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Airborne Allergen Exposure As a Quantum Phenomenon
Abstracts AB187
J ALLERGY CLIN IMMUNOL VOLUME 133, NUMBER 2
Airborne Allergen Exposure As a Quantum Phenomenon Dr. Gert Doekes, PhD1, Dr. Peter S. Thorne, PhD2, Dr. Ingrid Sander, PhD3, Dr. Inge Wouters, PhD4, Dr. Wijnand Eduard, PhD5, Dr. Dick Heederik, PhD6; 1Institute for Risk Assessment Sciences, University Utrecht, NL, Utrecht, Netherlands, 2University of Iowa, Iowa City, IA, 3Institute for Prevention and Occupational Medicine, Ruhr-University Bochum, Bochum, Germany, 4Institute for Risk Assessment Sciences, University Utrecht, Utrecht, Netherlands, 5National Institute of Occupational Health, Oslo, Norway, 6Institute for Risk Assessment Sciences, Utrecht, Netherlands. RATIONALE: IgE sensitization to potent allergens may occur at average airborne concentrations <0.1-1 ng/m3. Measured levels in parallel samples or job categories show however an often high variability that cannot be explained by sampling or assay errors. We therefore focused on characteristics of allergenic particles. METHODS: Airborne dust was collected in bakeries with a low-flow (2 L/ min per filter) parallel sampling unit (PSU), and allergens of wheat and fungal aamylase measured by EIA. Total numbers of wheat flour and amylase particles were estimated, as collected on the filters or inhaled during the work day. RESULTS: High CV values for amylase could be explained by a high (>90%) allergen content of the enzyme particles, of which each (diameter 10-20 mm) would contain 0.8-8 ng of allergen, and 4-8-hr monitoring, even at ‘high’ amylase exposure, would lead to Poisson-distributed numbers of <5-10 amylase particles per sample. As a consequence, sensitizing timeweighted average levels of <1 ng/m3 correspond to inhalation of <1 inhaled amylase particle per day. In contrast, the estimated number of wheat flour particles in the same samples was >100,000/filter, with approximately 100 pg allergen per particle. CONCLUSIONS: The quantum nature of allergen exposure should be taken into account in airborne measurements and exposure-sensitization analyses. Sensitization at average levels of <1 ng/m3 may be due to incidentally inhaled ‘peaks’ of <10-100 allergen particles, followed by days or even weeks without exposure. Calculations for allergenic particles from mites, pets and pollen suggest that similar conclusions apply to exposure and sensitization to many common and work-related allergens.
646
Computer-Aided Design Of An Allergen Challenge Theatre William H. Yang, MD, Jimmy Yang, MBA, Robert Perrins, P.Eng, Suzanne Kelly, PhD, Jacob Karsh, MD; Red Maple Trials Inc., Ottawa, ON, Canada. RATIONALE: Allergen challenge theatres (ACT) expose sensitive subjects to predetermined concentrations of allergen in a controlled environment to induce clinical symptoms and measure effects of medication. Computer modeling can be used to optimize the allergen delivery system. METHODS: Computational Fluid Dynamics (CFD) analysis was used to govern technical development of an ACT. Extensive CFD analysis was used to optimize room ventilation and the targeted flow of allergen to each participant’s head. The analysis was used to characterize allergen concentrations between 1000 - 5000 grains/m3 and size variations from 10 to 60 mm. Modeling included simulation of 111 participants and their related heat load, in a 133m2 clean room. The modelling and design will be validated in the actual facility using an array of impact samplers and laser particle counters monitoring 20 sample locations, in 4 zones controlled by a real-time control system. RESULTS: The most important variables for allergen delivery were established by >40 repeated CFD simulations evaluating duct inlet and outlet configurations and air flow velocities to allow pollen to flow across the room from front to back. The model indicated that pre-determined stable allergen concentrations can be achieved within <10 minutes after start-up and maintained over the exposure duration. CONCLUSIONS: CFD permits optimization of allergen delivery systems to ensure accurate and consistent allergen concentrations throughout a large chamber, to effectively manage large test groups. More consistent allergen levels have the potential to decrease the number of subjects needed to power a study.
647
Evaluation Of a Compact Ionic Capture Device For Airborne Allergens In Inner City Schools Dr. Julian Gordon, PhD1, Ms. Prasanthi Gandhi, MBA, MPH1, Dr. Gajendra Shekhawat, PhD2, Ms. Ann Bailey, BA3, Dr. Wanda Phipatanakul, MD, MS, FAAAAI4; 1Inspirotec LLC, Chicago, IL, 2Northwestern University, Evanston, IL, 3Channing Laboratory, Boston, MA, 4 Boston Children’s Hospital, Boston, MA. RATIONALE: We evaluated the performance of a compact ion capture device (cICD) for the sampling of a set of airborne allergens and endotoxin in school classrooms as part of a larger study of the relation of allergen exposure to asthma in an inner city school system. Since smaller particles penetrate deeper in the lungs, we determined size distribution of captured particles. METHODS: Samples were collected over 4 days in 3 rooms at 3 time intervals. Multiplex assays for allergens (MARIAä) and Endotoxin were by Indoor Biotechnologies. Size distributions of particles collected were measured directly on the electrodes of the cICDs with a Bruker dimension ICON AFM system with sub-nm resolution. Imaging was done in tapping mode with super harp silicon probes. RESULTS: Means and standard deviations over all locations in fg/liter of air were Feld 1 (1.7+/-1.7); Can f1 (0.7+/-0.5), Mus m1 (1.9+/-1.3) and endotoxin (28+/-7). Seven other allergens were undetectable. There was 100% qualitative agreement with parallel determinations made by a reference method using a full size ion capture device and measurements as mg/gram of dust. AFM measurements on the cICD showed particles captured down to less than 200nm. The particles were distributed uniformly across the surface and consistent in size. CONCLUSIONS: The cICD is an extremely inexpensive, quiet, compact and simple device that can be unobtrusively deployed in critical locations without sacrificing performance. The ability to capture particles in a size range that is lower than currently used methods provides the opportunity to determine the fraction most significant for asthma provocation.
648
Relevance Of Sensitization To Blomia Tropicalis, Dermatophagoides and Tropomyosin- Containing Antigens Among Atopics Living In a Tropical Region Dr. Beverly K. Di Giorgi, MD, Dr. Sylvette Nazario, MD, Dr. Fernando J. Lopez, MD, Dr. Javier A. Mendez, MD; University of Puerto Rico School of Medicine, San Juan, PR. RATIONALE: Allergens produced by dust mites are among the most common triggers of asthma. Pyroglyphids (Dermatophagoides farina, D. pteronyssinus and Euroglyphus maynei) are the predominant specie worldwide. In tropical areas, storage mite sensitization, including Blomia tropicalis (Bt) has been reported, but its role in allergic manifestation and cross reactivity with other tropomyosin- containing antigens, has been less well described. METHODS: Evaluate prevalence of Bt, Dermatophagoides, cockroach, crustacean, and aspirin sensitization among atopic adults attending a community Allergy Clinic in San Juan, Puerto Rico form August 2012 to 2013; and compare with atopic manifestations including allergic rhinitis, conjunctivitis, asthma, urticaria, anaphylaxis, food allergy and atopic dermatitis. RESULTS: Fifty records were reviewed. The average age was 43.3 years and 70% were female. Allergic rhinitis was the most common atopic manifestation (70%), followed by asthma and urticaria (40% and 40%, respectively). 8% of subjects were sensitized exclusively to Dermatophagoides, 6% to Blomia, 16% to neither and 70% to both. Sensitization to Dermatophagoides and Blomia, was associated to rhinitis (p50.052), but not to asthma, anaphylaxis nor atopic dermatitis. Subjects sensitized to either mites were less likelihood to suffer urticaria (p50.021, OR 50.132). Cockroach sensitization but not crustacean sensitization was significantly associated to mite sensitivity (p50.005). CONCLUSIONS: Blomia tropicalis is an important inhalant allergen among adults suffering allergic rhinitis in San Juan, Puerto Rico but not to anaphylaxis emphasizing its role as a domestic rather than storage mite.
MONDAY
645
J ALLERGY CLIN IMMUNOL VOLUME 133, NUMBER 2
Airborne Allergen Exposure As a Quantum Phenomenon Dr. Gert Doekes, PhD1, Dr. Peter S. Thorne, PhD2, Dr. Ingrid Sander, PhD3, Dr. Inge Wouters, PhD4, Dr. Wijnand Eduard, PhD5, Dr. Dick Heederik, PhD6; 1Institute for Risk Assessment Sciences, University Utrecht, NL, Utrecht, Netherlands, 2University of Iowa, Iowa City, IA, 3Institute for Prevention and Occupational Medicine, Ruhr-University Bochum, Bochum, Germany, 4Institute for Risk Assessment Sciences, University Utrecht, Utrecht, Netherlands, 5National Institute of Occupational Health, Oslo, Norway, 6Institute for Risk Assessment Sciences, Utrecht, Netherlands. RATIONALE: IgE sensitization to potent allergens may occur at average airborne concentrations <0.1-1 ng/m3. Measured levels in parallel samples or job categories show however an often high variability that cannot be explained by sampling or assay errors. We therefore focused on characteristics of allergenic particles. METHODS: Airborne dust was collected in bakeries with a low-flow (2 L/ min per filter) parallel sampling unit (PSU), and allergens of wheat and fungal aamylase measured by EIA. Total numbers of wheat flour and amylase particles were estimated, as collected on the filters or inhaled during the work day. RESULTS: High CV values for amylase could be explained by a high (>90%) allergen content of the enzyme particles, of which each (diameter 10-20 mm) would contain 0.8-8 ng of allergen, and 4-8-hr monitoring, even at ‘high’ amylase exposure, would lead to Poisson-distributed numbers of <5-10 amylase particles per sample. As a consequence, sensitizing timeweighted average levels of <1 ng/m3 correspond to inhalation of <1 inhaled amylase particle per day. In contrast, the estimated number of wheat flour particles in the same samples was >100,000/filter, with approximately 100 pg allergen per particle. CONCLUSIONS: The quantum nature of allergen exposure should be taken into account in airborne measurements and exposure-sensitization analyses. Sensitization at average levels of <1 ng/m3 may be due to incidentally inhaled ‘peaks’ of <10-100 allergen particles, followed by days or even weeks without exposure. Calculations for allergenic particles from mites, pets and pollen suggest that similar conclusions apply to exposure and sensitization to many common and work-related allergens.
646
Computer-Aided Design Of An Allergen Challenge Theatre William H. Yang, MD, Jimmy Yang, MBA, Robert Perrins, P.Eng, Suzanne Kelly, PhD, Jacob Karsh, MD; Red Maple Trials Inc., Ottawa, ON, Canada. RATIONALE: Allergen challenge theatres (ACT) expose sensitive subjects to predetermined concentrations of allergen in a controlled environment to induce clinical symptoms and measure effects of medication. Computer modeling can be used to optimize the allergen delivery system. METHODS: Computational Fluid Dynamics (CFD) analysis was used to govern technical development of an ACT. Extensive CFD analysis was used to optimize room ventilation and the targeted flow of allergen to each participant’s head. The analysis was used to characterize allergen concentrations between 1000 - 5000 grains/m3 and size variations from 10 to 60 mm. Modeling included simulation of 111 participants and their related heat load, in a 133m2 clean room. The modelling and design will be validated in the actual facility using an array of impact samplers and laser particle counters monitoring 20 sample locations, in 4 zones controlled by a real-time control system. RESULTS: The most important variables for allergen delivery were established by >40 repeated CFD simulations evaluating duct inlet and outlet configurations and air flow velocities to allow pollen to flow across the room from front to back. The model indicated that pre-determined stable allergen concentrations can be achieved within <10 minutes after start-up and maintained over the exposure duration. CONCLUSIONS: CFD permits optimization of allergen delivery systems to ensure accurate and consistent allergen concentrations throughout a large chamber, to effectively manage large test groups. More consistent allergen levels have the potential to decrease the number of subjects needed to power a study.
647
Evaluation Of a Compact Ionic Capture Device For Airborne Allergens In Inner City Schools Dr. Julian Gordon, PhD1, Ms. Prasanthi Gandhi, MBA, MPH1, Dr. Gajendra Shekhawat, PhD2, Ms. Ann Bailey, BA3, Dr. Wanda Phipatanakul, MD, MS, FAAAAI4; 1Inspirotec LLC, Chicago, IL, 2Northwestern University, Evanston, IL, 3Channing Laboratory, Boston, MA, 4 Boston Children’s Hospital, Boston, MA. RATIONALE: We evaluated the performance of a compact ion capture device (cICD) for the sampling of a set of airborne allergens and endotoxin in school classrooms as part of a larger study of the relation of allergen exposure to asthma in an inner city school system. Since smaller particles penetrate deeper in the lungs, we determined size distribution of captured particles. METHODS: Samples were collected over 4 days in 3 rooms at 3 time intervals. Multiplex assays for allergens (MARIAä) and Endotoxin were by Indoor Biotechnologies. Size distributions of particles collected were measured directly on the electrodes of the cICDs with a Bruker dimension ICON AFM system with sub-nm resolution. Imaging was done in tapping mode with super harp silicon probes. RESULTS: Means and standard deviations over all locations in fg/liter of air were Feld 1 (1.7+/-1.7); Can f1 (0.7+/-0.5), Mus m1 (1.9+/-1.3) and endotoxin (28+/-7). Seven other allergens were undetectable. There was 100% qualitative agreement with parallel determinations made by a reference method using a full size ion capture device and measurements as mg/gram of dust. AFM measurements on the cICD showed particles captured down to less than 200nm. The particles were distributed uniformly across the surface and consistent in size. CONCLUSIONS: The cICD is an extremely inexpensive, quiet, compact and simple device that can be unobtrusively deployed in critical locations without sacrificing performance. The ability to capture particles in a size range that is lower than currently used methods provides the opportunity to determine the fraction most significant for asthma provocation.
648
Relevance Of Sensitization To Blomia Tropicalis, Dermatophagoides and Tropomyosin- Containing Antigens Among Atopics Living In a Tropical Region Dr. Beverly K. Di Giorgi, MD, Dr. Sylvette Nazario, MD, Dr. Fernando J. Lopez, MD, Dr. Javier A. Mendez, MD; University of Puerto Rico School of Medicine, San Juan, PR. RATIONALE: Allergens produced by dust mites are among the most common triggers of asthma. Pyroglyphids (Dermatophagoides farina, D. pteronyssinus and Euroglyphus maynei) are the predominant specie worldwide. In tropical areas, storage mite sensitization, including Blomia tropicalis (Bt) has been reported, but its role in allergic manifestation and cross reactivity with other tropomyosin- containing antigens, has been less well described. METHODS: Evaluate prevalence of Bt, Dermatophagoides, cockroach, crustacean, and aspirin sensitization among atopic adults attending a community Allergy Clinic in San Juan, Puerto Rico form August 2012 to 2013; and compare with atopic manifestations including allergic rhinitis, conjunctivitis, asthma, urticaria, anaphylaxis, food allergy and atopic dermatitis. RESULTS: Fifty records were reviewed. The average age was 43.3 years and 70% were female. Allergic rhinitis was the most common atopic manifestation (70%), followed by asthma and urticaria (40% and 40%, respectively). 8% of subjects were sensitized exclusively to Dermatophagoides, 6% to Blomia, 16% to neither and 70% to both. Sensitization to Dermatophagoides and Blomia, was associated to rhinitis (p50.052), but not to asthma, anaphylaxis nor atopic dermatitis. Subjects sensitized to either mites were less likelihood to suffer urticaria (p50.021, OR 50.132). Cockroach sensitization but not crustacean sensitization was significantly associated to mite sensitivity (p50.005). CONCLUSIONS: Blomia tropicalis is an important inhalant allergen among adults suffering allergic rhinitis in San Juan, Puerto Rico but not to anaphylaxis emphasizing its role as a domestic rather than storage mite.
MONDAY
645