House Dust Mite Sublingual Immunotherapy Shows Promise in Atopic Dermatitis

Patients with atopic dermatitis (AD) senstitized to the house dust mite (HDM) Dermatophagoides pteronyssinus (Dpt) exhibited significant improvements in disease severity when administrered a Dpt sublingual immunotherapy (SLIT). Results were published in The Journal of Allergy and Clinical Immunology: In Practice.

In recent years, increased knowledge on the pathogenesis of AD has highlighted the central role of type 2 immune response. Along with therapeutic advancements observed with biologics and Janus kinase inhibitors, researchers noted that allergen immunotherapy has been considered as an effective, precision medicine treatment for immunoglobulin E (IgE)-mediated diseases.

“Subcutaneous immunotherapy (SCIT) has shown the potential to provide long-term disease control, even after treatment completion,” said the study authors. “Over the past 30 years, SLIT has been introduced in allergy practice, with an efficacy comparable to that of SCIT, but with a safer profile allowing for unsupervised administration by the patient.”

They sought to investigate the role of SLIT as an add-on treatment for patients with AD sensitized to HDM.

In the randomized, double-blind, placebo-controlled, 18-month clinical trial, 91 patients aged 3 years or older, with a SCORing Atopic Dermatitis (SCORAD) score greater than or equal to 15 and positive skin prick test result and/or IgE to Dpt were enrolled from the Clinical Research Unit of Ribeirão Preto Medical School Hospital, University of São Paulo, Brazil. Patients were recruited between May 2018 and June 2020. Participants were stratified according to age (< 12 and ≥ 12 years) to receive HDM SLIT or placebo 3 days a week for 18 months.

“Background therapy for AD was maintained according to the current guidelines and experts’ recommendations; however, the treatment was individualized for each patient,” explained researchers.

“During the trial, topical corticosteroids, topical immunosuppressors, and systemic immunosuppressants were administered. Oral corticosteroids were used only in short courses as rescue therapy for severe exacerbations. Treatment with omalizumab was allowed in patients who had received omalizumab previously.”

The primary outcome assessed was a greater than or equal to 15-point decrease in SCORAD score, with secondary outcomes including decreases in SCORAD and objective SCORAD, Eczema Area and Severity Index, visual analog scale for symptoms, and pruritus scale scores; Investigator’s Global Assessment (IGA) 0/1; and decrease greater than or equal to 4 points in Dermatology Life Quality Index.

Of the study cohort, 66 patients completed the 18-month treatment, of whom 35 received HDM SLIT and 31 received placebo. Most patients presented with moderate and severe disease, as assessed by SCORAD and objective SCORAD.

After 18 months, a greater proportion of patients in the HDM SLIT group showed greater than or equal to a 15-point decrease in SCORAD score vs the placebo group (74.2% vs 58%; relative risk [RR], 1.28; 95% CI, 0.89-1.83).

Moreover, a greater proportion of patients in the HDM SLIT group vs placebo reported significant SCORAD score decreases from baseline (55.6% vs 34.5%; mean difference, 20.4; 95% CI, 3.89-37.3), significant objective SCORAD score decreases (56.8% vs 34.9%; mean difference, 21.3; 95% CI, 0.66-41.81), and IGA 0/1 (14 of 35 vs 5 of 31; RR, 2.63; 95% CI, 1.09-6.39) at 18 months.

“Our results warrant further studies to investigate the optimal duration and dose as well as the long-term efficacy and possibility of sustained effects of HDM SLIT in patients with AD,” concluded researchers.

Reference

Langer SS, Cardili RN, Melo JML, Efficacy of house dust mite sublingual immunotherapy in patients with atopic dermatitis: A randomized, double-blind, placebo-controlled trial. J Allergy Clin Immunol Pract. 2022 Feb;10(2):539-549.e7. doi:10.1016/j.jaip.2021.10.060