Comparison of Innate Lymphoid Cells from Tissue and Blood in Chronic Tonsillitis and Tonsillar Hypertrophy

Adenotonsillar hypertrophy is defined as the adenoid and tonsil tissue being larger than normal. Recurrent tonsillitis describes frequent tonsil infections. Although both diseases are very common especially in childhood, their etiology has not been clearly revealed yet. Innate lymphoid cells (ILCs) are the innate immune response of T lymphocytes that contribute to immune responses by secreting effector cytokines and regulating the functions of other innate and adaptive immune cells. While ILCs perform some immune functions alone, they share some tasks with T cells. The aim of this study is to reveal the role of innate lymphoid cells, a cell group on which studies have focused in recent years, in adenotonsillar hypertrophy and recurrent tonsillitis diseases in childhood. Although cytokine profile and T lymphocyte activation were studied in children with recurrent tonsillitis in the literature review, native lymphoid cell analysis was not performed. Tissue and blood samples of pediatric patients who applied to our clinic and had tonsillectomy indication were taken forthe study. The patients were divided into two groups as tonsillar hypertrophy (n=12) and recurrent tonsillitis (n=12). ILC rates, IL-10, IL-17 and IFN-γ secreting T lymphocyte rates were examined in blood and tonsil tissue samples taken from all patients. In the analyzes made as a result of the study, it was seen that the ILC3s in the tonsillar tissue and blood of the recurrent tonsillitis group were statistically significantly higher than the IL-17 tonsillar hypertrophy group. In the hypertrophy group, ILC2s were found to be statistically significantly higher in the analysis of tonsil tissue and blood. According to the study data, it was concluded that ILC3s are the dominant innate lymphoid cell group in recurrent tonsillitis and that it is a triggering factor for Th17 responses in acquired immunity in recurrent tonsillitis. Keywords: Palatine Tonsil, Tonsillitis, Hypertrophy, CD4-Positive T-Lymphocytes