713:
Biological effect of IL-33R/ST2 in atopic asthmatic children; serum IL-33 changes by administration of omalizumab
Monday, March 5, 2018
South Hall A2 (Convention Center)
Yosuke Baba, MD, PhD, Hiromichi Yamada, MD, Toshiyuki Yoneyama, MD, Tomoaki Yokokura, MD, Susumu Yamazaki, MD, PhD, Eisuke Inage, MD,PhD, Mari Mori, MD, Yoshikazu Ohtsuka, MD, PhD, Masato Kantake, MD, PhD, Toshiaoki Shimizu, MP, PhD
RATIONALE: To analyze serum ST2 changes in severe atopic asthma in children by administration of omalizumab. And also find a correlation between the serum ST2 concentration and respiratory function measured by forced oscillation technique.

METHODS: We performed a retrospective study of patients with atopic asthma in children over 6 years old. The subjects of the present study are 9 patients who received omalizumab as a treatment for bronchial asthma in our department in 2016-2017. There were aged from 7-13 years (median 9 years 6 months). The patients were administered in doses of omalizumab determined from body weight and serum IgE levels. We investigated blood examinations and respiratory function, compared with before administration. Blood examination also contains of their serum levels of antigen-specific IgE, IL-33, ST2.

RESULTS: We confirmed that ST2 levels did not change, but a significantly lower concentration of IL-33 level was detected in after-administration group, suggesting the improvement of allergic reaction in bronchial epithelial cells. We are currently measuring the concentration of soluble ST2 in some samples.

CONCLUSIONS: It has already reported that IL-33 plays important roles in inflammation in atopic asthma. It can be inferred from previous reports so far that ST2 was an isolated receptor that was considered to the context of inflammatory and allergic disease. On the other hand, it remains possible that soluble ST2 as decoy receptor selectively inhibited the expressions of membrane bound type ST2. The mechanism is still unknown, but we speculate that ST2, especially soluble ST2, is an important factor in atopic asthma in children.