Furukawa Toshiki, Sakagami Takuro, Koya Toshiyuki, Hasegawa Takashi, Kawakami Hidenori, Kimura Yosuke, Hoshino Yoshifumi, Sakamoto Hirotaka, Shima Kenjiro, Tsukioka Keisuke, Toyama Mio, Hayashi Masachika, Kagamu Hiroshi, Suzuki Ei-Ichi, Narita Ichiei
Division of Respiratory Medicine, Department of Homeostatic Regulation and Development, Graduate School of Medical and Dental Sciences, Niigata University , Niigata , Japan , and.
J Asthma. 2015 May;52(4):417-22. doi: 10.3109/02770903.2014.975357. Epub 2014 Nov 11.
Eosinophilic inflammation in the respiratory tract is a hallmark of bronchial asthma. In naïve cases, the inflammatory profile is associated with disease severity and reactivity to inhaled corticosteroids (ICS). Sustained airway eosinophilia has been reported during ICS treatment. However, the immunological characteristics of these cases are not known and it is unclear if this situation contributes to asthma control. This study was performed to determine the answer of these questions.
To compare phenotypes of eosinophilic and non-eosinophilic asthma (EA and NEA, respectively) under ICS treatment, clinical data were obtained from asthmatic subjects (n = 22) and healthy controls (n = 10), and the leukocyte compositions of induced sputum and peripheral blood were determined. T lymphocyte profiles in systemic blood were assessed by flow cytometry.
A higher frequency of emergency room visits was observed in the NEA group, which had a higher neutrophil count relative to the total inflammatory cell population in induced sputum than the EA group (59.5 versus 36.6%; p < 0.01). The fraction of helper T (Th)17 lymphocytes as well as the ratio of Th17 to regulatory T cells (Treg) in the peripheral blood was higher in the NEA than in the EA group (0.24 versus 0.13; p < 0.05).
Th17 were more prevalent than Treg cells in the peripheral blood of NEA patients under ICS treatment, corresponding to neutrophil-dominant airway inflammation and a severe asthmatic phenotype. Thus, an imbalance in Th17/Treg may be associated with the pathogenesis of NEA in patients undergoing ICS treatment.
呼吸道嗜酸性粒细胞炎症是支气管哮喘的一个标志。在初发病例中，炎症特征与疾病严重程度及对吸入性糖皮质激素（ICS）的反应性相关。已有报道称在ICS治疗期间气道嗜酸性粒细胞持续存在。然而，这些病例的免疫学特征尚不清楚，且这种情况是否有助于哮喘控制也不明确。本研究旨在确定这些问题的答案。
为比较ICS治疗下嗜酸性粒细胞性哮喘和非嗜酸性粒细胞性哮喘（分别为EA和NEA）的表型，从哮喘患者（n = 22）和健康对照者（n = 10）获取临床数据，并测定诱导痰和外周血中的白细胞组成。通过流式细胞术评估全身血液中的T淋巴细胞谱。
NEA组的急诊就诊频率更高，其诱导痰中中性粒细胞计数相对于总炎症细胞群体的比例高于EA组（59.5%对36.6%；p < 0.01）。NEA组外周血中辅助性T（Th）17淋巴细胞的比例以及Th17与调节性T细胞（Treg）的比例高于EA组（0.24对0.13；p < 0.05）。
在接受ICS治疗的NEA患者外周血中，Th17比Treg细胞更普遍，这与以中性粒细胞为主的气道炎症和严重的哮喘表型相对应。因此，Th17/Treg失衡可能与接受ICS治疗的患者NEA的发病机制有关。
