Emami Ardestani Mohammad, Zaerin Omid
Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
Tanaffos. 2015;14(2):134-40.
Chronic obstructive pulmonary disease (COPD) is a non-specific inflammation, which involves the airways, lung parenchyma and pulmonary vessels. The inflammation causes the activation of inflammatory cells and the release of various inflammatory mediators such as interleukin-8 (IL-8), IL-6 and tumor necoris factor alpha (TNF-a). The purpose of the present study was to measure serum IL-6, C-reactive protein (CRP) (as a positive phase reactant) and albumin level (as a negative phase reactant) in COPD patients (only due to cigarette smoking not bio-mass), non COPD smokers and healthy subjects using enzyme-linked immunosorbent assay (ELISA); we compared the differences in inflammatory factors among groups.
A total of 180 males were enrolled in this study and divided into three equal groups. The first group was 60 smokers who had COPD. The second group included 60 smokers without COPD and the third group consisted of people who were not smokers and did not have COPD; 5 mL of venous blood was taken from all participants and it was collected in a test tube containing anticoagulant and then centrifuged at 3000 rpm for 10 minutes. Serum was separated and used to measure the amount of IL-6, CRP and albumin. Spirometry was performed according to the criteria set by the American Thoracic Society.
The mean serum level of IL-6 was 83.2±7.5 pg/mL in group I, 54.9±24.3 pg/mL in group II and 46.9±10.4 pg/mL in group III. There was a significant difference among the three groups (P<0.001). The mean serum level of CRP was 28.9±14.9 mg/dL in the first group, 19.9±8.5 mg/dL in the second group and 4.2±2.3 mg/dL in the third group (P=0.02). But by controlling the confounding effects of age, this difference was not significant (P=0.49). The mean serum level of albumin was I 4.1±0.57 mg/dL in group I, 4.3±0.56 mg/dL in group II and 4.1±0.53 mg/dL in group III. There was no significant difference among the three groups in this regard (P=0.099).There was a significant inverse relationship between serum levels of IL-6 and FEV 1 (r=-0.341, P<0.001). Moreover, there was a significant inverse relationship between serum levels of IL-6 and FEV1/FVC (r=-0.309, P<0.001). Serum albumin level was not different among various stages. Level of CRP and IL6 increased as the stage of COPD got worse in smokers.
Our study showed that serum level of IL-6 predicts development of COPD in smokers with a high sensitivity among all inflammatory factors namely CRP, IL-6, and albumin.
慢性阻塞性肺疾病（COPD）是一种非特异性炎症，累及气道、肺实质和肺血管。这种炎症会导致炎症细胞活化，并释放各种炎症介质，如白细胞介素-8（IL-8）、IL-6和肿瘤坏死因子α（TNF-α）。本研究的目的是使用酶联免疫吸附测定（ELISA）法检测COPD患者（仅由吸烟而非生物质引起）、非COPD吸烟者和健康受试者血清中的IL-6、C反应蛋白（CRP）（作为正相反应物）和白蛋白水平（作为负相反应物）；我们比较了各组炎症因子的差异。
本研究共纳入180名男性，分为三组，每组60人。第一组为60名患有COPD的吸烟者。第二组包括60名无COPD的吸烟者，第三组为不吸烟且无COPD的人。从所有参与者中采集5 mL静脉血，收集到含有抗凝剂的试管中，然后以3000 rpm离心10分钟。分离血清并用于检测IL-6、CRP和白蛋白的含量。根据美国胸科学会设定的标准进行肺功能测定。
第一组血清IL-6的平均水平为83.2±7.5 pg/mL，第二组为54.9±24.3 pg/mL，第三组为46.9±10.4 pg/mL。三组之间存在显著差异（P<0.001）。第一组血清CRP的平均水平为28.9±14.9 mg/dL，第二组为19.9±8.5 mg/dL，第三组为4.2±2.3 mg/dL（P=0.02）。但在控制年龄的混杂效应后，这种差异不显著（P=0.49）。第一组血清白蛋白的平均水平为4.1±0.57 mg/dL，第二组为4.3±0.56 mg/dL，第三组为4.1±0.53 mg/dL。在这方面，三组之间无显著差异（P=0.099）。血清IL-6水平与第一秒用力呼气容积（FEV1）之间存在显著负相关（r=-0.341，P<0.001）。此外，血清IL-6水平与FEV1/用力肺活量（FVC）之间也存在显著负相关（r=-0.309，P<0.001）。不同阶段的血清白蛋白水平无差异。吸烟者中，CRP和IL-6水平随COPD病情加重而升高。
我们的研究表明，在所有炎症因子（即CRP、IL-6和白蛋白）中，血清IL-6水平对吸烟者COPD的发生具有较高的预测敏感性。
