冠狀動脈疾病是一種多因子影響的慢性發炎疾病，IL-1ra為發炎反應引發的抗發炎性細胞激素，可有效降低發炎反應所引起的過度傷害，我們進一步假設IL-1ra與發炎性媒介物間的濃度變化失去平衡對此疾病是有影響。在此篇研究中，我們篩選70位健康對照組 (healthy controls)，95位冠狀動脈疾病 (CAD) 的患者共165人，分析兩組間冠狀動脈疾病的危險因子、血清中IL-1ra及其它發炎的細胞激素濃度，並探討IL-1ra濃度變化對此疾病是否有影響。結果顯示，(1) CAD的危險因子中BMI、收縮壓、抽煙、高血壓、血糖、HDL-膽固醇及三酸甘油酯在兩組間有顯著差異；(2) CAD組抗發炎性細胞激素IL-1ra濃度比健康對照組顯著增加 (P<0.01)，但具抗氧化的Bilirubin上濃度比健康對照組顯著減少，CAD組的發炎性檢驗指標hs-CRP、IL-6、白血球總數、嗜中性球比健康對照組顯著增加：(3) 二組間IL-1ra與HDL-膽固醇、Bilirubin濃度呈負相關，但與危險因子中的血糖濃度、BMI、TG皆呈正相關，與發炎性檢驗指標hs-CRP、IL-6、WBC也呈現正相關；(4) 以IL-1ra依濃度高低級別分析，最高濃度級別比最低濃度級別會增加罹患CAD的危險 (odds ratio, 2.57:95% CI, 1.119 to 5.914: P=0.026)。本研究結果顯示，冠心症患者血中IL-1ra濃度有增加的趨勢。這可能是為避免發炎反應的過度傷害，具抗發炎的生物活性物質如：膽紅素與IL-1ra等在冠心症患者血中濃度升高的原因。

Previous studies show that coronary artery disease (CAD) is a multi-factors and chronic inflammatory disease. IL-1ra is a naturally occurring anti-inflammatory molecules that block the action of IL-1. However, little is known about the dysbalance among IL-1ra, bilirubin, and inflammatory mediators in CAD. We attempted to investigate the relationships between inflammatory mediators and serum IL-1ra levels in patients with CAD. In 95 patients with angiographically defined CAD, and 70 healthy controls were studied in a case-control manner. Serum levels of IL-1ra, IL-6, bilirubin, hs-CRP and the risk factor of CAD were examined. Our major finding include: (1) The risk factors such as elevated BMI, systolic BP, smoking, hypertension, blood glucose, and TG was more frequently found in the CAD group than the control group ( p ＜ 0.001). The HDL-C was significantly higher in control group than the CAD group; (2) Five different inflammatory markers were significantly elevated including IL-1ra, hs-CRP, IL-6, leukocyte count, and neutrophil percentage between healthy controls and CAD patients. In contrast, control group with elevated bilirubin than CAD group ( p ＜ 0.001); (3) By contrast, levels of IL-1ra and other variables such as blood glucose, BMI, TG, IL-6, hs-CRP, and leukocyte count were significantly correlated ( p ＜ 0.01) in all study subjects. In contrast, the levels of IL-1ra were inversed correlation in bilirubin, and HDLC; (4) In the multiple logistic regression analysis, adjustment was made for variables. The relative risk of CAD for the highest quartile of IL-1ra, as compared with the lowest quartile, had an odds ratio 2.57 (95% confidence intervals, 1.119-5.914, p=0.026) increase in risk for CAD. In conclusion, we find a significant association of elevated IL-1ra in the patients with CAD. Thus, in part, may be explained by the anti-inflammatory effects of IL-1ra and bilirubin on CAD.