집먼지 진드기 알레르기 비염 소아의 설하면역치료에서 혈청 IL-17의 임상적 의미

Abstract

Objectives: It was proposed that a new subset of lymphocyte, T helper (TH)-17 cells and its key cytokine interleukin (IL)-17 have a regulatory function in allergic diseases and a relation to allergic severity. However, there has been a lack of studies about TH17 cells or IL-17 focused on allergic rhinitis (AR), and their roles in AR still remain uncertain. Therefore, we sought to investigate the clinical relevance of serum IL-17 levels in AR patients treated with sublingual immunotherapy (SLIT) to identify the function of TH17 cells and IL-17 in AR. Materials & Methods: The pediatric patients with AR to house dust mite (HDM) starting to receive SLIT in Seoul National University Hospital between June 2008 and April 2009 (n=26), and between Feburary 2010 and August 2010 (n=14) were enrolled. Twenty six patients continued treatment and completed symptom diaries for two years, and 14 patients for one year. We collected blood samples before and 1 year and 2 year after starting SLIT and detected serum IL-17 levels via ELISA. In addition, serum total IgE, serum eosinophil cationic protein (ECP), blood eosinophil counts, and serum HDM-specific IgE and IgG4 were analyzed. Results: Longer onset of symptoms and moderate to severe symptom according to Allergic Rhinitis and its Impact on Asthma classification were significantly related to higher serum IL-17 levels before starting SLIT. Total symptom scores and medication scores significantly decreased as SLIT proceeded for 2 years. Serum IL-17 levels, total IgE, ECP and blood eosinophil counts did not show significant change during the same period. HDM-specific IgE significantly increased between the baseline and the first year of SLIT, while HDM-specific IgG4 had no significant change. Serum total IgE, and blood eosinophil counts did not correlate with serum IL-17 levels during SLIT. There was a significant positive correlation between serum ECP and IL-17 levels at the baseline, the first year and the second year. The ineffective group showed significantly increased serum IL-17 levels at the first year compared to the baseline, while the effective group showed decreased serum IL-17 levels. These findings show that changes of serum IL-17 levels for 1 year had an inverse relationship with the effectiveness of SLIT. Increased serum total IgE levels at the first and second year compared to the baseline were also inversely related to the effectiveness of SLIT. Changed serum IL-17 levels at the first year was the most significant factor in relation to the effectiveness of SLIT by multivariate analysis. Conclusions: Serum IL-17 levels in AR were correlated with duration from symptom onset, symptom severity and serum ECP levels. Changes of serum IL-17 levels during SLIT are expected to be a prognostic factor to predict the effectiveness of SLIT. Thus, IL-17 and TH17 cells might have an important role in allergic rhinitis pathogenesis.