- Email: [email protected]
Der f1 allergen levels in the Nerthelands: Misclassification of house dust mite allergen exposure in studies measuring only der p1?
J ALLERGY CLIN IMMUNOL VOLUME 111, NUMBER 2
46 House Der fl Allergen Levels in The Netherlands: Misclassification of Dust Mite Allergen Exposure in Studies Measuring Only Der pl? A. Pronk ], G. Doekes ], M. Hady 2, P. Steerenberg 3, J. van Amsterdam3, B. Brunekreefl; Ilnstitute for Risk Assessment Sciences, University Utrecht, Utrecht, NETHERLANDS, 2Municipal Health Service, Utrecht, NETHERLANDS. 3National Institute for Public Health and the Environment, Bilthoven, NETHERLANDS. RATIONALE: Many studies in NW-Europe on mite allergen exposure have only measured the major allergen Der pl. Since recent data suggest that D. farinae allergens may be of equal importance, we compared house dust concentrations of Der pl and Der fl and their correlations. METHODS: House dust samples were collected in an inner city (n=63) and a suburban (n=100) population of school children, in spring 2000 and fall 2001, respectively. Extracts made in PBS-Tween were analyzed for Der p I and Der fl by enzyme immunoassays (Indoor BiotechnologiesTM). We further (re-)analyzed 20 dust extracts from a study in fall 1990, in which Der pl had been measured previously with another enzyme immunoassay (ALKTM). RESULTS: Der p l and Der fl concentrations showed log-normal distributions in the same orders of magnitude, especially in the tall 2001 study, with geometric means for Der pl 2.60, 1.41 and 1.19, and for Der fl 6.85, 0.96 and 0.27 mg/g, in mattress, bedroom floor and living room floor dust, respectively. Correlations between pl and fl concentrations were very low: Pearson's R for In-transformed values from -0.12 to 0.27 in various subsamples. Analysis of stored extracts confirmed the previously tound Der plconcentrations, and revealed that Der fl bad already been present at relatively high levels in house dust in 1990. CONCLUSIONS: House dust mite allergen exposure in population studies may-~tepending on the relative abundance of D. farinae in the study region-be seriously underestimated, if only Der p l is used as marker of exposure.
Funding: Dutch Ministr3, o)CEnvironrnent, Utrecht Municipality
547 Proteolytic Activityof House Dust--Exposure Levelsin Homes J. Baker, P. Meighan, R. Pirzad, T. Cooke; Acaris Ltd, Cambridge, UNITED KINGDOM. RATIONALE: There is an increasing awareness that active peptidase enzymes play a very important role in the pathology of asthma. The presence of active proteolytic allergens can be easily demonstrated in house dust using both fluorogenic and chromogenic peptides. We have conducted a survey of 60 homes in the United Kingdom using these techniques to map out the levels of the active allergenic peptidases Der p 1 and Der p 3. METHODS: Domestic dust was collected in clean vacuum bags from soft furnishings in subjects homes, the dust was then analyzed using a simple peptidase assay for Der p 1 and Der p 3. This was then correlated with measured concentrations of Der p 1 using ELISA. RESULTS: Der p 1 levels and active peptidase allergens activities were analyzed and demonstrated a correlation of (r = 0.710), n = 150 in subjects mattresses. The greatest factors to affect the levels of both Der p 1 and proteolytically active allergens were the age of the mattress, physical location of the rooms in terms of temperature and humidity and the level of dust generally present. CONCLUSIONS: A good correlation can be demonstrated between the levels of Der p l and a measure of proteolytically active allergens also from Dermatophagoides species. The use of specific peptidase assays are a good marker for the presence of allergens from Dermatophagoides species.
Funding: Self-funded
548 Efficacy of Extermination/Intensive Cleaning in Reduction of Cockroach Allergen in Inner-City North Carolina Homes M. Sever I, S. Arbes, Jr. I, J. C. Gore 2, L. Liu l , E. Long3, J. Archer 3. E. Nuebier4, M. Walter4, H. Mitchell 4, C. Schal 2. D. C. ZeldinJ; INIEHS/NIH,
Abstracts
$205
Research Triangle Park, NC, 2North Carolina State University, Raleigh, NC, 3CODA, Durham, NC, 4Rho, Inc, Chapel Hill, NC. RATIONALE: Attempts to reduce cockroach allergen in inner-city homes have been largely unsuccessful. This 6-month lbllow-up study assessed the efficacy of an intensive and targeted cockroach extermination and allergen removal program to reduce Blattella germanica 1 (Bla g I) levels. METHODS: Homes with moderate to heavy cockroach infestations were randomly assigned to intervention in= 16) or nonintervention (n= 15) treatments. After baseline trapping, vacuumed dust sampling, and spatial analysis of Bla g 1 allergen distribution (from a multiple swab sampling technique), intervention homes were extensively cleaned, cockroaches exterminated, and occupant education was conducted. Monthly tbllow-up trapping and Bla g 1 distribution data were used to target insecticide placement and to guide repeated cleaning activities. Mean differences in log allergen concentrations (Units/gram dust) were assessed by paired T-tests. RESULTS: Mean numbers of trapped cockroaches in the intervention homes were reduced from 308 at baseline to 12 at the 6-month visit. In the intervention group, compared to baseline, there were significant reductions (p<0.005) in mean Bla g 1 concentrations in the kitchen (1285 vs 89), bedroom bed (14 vs 2), bedroom floor (125 vs 20) and family room floor and sofa (39 vs 9). There were no significant differences in trapped cockroaches or mean Bla g 1 concentrations between baseline and 6months in the nonintervention homes. CONCLUSIONS: This intensive, targeted intervention lead to dramatic reductions in trapped cockroaches and Bla g I concentrations at 6 months. On average the Bla g 1 concentration in beds was reduced below levels that are considered clinically relevant.
549 The Effect of Dehumidification/HEPA Filtration on Dew Point and Airborne Mold Spore Counts in Day Care Centers J. A. Bernstein j, M. S. Crandall 2, B. P. Lanphear 3. A. S. Perez 4, R. Floyd t, L. Levine4; qnternal Medicine/Division of Immunology/Allergy Section, University of Cincinnati College of Medicine, Cincinnati, OH, 2Indoor Environmental Services, Cincinnati, OH, 3General Pediatrics/Division of Epidemiology, Children's Hospital Medical Center, Cincinnati, OH, 4Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH. RATIONALE: Indoor relative humidity <50% reduces dust mites but less is known about mold allergen. We investigated the effect of dehumidification/HEPA filtration on dew point (DP) and airborne mold spore counts in daycare centers (DCCs). METHODS: Two DCCs (DCC 1-2 y/o with 8 rooms; DCC 2-15 y/o with 6 rooms) were selected. Pre-intervention fungal air sampling (CFU/m3), initiated in August, was performed every 3 months in all DCC rooms for 1 year. Electronic data loggers continuously measured outdoor and indoor room DP and temperature. A Santa Fe dehumidification/HEPA unit (Therma-Stor Products, Madison, WI) was installed in half the rooms, matched by square footage. Room thermostats were controlled similarly and doors/windows remained closed whenever possible throughout the study. RESULTS: Dehumidification lowered the average DP across DCCs from baseline by 16.3~ vs. non-intervention rooms by 12.8~ across all time periods after adjustment for temperature (p<.001). The mean value of airborne mold spores was significantly lower across DCCs in intervention (61.6 --_ 14.5 CFU/m3) vs. non-intervention (166 -+ 93.7 CFU/m3) rooms (p<.01). Because of extreme baseline variability of mold spore counts, median _+interquartile ranges were analyzed: the mean fungal counts were lower across DCCs but not statistically significant in intervention (1(1 _+ 9.5) vs. non-intervention (53.7 -+ 32.5) rooms (p = .20). CONCLUSIONS: Dehumidification is effective at controlling indoor DP in DCCs and in conjunction with HEPA filtration can reduce airborne mold spore counts. Interventions designed to improve air quality in commercial buildings are possible.
Funding: Proctor and Gamble
46 House Der fl Allergen Levels in The Netherlands: Misclassification of Dust Mite Allergen Exposure in Studies Measuring Only Der pl? A. Pronk ], G. Doekes ], M. Hady 2, P. Steerenberg 3, J. van Amsterdam3, B. Brunekreefl; Ilnstitute for Risk Assessment Sciences, University Utrecht, Utrecht, NETHERLANDS, 2Municipal Health Service, Utrecht, NETHERLANDS. 3National Institute for Public Health and the Environment, Bilthoven, NETHERLANDS. RATIONALE: Many studies in NW-Europe on mite allergen exposure have only measured the major allergen Der pl. Since recent data suggest that D. farinae allergens may be of equal importance, we compared house dust concentrations of Der pl and Der fl and their correlations. METHODS: House dust samples were collected in an inner city (n=63) and a suburban (n=100) population of school children, in spring 2000 and fall 2001, respectively. Extracts made in PBS-Tween were analyzed for Der p I and Der fl by enzyme immunoassays (Indoor BiotechnologiesTM). We further (re-)analyzed 20 dust extracts from a study in fall 1990, in which Der pl had been measured previously with another enzyme immunoassay (ALKTM). RESULTS: Der p l and Der fl concentrations showed log-normal distributions in the same orders of magnitude, especially in the tall 2001 study, with geometric means for Der pl 2.60, 1.41 and 1.19, and for Der fl 6.85, 0.96 and 0.27 mg/g, in mattress, bedroom floor and living room floor dust, respectively. Correlations between pl and fl concentrations were very low: Pearson's R for In-transformed values from -0.12 to 0.27 in various subsamples. Analysis of stored extracts confirmed the previously tound Der plconcentrations, and revealed that Der fl bad already been present at relatively high levels in house dust in 1990. CONCLUSIONS: House dust mite allergen exposure in population studies may-~tepending on the relative abundance of D. farinae in the study region-be seriously underestimated, if only Der p l is used as marker of exposure.
Funding: Dutch Ministr3, o)CEnvironrnent, Utrecht Municipality
547 Proteolytic Activityof House Dust--Exposure Levelsin Homes J. Baker, P. Meighan, R. Pirzad, T. Cooke; Acaris Ltd, Cambridge, UNITED KINGDOM. RATIONALE: There is an increasing awareness that active peptidase enzymes play a very important role in the pathology of asthma. The presence of active proteolytic allergens can be easily demonstrated in house dust using both fluorogenic and chromogenic peptides. We have conducted a survey of 60 homes in the United Kingdom using these techniques to map out the levels of the active allergenic peptidases Der p 1 and Der p 3. METHODS: Domestic dust was collected in clean vacuum bags from soft furnishings in subjects homes, the dust was then analyzed using a simple peptidase assay for Der p 1 and Der p 3. This was then correlated with measured concentrations of Der p 1 using ELISA. RESULTS: Der p 1 levels and active peptidase allergens activities were analyzed and demonstrated a correlation of (r = 0.710), n = 150 in subjects mattresses. The greatest factors to affect the levels of both Der p 1 and proteolytically active allergens were the age of the mattress, physical location of the rooms in terms of temperature and humidity and the level of dust generally present. CONCLUSIONS: A good correlation can be demonstrated between the levels of Der p l and a measure of proteolytically active allergens also from Dermatophagoides species. The use of specific peptidase assays are a good marker for the presence of allergens from Dermatophagoides species.
Funding: Self-funded
548 Efficacy of Extermination/Intensive Cleaning in Reduction of Cockroach Allergen in Inner-City North Carolina Homes M. Sever I, S. Arbes, Jr. I, J. C. Gore 2, L. Liu l , E. Long3, J. Archer 3. E. Nuebier4, M. Walter4, H. Mitchell 4, C. Schal 2. D. C. ZeldinJ; INIEHS/NIH,
Abstracts
$205
Research Triangle Park, NC, 2North Carolina State University, Raleigh, NC, 3CODA, Durham, NC, 4Rho, Inc, Chapel Hill, NC. RATIONALE: Attempts to reduce cockroach allergen in inner-city homes have been largely unsuccessful. This 6-month lbllow-up study assessed the efficacy of an intensive and targeted cockroach extermination and allergen removal program to reduce Blattella germanica 1 (Bla g I) levels. METHODS: Homes with moderate to heavy cockroach infestations were randomly assigned to intervention in= 16) or nonintervention (n= 15) treatments. After baseline trapping, vacuumed dust sampling, and spatial analysis of Bla g 1 allergen distribution (from a multiple swab sampling technique), intervention homes were extensively cleaned, cockroaches exterminated, and occupant education was conducted. Monthly tbllow-up trapping and Bla g 1 distribution data were used to target insecticide placement and to guide repeated cleaning activities. Mean differences in log allergen concentrations (Units/gram dust) were assessed by paired T-tests. RESULTS: Mean numbers of trapped cockroaches in the intervention homes were reduced from 308 at baseline to 12 at the 6-month visit. In the intervention group, compared to baseline, there were significant reductions (p<0.005) in mean Bla g 1 concentrations in the kitchen (1285 vs 89), bedroom bed (14 vs 2), bedroom floor (125 vs 20) and family room floor and sofa (39 vs 9). There were no significant differences in trapped cockroaches or mean Bla g 1 concentrations between baseline and 6months in the nonintervention homes. CONCLUSIONS: This intensive, targeted intervention lead to dramatic reductions in trapped cockroaches and Bla g I concentrations at 6 months. On average the Bla g 1 concentration in beds was reduced below levels that are considered clinically relevant.
549 The Effect of Dehumidification/HEPA Filtration on Dew Point and Airborne Mold Spore Counts in Day Care Centers J. A. Bernstein j, M. S. Crandall 2, B. P. Lanphear 3. A. S. Perez 4, R. Floyd t, L. Levine4; qnternal Medicine/Division of Immunology/Allergy Section, University of Cincinnati College of Medicine, Cincinnati, OH, 2Indoor Environmental Services, Cincinnati, OH, 3General Pediatrics/Division of Epidemiology, Children's Hospital Medical Center, Cincinnati, OH, 4Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH. RATIONALE: Indoor relative humidity <50% reduces dust mites but less is known about mold allergen. We investigated the effect of dehumidification/HEPA filtration on dew point (DP) and airborne mold spore counts in daycare centers (DCCs). METHODS: Two DCCs (DCC 1-2 y/o with 8 rooms; DCC 2-15 y/o with 6 rooms) were selected. Pre-intervention fungal air sampling (CFU/m3), initiated in August, was performed every 3 months in all DCC rooms for 1 year. Electronic data loggers continuously measured outdoor and indoor room DP and temperature. A Santa Fe dehumidification/HEPA unit (Therma-Stor Products, Madison, WI) was installed in half the rooms, matched by square footage. Room thermostats were controlled similarly and doors/windows remained closed whenever possible throughout the study. RESULTS: Dehumidification lowered the average DP across DCCs from baseline by 16.3~ vs. non-intervention rooms by 12.8~ across all time periods after adjustment for temperature (p<.001). The mean value of airborne mold spores was significantly lower across DCCs in intervention (61.6 --_ 14.5 CFU/m3) vs. non-intervention (166 -+ 93.7 CFU/m3) rooms (p<.01). Because of extreme baseline variability of mold spore counts, median _+interquartile ranges were analyzed: the mean fungal counts were lower across DCCs but not statistically significant in intervention (1(1 _+ 9.5) vs. non-intervention (53.7 -+ 32.5) rooms (p = .20). CONCLUSIONS: Dehumidification is effective at controlling indoor DP in DCCs and in conjunction with HEPA filtration can reduce airborne mold spore counts. Interventions designed to improve air quality in commercial buildings are possible.
Funding: Proctor and Gamble