Large-scale provocation studies identify maladaptive responses to ubiquitous aeroallergens as a correlate of severe allergic rhinoconjunctivitis and asthma.

Background: Allergic asthma (AA) and allergic rhinoconjunctivitis (ARC) are common comorbid environmentally triggered diseases. We hypothesized that severe AA/ARC reflects a maladaptive or unrestrained response to ubiquitous aeroallergens.

Methods: We performed provocation studies wherein six separate cohorts of persons (total n = 217) with ARC, with or without AA, were challenged once or more with fixed concentrations of seasonal or perennial aeroallergens in an aeroallergen challenge chamber (ACC).

Repetitive aeroallergen challenges elucidate maladaptive epithelial and inflammatory traits that underpin allergic airway diseases.

Background: Signifying the 2-compartments/1-disease paradigm, allergic rhinoconjunctivitis (ARC) and asthma (AA) are prevalent, comorbid conditions triggered by environmental factors (eg, house dust mites [HDMs]). However, despite the ubiquity of triggers, progression to severe ARC/AA is infrequent, suggesting either resilience or adaptation.

Objective: We sought to determine whether ARC/AA severity relates to maladaptive responses to disease triggers.

Clinical standardization of two controlled allergen challenge facilities: The Environmental Exposure Unit and the Biogenics Research Chamber.

Background: Controlled allergen challenge facilities (CACF), in disparate geographic regions with dissimilar engineering and base populations, have historically functioned as single, independent sites in clinical allergy trials. We aimed to demonstrate "between-unit reproducibility" to allow controlled challenge trials of participants using 2 CACFs.

Objective: To compare and standardize 2 CACFs located in Kingston, Ontario, Canada, and San Antonio, Texas, by examining participant-reported symptom severity during qualifying and treatment visits and evaluating response to treatment, while using the same allergen.

Redness response phenotypes of allergic conjunctivitis in an allergen challenge chamber.

Background: There are few direct data concerning symptom dynamics of allergic conjunctivitis (AC) in an allergen challenge chamber (ACC).

Objective: To determine the AC dynamics on subsequent exposures to ragweed pollen (RW) in individuals with allergic rhinitis in an ACC. To determine whether consecutive exposures in an ACC have any persistent detrimental ocular physical effects.

Preservation of epithelial cell barrier function and muted inflammation in resistance to allergic rhinoconjunctivitis from house dust mite challenge.

Background: An emerging paradigm holds that resistance to the development of allergic diseases, including allergic rhinoconjunctivitis, relates to an intact epithelial/epidermal barrier during early childhood. Conceivably, the immunologic and genomic footprint of this resistance is preserved in nonatopic, nonallergic adults and is unmasked during exposure to an aeroallergen.

Objective: The aim of this study was to obtain direct support of the epithelial/epidermal barrier model for allergic rhinoconjunctivitis.

Cockroach sensitization mitigates allergic rhinoconjunctivitis symptom severity in patients allergic to house dust mites and pollen.

Background: Modifiers of symptom severity in patients with allergic rhinoconjunctivitis (AR) are imprecisely characterized. The hygiene hypothesis implicates childhood microbial exposure as a protective factor. Cockroach sensitization (C+) might be a proxy for microbial exposure.

Responsiveness to timothy grass pollen in individuals without known natural exposure in an allergen challenge chamber.

Background: The responsiveness to a nonendemic grass species is unknown and cannot be research without an allergen challenge chamber.

Objective: To determine the clinical responsiveness to timothy grass pollen (TGP) in participants without known natural exposure in an allergen challenge chamber (ACC).

Methods: Of the 26 screened participants, 22 met screening criteria and completed the 2 chamber exposures.

Effect of confounding cofactors on responses to pollens during natural season versus pollen challenge chamber exposure.

Background: The severity of allergic rhinoconjunctivitis (AR) symptomatology elicited after exposure to pollen in the absence versus the presence of confounding cofactors, such as in a pollen challenge chamber (PCC) and the natural pollinating season, respectively, might differ.

Objective: We sought to determine the correlation of AR severity in the natural season versus out-of-season PCC exposures.

Methods: Twenty-four Virginia live oak (VLO)-positive, 14 VLO-negative, 16 mountain cedar (MC)-positive, 8 MC-negative, and 26 ragweed-positive participants recorded AR symptoms (total symptom score [TSS]) during the VLO, MC, and ragweed pollinating seasons and during 2 consecutive PCC exposures of 3 hours each to these pollens separately.

Responses to ragweed pollen in a pollen challenge chamber versus seasonal exposure identify allergic rhinoconjunctivitis endotypes.

Background: The level of concordance between allergic symptoms induced on exposure to pollen in a pollen challenge chamber (PCC) versus the natural season is unknown.

Objective: We sought to test the hypothesis that the symptom levels of allergic rhinoconjunctivitis elicited after out-of-season exposure to short ragweed in a PCC and during the natural season for giant ragweed pollen are highly correlated.

Methods: Thirty-one ragweed-sensitive participants recorded symptoms for 15 days during the natural giant ragweed season in San Antonio, Texas.