Sensitization to cat allergen is associated with asthma in older men and predicts new-onset airway hyperresponsiveness. The Normative Aging Study.
To explore the relationship between sensitization to inhalant allergens and adult asthma, we performed two nested case-control studies of men being followed in the VA Normative Aging Study. In Study A, 46 subjects (mean age, 61.2 +/- 8.1 yr) with symptoms of asthma and an abnormal methacholine challenge test (cases) were compared with 92 age- and smoking-history-matched subjects, who denied symptoms and had normal methacholine challenge tests (controls). The age of onset of wheezing symptoms for the cases was 49.0 +/- 15.7 yr. Serum IgE reactivity to the aeroallergens Der P 1 and 2, cat, ragweed, and mouse was compared in cases and controls. Cases were more likely to be sensitized to cat allergen (23.9% versus 4.4%, p < 0.001) than were controls. Prevalences of sensitization to Der p 1, Der p 2, ragweed, and mouse were low and similar in the two groups. In Study B, 33 cases who developed new onset airway hyperresponsiveness on methacholine challenge testing were compared with 66 age-matched controls who maintained normal methacholine challenge tests. Cases had a higher prevalence of serum IgE reactivity to cat allergen (18.2% versus 6.1%, p = 0.059) and Der p 2 (21.2% versus 10.6%, p = 0.153) measured in serum obtained 3 yr before the development of airway hyperresponsiveness. These results suggest that in older men, sensitization to cat allergen is associated with asthma and that sensitization predates airway hyperresponsiveness to methacholine.
Litonjua
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Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Sparrow
D
D
Weiss
S T
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O'Connor
G T
GT
Long
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Ohman
J L
JL
D000368:Aged; D000485:Allergens / Q000276:immunology*; D000818:Animals; D001249:Asthma / Q000276:immunology*; D016535:Bronchial Hyperreactivity / Q000139:chemically induced / Q000276:immunology*; D016022:Case-Control Studies; D002415:Cats / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged
D000485:Allergens; D016210:Methacholine Chloride; D007073:Immunoglobulin E