Efficacy and Safety of Sublingual Immunotherapy in Elderly Rhinitis Patients Sensitized to House Dust Mites

Abstract

Purpose: This study aims to determine the efficacy and safety of house dust mite (HDM)-sublingual immunotherapy (SLIT) in elderly patients with AR.

Methods: A total of 45 patients aged ≥ 60 years with HDM-induced AR who had ≥ 3 A/H ratio on skin prick test and/or ≥ 0.35 IU/L to both Dermatophagoides farinae and Dermatophagoides pteronyssinus by ImmunoCAP were enrolled in 4 university hospitals. To evaluate additional effects of HDM-SLIT, they were randomized to the SLIT-treated group (n = 30) or control group (n = 15). Rhinoconjunctivitis total symptom score (RTSS), rhinoscopy score, Korean rhinoconjunctivitis quality of life questionnaire, rhinitis control assessment test, asthma control test scores, and adverse reactions, were assessed at the first visit (V1) and after 1 year of treatment (V5); for immunological evaluation, serum levels of HDM-specific immunoglobulin A/IgE/IgG1/IgG4 antibodies and basophil response to HDMs were compared between V1 and V5 in both groups.

Results: There were no significant differences in demographics, RTSS, skin reactivity to HDMs, or serum total/specific IgE levels to HDMs (P < 0.05, respectively) between the 2 groups. Nasal symptom score and RTSS decreased significantly at year 1 in the 2 groups (P < 0.05). There were no significant differences in percent decrease in nasal symptom score and RTSS at year 1 between the 2 groups (P < 0.05); however, rhinoscopic nasal symptom score decreased significantly in the SLIT-treated group (P < 0.05). Immunological studies showed that serum specific IgA levels (not specific IgE/IgG) and CD203c expression on basophils decreased significantly at V5 in the SLIT-treated group (P = 0.011 and P = 0.001, respectively), not in the control group. The control group required more medications compared to the treatment group, but there were no differences in adverse reactions.

Conclusions: It is suggested that HDM-SLIT for 1 year could induce symptom improvement and may induce immunomodulation in elderly rhinitis patients.

Keywords: Allergic rhinitis; elderly; house dust mite; sublingual immunotherapy.

Fig. 1. Number of participating patients assessed for eligibility that completed the study.

ITT, intention to treat; PP, per protocol.

Fig. 2. Changes in nasal symptoms, nasal congestion, nasal secretions and redness before (visit 1, V1) and after treatment (visit 5, V5) in the treatment and control groups. All scores were analyzed by Wilcoxon's signed rank test.

NS, not significant.

Fig. 3. Changes in serum specific antibodies to Dermatophagoides farinae by ELISA before (visit 1, V1) and after the treatment (visit 5, V5) in the treatment and control groups. All values are presented as absorbance value x 1,000 and compared by using Wilcoxon's signed rank test.

ELISA, enzyme-linked immunosorbent assay; Ig, immunoglobulin; NS, not significant.

Fig. 4. Changes in basophil CD203c expression with additions of Dermatophagoides farinae before (visit 1, V1) and after the treatment (visit 5, V5) in the treatment (A) and control groups (B). Wilcoxon's signed rank test was applied to compare the results between the 2 groups.

NS, not significant.