Cytokine. 2012 Jul;59(1):18-9. doi: 10.1016/j.cyto.2012.04.007. Epub 2012 May 5.
To the Editor, we read with great interest the article by Chung et al. which appeared recently in the journal. In that paper the authors reported that the decreased IL-18 response in severe pneumonia group vs. non-severe group was observed regardless of asthma status of the patients, whose findings were somewhat different from ours on non-asthmatic patients which showed higher serum levels of IL-18 in severe cases of pneumonia than in mild cases in terms of both in children and in adults. In this point, the timing of venous sampling must be an important factor in explaining the discrepant results. Our previous results suggest that the level of IL-18 in blood as a marker of disease severity should cautiously be interpreted considering a timing of sampling; a value of IL-18 in a blood sample which is obtained at the first visit to the hospital does not always represent the highest level of IL-18 because of the fact that the time which elapsed from the onset of illness to the blood sampling may vary among patients. Analyses on sequential samples, therefore, must be necessary to fully understand the perplexing nature of cytokine activation during Mycoplasma pneumoniae infection.
致编辑，我们饶有兴趣地阅读了 Chung 等人最近在该期刊上发表的文章。在该文中，作者报道了重症肺炎组与非重症肺炎组相比，IL-18 反应下降，而不论患者的哮喘状态如何，这与我们在非哮喘患者中的发现有些不同，我们的研究显示，在儿童和成人中，重症肺炎患者的血清 IL-18 水平均高于轻症肺炎患者。在这一点上，静脉采血的时间可能是解释差异结果的一个重要因素。我们之前的结果表明，IL-18 作为疾病严重程度的标志物，其水平的解释应慎重考虑采样时间；由于从发病到采血的时间在患者之间可能有所不同，因此，在医院首次就诊时采集的血液样本中的 IL-18 值并不总是代表最高水平的 IL-18。因此，必须对连续样本进行分析，以充分了解肺炎支原体感染期间细胞因子激活的复杂性。
