The roles of a Th2 cytokine and CC chemokine in children with stable asthma: Potential implication in eosinophil degranulation

Abstract

Th2 cytokine IL-5 and CC chemokine eotaxin are thought to be key regulators of eosinophils in bronchial asthma. However, their involvement in children with stable asthma (SA) has not been determined. We investigated the roles of IL-5 and eotaxin in eosinophil degranulation in children with SA. Induced sputum was obtained from 30 SA, 21 allergic rhinitis (AR), and 22 non-atopic healthy control (HC) children. We measured sputum levels of IL-5, eotaxin, and eosinophil indices [percentage eosinophils, eosinophil-derived neurotoxin (EDN), and eosinophil- cationic protein (ECP)]. We also examined correlations of IL-5 and eotaxin with eosinophil indices. Sputum percentage eosinophils and EDN and ECP levels were significantly higher in the SA group than in the HC group, while only the sputum EDN and ECP levels were significantly higher in the AR group than in the HC group. Unexpectedly, sputum levels of IL-5 were not significantly different among the three groups; however, the levels of eotaxin were higher in the SA group when compared to the HC group. No significant correlations were found between IL-5 and percentage eosinophils, EDN, or ECP levels; in contrast, eotaxin levels correlated significantly with percentage eosinophils (R­= 0.638; p = 0.0001), EDN (R­= 0.522; p = 0.003), and ECP levels (R­= 0.630 and p = 0.0002). The elevated levels and good correlations of eotaxin with sputum eosinophil indices, and no elevation or correlation of IL-5 with these indices, suggest that CC chemokine eotaxin may play a more important role in eosinophil degranulation in children with SA.

Eosinophil-derived neurotoxin: a novel biomarker for diagnosis and monitoring of asthma

“…Sputum eotaxin correlated significantly with sputum EDN, ECP, and eosinophil percentage. However, sputum interleukin-5 correlated only with sputum EDN levels, not sputum ECP levels or sputum eosinophil percentage24). In conclusion, sputum EDN levels may aid differential diagnosis of asthma and AR.…”

CCL11 as a potential diagnostic marker for asthma?

“…Inhaled allergen activates mast cells and Th2 lymphocytes in the lung to generate the cytokines IL-4, IL-13 and TNF-a, which stimulates the release of CCL11 by epithelial cells, fibroblasts, endothelial cells [24,31,45,46]. As the most potent and selective chemoattractant for eosinophils [8,17], CCL11 can stimulate migration [32], adhesion and recruitment of eosinophils into the airways [11,47,48], in cooperation with other mediators, such as RANTES and IL-5 [49,50]. This subsequently induces eosinophils to release more ECP, oxidising agents and CCL11 [8].…”

Measuring eosinophiluria, urinary eosinophil cationic protein and urinary interleukin-5 in patients with Lupus Nephritis

“…No article has yet been published in the literature about the uIL-5/Cr ratio in SLE. The increased levels of uIL-5 can justify the appearance of eosinophils and ECP in urine of the SLE patients studied because the cytokine IL-5, which is a key Th2 cytokine in eosinophil biology, is involved in eosinophil differentiation, maturation, migration and activation of these cells [ 37 ].…”