Increased interleukin-4 and decreased interferon-γ levels in serum of children with asthma

Background and purposeImmune and inflammatory responses, mediated by cytokines, play important roles in the pathophysiology of asthma. These responses are associated with over expression of T helper (Th)-2 cytokine, particularly interleukin (IL)-4 and IL-5, and decreased expression of Th-1 cytokine, IL-2 and IFN-γ. We hypothesized that there would be an imbalance in the levels of circulating IL-4 and IFN-γ in the asthmatic subjects.MethodWe investigated serum levels of IL-4 and IFN-γ among eighty children (18 steroid-naïve, 30 steroid-treated children with asthma and 32 healthy controls) using commercially available ELISA kits.ResultsSerum level of IL-4 was significantly higher in steroid-naïve group of asthmatic children compared to the healthy control subjects and was lower in steroid-treated group though the level was statistically not significant. In contrast, serum levels of IFN-γ were significantly lower in both steroid-naïve and steroid-treated groups of asthmatic children compared to healthy control subjects.ConclusionThe results of our study suggest that serum level of IL-4 may be elevated in concert with decreased level of IFN-γ in asthma. Determination of serum levels of IL-4 and IFN-γ may be a useful tool for understanding the disease processes in asthma.

► We studied serum levels of interleukin (IL)-4 and interferon (IFN)-γ in children with asthma.
► The results showed significantly higher level of IL-4 in serum of steroid-naive asthmatic children compared to control subjects.
► The level of IL-4 was lower in steroid-treated asthmatic children compared to steroid-naïve asthmatic children.
► The levels of IFN-γ were significantly lower in both steroid-naïve and steroid-treated asthmatic children.