Long-term efficacy of house dust mite sublingual immunotherapy on clinical and pulmonary function in patients with asthma and allergic rhinitis

Abstract

Background: A previous study reported that house dust mite (HDM) sublingual immunotherapy (SLIT) for 48 weeks was effective as add-on treatment for allergic asthma; however, data regarding its long-term efficacy are scarce.

Objective: We sought to evaluate the effect of HDM SLIT on asthma control, pulmonary function, and airway inflammation and remodeling throughout the 5-year treatment period.

Methods: A total of 140 patients with asthma and allergic rhinitis sensitized to HDM were randomized to receive either drugs alone or drugs plus SLIT for 5 years. The 5-item Asthma Control Questionnaire (ACQ-5), Asthma Quality of Life Questionnaire (AQLQ), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), spirometry, quantitative computed tomography, and type 2 biomarkers were assessed.

Results: An improvement in the ACQ-5, AQLQ, and RQLQ scores was observed in the SLIT group compared with the control group. HDM SLIT increased lung function and reduced the percentage of airway wall area. The levels of fractional exhaled nitric oxide (Feno), blood eosinophil, serum specific IgE for HDM, and total IgE decreased and were sustained during the 5 years. The change in type 2 biomarkers correlated with change in the AQLQ score. On the basis of receiver-operating characteristic analysis for predicting responders, the area under the receiver-operating characteristic curve in FEV₁% predicted, airway wall area, Feno, and specific IgE was high. Multivariate regression analysis showed that the strongest predictor of responders was Feno.

Conclusions: HDM SLIT continued to provide sustained efficacy, improve lung function, and prevent progression of airway inflammation and remodeling in asthma throughout the 5-year treatment period.

Keywords: Airway inflammation; allergic rhinitis; asthma; house dust mite sublingual immunotherapy; long-term efficacy; pulmonary function; quality of life; remodeling; symptom; type 2 biomarker.

Fig 1

Effect of HDM SLIT on asthma control (A) and QoL (B and C) during the 5-year treatment in patient with asthma and allergic rhinitis. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001 vs matched control.

Fig 2

Effect of HDM SLIT on pulmonary function during the 5-year treatment in patient with asthma and allergic rhinitis. ∗∗P < .01; ∗∗∗P < .001 vs matched control.

Fig 3

Effect of HDM SLIT on airway dimension during the 5-year treatment in patient with asthma and allergic rhinitis. ∗∗P < .01; ∗∗∗P < .001 vs matched control.

Fig 4

Effect of HDM SLIT on Feno (A), blood eosinophils (B), s-IgE for HDM (C), and t-IgE (D) during the 5-year treatment in patient with asthma and allergic rhinitis. ∗P < .05; ∗∗P < .01 vs matched control.

Fig 5

ROC curves for prebronchodilator FEV₁% predicted (A), WA/Ao (B), Feno (C), and s-IgE for HDM (D) distinguishing responder from nonresponder in asthmatic patients with SLIT. The optimal cutoff values (sensitivity, specificity): prebronchodilator FEV₁% predicted of 88.3%, WA/Ao of 71.7%, Feno of 19.0 ppb, and s-IgE for HDM of 7.47 kU/L.