The clinical significance of noninvasive inflammatory markers in exhaled breath condensate and induced sputum in persistent asthmatic patients / 中华内科杂志

ABSTRACT

Objective To assess the clinical significance of three different noninvasive airway inflammatory indices in induced sputum and exhaled breath condensate ( EBC ) from persistent asthmatic patients.Methods Moderate and severe asthmatic patients were prescribed inhaled corticosteroids combined with long-acting β2 agonists for a month.The symptom scores and percentage of predicted value of forced expiratory volume in one second ( FEV1 ) ( FEV1% pred) were measured while the concentrations of H2O2,NO3-/NO2-,and cysteinyl-leukotriene E4(LTE4) in induced sputum and EBC were detected before and after therapy.Results A total of twenty-five subjects with moderate and severe asthma were enrolled.By combined therapy for one month the asthma aymptoms relieved and FEV1% pred improved significantly (P<0.01).The concentrations of H2O2,NO3-/NO2- arid LTE4in induced sputum and EBC declined significantly(P<0.01) although the concentrations were still higher than those at normal baseline.More marked reduction of H2O2 and NO3-/NO2- compared to LTE4was observed.It was revealed that the concentrations of H2O2 and NO3-/NO2- but not of LTE4in EBC were negatively correlated with FEV1% pred (P <0.01) and positively with symptom scores.Such correlations were also found in H2O2 in induced sputum with FEV1 % pred and symptom scores as well as NO3-/NO2- in induced sputum with FEV1 % pred.The improvement of FEV1 % pred after treatment was positively correlated with the reduction of H2O2 and NO3-/NO2- both in induced sputum and EBC.Correlation analysis also demonstrated three inflammatory indices were equivalent in induced sputum and EBC( correlation coefficient of H2O2,NO3-/NO2- and LTE4,0.759,0.826 and 0.653,respectively.P < 0.01 ).Conclusions (1) Combined therapy with inhaled corticosteroid plus long-acting β2 agonist significantly improves the clinical symptoms and lung function of patients with moderate and severe asthma companied with marked suppression of airway inflammation.(2) Both of EBC and induced sputum sampling are valuable noninvasive procedures for detecting asthma airway inflammation,however,EBC technique is superior in safety and reproducibility.(3) H2O2 and NO3-/NO2- seem to be more sensitive indices in diagnosis and monitoring asthma compared to LTE4.