Dept of Respiratory Disease, Changzheng Hospital, Shanghai, China.
Eur Respir J. 2010 Apr;35(4):757-60. doi: 10.1183/09031936.00034409.
The chitinase-like protein YKL-40, which binds chitin but lacks chitinase activity, has been found to be either the cause or a biomarker for asthma. The aim of our study was to investigate whether serum YKL-40 levels are increased in Chinese patients with asthma and identify its correlation to acute exacerbation, total serum immunoglobulin (Ig)E, the percentage of peripheral blood eosinophils and lung function. We quantified serum YKL-40 levels, total IgE levels and peripheral blood eosinophil percentages in patients with asthma, as well as in controls from the communities surrounding our hospital. The lung function of asthma subjects was also measured. Our data showed that the serum YKL-40 levels were significantly elevated in patients with asthma compared with controls and, when the asthma subjects were stratified, serum YKL-40 levels in the exacerbation group were higher than those in the stable and control groups. In addition, serum YKL-40 levels correlated positively with total serum IgE levels and the percentage of peripheral blood eosinophils, but correlated inversely with lung functions. Thus, we conclude that YKL-40 is found in increased quantities in the serum of Chinese patients with asthma, and its level correlates with exacerbation attacks, indicating that high levels of serum YKL-40 may be a biological characteristic of the exacerbation of asthma.
几丁质酶样蛋白 YKL-40 能与几丁质结合但缺乏几丁质酶活性，它被发现既是哮喘的病因，也是哮喘的生物标志物。我们的研究旨在调查中国哮喘患者的血清 YKL-40 水平是否升高，并确定其与急性加重、总血清免疫球蛋白 (Ig)E、外周血嗜酸性粒细胞百分比和肺功能的相关性。我们定量检测了哮喘患者及我院周边社区对照者的血清 YKL-40 水平、总 IgE 水平和外周血嗜酸性粒细胞百分比，还测量了哮喘患者的肺功能。我们的数据显示，与对照组相比，哮喘患者的血清 YKL-40 水平显著升高，且在按哮喘患者分层后，急性加重组的血清 YKL-40 水平高于稳定组和对照组。此外，血清 YKL-40 水平与总血清 IgE 水平和外周血嗜酸性粒细胞百分比呈正相关，与肺功能呈负相关。因此，我们得出结论，YKL-40 在我国哮喘患者的血清中含量增加，其水平与加重发作相关，这表明血清 YKL-40 水平升高可能是哮喘加重的一个生物学特征。
