痰炎性标志物对支气管激发试验阳性的亚急性和慢性咳嗽的鉴别诊断价值

目的:检测激发试验阳性的亚急性、慢性咳嗽患者诱导痰中嗜酸性粒细胞(Eos)、嗜酸粒细胞阳离子蛋白(ECP)水平,探讨其对亚急性、慢性咳嗽鉴别诊断的临床价值。方法:55例激发试验阳性的亚急性、慢性咳嗽患者均行肺功能、血常规、胸片、鼻窦CT、诱导痰检查,其中Eos计数和ECP水平的检测分别运用瑞氏染色和直接免疫荧光方法。结果:55例激发试验阳性的咳嗽患者中36例诊断为咳嗽变异性哮喘(CVA),6例诊断为慢性阻塞性肺病(COPD),8例诊断为感染后咳嗽,5例诊断为上气道咳嗽综合征(UACS)。以乙酰甲胆碱PC20FEV1.0作为评价气道高反应性的指标,CVA组与各个非哮喘组相比差异无统计学意义,支气管激发试验诊断哮喘的阳性预测值为65.5%。CVA组、COPD组、感染后咳嗽组以及UACS组诱导痰Eos计数分别为(9.2±5.4)%,(2.5±1.3)%,(2.3±0.6)%和(1.9±1.2)%,ECP水平分别为(227±56),(59±14),(46±18)和(42±24)μg/L,CVA组患者诱导痰Eos数量和ECP水平明显高于非CVA组(P<0.01),诱导痰联合支气管激发试验诊断哮喘的阳性预测值为89.5%。结论:联合应用诱导痰炎性标志物和支气管激发试验,可提高诊断咳嗽变异性哮喘的准确性。

Differential Diagnosis Value of Inflammatory Markers in Induced Sputum of Subacute Cough and Chronic Cough Patients with Positive Bronchial Provocative Test

Objective: To investigate percentage of eosinophil(Eos) and level of eosinophil cationic protein(ECP) in induced sputum of subacute cough and chronic cough patients with positive bronchial provocative test and to determine their value in differential diagnosis.Methods: All 55 cases of subacute cough and chronic cough with positive bronchial provocative test underwent lung function test,blood test,chest X-ray,nasal cavity CT,and sputum induction assays.The numbers of Eos and levels of ECP in induced sputum were measured by Wright's stain and direct immunofluorescence technology,respectively.Results: Of the 55 patients,36 with positive bronchial provocative test were diagnosed as cough variant asthma(CVA),6 patients were diagnosed as chronic obstructive pulmonary disease(COPD),8 patients were diagnosed as post-infectious cough,and 5 patients were diagnosed as upper airway cough syndrome(UACS).Significantly,there was no significant difference between CVA and non-asthma patients in airway hyper-responsiveness determined by methacholine PC20 FEV1.0.The positive predictive value(PPV) of the bronchial provocative test was 65.5%.The numbers of Eos in patients with CVA,COPD,post-infectious cough and UACS were(9.2±5.4) %,(2.5±1.3) %,(2.3±0.6) % and(1.9±1.2) % respectively,and ECP levels of four groups were(227±56),(59±14),(46±18) and(42±24) g/L respectively.The number of Eos and the level of ECP in CVA group were significantly higher than non-asthma groups(P<0.01).The PPV of induced sputum combined with bronchial provocative test was 89.5%.Conclusion: The inflammatory markers in induced sputum combined with bronchial provocative test would increase the diagnostic accuracy of cough variant asthma.