Technical and clinical validation of an environmental exposure unit for ragweed

Abstract

BackgroundAllergic rhinitis is a common condition, with ragweed pollen one of the more prevalent aeroallergens. Environmental exposure units such as the Allergen BioCube® are valuable models for clinical allergy studies. A study was conducted to validate the Allergen BioCube for uniform ragweed pollen concentrations and clinically relevant sign and symptom responses to ragweed exposure.MethodsRagweed pollen concentrations were measured on 3 consecutive days in the Allergen BioCube and verified by Rotorod collection and continuous laser particle count measurements. Subjects (N=10) were exposed to ragweed pollen in the BioCube for 3 hours per day for 3 consecutive days. Subjects assessed their nasal itching, sneezing, rhinorrhea, and nasal congestion during each BioCube exposure; total nasal symptom score was computed. Peak nasal inspiratory flow was also assessed during BioCube exposure.ResultsUniform ragweed pollen concentrations were obtained throughout each of the 3-hour testing periods in the Allergen BioCube, both spatially and temporally, at all subject positions, with a low mean standard deviation of 10%. Pronounced increases in mean total nasal symptom scores (6.7±0.94 to 7.6±0.86, last 90 minutes of exposure) occurred for all three BioCube ragweed pollen exposure visits. Mean peak nasal inspiratory flow decreased 24% at 3 hours of BioCube exposure on Day 3. No safety issues of concern occurred in this study.ConclusionThe Allergen BioCube achieved technical and clinical validation for ragweed allergen. Ragweed pollen concentration was uniform both temporally and spatially. Allergic rhinitis signs and symptoms were induced in subjects during exposure to ragweed in the BioCube at clinically meaningful levels for allergy studies.

<p>Iodixanol nasal solution reduces allergic rhinoconjunctivitis signs and symptoms in Allergen BioCube^&reg;:&nbsp;a randomized clinical trial</p>

“…Spatial and temporal uniformity of allergen concentrations was verified with continuous laser particle counter measurements every 10 minutes whenever the unit was in use. Prior to this study, technical validation of the BioCube was performed using Rotorod collection and laser particle counts to ensure reproducibility of consistent and uniform ragweed pollen concentration in the BioCube 8. Prior clinical validation of the BioCube for ragweed pollen was also conducted; mean TNSS increased by 4.96 units from pre- to post-BioCube ragweed pollen exposure 8.…”

“…Environmental exposure units (EEUs), first developed in the 1980s, allow for allergen specificity, control over antigen exposure levels, temperature, and air quality, and provide an accurate way of tracking self-reported and physician-observed symptoms for determining response to medication. The Allergen BioCube ® (ABC ® ) is an EEU that has been technically and clinically validated for both Timothy-grass7 and ragweed8 exposures.…”

Iodixanol Nasal Solution Reduces Allergic Rhinoconjunctivitis Signs and Symptoms in Allergen BioCube®: Randomized Clinical Trial

“…A ragweed pollen concentration of 4,000±400 grains/m 3 (Ambrosia artemesiifolia) was used, similar to that used in other EEUs and peak environmental levels, and is capable of producing AR symptoms that are high enough for assessment of therapeutic treatment effi cacy [9][10][11][12] Spatial and temporal uniformity of allergen concentrations was verifi ed with continuous laser particle counter measurements every 10 minutes whenever the unit was in use. Prior to this study, technical validation of the BioCube was performed using Rotorod collection and laser particle counts to ensure reproducibility of consistent and uniform ragweed pollen concentration in the BioCube [8]. Prior clinical validation of the BioCube for ragweed pollen was also conducted; mean TNSS increased by 4.96 units from pre-to post-Biocube ragweed pollen exposure [8].…”

“…Environmental exposure units (EEUs), fi rst developed in the 1980s are allow for allergen specifi city, control over antigen exposure levels, temperature, and air quality, and provide an accurate way of tracking self-reported and physician-observed symptoms for determining response to medication. The Allergen BioCube ® (ABC) is an EEU that has been technically and clinically validated for both Timothy [7] and ragweed [8], exposures.…”

Technical and clinical validation of the Allergen BioCube® for timothy grass

“…Timothy grass is native to Europe and is widely available in the U.S. as horse feed and lawn grass. The Allergen BioCube has also been validated for ragweed and dust mites , used in drug efficacy studies , and shown to induce AR symptomatology similar to the natural environment .…”