Study of Urinary Leukotriene E4 and Eosinophil Cationic Protein in Nasopharyngeal Aspiration from Wheezing Infants

Kwon, Soo Jeong; Koo, Bon Seok; Lee, Ha Baik; Oh, Jae Won

Abstract

PURPOSE
Although early detection of airway inflammation is important to enable early prevention and treatment, it is not easy to differentiate clinically between respiratory virus- induced bronchiolitis and infantile asthma during a wheezing attack. Leukotriens (LTs) are known as a mediator of airway adhesions and inflammations, such as constricted airways and increased mucus secretions. Eosinophil cationic protein (ECP) is one of the cytotoxic proteins released from the granules of activated eosinophils, which have a role in the pathogenesis of airway inflammation. The aim of our study was to evaluate differences in urinary LTE4 and nasopharyngeal ECP levels between children with bronchiolitis and children with infantile asthma by using noninvasive techniques. METHODS: We recruited 32 children whose chief complaint was wheezing (20 non-atopic and 12 atopic children) and 18 controls without wheezing for this study. Urine and nasopharyngeal samples were collected on the day of admission. Samples were stored at -70degrees C until measurement. Nasopharyngeal ECP were measured by using UniCap (Pharmacia CAP FEIA, Pharmacia Diagostics, Uppsala, Sweden). Urine LTE4 level were measured by ACE enzyme immunoassay kit (Cayman Chemical, Ann Arbor, MI, USA). RESULTS: Children with infantile asthma have significantly higher LTE4 levels than children with bronchiolitis. Nasopharyngeal ECP levels were significantly different in children with/without wheezing. Furthermore, urinary LTE4 was significantly correlated with nasopharyngeal ECP, serum total eosinophil, serum IgE level, and respiratory symptoms. CONCLUSION: Urinary LTE4 and nasopharyngeal ECP were significantly different between children with bronchiolitis and infantile asthma. Further studies are needed to investigate the clinical application of our findings.