NASAL LAVAGE CYTOKINES IN NORMAL, ALLERGIC, AND ASTHMATIC SCHOOL-AGE-CHILDREN

Inflammation can be demonstrated in the airway mucosa of asthmatics, e ven in the absence of overt symptoms, but the pathogenesis of this chr onic inflammation is incompletely defined. It has been suggested that inflammatory cytokines produced by epithelium may play important roles in this process. Therefore, we measured the cytokines interleukin-8 ( IL-8), IL-6, and granulocyte-macrophage colony-stimulating factor (GM- CSF) in nasal lavage fluids from school-age children who were (1) ''no rmal'' (nonallergic/nonasthmatic), (2) allergic to house-dust mite ant igen but nonasthmatic (no history of wheezing), or (3) allergic and as thmatic (history of greater than or equal to 10 wheezing episodes). Ch ildren underwent a single nasal ravage procedure while asymptomatic an d on no anti-inflammatory medications or antihistamines. In addition t o cytokine concentrations, cell counts, differentials, albumin, histam ine, and eosinophil cationic protein (ECP) concentrations were determi ned in nasal lavage fluids. Significant increases in IL-8 and ECP were observed in asthmatics compared with both normals and allergic nonast hmatics. Overall, IL-8 in nasal lavage fluids correlated significantly with ECP. Allergic nonasthmatics did not have significant increases i n cytokines or other mediators compared with normal subjects. Concentr ations of IL-6 did not differ significantly among the three groups, an d GM-CSF was undetectable in all samples tested. We conclude that incr eased IL-8 production and eosinophil activation are characteristic of the airways of asthmatic children when asymptomatic, and we speculate that IL-8 plays a role in the maintenance of airway inflammation in as thma.