Quantitative assessment of exposure to dog (Can f 1) and cat (Fel d 1) allergens: Relation to sensitization and asthma among children living in Los Alamos, New Mexico☆,☆☆,★

https://doi.org/10.1016/S0091-6749(95)70286-5Get rights and content

Abstract

Background: Our objective was to identify the allergens associated with asthma among schoolchildren in an area of the United States where dust mite growth is expected to be poor. Los Alamos, N.M., was chosen because it has low rainfall and is at high altitude (7200 feet), making it very dry. One hundred eleven children (12 to 14 years old) from the middle school who had been previously classified according to bronchial hyperreactivity to histamine (BHR) were studied. Methods: Sera were assayed for IgE antibodies to mite, cat, dog, cockroach, Russian thistle, and grass pollen, with both CAP system fluoroimmunoassay (Kabi Pharmacia, Uppsala, Sweden) and conventional RAST. Allergens were measured in dust samples from 109 homes with two-site assays for mite (Der p 1 and Der f 1), cat (Fel d 1), dog (Can f 1), and cockroach (Bla g 2). Results: Concentrations of dog and cat allergens were elevated in almost all houses with pets but were also high in a significant proportion of the houses without pets. Levels of mite allergen were less than 2 μg/gm in 95% of the houses, and cockroach was undetectable in all but two of the houses. Among the 21 with BHR who had symptoms, 67% had IgE antibody to dog and 62% had IgE antibody to cat. For these allergens IgE antibody was strongly associated with asthma (p < 0.001). By contrast, the presence of IgE antibody to mite, cockroach, or grass pollen was not significantly associated with asthma. Conclusion: The high prevalence of IgE antibody to cat and dog allergens among these children is in keeping with the presence of cat and/or dog allergen in most of the houses. Furthermore, sensitization (as judged by IgE antibodies) to cat and dog allergens was strongly associated with asthma. On the other hand, no clear relationship was found between sensitization or symptoms and the current level of allergen in individual houses. The results show that in this mite-and cockroach-free environment sensitization to domestic animals was the most significant association with asthma. (J Allergy Clin Immunol 1995;96:449-56.)

Section snippets

Subjects

Approval for the study was obtained from the school board and administration of the Los Alamos, N.M., school system, the University of Virginia Human Investigation Committee, and the Los Alamos Medical Center. Phase I of the study consisted of enrollment of 567 children (12 to 14 years old) in the seventh and eighth grades at Los Alamos Middle School during 1 week of March 1992. An in-school respiratory questionnaire was administered to all consenting children, and a similar questionnaire was

Exposure to indoor allergens

The homes of 109 children were visited and dust samples were assayed for dog, cat, dust mite, and cockroach allergens. The levels of dog and cat allergens were very high, in keeping with the fact that dogs were present in 65 homes and cats were present in 44 homes (Fig. 1). At least four samples of dust were obtained from each house, and in keeping with previous reports the values shown are the highest level found. At least 10 μg Can f 1 per gram of dust was found in 65% of the homes, and at

DISCUSSION

Our results showed that of the homes sampled in Los Alamos, 50% had more than 8 μg of cat allergen per gram of dust, whereas 65% had more than 10 μg dog allergen per gram. By contrast, only 4% and 2% had significant levels of dust mite or cockroach allergen, respectively. A threshold level for cat allergen has been proposed previously.12 Threshold levels for dog allergen have not been proposed. From our results it is clear that at least 95% of the houses with a dog have more than 10 μg/gm of

Acknowledgements

We thank Dr. Jim Sussman, Marlene Muller, and Debbie Claytor for their help and hospitality in Los Alamos. We are grateful to Nicolle Couture for technical assistance and to Lisa Vailes for helpful laboratory advice, to David Jeffus and Nancy Malone for preparing the manuscript, and to Madeleine Watkins for preparing the figures. In addition, we are grateful to Dr. Jonathan Samet for suggesting Los Alamos as a site for the study.

References (28)

  • LG Arlian et al.

    Prevalence of dust mites in the homes of asthmatics living in eight different geographical areas of the United States

    J ALLERGY CLIN IMMUNOL

    (1992)
  • R Sporik et al.

    House dust mite exposure as a cause of asthma [Editorial]

    Clin Exp Allergy

    (1992)
  • R Sporik et al.

    Exposure to house dust mite allergen (Der p I) and the development of asthma in childhood: a prospective study

    N Engl J Med

    (1990)
  • D Charpin et al.

    Altitude and allergy to house dust mites: a paradigm of the influence of environmental exposure on allergen sensitization

    Am Rev Resp Dis

    (1991)

    • Cited by (0)

    ☆

    From aUniversity of Virginia Health Sciences Center, Department of Internal Medicine, Division of Asthma and Allergic Diseases, Charlottesville; bRespiratory Unit, Great Ormond Street Hospital for Children, London; and cLos Alamos Medical Center.

    ☆☆

    Supported by National Institutes of Health grants AI-20565 and U01-AI-34607.

    ★

    Reprint requests: Thomas A.E. Platts-Mills, MD, PhD, UVA Health Sciences Center, Asthma and Allergic Diseases Center, Box 225, Charlottesville, VA 22908.

    View full text
    Copyright © 1995 Mosby, Inc. All rights reserved.