An epidemiologic study on the relationship between pulmonary function decline and serum cytokine level.

研究横断面血清细胞因子水平与纵向肺功能下降的关系，以检验血清细胞因子水平是否能预测随年龄增长而加速的肺功能下降。受试者为男性工人，自1985年以来一直进行肺功能下降的纵向随访。除常规肺功能指标如1秒用力呼气量外，还分析了肺时间常数分布的时间域肺功能指标。采用Tollerud等人设计的高灵敏度化学发光双抗体夹心法测定血清IL-4、IL-6和干扰素-γ浓度。对328名肺功能得到至少6年可接受随访的受试者进行了分析，发现这三种细胞因子在受试者之间都有很大的变异性。它们的分布极大地向正值倾斜。这一点在干扰素-伽马中尤为明显。血清细胞因子水平与皮肤和呼吸系统过敏史无明显关系。血清细胞因子水平与慢性呼吸道症状、吸烟或其他生活方式因素之间未发现明显的相关性。然而，作为回归系数计算的几个纵向肺功能指数与血清细胞因子水平显著相关。这些发现并不一定意味着血清细胞因子测量在预测肺功能下降方面是有用的，因为它们在受试者之间有很大的变异性。还需要进一步的工作，特别是在大样本的队列环境中研究血清细胞因子水平的受试者内变异性。

The association between cross-sectional serum cytokine level and longitudinal pulmonary function decline was investigated in order to examine whether or not the serum cytokine level can predict an accelerated pulmonary function decline with aging. Subjects were the male workers who have been longitudinally followed-up since 1985 in terms of pulmonary function decline. In addition to routine spirometric indices such as forced expiratory volume in one second, time domain spirometric indices for lung time constant distribution were analyzed. Serum concentration of interleukin-4, interleukin-6, and interferon-gamma was measured utilizing the high-sensitivity chemiluminescence ELISA method devised by Tollerud and co-workers. Analysis was conducted on 328 sub-jects whose pulmonary function have been acceptably followed-up for at least 6 years.A large between-subject variability was recognized in all of the three types of cytokine. Their distribution was greatly skewed towards positive. That is especially marked in interferon-gamma. There was no evident relationship between serum cytokine level and allergic history of skin and respiratory system. No clear association was found either between serum cytokine level and chronic respiratory symptoms, smoking or other life style factors. Several longitudinal pulmonary function indices calculated as a regression coefficient, however, were significantly associated with the serum cytokine level. These findings do not necessary mean the usefulness of serum cytokine measurement in predicting pulmonary function decline, because of their large between-subject variability. Further work will be needed especially to study within-subject variability of serum cytokine level in a cohort setting of a large sample.