Published Online: June 2012
In countries with temperate climates, the risk for asthma attacks requiring hospital care in patients older than 3 is increased by infections with rhinovirus (RV, the “common cold virus”) together with sensitization and exposure to environmental allergens. Whether these observations can be generalized to children living in countries with tropical climates is not clear and is important to know in order to gain a better understanding for the underlying causes of asthma attacks among children living in countries with different environmental exposures. This information can help to guide the development of new and better treatments (e.g., anti-viral medications, including vaccines, and/or therapies to decrease allergic inflammation).
In an article published in The Journal of Allergy and Clinical Immunology (JACI), doctors from the University of Virginia and the Hospital Nacional de Niños in San José, Costa Rica, report the results of a collaborative study that addresses this issue. Ninety-six children (ages 7-12 years) who were treated for acute wheezing in a Costa Rican emergency room participated in the study, together with 65 children with asthma that was stable at the time of enrollment, and 126 non-asthmatic controls. Methods such as gene sequencing were used to identify viral pathogens in nasal secretions. The results were examined in relation to wheezing and the allergic status of each child.
Results and implications: Most of the wheezing children (96%) were atopic, and a large majority of them (93%) were sensitized to dust mite allergen. More strikingly, the concentration (titers) of IgE antibodies to dust mite among children enrolled for wheezing, as well as those with stable asthma, were significantly greater than to any other allergen tested. Additionally, 75% of the rhinovirus pathogens detected were group C strains, but both group A and group C strains were significantly associated with acute wheezing.
Children who had the greatest risk for an asthma attack caused by RV (both group A and C strains) were those who had high titers of IgE antibody to dust mite allergen (>17.5 IU/ml).
The results from this study provide strong evidence that characterizing the atopic status of asthmatic children in greater detail, including their total IgE levels and titers of allergen-specific IgE antibodies, is needed to enhance future investigations focused on the role of allergic inflammation in increasing the risk of RV-induced attacks of asthma and for identifying children who are most likely to benefit from new therapies, including allergen-specific treatments.
The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.