Bronchodilator responsiveness and serum total IgE levels in families of probands with severe early-onset COPD

Bronchodilator responsiveness has been associated with a subsequent acceler ated decline in forced expiratory volume in one second (FEV1), Therefore, b ronchodilator responsiveness and total serum immunoglobulin E(IgE) levels w ere assessed in 184 adult first-degree relatives of probands with severe ea rly-onset chronic obstructive pulmonary disease (COPD) and a control group. Greater bronchodilator responsiveness was found among current smokers or ex smokers who were first-degree relatives of early-onset COPD probands than i n currently or exsmoking controls, expressed as increase in FEV1 as a perce ntage of baseline (5.8+/-8.1 versus 2.9+/-5.1%, p<0.01), absolute increase in FEV1 from baseline (120+/-130 versus 60+/-110 mL, p<0.05), and increase in FEV1 as a percentage of the predicted value (3.6+/-4.1 versus 2.2+/-3.9% , p<0.05). However, elevated total serum IgE Levels were not found in first -degree relatives of early-onset COPD probands compared with control subjec ts. The increased bronchodilator responsiveness among currently smoking/exsmoki ng first-degree relatives of early-onset COPD probands suggests that these individuals may have enhanced susceptibility to the detrimental effects of cigarette smoking.