Evaluation of eosinophilic and neutrophilic functions during inflammatory processes in atopic and nonatopic astmatic children

Introduction: Asthma is a chronic inflammatory disease of the airways, accompanied by structural changes in many cells and in which cellular elements play a part. The pattern of inflammation in the airways seems to be similar in all age groups in all clinical forms. The increase in the number of eosinophils in the peripheral blood and secretions in the airway is a characteristic of asthma. In the individuals with atopic asthma, the eosinophilsare collectedin the airway depending on theTh2 cytokines secreted by CD4 + Th2 cells. IL-5is thought to play an important role in the eosinophilic inflammation. The number of neutrophilsin the airways increase proportionally with the severity of asthma and IL-8 plays an important role in this process.The airway epithelium is not permeable because of the close ties in its structure, butin asthma, the permeability is significantly increased causing the allergens and the irritating agents to reach the basal layer more easily and resulting in more tissue damage. In this study, in order to compare the neutrophilic and eosinophilic inflammation in children with atopic and non-atopic asthma the IL-8 and the IL-5; in order to demonstrate the tissue damage the MMP-9, and to demonstrate the epithelial injury, the and soluble E-cadherin in condensed breathing air will be studied.Method: A total of 78 patients who were diagnosed with atopic asthma (n=39) and non-atopic asthma (n=39) at Celal Bayar University, Department ofPediatric Immunology and Allergic Diseases, were included in the study. The atopic asthmagroup consisted of patients with a positiveallergen skin prick test with at least one proteolytic aeroallergen (house dust mites, yeast mixture and olive). The non-atopic asthma group consisted of patients with anegative skin prick test with aeroallergens. The patients in the non-atopic asthma group were included in the study with a one to one matching with the patients in the atopic asthma group in terms of age. On the day that the children were included in the study, serum samples for IgE, and complete blood count to determine the eosinophil count were obtained.The measurements were performed on the same day. Similarly, on the same day, the samples for IL-5, IL-8, MMP-9 and condensed breathing air sample for the measurement of E-cadherin were obtained and were stored at-80oCto evaluate at the end of the study.Results: The MMP-9 levels were found to be higher compared in children with atopic asthma compared to the children with non-atopicasthma, in the condensed breathing air samples. Similarly, the E-cadherin levels, which is a parameter of lung injury, was also higher in these children. However, the IL-5 and the IL-8 levels in the condensed breathing air sampleswere not different in children with atopic and non-atopicasthma.Conclusion:The higher MMP-9 levels in patients with atopic asthma, in the condensed breathing air samples, and its significant correlation with the IL-8 and sE-cadherin levels show that the proteolytic allergens cause more tissue damage,inflammatory cytokine release andremodeling. There were no significant statistical differences between the groups in terms of sE-cadherin levels. However the children with atopic asthma had a 0.08 p-value, which was very close to be significant. Considering this fact, and the positive correlation between the IL-8 and the sE-cadherin, it can be postulated that the inflammation due to the exposure to allergens in atopic asthmais more severe and the epithelial fragility and spill are higher in this group.As markers of allergic inflammation in asthmatic children, EBC can be used as a noninvasive alternative to the invasive procedures. It can also be used in the future studies.