Development of nasal allergen challenge with cockroach in children with asthma

Abstract

Background: Nasal allergen challenge (NAC) could be a means to assess indication and/or an outcome of allergen-specific therapies, particularly for perennial allergens. NACs are not commonly conducted in children with asthma, and cockroach NACs are not well established. This study's objective was to identify a range of German cockroach extract doses that induce nasal symptoms and to assess the safety of cockroach NAC in children with asthma.

Methods: Ten adults (18-37 years) followed by 25 children (8-14 years) with well-controlled, persistent asthma and cockroach sensitization underwent NAC with diluent followed by up to 8 escalating doses of cockroach extract (0.00381-11.9 µg/mL Bla g 1). NAC outcome was determined by Total Nasal Symptom Score (TNSS) and/or sneeze score. Cockroach allergen-induced T-cell activation and IL-5 production were measured in peripheral blood mononuclear cells.

Results: 67% (6/9) of adults and 68% (17/25) of children had a positive NAC at a median response dose of 0.120 µg/mL [IQR 0.0380-0.379 µg/mL] of Bla g 1. Additionally, three children responded to diluent alone and did not receive any cockroach extract. Overall, 32% (11/34) were positive with sneezes alone, 15% (5/34) with TNSS alone, and 21% (7/34) with both criteria. At baseline, NAC responders had higher cockroach-specific IgE (P = .03), lower cockroach-specific IgG/IgE ratios (children, P = .002), and increased cockroach-specific IL-5-producing T lymphocytes (P = .045). The NAC was well tolerated.

Conclusion: We report the methodology of NAC development for children with persistent asthma and cockroach sensitization. This NAC could be considered a tool to confirm clinically relevant sensitization and to assess responses in therapeutic studies.

Trial registration: ClinicalTrials.gov NCT02710136.

Keywords: allergic rhinitis; asthma; children; cockroach allergy; inner city; nasal allergen challenge.

© 2021 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Figures

Figure 1 –. Pediatric Response to Nasal Allergen Challenge with German Cockroach Extract.

Error bars represent 95% confidence limits.

Figure 2 –. German CR Skin Prick Test Wheal, CR-specific IgE, and Pediatric CR-specific IgG and IgG/IgE in NAC-positive versus NAC-negative Participants.

Bars show the geometric mean with 95% CI.

Figure 3 –. German Cockroach-Specific IL-5 (A) and T Cell (B) Activation for Combined Adult and Pediatric Populations.

Bars shown the geometric mean ± 95% confidence intervals.