Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Allergy. 2010 Nov;65(11):1414-22. doi: 10.1111/j.1398-9995.2010.02412.x.
Relationships among allergen-specific IgE levels, allergen exposure and asthma severity are poorly understood since sensitization has previously been evaluated as a dichotomous, rather than continuous characteristic.
Five hundred and forty-six inner-city adolescents enrolled in the Asthma Control Evaluation study underwent exhaled nitric oxide (FE(NO)) measurement, lung function testing, and completion of a questionnaire. Allergen-specific IgE levels and blood eosinophils were quantified. Dust samples were collected from the participants' bedrooms for quantification of allergen concentrations. Participants were followed for 12 months and clinical outcomes were tracked.
Among sensitized participants, allergen-specific IgE levels were correlated with the corresponding settled dust allergen levels for cockroach, dust mite, and mouse (r = 0.38, 0.34, 0.19, respectively; P < 0.0001 for cockroach and dust mite and P = 0.03 for mouse), but not cat (r = -0.02, P = 0.71). Higher cockroach-, mite-, mouse-, and cat-specific IgE levels were associated with higher FE(NO) concentrations, poorer lung function, and higher blood eosinophils. Higher cat, dust mite, and mouse allergen-specific IgE levels were also associated with an increasing risk of exacerbations or hospitalization.
Allergen-specific IgE levels were correlated with allergen exposure among sensitized participants, except for cat. Allergen-specific IgE levels were also associated with more severe asthma across a range of clinical and biologic markers. Adjusting for exposure did not provide additional predictive value, suggesting that higher allergen-specific IgE levels may be indicative of both higher exposure and a greater degree of sensitization, which in turn may result in greater asthma severity.
过敏原特异性 IgE 水平、过敏原暴露与哮喘严重程度之间的关系尚未明确，因为致敏以前被评估为二分类而非连续特征。
546 名参与哮喘控制评估研究的城市内青少年接受了呼出气一氧化氮（FE(NO)）测量、肺功能测试和问卷调查。测定了过敏原特异性 IgE 水平和血嗜酸性粒细胞计数。采集参与者卧室的灰尘样本以定量评估过敏原浓度。对参与者进行了 12 个月的随访并跟踪了临床结局。
在致敏参与者中，过敏原特异性 IgE 水平与相应的蟑螂、尘螨和鼠过敏原的定居灰尘水平相关（分别为 r = 0.38、0.34、0.19；蟑螂和尘螨 P < 0.0001，鼠 P = 0.03），但与猫不相关（r = -0.02，P = 0.71）。较高的蟑螂、螨、鼠和猫过敏原特异性 IgE 水平与更高的 FE(NO)浓度、更差的肺功能和更高的血嗜酸性粒细胞计数相关。较高的猫、尘螨和鼠过敏原特异性 IgE 水平也与恶化或住院的风险增加相关。
除了猫之外，致敏参与者中过敏原特异性 IgE 水平与过敏原暴露相关。过敏原特异性 IgE 水平也与一系列临床和生物学标志物提示的更严重哮喘相关。调整暴露因素后并未提供额外的预测价值，这表明较高的过敏原特异性 IgE 水平可能既指示了更高的暴露水平，也指示了更强的致敏程度，进而可能导致更严重的哮喘。
