Kikuchi Shinya, Kikuchi Izumi, Takaku Yotaro, Kobayashi Takehito, Hagiwara Koichi, Kanazawa Minoru, Nagata Makoto
Department of Respiratory Medicine, Saitama Medical University, Saitama 228-8522, Japan.
Int Arch Allergy Immunol. 2009;149 Suppl 1:87-93. doi: 10.1159/000211379. Epub 2009 Jun 3.
There is evidence that eosinophils and neutrophils are simultaneously increased in the airways of some patients with chronic refractory asthma. The mechanisms by which neutrophils accumulate in the airways of asthmatics remain to be elucidated, however, chemoattractants for neutrophils such as CXC chemokines may affect either the accumulation or functional status of neutrophils in such patients. The objective of the present study was to identify the CXC chemokine responsible for the neutrophilic and possibly eosinophilic inflammation observed in the airways of patients with refractory asthma.
Following the inhalation of hypertonic saline, induced sputum was obtained from 14 healthy controls, 16 patients with mild well-controlled nonrefractory asthma, and 14 patients with refractory asthma. Concentrations of CXC chemokines and differential inflammatory cell counts were determined.
The percentages of induced sputum eosinophils were significantly higher both in patients with nonrefractory asthma and in patients with refractory asthma. On the other hand, the percentages of neutrophils were increased only in sputum from patients with refractory asthma. The concentration of IL-8, but not ENA-78 or GRO-alpha, was also significantly increased in induced sputum from patients with refractory asthma. The concentration of IL-8 correlated significantly with the percentages of neutrophils.
The results of the present study suggest that IL-8, but not ENA-78 or GRO-alpha, may contribute to the observation of neutrophilic inflammation in patients with refractory asthma.
有证据表明，在一些慢性难治性哮喘患者的气道中，嗜酸性粒细胞和中性粒细胞同时增加。然而，哮喘患者气道中中性粒细胞积聚的机制仍有待阐明，中性粒细胞的趋化因子如CXC趋化因子可能会影响此类患者中性粒细胞的积聚或功能状态。本研究的目的是确定导致难治性哮喘患者气道中出现中性粒细胞炎症以及可能的嗜酸性粒细胞炎症的CXC趋化因子。
吸入高渗盐水后，从14名健康对照者、16名轻度病情得到良好控制的非难治性哮喘患者和14名难治性哮喘患者中获取诱导痰。测定CXC趋化因子的浓度和炎症细胞分类计数。
非难治性哮喘患者和难治性哮喘患者诱导痰中嗜酸性粒细胞的百分比均显著更高。另一方面，仅难治性哮喘患者痰液中的中性粒细胞百分比增加。难治性哮喘患者诱导痰中IL-8的浓度显著升高，而ENA-78或GRO-α的浓度未升高。IL-8的浓度与中性粒细胞的百分比显著相关。
本研究结果表明，IL-8而非ENA-78或GRO-α可能是导致难治性哮喘患者出现中性粒细胞炎症的原因。
