Expression of interleukin-4, interleukin-9 and interleukin-13 in peripheral blood mononuclear cells of cystic fibrosis patients with and without allergy

Abstract

Bronchial hyperresponsiveness (BHR) and mucus overproduction are common in CF pulmonary disease and allergic reactions can be frequently observed in cystic fibrosis (CF) lung disease. However, the underlying pathophysiological mechanisms are far from being completely understood. Therefore the expression of the Th2 type cytokines interleukin (IL)-4, IL-9 and IL-13 in CF patients with allergy was compared to patients without allergy. Peripheral blood mononuclear cells (PBMC) samples from 9 allergic CF patients and 8 non-allergic CF patients were obtained. In situ hybridization and immunocytochemistry were performed to determine mRNA and protein expression of IL-4, IL-9, and IL-13 in PBMC. PBMC from allergic CF patients expressed significantly more IL-13 mRNA and protein compared to non-allergic patients (p < 0.05). There was no significant difference for IL-4 and IL-9 between the two groups. In both groups IL-9 mRNA and protein expression were significantly higher compared to IL-4 and IL-13 expression (p < 0.05). These results suggest that IL-13 plays an important role in allergic disease in CF. Moreover, IL-9 may be important in CF disease whether allergy is present or not as it may contribute to BHR and mucus overproduction.