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1.
Clin Exp Allergy ; 38(10): 1635-43, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18702654

ABSTRACT

BACKGROUND: Exposure to pets in childhood has been associated with a reduced risk of wheezing and atopy. OBJECTIVE: Our objective was to determine whether the effects of pet exposure on immune development and atopy in early childhood can be explained by alterations in exposure to innate immune stimuli in settled dust. METHODS: Two hundred and seventy-five children at increased risk of developing allergic diseases were evaluated to age 3 years for pet ownership, blood cell cytokine responses, and atopy. Can f 1, Fel d 1, endotoxin, ergosterol, and muramic acid were measured in settled dust from 101 homes. RESULTS: Dog exposure at birth was associated with decreased atopic dermatitis (AD) (12% vs. 27%; P=0.004) and wheezing (19% vs. 36%; P=0.005) in year 3. The rates of AD (23%) and wheezing (42%) in year 3 were relatively high in children who acquired dogs after birth. The prevalence of dog sensitization (10-12%) did not vary according to dog exposure. Can f 1 levels in bedroom dust were positively associated with IL-10 (r=0.26; P=0.01), IL-5 (r=0.34, P<0.001), and IL-13 (r=0.28; P=0.004) responses at age 1, and IL-5 (r=0.24; P=0.022) and IL-13 (r=0.25; P=0.015) responses at age 3. In contrast, endotoxin was associated with IFN-gamma (r=0.31; P=0.002) and IL-13 (r=0.27; P=0.01) responses at age 3 but not at age 1, and similar relationships were present for muramic acid. Adjustment for levels of innate immune stimuli in house dust did not significantly affect the relationships between Can f 1 and cytokine responses. CONCLUSIONS: Exposure to dogs in infancy, and especially around the time of birth, is associated with changes in immune development and reductions in wheezing and atopy. These findings are not explained by exposure to endotoxin, ergosterol, or muramic acid.


Subject(s)
Allergens/immunology , Animals, Domestic/immunology , Cytokines/biosynthesis , Dogs/immunology , Hair/immunology , Hypersensitivity, Immediate/etiology , Respiratory Sounds/etiology , Age Factors , Allergens/metabolism , Animals , Child, Preschool , Cytokines/immunology , Family Characteristics , Follow-Up Studies , Humans , Hypersensitivity, Immediate/immunology , Immunoglobulin E/blood , Infant , Infant, Newborn , Respiratory Sounds/immunology
2.
Clin Exp Allergy ; 37(7): 1033-9, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17581196

ABSTRACT

BACKGROUND: Cockroach allergy is an important cause of inner city asthma. To perform valid studies on the diagnosis and treatment of cockroach allergy, biological potencies of test extracts need to be established, and a surrogate in vitro test for biological potency should be chosen. METHODS: Sixty-two cockroach-allergic adult subjects were recruited for quantitative skin testing with three commercial German cockroach extracts. The intradermal D50 values were determined using linear interpolation, and the biologic potencies were determined from D50 data. The extracts were also analysed for relative potency, using a competition ELISA, and for specific allergen content, using a two-site ELISA. RESULTS: Estimates of each extract's D50 were analysable in 48-55 subjects, with D50s between 10.3 and 11.8. All three extracts were bioequivalent using pre-set criteria. The biological potencies of the extracts were 1738-8570 bioequivalent allergy units (BAU)/mL (geometric mean=3300), and these relative potencies were similar to those estimated by competition ELISA and specific allergen content. IgE against cockroach allergens were detected in sera from 34 subjects with analysable D50s, and 17 subjects had IgE directed against specific cockroach allergens. Although the presence of anti-Bla g 5 correlated with the subjects' skin test responses for 2/3 extracts, no single allergen was immunodominant. Antibody responses among the subjects were heterogeneous. CONCLUSIONS: Although commercial cockroach extracts are relatively low in potency, immunotherapeutic doses should be achievable. Biological potency may be estimated using D50 testing, a combination of specific allergen determinations, or by an overall potency assay such as the competition ELISA. CAPSULE SUMMARY: The biological potency of three German cockroach allergen extracts, determined in an inner city population, was 1738-8570 BAU/mL. No one allergen was immunodominant, and surrogate in vitro testing methods were examined.


Subject(s)
Allergens/administration & dosage , Cockroaches/immunology , Desensitization, Immunologic/methods , Hypersensitivity/therapy , Insect Proteins/immunology , Urban Health , Adult , Allergens/analysis , Animals , Antigens, Plant , Aspartic Acid Endopeptidases/analysis , Dose-Response Relationship, Immunologic , Erythema/immunology , Female , Humans , Hypersensitivity/immunology , Immunoglobulin E/blood , Injections, Intradermal , Intradermal Tests , Male , Middle Aged , Quality Control , United States
3.
Clin Exp Allergy ; 36(8): 1097-103, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16911366

ABSTRACT

BACKGROUND: High serum levels of cat-specific IgG and IgG4 are associated with protection against allergic sensitization to cat, but whether this association applies to other animal allergens remains unclear. OBJECTIVE: To determine if high levels of mouse-specific IgG and IgG4 are associated with a decreased risk of mouse skin test sensitivity. METHODS: Two hundred and sixty workers of a mouse facility underwent skin prick testing and completed a questionnaire. Serum levels of mouse-specific IgG and IgG4 were quantified by solid-phase antigen binding assays. Room air samples were collected and airborne Mus m 1 was quantified by ELISA. RESULTS: Forty-nine participants had a positive skin prick test to mouse. Mouse-specific IgG was detected in 219 (84%) participants and IgG4 was detected in 72 (28%) participants. A detectable mouse-specific IgG4 level was associated with an increased risk of mouse skin test sensitivity (odds ratios (OR) 6.4, 95% confidence intervals (CI) 3.3-12.4). Mouse-specific IgG and IgG4 were both positively correlated with mouse allergen exposure (r(s)=0.31, P=0.0001, and r(s)=0.27, P=0.0006, respectively). The odds of skin test sensitivity peaked at moderate levels of IgG4, but decreased at the highest levels of mouse-specific IgG4. In contrast, the odds of skin test sensitivity increased monotonically with IgG levels. CONCLUSIONS: A detectable level of mouse-specific IgG4 is associated with an increased risk of skin test sensitivity to mouse. However, the highest IgG4 levels appear to be associated with an attenuated risk of mouse skin test sensitivity, suggesting that induction of high levels of IgG4 through natural exposure may protect against the development of allergic sensitization.


Subject(s)
Air Pollutants, Occupational/immunology , Allergens/immunology , Animal Husbandry , Hypersensitivity/immunology , Immunoglobulin G/immunology , Occupational Diseases/immunology , Adult , Allergens/analysis , Animals , Cross-Sectional Studies , Female , Humans , Logistic Models , Male , Medical Laboratory Personnel , Mice , Middle Aged , Risk , Sensitivity and Specificity , Skin Tests
4.
Clin Exp Allergy ; 35(10): 1347-53, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16238795

ABSTRACT

BACKGROUND: High levels of allergen-specific IgG have been associated with clinical efficacy in immunotherapy studies, but whether this antibody isotype is associated with clinical tolerance in the setting of environmental exposure remains unclear. OBJECTIVE: To determine if mouse allergen-specific IgG (mIgG) and IgG4 (mIgG4) levels are associated with mouse-related symptoms among IgE-sensitized laboratory workers. METHODS: Fifty-eight workers with either skin test or serologic evidence of IgE-mediated mouse sensitization were studied. Symptom data were obtained by a questionnaire. Serum levels of mouse-specific IgG, IgG4, and IgE were quantified by a solid-phase antigen-binding assay (IgG) and RAST (IgG4 and IgE), and the relationships between mouse-specific serologic responses and mouse-related symptoms were analysed. RESULTS: Twenty-three (39.7%) participants reported mouse-related symptoms. Mouse-specific IgG and IgG4 levels were not associated with mouse-related symptoms among the study population as a whole. Among the 29 (50%) participants with detectable mouse-specific IgE (mIgE), higher mouse-specific IgG and IgG4 levels were associated with a decreased risk of symptoms, after adjusting for mIgE level (odds ratio (OR) 0.3, 95% confidence interval (CI): 0.1-1.4, and OR 0.3, 95% CI: 0.04-2.6, respectively). Higher levels of mIgG and mIgG4 remained associated with a decreased risk of symptoms after additional adjustment for sex and handling of mice (OR 0.1, 95% CI: 0.02-0.7, and OR 0.2, 95% CI: 0.02-2.1, respectively). Higher mIgG : IgE and mIgG4 : IgE ratios were also associated with a decreased risk of symptoms after adjusting for these confounders (OR 0.1, 95% CI: 0.02-0.7, and OR 0.2, 95% CI: 0.02-0.92, respectively). CONCLUSION: Among workers with detectable mIgE, higher mIgG and mIgG4 levels are associated with a decreased risk of mouse-related symptoms. High serum levels of mIgG or mIgG4 may be markers for clinical tolerance among laboratory mouse workers with detectable mIgE, but these findings need to be confirmed in larger, prospective studies.


Subject(s)
Hypersensitivity/immunology , Immunoglobulin E/blood , Immunoglobulin G/blood , Medical Laboratory Personnel , Occupational Diseases/immunology , Adult , Air Pollutants, Occupational/immunology , Allergens , Animals , Biomarkers/blood , Cross-Sectional Studies , Female , Humans , Hypersensitivity/etiology , Immune Tolerance/immunology , Male , Mice , Middle Aged , Occupational Diseases/etiology , Occupational Exposure/adverse effects , Occupational Exposure/analysis , Skin Tests
6.
Ann Allergy Asthma Immunol ; 87(1): 60-4, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11476465

ABSTRACT

BACKGROUND: Although the importance of cockroach allergen in chronic asthma has now been well defined, little progress has been made in the control of cockroach allergen in infested homes. OBJECTIVE: The objective of this study was to examine the ability of a combination of professional pest extermination and household cleaning using a solution of sodium hypochlorite to reduce cockroach infestation and allergen levels in cockroach infested homes. METHODS: Seventeen cockroach-infested homes were studied with three homes serving as controls. In the intervention homes, a professional exterminator applied 0.05% abamectin twice at 2-week intervals at study entry and a professional cleaner cleaned the homes before and after the extermination. All washable surfaces were cleaned throughout the study with a solution of 0.5% hypochlorite. Monthly home visits were conducted to inspect the home, interview the homeowner, place passive cockroach traps, and to collect settled dust samples from the kitchen, bedroom, and TV/living room. RESULTS: The number of cockroaches in the passive traps decreased rapidly after the initial intervention in most homes. Median Blatella germanica allergen 1 levels in the settled dust samples fell by 91% in the kitchen, 78% in the bedroom, and 77% in the living room over the course of the study in the intervention homes but gradually rose in the control homes. The overall reductions were very similar to those seen in a previous study with a similar protocol except for the use of the sodium hypochlorite. CONCLUSIONS: Successful extermination is possible in most inner-city homes and cockroach allergen levels can be reduced by 80% to 90%. However, 0.5% sodium hypochlorite did not seem to improve allergen reduction, and in many homes, allergen levels remained above the proposed threshold of 8 U/g of dust throughout the study.


Subject(s)
Air Pollution, Indoor/analysis , Air Pollution, Indoor/prevention & control , Cockroaches/immunology , Disinfectants/pharmacology , Sodium Hypochlorite/pharmacology , Allergens/analysis , Allergens/drug effects , Animals
7.
Clin Exp Allergy ; 31(7): 1086-93, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11468000

ABSTRACT

BACKGROUND: To facilitate allergen removal from indoor environments, it would be helpful to have household cleaning products that modified allergenic activity. Because NaOCl dissolves proteins in high concentrations and is both capable of killing bacteria and viruses and inactivating viral antigens at somewhat lower concentrations, we explored its effects on Mus m 1 and other indoor allergens. OBJECTIVE: To examine the ability of NaOCl to reduce the allergenicity of Mus m 1 and other indoor allergens. METHODS: Using purified mouse urinary allergen, we examined the effect on protein measured by Coomassie protein assay and on Mus m 1 measured by ELISA. We also examined the effects using SDS/PAGE and Western blots probed with sheep anti-Mus m 1 and with allergic human serum. RESULTS: When NaOCl and Mus m 1 were combined in a molar ratio of 100 : 1, IgE binding to Mus m 1 on Western blot was significantly reduced. At higher NaOCl concentrations the protein appeared to fragment and eventually became undetectable. Fragmentation appeared to be random in that peptides of a wide range of apparent molecular weight were produced. The reaction was complete within 1-2 min at OCl : pr ratios of greater than 200 : 1 and was optimal at pH 7.4. Immunological activity of other allergens (Fel d 1, Bla g 1, Der p 1) was decreased in vitro and dried allergen extracts were removed from surfaces. Adding an extraneous protein, BSA, to NaOCl:Mus m 1 solutions decreased the effect of NaOCl on the allergen. CONCLUSIONS: We concluded that NaOCl at concentrations commonly used in household products is capable of dramatically affecting allergenic protein.


Subject(s)
Allergens/metabolism , Peptide Fragments/metabolism , Animals , Antigens, Dermatophagoides , Antigens, Plant , Chlorine/metabolism , Electrophoresis, Polyacrylamide Gel , Glycoproteins/metabolism , Hydrogen-Ion Concentration , Kinetics , Male , Mice , Mice, Inbred C57BL , Peptide Fragments/immunology , Peptide Fragments/isolation & purification , Proteins/metabolism , Sodium Dodecyl Sulfate/metabolism , Sodium Hypochlorite/metabolism
9.
J Allergy Clin Immunol ; 107(3 Suppl): S422-9, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11242603

ABSTRACT

Cockroach infestations have been indicated as a major contributor to asthma throughout the world. Several studies have shown that large numbers of asthmatic patients are sensitized to cockroach allergens. Eliminating this pest from homes, schools, and public buildings involves a long-term commitment to a rational extermination process. This article covers the characteristics of the major cockroach species that invade homes, assesses the role of environmental exposure to cockroaches in asthma, and provides an intervention program for their extermination.


Subject(s)
Air Pollution, Indoor/prevention & control , Allergens/analysis , Cockroaches , Animals , Cockroaches/immunology , Humans
10.
J Allergy Clin Immunol ; 107(1): 48-54, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11149990

ABSTRACT

BACKGROUND: Children with asthma have a high prevalence of environmental allergies, especially to indoor allergens. The relationships of exposure to indoor allergens (dust mites, cat, dog, cockroach, and molds) and other host factors to allergy sensitization have not been evaluated simultaneously in a large cohort. OBJECTIVES: We studied 1041 children aged 5 to 12 years with mild-to-moderate asthma to determine risk factors associated with having positive allergy skin test responses to indoor allergens. Also, we described, compared, and contrasted 6 allergens in the home environments of these children from 8 North American cities. METHODS: Data were used from baseline visits of the Childhood Asthma Management Program. Patients' sensitivities to house dust mites (Dermatophagoides farinae and Dermatophagoides pteronyssinus), cats, dogs, cockroaches, and molds were examined for relationships to demographic variables, home dust allergen exposures, number of other positive allergy skin test responses, total serum IgE levels, and smoking in the home. RESULTS: San Diego (78.5%) and Toronto (59.3%) had the topmost percentages of homes with moderate-to-high house dust mite levels. Boston (21.5%), St Louis (16.3%), and Baltimore (13.4%) had the highest percentages of homes with detectable levels of cockroach allergen. For house dust mites, the higher the level of allergen exposure, the more likely patients were to have positive allergy skin test responses, with relative odds of 9.0 (95% confidence interval, 5.4-15.1) for those exposed to high mite levels (>10.0 microg/g dust) relative to those unexposed. Even exposure to low levels of mite allergen (0.020-2.0 microg/g) was found to be a significant risk factor for sensitization. For cockroach allergen, those with detectable home exposure were more likely to have positive skin test responses (relative odds, 2.2; 95% confidence interval, 1.3-3.8) than those with undetectable exposure. In contrast, levels of exposure to cat, dog, and mold allergens were not related to sensitization rates. For cat allergen, this may reflect lower rates of cat ownership among highly sensitized subjects. Furthermore, the number of allergy skin test responses that were positive, excluding the test for the outcome of interest for each model, and total serum IgE levels were strong independent predictors of sensitization. CONCLUSIONS: Levels of exposure determined by house dust analysis are important determinants of sensitization for dust mite and cockroach allergen. This relationship was not demonstrable for cat, dog, or mold allergens, possibly because of confounding factors. For all allergens studied, the degree of atopy, determined by the total number of positive skin test responses or by total serum IgE levels, is an important contributing risk factor for sensitization.


Subject(s)
Allergens/analysis , Asthma/immunology , Cockroaches/immunology , Dust/analysis , Mites/immunology , Air Pollution, Indoor/statistics & numerical data , Animals , Asthma/diagnosis , Asthma/epidemiology , Cats/immunology , Child , Child, Preschool , Cross-Sectional Studies , Dogs/immunology , Dose-Response Relationship, Immunologic , Female , Humans , Hypersensitivity, Immediate/immunology , Immunoglobulin E/blood , Male , Risk Factors , Skin Tests
11.
Ann Allergy Asthma Immunol ; 87(6 Suppl 3): 44-7, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11770683

ABSTRACT

LEARNING OBJECTIVES: The purpose of this review is to describe recommended methods of decreasing exposure to indoor allergens. DATA SOURCES: Data were obtained from published studies and reviews. STUDY SELECTION: The reviewed studies met these criteria: 1) measurement of environmental allergens; 2) selection of participants with clearly defined allergic airway disease confirmed by detection of allergen-specific immunoglobulin E; and 3) clearly defined clinical and environmental outcomes. The studies were conducted as controlled clinical trials and the results between treated and control groups were compared with appropriate statistics. RESULTS: The results of these studies show that installing allergen proof encasings and washing bedding frequently reduces house-dust mite exposure by 10-fold or more and significantly improves clinical measures of asthma. Washing pets reduces allergen levels temporarily. Excluding the pet from the bedroom while installing allergen-proof encasings and operating air cleaner reduces airborne allergens although having no significant effect on allergic symptoms. Cockroach populations can be controlled for over 6 months and allergens can be reduced with controlled pesticide application and cleaning, but clinical correlates have not been reported. Methods to improve adherence to environmental control measures have not been tested but effective methods can be recommended from literature on medication adherence. CONCLUSIONS: For patients allergic to indoor allergens, reasonable recommendations include installation of allergen-impermeable encasings, frequent laundering of bedding, removing furred pets from the home, and controlling of cockroach populations with effective pesticides using the principles of integrated pest management.


Subject(s)
Air Pollution, Indoor/adverse effects , Air Pollution, Indoor/prevention & control , Allergens/adverse effects , Asthma/prevention & control , Environmental Exposure/prevention & control , Hypersensitivity/prevention & control , Animals
12.
J Allergy Clin Immunol ; 106(6): 1070-4, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11112888

ABSTRACT

BACKGROUND: Although mouse allergen is a well-defined cause of IgE-mediated hypersensitivity in occupational settings, it has not been well studied in the general population. OBJECTIVE: We sought to determine the prevalence of mouse allergen in inner-city homes. METHODS: A subset of 608 homes from the National Cooperative Inner-City Asthma Study population had dust samples adequate for analysis of mouse allergen. In addition, data regarding the demographics and housing of the subjects were related to the mouse allergen levels. RESULTS: Ninety-five percent of all homes had detectable mouse allergen (Mus m 1) in at least one room, with the highest levels found in kitchens (kitchen: range, 0-618 microg/g; median, 1.60 microg/g; bedroom: range, 0-294 microg/g; median, 0.52 microg/g; television-living room: range, 0-203 microg/g; median, 0. 57 microg/g). By city, 100% of the kitchens in Baltimore had detectable mouse allergen, with the lowest percentage (74%) in Cleveland. Mouse allergen levels correlated among rooms (R = 0.65-0. 75). Forty-nine percent of the homes had reported problems with mice within the last year, and 29% of the homes had evidence of mice in one or more rooms on home inspection and had higher levels of mouse allergen (P =.0001). Higher allergen levels were also associated with evidence of cockroach infestation in any room (P =.006). None of the other subject or housing demographics evaluated were associated with a higher prevalence or level of mouse allergen. CONCLUSIONS: We conclude that mouse allergen is widely distributed in inner-city homes and that cockroach infestation is associated with high mouse allergen levels.


Subject(s)
Allergens/analysis , Housing , Mice/immunology , Allergens/adverse effects , Animals , Asthma/etiology , Asthma/immunology , Child , Child, Preschool , Female , Housing/statistics & numerical data , Humans , Male , Urban Population/statistics & numerical data
13.
J Allergy Clin Immunol ; 106(6): 1075-80, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11112889

ABSTRACT

BACKGROUND: Although mouse allergen is known to cause occupational asthma in laboratory workers, its potential significance in home environments has never been studied. OBJECTIVE: This study was designed to define the prevalence of mouse sensitivity and its relationship to mouse allergen exposure and disease activity in inner-city children with asthma. METHODS: A subset of 499 subjects from the National Cooperative Inner-City Asthma Study had dust samples adequate for mouse allergen analysis, as well as valid puncture skin test (PST) results. Data were analyzed to relate mouse allergen exposure and other risk factors to mouse sensitization and asthma morbidity. RESULTS: Eighty-nine (18%) of the 499 children had a positive mouse skin test response. Children whose homes had mouse allergen levels above the median (1.60 microg/g) in the kitchen had a significantly higher rate of mouse sensitization (23% vs 11%, P =. 007). Atopy was also significantly related to mouse sensitization, with 40% of those with more than 4 positive PST responses having mouse sensitivity compared with 4% of those with no other positive PST responses (P <.0001). When atopy and exposure were considered together, 53% of those with more than 4 positive PST responses and allergen levels above the median had a positive PST response to mouse allergen compared with 22% of those with more than 4 positive PST responses and allergen levels below the median (P <.0001). The relationship among mouse allergen exposure, sensitization, and any measures of asthma morbidity was not statistically significant. CONCLUSIONS: Mouse allergen may be an important indoor allergen in inner-city children with asthma, with exposure and atopy contributing to mouse sensitization.


Subject(s)
Allergens/analysis , Housing , Mice/immunology , Animals , Asthma/immunology , Child , Child, Preschool , Environmental Exposure/analysis , Female , Humans , Hypersensitivity, Immediate/immunology , Immunization , Male , Socioeconomic Factors , Urban Health
15.
J Allergy Clin Immunol ; 105(6 Pt 1): 1077-84, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10856139

ABSTRACT

During the past several years, immunoassays for specific IgE antibodies have been refined to permit reporting results in mass units. Thus quantitative immunoassays for IgE antibodies may be an adjunct to skin tests. In cases of food allergy among children with atopic dermatitis, cutoff values for IgE antibody concentrations to egg, milk, peanut, and fish have been derived to provide 95% positive and 90% negative predictive values. Food-specific IgE antibody determinations can also be used to predict which food allergies are resolving spontaneously. Elevated egg-specific IgE antibody levels in infancy are associated with significantly increased risk for development of inhalant allergies later in childhood. In cases of inhalant allergy, specific IgE antibody levels correlate closely with results of inhalation challenge studies in cat-sensitive persons. Also, mite-specific IgE antibody levels correlate significantly with the mite allergen contents of reservoir dust in the homes of mite-sensitive persons. Immunoassays for quantitation of specific IgE antibodies may be used to document allergen sensitization over time and to evaluate the risk of reaction on allergen exposure. However, immunoassays and skin tests are not entirely interchangeable, and neither will replace the other in appropriate circumstances.


Subject(s)
Antibodies, Anti-Idiotypic/blood , Hypersensitivity/blood , Child, Preschool , Food Hypersensitivity/blood , Humans , Immunoassay , Immunoglobulin E/immunology , Infant
16.
J Allergy Clin Immunol ; 105(4): 704-10, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10756219

ABSTRACT

BACKGROUND: Zafirlukast, a leukotriene antagonist, has been shown to have protective effects against a variety of asthma triggers. OBJECTIVE: Our purpose was to evaluate zafirlukast's effects on upper and lower airway responses to cat allergen exposure with use of a well-characterized cat exposure model. METHODS: In a double-blind, placebo-controlled, cross-over trial 18 subjects with cat-induced asthma were randomly assigned to receive 1 week each of zafirlukast or placebo followed by a 1-hour cat challenge. Upper and lower respiratory symptoms were rated and spirometry and acoustic rhinometry were performed. Challenges were stopped early if the subject was too uncomfortable or had a >50% decrease in FEV(1). RESULTS: Overall changes in FEV(1) were significantly different with zafirlukast treatment (P = .02). Significant differences in FEV(1) change were detected at 15 and 30 minutes (P = .027 and .05, respectively) but not at 45 and 60 minutes. Changes in acoustic rhinometry were also significantly different at 15 and 30 minutes (P =.05 and .0005, respectively) but not at 45 and 60 minutes. Challenge length was significantly longer with zafirlukast versus placebo after adjustment for differences in allergen exposure (P = .022). Respiratory symptom scores were significantly different (lower respiratory, P < .001; upper respiratory, P = .038) through the first 30 minutes of the challenge after adjustment for allergen exposure. CONCLUSIONS: Zafirlukast was significantly more effective than placebo in preserving pulmonary function and nasal anatomy and extending challenge length when cat-sensitive asthmatic subjects were exposed to high levels of cat allergen.


Subject(s)
Cats/immunology , Leukotriene Antagonists/therapeutic use , Respiratory Hypersensitivity/immunology , Tosyl Compounds/therapeutic use , Adult , Allergens/adverse effects , Allergens/immunology , Animals , Asthma/drug therapy , Double-Blind Method , Female , Forced Expiratory Volume , Glycoproteins , Humans , Indoles , Male , Middle Aged , Phenylcarbamates , Sulfonamides
17.
J Allergy Clin Immunol ; 104(4 Pt 1): 842-6, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10518830

ABSTRACT

BACKGROUND: Allergen avoidance has been shown to improve the morbidity and physiology of asthma. Although cockroach allergen has been implicated in chronic asthma, little work has been reported on the feasibility of allergen removal from infested homes. OBJECTIVE: The objective of this study was to examine the effect of professional pest control and home cleaning on cockroach infestation and allergen concentrations in settled dust samples from the kitchens, bedrooms, and television-living rooms of inner-city homes. METHODS: Thirteen homes in inner-city Baltimore, Maryland, received a professional cleaning, with vacuuming and a thorough cleaning in the kitchen. Pest control technicians applied abamectin 0.05% gel to the kitchen and, to a limited extent, to the rest of the home and the cleaning was repeated. Technicians visited monthly from month 2 to month 8 to inspect, collect dust samples, and place passive cockroach traps. Bla g 1 concentrations in dust extract were measured by means of ELISA. RESULTS: The number of cockroaches captured in passive traps decreased rapidly in 11 homes, but complete extermination was achieved in only 7 homes. Bla g 1 concentrations were reduced by 93% in kitchens, 77% in television-living rooms, and 74% in bedrooms. The relative reduction in cockroach allergen was not related to successful extermination or to signs of poor house-cleaning. CONCLUSION: We concluded that cockroach extermination is feasible in inner-city homes but that standard house-cleaning procedures are only partially effective in removing residual allergen over 8 months.


Subject(s)
Allergens , Asthma/prevention & control , Cockroaches/immunology , Housing , Insect Control , Animals , Aspartic Acid Endopeptidases , Baltimore , Dust , Household Work , Humans , Urban Population
18.
Environ Health Perspect ; 107 Suppl 3: 439-50, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10346992

ABSTRACT

The prevalence and severity of asthma has increased in the last 20 years, and the greatest increase has been seen among children and young adults living in U.S. inner cities. The reasons for this increase are obviously complex, but include environmental exposures to allergens and pollutants, changing patterns of medication, and the psychosocial stresses of living in poor inner-city neighborhoods. This paper presents an overview of environmental, immunologic, and genetic factors associated with asthma morbidity and mortality. This overview can be used to provide a framework for designing an interdisciplinary research program to address the complexities of asthma etiology and exacerbation. The strongest epidemiologic association has been found between asthma morbidity and the exposure of immunologically sensitive asthmatic patients to airborne allergens. Our current understanding of the process of sensitization suggests that there is a strong genetic predisposition to form IgE to allergenic proteins on airborne particles. Much of this work has been conducted with animal models, but in a number of instances, specific confirmation has been reported in humans. Sensitized individuals respond to inhaled exposure with immediate mast-cell dependent inflammation that may be augmented by pollutant particles, especially diesel exhaust particles. Relatively little is known about the methods of assessing exposure to airborne pollutants, especially biologically active particulates. However, to examine the relationship of morbidity in genetically predisposed individuals, it will be important to determine the most relevant method of making this assessment.


Subject(s)
Asthma/etiology , Adult , Allergens , Animals , Asthma/epidemiology , Asthma/genetics , Child , Environmental Exposure , Environmental Pollutants/adverse effects , Female , Health Services Accessibility , Humans , Inflammation/etiology , Inflammation/genetics , Male , Ozone/adverse effects , Poverty , Stress, Psychological , United States/epidemiology , Urban Health
19.
J Allergy Clin Immunol ; 103(5 Pt 1): 773-9, 1999 May.
Article in English | MEDLINE | ID: mdl-10329809

ABSTRACT

BACKGROUND: Skin testing and RASTs are the most commonly used methods for the diagnosis of allergy. Questions remain, however, as to the accuracy of these tests, particularly with regard to the role of intradermal skin tests (IDSTs) in the evaluation of respiratory allergy. OBJECTIVE: The purpose of this study was to determine the predictive value of skin prick tests (SPTs), IDSTs, and RASTs in the diagnosis of cat allergy. METHODS: Patients were challenged with a well-characterized cat exposure model after evaluation by history, SPTs, IDSTs (if SPT results were negative), and RASTs. All patients were evaluated with respect to their upper respiratory responses, although only those patients with asthma were included in the analysis of lower airway responses. Challenge results were considered positive if the mean upper respiratory symptom score was 0.5 or more, the mean lower respiratory symptom score was 0.4 or more, or the maximum fall in FEV1 value was 15% or more. RESULTS: One hundred twenty patients were evaluated. SPT values were positive in 81 patients; of the remaining 39 patients, IDST values were positive in 26 patients. RASTs were performed in 89 patients; the values were positive in 45 of 51 patients with a positive SPT value and were negative in all patients with a negative SPT value. When any positive challenge outcome was considered, positive challenge results were seen in 38 of 41 patients with a positive SPT score, in 10 of 39 patients with a negative SPT score, in 6 of 26 patients with a positive IDST score, in 4 of 13 patients with a negative IDST score, in 27 of 27 patients with a positive RAST score, and in 12 of 44 patients with a negative RAST score. CONCLUSION: Although both SPT and RAST values exhibited excellent efficiency in the diagnosis of cat allergy, IDST scores added little to the diagnostic evaluation.


Subject(s)
Cats/immunology , Intradermal Tests , Radioallergosorbent Test , Respiratory Hypersensitivity/diagnosis , Skin Tests , Adult , Allergens/administration & dosage , Animals , Female , Forced Expiratory Volume , Humans , Male , Middle Aged
20.
J Allergy Clin Immunol ; 103(3 Pt 1): 501-6, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10069886

ABSTRACT

BACKGROUND: Cockroach allergen is important in asthma. Practical methods to reduce exposure are needed. OBJECTIVE: We sought to evaluate the effectiveness of house cleaning and professional extermination on lowering cockroach antigen levels in inner-city dwellings. METHODS: As part of the National Cooperative Inner-City Asthma Study intervention, 265 of 331 families with asthmatic children who had positive skin test responses to cockroach allergen consented to a professional home extermination with 2 applications of a cockroach insecticide (Abamectin, Avert) combined with directed education on cockroach allergen removal. On a random subset of 48 homes undergoing cockroach extermination in the intervention group, Bla g 1 was measured in settled dust from the kitchen, bedroom, and TV/living room. The first sample was collected 1 week before extermination, with additional samples after the exterminations at approximately 2, 6, and 12 months after the first sample. Self-reported problems with cockroaches were collected at baseline and after 12 months of follow-up in both the intervention and control group. RESULTS: The geometric mean kitchen level of Bla g 1 decreased at 2 months (33.6 U/g) relative to preextermination levels (68.7 U/g, P <.05). The percent of kitchens with over 8 U/g of Bla g 1 followed a similar pattern, but only the decrease from preextermination to 6-month levels was significant (86.8% vs 64.3%, P <.05). By the 12-month visit, the allergen burden had returned to or exceeded baseline levels. Except for an increase in the bedroom at 2 months (8.9 U/g vs 11.1 U/g, P <.05), no other significant change was seen. Only about 50% of the families followed the cleaning instructions; no greater effect was found in these homes. Self-reported problems with cockroaches showed no difference between the intervention and control group after 1 year of follow-up. CONCLUSIONS: Despite a significant, but short-lived, decrease the cockroach allergen burden remained well above levels previously found to be clinically significant.


Subject(s)
Allergens/adverse effects , Asthma/prevention & control , Cockroaches/immunology , Dust/analysis , Housing , Insect Control , Insect Proteins/adverse effects , Allergens/analysis , Animals , Antigens, Plant , Asthma/epidemiology , Asthma/etiology , Cross-Sectional Studies , Environmental Exposure , Humans , Insect Proteins/analysis , Program Evaluation , United States/epidemiology , Urban Population
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