Modulation of mucosal/systemic antibody response after sublingual immunotherapy in mite‐allergic children

Abstract

There have been no data on sublingual immunotherapy (SLIT) in Brazilian patients sensitized to house dust mites. This study aimed to evaluate the mucosal/systemic antibody response changes and clinical efficacy after SLIT using Dermatophagoides pteronyssinus (Dpt) allergens with or without bacterial extracts in mite-allergic Brazilian children. Patients with allergic rhinitis and asthma were selected for a double-blind, placebo-controlled trial randomized to three groups: DPT (Dpt extract, n = 34), DPT+MRB (Dpt plus mixed respiratory bacterial extracts, n = 36), and Placebo (n = 32). Total symptom and medication scores for rhinitis/asthma, skin prick test (SPT) to Dpt, and measurements of Dpt-, Der p 1-, Der p 2-specific serum IgE, IgG4, IgG1, and specific salivary IgA were evaluated at baseline and after 12 and 18 months of treatment. A significant long-term decline in total symptom/medication scores was observed only in active groups (DTP and DPT+MRB). There was no significant change in SPT results in all groups. SLIT using Dpt allergen alone induced increased levels of serum IgG4 to Dpt, Der p 1, and Der p 2, serum IgG1 and salivary IgA to Dpt and Der p 1. SLIT with Dpt plus bacterial extracts was able to decrease IgE levels, particularly to Der p 2, to increase salivary IgA levels to Der p 1, but had no changes on specific IgG4 and IgG1 levels. All children undergoing SLIT showed clinical improvement, but a long-term reduction in symptom/medication scores with modulation of mucosal/systemic antibody responses were seen only in active groups (DPT and DPT+MRB).