Guan Wei-Jie, Zheng Jin-Ping, Shi Xu, Xie Yan-Qing, Jiang Cai-Yu, Gao Yi, Zhu Zheng, An Jia-Ying, Yu Xin-Xin, Liu Wen-Ting
State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang Road, Guangzhou, Guangdong, China.
Lung. 2014 Oct;192(5):701-9. doi: 10.1007/s00408-014-9612-7. Epub 2014 Jun 24.
Response-dose ratio (RDR) and cumulative provocative dosage (PD) are useful indices reflecting airway responsiveness in asthma.
To compare the diagnostic value of RDR and PD, by conducting leukotriene D4 (LTD4-BPT) and methacholine bronchial provocation test (MCh-BPT), in different asthma control levels.
Healthy subjects and asthmatic patients underwent LTD4-BPT and MCh-BPT, at 2-14-day interval. This entailed assessment of the distribution characteristics, correlation, and diagnostic value of PD inducing 20% fall in forced expiratory volume in one second (PD20FEV1) and the RDR, defined as FEV1 fall (%) at the final step divided by the corresponding provocative dosage.
Twenty uncontrolled, 22 partly controlled, 20 controlled asthmatics, and 21 healthy subjects were enrolled. Log10RDR was positively correlated with log10PD20FEV1 in both BPTs (all P < 0.05). Poorer asthma control was associated with significantly lower PD20FEV1 and higher RDR (both P < 0.05). The differences in PD20FEV1 and RDR between partly controlled and controlled asthma were unremarkable (both P > 0.05). Compared with log10PD20FEV1, the log10RDR yielded similar diagnostic values in both BPTs. A lower percentile of RDR (≤ 25th percentile) was associated with higher baseline FEV1 (P < 0.05) and an increased proportion of well-controlled asthmatic patients. The combination of RDR and PD20FEV1 led to an increased diagnostic value compared with either parameter alone.
RDR is a surrogate of PD20FEV1 for BPTs in asthma. This finding was not modified by different asthma control levels or the types of bronchoprovocants.
反应剂量比（RDR）和累积激发剂量（PD）是反映哮喘气道反应性的有用指标。
通过进行白三烯D4（LTD4 - BPT）和乙酰甲胆碱支气管激发试验（MCh - BPT），比较RDR和PD在不同哮喘控制水平下的诊断价值。
健康受试者和哮喘患者每隔2 - 14天进行一次LTD4 - BPT和MCh - BPT。这需要评估诱导一秒用力呼气量下降20%的PD（PD20FEV1）的分布特征、相关性和诊断价值，以及RDR，RDR定义为最后一步时FEV1下降百分比（%）除以相应的激发剂量。
纳入了20例未控制、22例部分控制、20例控制良好的哮喘患者以及21例健康受试者。在两种激发试验中，log10RDR与log10PD20FEV1均呈正相关（所有P < 0.05）。哮喘控制越差，PD20FEV1越低，RDR越高（均P < 0.05）。部分控制和控制良好的哮喘之间，PD20FEV1和RDR的差异不显著（均P > 0.05）。与log10PD20FEV1相比，log10RDR在两种激发试验中具有相似的诊断价值。较低百分位数的RDR（≤第25百分位数）与较高的基线FEV1相关（P < 0.05），且控制良好的哮喘患者比例增加。与单独使用任一参数相比，RDR和PD20FEV1联合使用可提高诊断价值。
在哮喘激发试验中，RDR是PD20FEV1的替代指标。这一发现不受不同哮喘控制水平或支气管激发剂类型的影响。
