Atopy as a risk factor for asthma severity

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Abstracts

Atopyas a Risk Factorfor AsthmaSeverity

Sally H Jot*, RA Wood§, Elizabeth Cotton Matsui*, 77" Pero.§, JM Curtin-Brosnan§, S Kanchanaraksa§, CS Rand§, Karen Callahan*, Lee Swartz*, Peyton A Eggleston§ *Johns Hopkins Hospital, Baltimore, MD §Johns Hopkins University, Baltimore, MD Exposure and sensitization to indoor allergens has shown to be a known risk factor for the development and persistence of asthma in children. The objective of this study was to evaluate the relationship between exposure and sensitization to indoor allergens and asthma severity in a predominantly suburban population. Children with asthma were recruited from 4 pediatric practices in the Baltimore, Maryland area for participation in the Home Study, a clinical trial evaluating the efficacy of environmental control measures. Upon recruitment, a detailed questionnaire regarding asthma severity was completed, prick skin tests (PST) to 14 common indoor and outdoor allergens were performed, and exposure to indoor allergens was assessed by measuring Bla g 2, Der pl, Der fl, Fel dl and Can fl levels in dust samples collected from the bedroom, kitchen, and living room. Children were considered to be exposed if levels were >2000ng/g Der pl, Der fl, Fel dl, and Can fl and > 1U/g for Bla g 2. Asthma severity was measured based on a composite symptom score, use of inhaled corticosteroids or other controller medications, and the need for prednisone or emergency room (ER) visits in the previous 6 months. Data were analyzed to determine if exposure, sensitization, or the combination of the two affected asthma severity. The study included 158 subjects with ages ranging from 6 to 17 years. Allergen levels above the threshold occurred in one or more rooms for Bla g 2 in 57% of homes, Der p I in 15%, Der fl in 36%, Fel d l in 37%. and Can fl in 48%. 32% of subjects had positive PST to cockroach. 55% to cat, 70% to one or both dust mites and 11% to dogs. No significant relationship was detected between allergen exposure or sensitization to any specific allergen and any measure of asthma severity. When the combination of exposure and sensitization to a specific allergen was analyzed, no significant relationships were detected, although there was a trend towards increased asthma severity as measured by ER visits in those with cockroach exposure and sensitization (P= 0.1). Significant relationships were detected between atopy, based on the number of positive PST, and ER visits, but not with other measures of asthma severity. When subjects with no positive PST were compared to those with >1 positive PST, there was a significant difference in the proportion with an ER visit (4.8% vs 33.6%, P=0.007). When subjects with 0-1 positive PST were compared to those with >2 positive PST, a similar difference was seen (6.7% vs 35.2%, P=0.002). The relationship between the number of positive PST and ER visits continued to be significant up to 5 positive PST (P=0.009). In summary, while asthma severity in this population was not significantly associated with specific allergen exposures or sensitivities, it was clearly associated with the degree of atopy.

101 Indoor Allergen Levelsin Homesof Asthmaticand HealthyChildren in Kuwait Mahdi A1-Mousawwi*, Hermione Lovel*, Nasser Behbehani§, Nermina Arifhodzick~,, Adnan Custovie~, Ashley A. WoodcockC *Manchester University, Manchester, UK §Kuwait University, Kuwait, Kuwait ¥Kuwait Allergy Center, Kuwait, Kuwait CWythenshawe Hospital, Manchester, UK Indoor allergens exposure in homes may be an important risk factor for the developement of asthma. We compared the levels of known indoor allergens (Der p 1, Der f 1, Fel d 1, Can f 1, Bla g 2) in homes of 152 asthma children and 268 controls. Two samples (living room and bed room) were obtained from each home. The dust sample was collected from the bedding and living room floors. A two-site monoclonal antibody-based ELISAs were used to determine the allergens levels. The geometric mean of Fel d 1 in the living room and bedding of asthmatic and control homes were 0.23, 0.22, 0.22, and 0.19 I-tg/g respectively. The geometric mean of Can f 1 in the

J ALLERGY CLIN IMMUNOL JANUARY 2002

living room and bedding of asthmatic and control homes were 0.13, 0.16, 0.20. and 0.18 lag/g respectively. The geometric mean of Bla g 2 in the living room and bedding of asthmatic and control homes were 0.32, 0.42, 0.23. and 0.32 ~tg/g respectively, b e r p 1 and Der f 1 were below the limits of detection in the majority of samples. CONCLUSION: Low levels of mite, cat, dog and cockroach allergens were found in Kuwaiti homes. There was no significant differences between asthmatic and control homes.

102

Oral Delivery of Cromolyn:Bioavailability and BioactivityAfter Oral Administrationin Animal Models

Donald Sarubbi*, Puchun Liu*, Ehud Arbit*, William Abraham§, Steven Dinh* *Emisphere Technologies, Tarrytown, NY §University of Miami at Mount Sinai Medical Center, Miami Beach, FL Cromolyn is used to treat mild to moderate bronchial asthma. While an oral dosage form can offer significant therapeutic advantages, it has been limited by its low oral bioavailability (