IgE-mediated and age-related bronchial hyperresponsiveness in patients with asthma. Relationship to family history of the disease

Objective: To uncover any differences in the age-related and IgE-mediated pathophysiology of the airways in asthmatics. Methods: We examined the relationship of both IgE-mediated bronchial hyperresponsiveness and the cell content of bronchoalveolar lavage fluid with a family history of asthma in 263 patients with asthma classified according to age at onset. Results: Bronchial hyperresponsiveness decreased significantly as age at onset increased in those without a family history. Responsiveness was significantly higher in patients who were ≥60 years of age at onset who had a family history than in those who did not (P < 0.05). The proportion of lymphocytes in bronchoalveolar lavage fluid was significantly higher in patients between 50 and 59 years old at onset who had a family history than those who did not (P < 0.05). These results suggest that bronchial hyperresponsiveness and the proportion of bronchoalveolar lavage lymphocytes differ according to the presence or absence of a family history, a finding which is closely related to IgE-mediated allergy in elderly patients at onset. Conclusions: Our findings suggest (i) the possibility of asthma induced by non-IgE-mediated allergy in elderly patients and (ii) that bronchial responsiveness is also influenced by IgE-mediated allergy and age at onset.