【摘要】 目的 研究活动期RA患者血清中细胞因子IL-18的表达，并探讨它们与疾病活动程度的关系。 方法 2008年12月-2010年1月将63例RA患者，根据DAS28将患者分为高度活动组和低度活动组，应用酶联免疫吸附法（ELISA）法检测63例RA患者和27例对照组的白细胞介素-18（IL-18）表达水平。分析IL-18的水平与临床指标的相关性。 结果 IL-18在活动期RA中表达水平高于低度活动组、对照组，分别为（238.88±41.75）、（189.11±40.62）、（185.42±44.93） pg/mL，有统计学意义（Plt;0.01）。RA活动组患者IL-18与外周血白细胞计数呈负相关（r=-0.628，Plt;0.05）。 结论 IL-18水平在RA活动期患者高表达，在RA发病和发展中起重要作用。【Abstract】 Objective To observe the expression of interleukin-18 (IL-18) in patients with active rheumatoid arthritis (RA). Methods A total of 63 patients with RA in our hospital from December 2008 to January 2010 were selected. The patients were divided into high activity group and low activity group according to the disease activity score 28 (DAS28). Levels of IL-18 in the serum in 63 patients and 27 control individuals were detected by ELISA technique. The relationship between IL-18 expression and the clinical indexes was analyzed. Results IL-18 serum levels were (238.88±41.75), (189.11±40.62), and (185.42±44.93) pg/mL In high activity group, low activity group and the control group respectively with a significant difference (Plt;0.01). The IL-18 level in high activity group was negative correlated with WBC counts. Conclusion Apparent expression of IL-18 is found in RA patients at the active phase, which plays an important role in the occurrence and development of RA.