Custovic A, Taggart S C, Francis H C, Chapman M D, Woodcock A
North West Lung Centre, Wythenshawe Hospital, Manchester, England.
J Allergy Clin Immunol. 1996 Jul;98(1):64-72. doi: 10.1016/s0091-6749(96)70227-0.
House dust mite allergens play an important role in inducing IgE-mediated sensitization and the development of bronchial hyperresponsiveness (BHR) and asthma. This study investigated the relationship between mite allergen exposure and the clinical activity and severity of asthma.
Nonsmoking adult patients with asthma (n = 53) were randomly recruited from the asthma registry of two large family practitioner surgeries. Each participant underwent skin testing with common inhalant allergens, a methacholine bronchoprovocation test, and pulmonary function testing on up to 3 separate occasions over a 4-week period. BHR was expressed both as PD20 and dose-response ratio (DRR), and the patients with patients with PD20 of less than 12.25 mumol methacholine were classified as methacholine reactors. Patients were also asked to record peak expiratory flow rate (PEFR) values at 2-hour intervals during waking hours for 1 month. Daily PEFR variability was calculated as amplitude percent mean. Dust samples were collected by vacuuming bedding, bedroom carpets and mattresses. In addition, in the homes of 32 subjects with positive skin test responses to mites, airborne samples were taken overnight for 8 hours with a personal sampler attached to each subject's pillow. Der p 1 and Der p 2 levels were determined by a two-site monoclonal antibody-based ELISA.
No difference in mite exposure was found between subjects who were sensitive to mites and those who were not. However, mite-sensitive methacholine reactors were exposed to significantly higher concentrations of Der p 1 in beds than mite-sensitive methacholine nonreactors (13.2 micrograms/gm and 1.45 micrograms/gm, respectively; p < 0.02). Der p 1 and Der p 2 were undetectable in 30 of 32 airborne samples. In mite-sensitive patients both Der p 1 and Der p 2 in beds significantly correlated with BHR (PD20: r = -0.49, DRR, r = 0.49; PD20: r = -0.46, DRR: r = 0.43) and amplitude percent mean PEFR (r = 0.38, r = 0.41) for Der p 1 and Der p 2, respectively. There was a significant negative correlation between exposure to Der p 1 and percent predicted FEV1 (r = -0.43). The correlation between Der p 2 and percent predicted FEV1 just failed to reach a significant level but showed a clear trend ( r = -0.35, p = 0.068).
Clinical activity and severity of asthma (measured by the level of BHR, PEFR variability, and percent predicted FEV1) in mite-sensitive patients is related to exposure to mite allergens in the dust reservoir, with levels in bed being an important indicator that correlated with disease activity.
屋尘螨过敏原在诱导IgE介导的致敏反应以及支气管高反应性（BHR）和哮喘的发展中起重要作用。本研究调查了螨过敏原暴露与哮喘临床活动及严重程度之间的关系。
从两个大型家庭医生诊所的哮喘登记处随机招募了53名不吸烟的成年哮喘患者。每位参与者接受常见吸入性过敏原皮肤试验、乙酰甲胆碱支气管激发试验以及在4周内分3次进行的肺功能测试。BHR用PD20和剂量反应比（DRR）表示，PD20小于12.25μmol乙酰甲胆碱的患者被归类为乙酰甲胆碱反应者。患者还被要求在清醒时间每隔2小时记录1个月的呼气峰值流速（PEFR）值。每日PEFR变异性以平均振幅百分比计算。通过用吸尘器清洁床上用品、卧室地毯和床垫来收集灰尘样本。此外，在32名对螨皮肤试验呈阳性反应的受试者家中，使用附着在每个受试者枕头的个人采样器进行8小时的夜间空气样本采集。采用基于双位点单克隆抗体的ELISA法测定Der p 1和Der p 2水平。
对螨敏感的受试者与不敏感的受试者之间在螨暴露方面未发现差异。然而，对螨敏感的乙酰甲胆碱反应者在床上接触的Der p 1浓度明显高于对螨敏感的乙酰甲胆碱无反应者（分别为13.2微克/克和1.45微克/克；p<0.02）。在32份空气样本中的30份中未检测到Der p 1和Der p 2。在对螨敏感的患者中，床上的Der p 1和Der p 2均与BHR（PD20：r=-0.49，DRR：r=0.49；PD20：r=-0.46，DRR：r=0.43）以及Der p 1和Der p 2的平均PEFR振幅百分比（r=0.38，r=0.41）显著相关。Der p 1暴露与预测的FEV1百分比之间存在显著负相关（r=-0.43）。Der p 2与预测的FEV1百分比之间的相关性刚刚未达到显著水平，但显示出明显趋势（r=-0.35，p=0.068）。
对螨敏感患者的哮喘临床活动及严重程度（通过BHR水平、PEFR变异性和预测的FEV1百分比衡量）与灰尘储存库中螨过敏原的暴露有关，床上的水平是与疾病活动相关的重要指标。
