquet et al study of DB-PC-RCT proved that patients on SLIT had a better QOL compared with the group of patients on placebo [103]. However, the results from the studies are controversial.…”

Monitoring of occupational and environmental aeroallergens – EAACI Position Paper

“…New methods accounting for the allergen content of pollen (27) may provide even better exposure estimates, but studies are still lacking in this regard. Regarding drug and immunotherapy trials in house dust mite allergy, EMEA has underlined the importance of validated methods to measure the exposure to these allergens serially (EMEA, 2005), even while levels of mite allergens often decrease during the trial (78).…”