Objective: To study the roles of IL-4, IL-5 and IgE in childhood cough variant asthma (CVA).
Methods: The IL-4 and IL-5 levels in peripheral blood mononuclear cell (PBMC) and the serum IgE levels were determined using ELISA in children with CVA in the acute stage (n=21) and in the convalesce stage (n=9). The samples from 30 children with acute bronchial asthma and from 30 healthy children were used as controls.
Results: The levels of PBMC IL-4 (91.57 +/- 12.19 ng/L) and IL-5 (13.28 +/- 0.31 ng/mL) in children with CVA in the acute stage were significantly higher than those in the convalesce stage (74.68 +/- 11.54 ng/L, 6.53 +/- 0.28 ng/mL) and also higher than those in the healthy controls (70.32 +/- 18.16 ng/L, 5.29 +/- 0.36 ng/mL) (P < 0.01). The levels of serum IgE in children with CVA in the acute stage (279.6 +/- 41.3 KU /L) were strikingly higher than those in the convalesce stage (153.8 +/- 37.5 KU/L) (P < 0.01). The levels of serum IgE in children with CVA either in the acute stage or in the convalesce stage were significantly higher than those in healthy controls (90.6 +/- 44.8 KU /L) (P < 0.01). There were no significant differences in the levels of IL-4, IL-5 and IgE between children with acute CVA and acute asthma.
Conclusions: A combined determination of PBMC IL-4 and IL-5 and serum IgE may be valuable for the diagnosis and the outcome evaluation of CVA. IL-4 and IL-5 may play a role in the pathogenesis of CVA. It is speculated that CVA may have similar pathogenesis to bronchial asthma since acute CVA patients have similar IL-4, IL-5 and IgE levels to children with acute bronchial asthma.