Bernstein D I, Ploysongsang Y, Mittman R J, Piyamahunt A, Bernstein I L
Division of Immunology, University of Cincinnati Medical Sciences Center.
Chest. 1992 Feb;101(2):437-41. doi: 10.1378/chest.101.2.437.
Single blind allergen (Ag) and saline solution bronchial challenges were performed on two successive study days in ten asthmatic subjects. Histamine challenges were performed before, at approximately 2 h (or after resolution of the immediate bronchial response [IR]), and 24 h after saline solution or Ag inhalation. Specific airway conductance (SGaw) was measured after delivery of challenge agents until a 50 percent fall in SGaw was observed. The SGaw was monitored over 8 h for immediate and late asthmatic responses (LAR). Results were expressed as provocative concentrations eliciting a 50 percent decrease in SGaw (SGawPC50HIS). No significant changes from baseline SGaw or SGawPC50HIS were demonstrated after saline solution. Eight subjects (dual reactors) exhibited both an IR and LAR after Ag and two had isolated IRs. Of the eight dual reactors, five had greater than 50 percent decreases in SGawPC50HIS immediately after resolution of the IR and six exhibited such decrements 24 h after Ag provocation. Mean baseline SGawPC50HIS (N = 10) on the Ag challenge day was 3.2 +/- 4.59 mg/ml and decreased to 0.92 +/- 4.56 mg/ml at 102 to 187 minutes after Ag (p = 0.0009) and was significantly decreased from baseline at 1.47 +/- 3.8 mg/ml 24 h after Ag (p = 0.0004). One of the two patients with isolated IR also showed an early onset increase in airway responsiveness (EOR). There was a significant correlation between the percentage of fall from baseline in SGawPC50HIS immediately after the IR and that at 24 h after Ag (r = 0.811, p = 0.005). There was no significant correlation between the decrease in SGawPC50HIS after the IR and the magnitude of the LAR. These data suggest that (1) the early events occurring prior to the LAR may determine changes in airway responsiveness observed at 24 h after Ag challenge, and (2) the EAR to histamine is not exclusively associated with the LAR.
在连续两天对10名哮喘患者进行了单盲变应原（Ag）和生理盐水支气管激发试验。在吸入生理盐水或Ag之前、约2小时后（或速发型支气管反应[IR]消退后）以及24小时后进行组胺激发试验。在给予激发剂后测量比气道传导率（SGaw），直至观察到SGaw下降50%。在8小时内监测SGaw以观察速发和迟发哮喘反应（LAR）。结果以引起SGaw下降50%的激发浓度（SGawPC50HIS）表示。生理盐水激发后，SGaw或SGawPC50HIS与基线相比无显著变化。8名受试者（双重反应者）在Ag激发后出现了速发反应和迟发反应，2名受试者仅有速发反应。在8名双重反应者中，5名在速发反应消退后立即出现SGawPC50HIS下降超过50%，6名在Ag激发后24小时出现这种下降。Ag激发日的平均基线SGawPC50HIS（N = 10）为3.2±4.59 mg/ml，在Ag激发后102至187分钟降至0.92±4.56 mg/ml（p = 0.0009），在Ag激发后24小时降至1.47±3.8 mg/ml，与基线相比显著下降（p = 0.0004）。两名仅有速发反应的患者中有一名也表现出气道反应性早期升高（EOR）。速发反应后立即出现的SGawPC50HIS相对于基线下降的百分比与Ag激发后24小时的下降百分比之间存在显著相关性（r = 0.811，p = 0.005）。速发反应后SGawPC50HIS的下降与迟发反应的严重程度之间无显著相关性。这些数据表明：（1）迟发反应之前发生的早期事件可能决定了在Ag激发后24小时观察到的气道反应性变化；（2）对组胺的早期气道反应并不完全与迟发反应相关。
