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Clinical validation of controlled grass pollen challenge in the Environmental Exposure Unit (EEU).

Ellis AK, Steacy LM, Hobsbawn B, Conway CE, Walker TJ - Allergy Asthma Clin Immunol (2015)

Bottom Line: Two separate groups allowed for the exploration of lower vs. higher pollen concentrations and subsequent effects on symptoms. 78 participants were screened, of whom 39 were eligible and attended the 2x3h EEU visits, plus 8 non-atopic controls.In comparison, mean TSS, TNSS and PNIF values in the lower pollen concentration (2500 grains/m3) group were only 13.3, 7.6, and 82 L/min, respectively.This study provides clinical validation of the ability to generate allergic rhinoconjunctivitis symptoms amongst grass-allergic individuals in the EEU.

View Article: PubMed Central - PubMed

Affiliation: Division of Allergy & Immunology, Department of Medicine, Queen's University, Kingston, ON Canada ; Allergy Research Unit, Kingston General Hospital, 76 Stuart Street, Kingston, ON K7L 2 V7 Canada.

ABSTRACT

Rationale: The Environmental Exposure Unit (EEU), a controlled allergen exposure model of allergic rhinitis (AR), has traditionally utilized ragweed pollen. We sought to clinically validate the use of grass pollen in the EEU.

Methods: Healthy volunteers with a history of AR symptoms during grass pollen season and supportive skin test responses attended the EEU for 3 hrs of rye grass pollen exposure (Lolium Perenne). Non-atopic controls were also recruited. Participants assessed individual rhinoconjunctivitis symptoms to generate Total Nasal Symptom Score (TNSS; max 12) and Total Symptom Score (TSS; max 24) and recorded Peak Nasal Inspiratory Flow (PNIF) q30min while in the EEU. Participants returned the following day for an additional 3 hrs of pollen exposure. Two separate groups allowed for the exploration of lower vs. higher pollen concentrations and subsequent effects on symptoms.

Results: 78 participants were screened, of whom 39 were eligible and attended the 2x3h EEU visits, plus 8 non-atopic controls. Mean TSS, TNSS and PNIF values amongst participants in the higher pollen concentration group (target 3500 grains/m3) after the first 3 hr exposure were 18.9, 9.7 and 68 L/min, respectively. In comparison, mean TSS, TNSS and PNIF values in the lower pollen concentration (2500 grains/m3) group were only 13.3, 7.6, and 82 L/min, respectively. The subsequent day of pollen exposure did not appreciably alter the maximal TSS/TNSSs, but rather resulted in a more rapid onset of symptomatology, with higher mean scores at the 30 min, 60 min and 90 min timepoints. The non-atopic controls remained asymptomatic.

Conclusions: This study provides clinical validation of the ability to generate allergic rhinoconjunctivitis symptoms amongst grass-allergic individuals in the EEU.

No MeSH data available.


Related in: MedlinePlus

Layout of the Environmental Exposure Unit (EEU).
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Fig2: Layout of the Environmental Exposure Unit (EEU).

Mentions: As described above, the Kingston EEU is a specifically engineered room located within Kingston General Hospital. The EEU setup, including location of chairs, feeder, fans, and Rotorod® sampling equipment, is illustrated in Figure 2. A custom engineered computer and laser-aided system disperses pollen, at a single point of delivery (Figure 2). The pollen is propelled, by selectively placed groups of directional fans, over the participant seating area. For the current study, rye grass pollen was sourced from Greer Laboratories (Lenoir, NC), and was independently tested for fungal and bacterial contamination (Paracel Laboratories, Ottawa, ON, Canada) prior to its use.Figure 2


Clinical validation of controlled grass pollen challenge in the Environmental Exposure Unit (EEU).

Ellis AK, Steacy LM, Hobsbawn B, Conway CE, Walker TJ - Allergy Asthma Clin Immunol (2015)

Layout of the Environmental Exposure Unit (EEU).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4316395&req=5

Fig2: Layout of the Environmental Exposure Unit (EEU).
Mentions: As described above, the Kingston EEU is a specifically engineered room located within Kingston General Hospital. The EEU setup, including location of chairs, feeder, fans, and Rotorod® sampling equipment, is illustrated in Figure 2. A custom engineered computer and laser-aided system disperses pollen, at a single point of delivery (Figure 2). The pollen is propelled, by selectively placed groups of directional fans, over the participant seating area. For the current study, rye grass pollen was sourced from Greer Laboratories (Lenoir, NC), and was independently tested for fungal and bacterial contamination (Paracel Laboratories, Ottawa, ON, Canada) prior to its use.Figure 2

Bottom Line: Two separate groups allowed for the exploration of lower vs. higher pollen concentrations and subsequent effects on symptoms. 78 participants were screened, of whom 39 were eligible and attended the 2x3h EEU visits, plus 8 non-atopic controls.In comparison, mean TSS, TNSS and PNIF values in the lower pollen concentration (2500 grains/m3) group were only 13.3, 7.6, and 82 L/min, respectively.This study provides clinical validation of the ability to generate allergic rhinoconjunctivitis symptoms amongst grass-allergic individuals in the EEU.

View Article: PubMed Central - PubMed

Affiliation: Division of Allergy & Immunology, Department of Medicine, Queen's University, Kingston, ON Canada ; Allergy Research Unit, Kingston General Hospital, 76 Stuart Street, Kingston, ON K7L 2 V7 Canada.

ABSTRACT

Rationale: The Environmental Exposure Unit (EEU), a controlled allergen exposure model of allergic rhinitis (AR), has traditionally utilized ragweed pollen. We sought to clinically validate the use of grass pollen in the EEU.

Methods: Healthy volunteers with a history of AR symptoms during grass pollen season and supportive skin test responses attended the EEU for 3 hrs of rye grass pollen exposure (Lolium Perenne). Non-atopic controls were also recruited. Participants assessed individual rhinoconjunctivitis symptoms to generate Total Nasal Symptom Score (TNSS; max 12) and Total Symptom Score (TSS; max 24) and recorded Peak Nasal Inspiratory Flow (PNIF) q30min while in the EEU. Participants returned the following day for an additional 3 hrs of pollen exposure. Two separate groups allowed for the exploration of lower vs. higher pollen concentrations and subsequent effects on symptoms.

Results: 78 participants were screened, of whom 39 were eligible and attended the 2x3h EEU visits, plus 8 non-atopic controls. Mean TSS, TNSS and PNIF values amongst participants in the higher pollen concentration group (target 3500 grains/m3) after the first 3 hr exposure were 18.9, 9.7 and 68 L/min, respectively. In comparison, mean TSS, TNSS and PNIF values in the lower pollen concentration (2500 grains/m3) group were only 13.3, 7.6, and 82 L/min, respectively. The subsequent day of pollen exposure did not appreciably alter the maximal TSS/TNSSs, but rather resulted in a more rapid onset of symptomatology, with higher mean scores at the 30 min, 60 min and 90 min timepoints. The non-atopic controls remained asymptomatic.

Conclusions: This study provides clinical validation of the ability to generate allergic rhinoconjunctivitis symptoms amongst grass-allergic individuals in the EEU.

No MeSH data available.


Related in: MedlinePlus