D3.141 - Serum levels of IL-10 and IFN-GAMMA in adolescents diagnosed with asthma in clinical remission without treatment

Asthma is the most common chronic disease in childhood, and 10% to 48% of affected children experience spontaneous remission during adolescence. However, the immune mechanisms behind this remission remain unclear. Our objective is to determine if there are differences in the serum levels of Interleukin 10 (IL-10) and Interferon Gamma (IFN-γ) in adolescents diagnosed with asthma in clinical remission without treatment (RA), compared with adolescents diagnosed with persistent asthma (AP), and non-asthmatic and non-atopic adolescents (NA). 

In the AP, AR, and NA groups, 18, 15, and 15 participants were enrolled, respectively, all between 12 and 17 years of age and from Lima, Perú. Participants with a history of asthma completed the "Asthma Control Test" (ACT) questionnaire for people over 12 years of age. All participants were interviewed and examined, and a standardized sample of peripheral blood was extracted to quantify eosinophil levels using an automated method. The serum levels of IL-10 and IFN-γ were measured using the ELISA technique. 

No significant differences were found in serum levels of (p=0.7133), IL-10 (p=0.2553) or the IL-10/IFN-γ ratio (p=0.0687) among the AP, RA, and NA groups. However, peripheral blood eosinophil levels were significantly higher in the AP group compared to NA (p=0.0464), particularly in those with allergic asthma (p=0.0075). No significant differences were observed between RA and NA or between RA and AP groups. 

Eosinophil levels in peripheral blood are higher in adolescents with persistent asthma (AP) compared to non-asthmatic adolescents (NA), particularly in those with allergic asthma. These elevated levels appear to be influenced by IFN-γ and IL-10 together. It is suggested that asthma persistence during adolescence may partly result from eosinophils producing proinflammatory Th1-type cytokines. Other studies have reported that eosinophils can secrete IFN-γ in response to both Th1 and Th2 stimuli, and this secretion is not reduced by IL-10, which instead promotes increased IL-12 production by eosinophils. There is no difference in peripheral blood eosinophil levels between NA and RA patients or between RA and AP patients. There was no difference in the serum levels of IFN-γ, IL-10 or in the IFN-γ/IL-10 ratio among patients diagnosed with RA, PA, and NA.