TOPLINE:

Among urban children with asthma who were sensitized to cockroaches, larger wheal sizes on a skin prick test, lower interleukin-10 (IL‑10) T‑cell responses and specific patterns of nasal gene expression were associated with nasal reactivity to cockroach allergen; certain dominance patterns of Blattella germanica (Bla g) allergens and immunoglobulin E (IgE) levels were associated with symptom severity.

METHODOLOGY:

• Researchers performed a nasal allergen challenge (NAC) with cockroach extract in 103 children with asthma (median age, 12 years; 56% boys) to identify allergic mechanisms that determined the severity of nasal responses to the challenge.
• The Total Nasal Symptom Score (TNSS) was used to assess symptom burden, and the Sneeze Score, derived from the TNSS (TSNEEZ) was used to count the number of sneezes.
• A positive NAC was defined as reaching a TNSS of 6 or more or a TSNEEZ of 3, with the reactive dose defined as the dose that resulted in a positive NAC.

TAKEAWAY:

• Larger wheal sizes on skin tests were associated with positive NAC outcomes and lower reactive doses (hazard ratio, 1.10; P < .001 for both), indicating that larger wheal sizes were related to higher reaction rates during the challenge.
• IL‑10 T‑cell responses were higher in children with a negative NAC than in those with a positive NAC (P < .001).
• German cockroach-specific IgE levels showed a negative association with symptom burden, whereas dominance of the Bla g 5 allergen correlated negatively with the mean TNSS and dominance of the Bla g 9 allergen correlated positively with the mean TSNEEZ (P < .05 for all).
• Higher expression of an eosinophil‑associated T2 inflammation module and a neutrophil‑associated chemotaxis module and lower expression of type I interferon, macrophage antimicrobial response, and epithelial barrier modules was associated with increased odds of having a positive NAC.

IN PRACTICE:

“[Our] results underscore the role of impaired epithelial and innate immune responses heightening susceptibility to allergen challenge and that symptoms can relate to both eosinophil and neutrophil associated patterns of inflammation,” the authors wrote.

SOURCE:

Lars Dunaway, PhD, with Rho Federal Systems Division, Inc., Durham, North Carolina, was the corresponding author of the study, which was published online as a short communication on March 18 in the Journal of Allergy and Clinical Immunology: Global. 

LIMITATIONS:

The results were limited to sensitized individuals.

DISCLOSURES:

This study was funded in whole or in part by federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services. Several authors reported receiving grants from the study funders. Some authors also reported receiving grants or contracts; research funding; consulting or personal fees; royalties and payment or honoraria for lectures, presentations, and bureaus and holding stock options in various pharmaceutical companies and institutions.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.