[Role of serum neutrophil elastase determination in the diagnosis of acute exacerbation of asthma in preschool children]

OBJECTIVE: To study the role of serum neutrophil elastase (NE) level in acute exacerbation of asthma in preschool children. METHODS: A total of 85 preschool children who were diagnosed with asthma between January 2008 and January 2010 were classified into acute exacerbation group (n=44) and non-acute exacerbation group (n=41). Thirty-five children who received physical examination served as the control group. The enzyme-linked immunosorbent assay was used to determine the serum levels of NE and interleukin-8 (IL-8). The receiver operating characteristic (ROC) curve was used for NE evaluation. RESULTS: Both the acute and non-acute exacerbation groups had higher serum levels of NE and IL-8 than the control group, and the acute exacerbation group had significantly higher serum levels of NE and IL-8 than the non-acute exacerbation group (P < 0.05). The serum level of NE was positively correlated with that of IL-8 (r=0.48, P < 0.05). With serum NE level >27.73 μg/L as the cut-off value for diagnosing acute exacerbation of asthma, the sensitivity was 65.9%, the specificity was 95.1%, and the area under the ROC curve was 0.87 (P < 0.01). CONCLUSIONS: The determination of serum NE level in preschool children with asthma helps to diagnose the acute exacerbation of asthma.