Dawson Joe, Cockerill Gillian W, Choke Edward, Belli Anne-Maria, Loftus Ian, Thompson Matt M
St. George's Vascular Institute, St. George's Hospital, London, United Kingdom.
J Vasc Surg. 2007 Feb;45(2):350-6. doi: 10.1016/j.jvs.2006.09.049.
Circulating plasma interleukin-6 (IL-6) concentrations are elevated in patients with abdominal aortic aneurysms (AAAs) compared with controls. In vitro studies suggest that the aneurysm is the source of the IL-6. Because IL-6 is an independent risk factor for cardiovascular mortality, elevation of this cytokine may be significant in these patients, who represent a group at increased risk from cardiovascular death. The aim of this study was to directly measure in vivo aortic IL-6 concentrations, testing the hypothesis that aneurysms secrete IL-6 into the circulation.
Before endovascular aneurysm repair took place, blood was sampled from the entire length of the aorta in 27 patients with AAA and nine with thoracic aneurysms (TAs). A control group consisted of 15 patients without aneurysms undergoing angiography. Plasma IL-6 was determined using enzyme-linked immunosorbent assay, and high-sensitivity C-reactive protein (hs-CRP) was measured turbidimetrically. Aneurysm surface area was calculated from axial computed tomography scans.
Mean IL-6 concentrations (pg/mL) were higher in the TA and AAA groups compared with controls (10.4 +/- 3.7 and 4.9 +/- 0.5 vs 2.7 +/- 0.5, P = .002). There was a significant difference in plasma IL-6 concentration corresponding to aneurysm position in the AAA (P = .002) and TA (P = .008) groups, with both patterns conforming to a linear trend. This pattern was not observed in the control group, in which no significant difference in IL-6 concentrations was found throughout the aorta. Peak IL-6 occurred earlier in TAs compared with AAAs (descending aorta vs iliac artery) corresponding to aneurysm position (P = .0007). Linear regression revealed a positive correlation between aneurysm surface area and mean plasma IL-6 (Spearman's correlation, P = .003). The mean surface areas of the TAs, at 0.07 m2 (interquartile range [IQR], 0.06 to 0.09), were higher than those of the AAAs at 0.03 m2 (IQR, 0.02 to 0.04; P = .002). High-sensitivity CRP was within normal limits, and no significant differences were found between the AAA group and the controls.
Circulating IL-6 is elevated within the aorta in patients with aneurysms and corresponds to aneurysm position. Furthermore, aneurysm surface area and mean plasma IL-6 are correlated. In the absence of any evidence of systemic inflammation in the form of elevated hs-CRP, these data support the hypothesis that aneurysms secrete IL-6 into the circulation. This may contribute to the high cardiovascular mortality observed in patients with aneurysms.
与对照组相比，腹主动脉瘤（AAA）患者循环血浆白细胞介素 - 6（IL - 6）浓度升高。体外研究表明动脉瘤是IL - 6的来源。由于IL - 6是心血管死亡的独立危险因素，这种细胞因子的升高在这些患者中可能具有重要意义，他们是心血管死亡风险增加的群体。本研究的目的是直接测量体内主动脉IL - 6浓度，检验动脉瘤向循环中分泌IL - 6的假设。
在进行血管内动脉瘤修复之前，从27例AAA患者和9例胸主动脉瘤（TA）患者的整个主动脉长度采集血液。对照组由15例接受血管造影且无动脉瘤的患者组成。使用酶联免疫吸附测定法测定血浆IL - 6，并通过比浊法测量高敏C反应蛋白（hs - CRP）。根据轴向计算机断层扫描计算动脉瘤表面积。
与对照组相比，TA组和AAA组的平均IL - 6浓度（pg/mL）更高（分别为10.4±3.7和4.9±0.5，而对照组为2.7±0.5，P = 0.002）。AAA组（P = 0.002）和TA组（P = 0.008）中，对应于动脉瘤位置处的血浆IL - 6浓度存在显著差异，两种模式均符合线性趋势。在对照组中未观察到这种模式，在整个主动脉中IL - 6浓度未发现显著差异。与AAA相比，TA中对应于动脉瘤位置的IL - 6峰值出现更早（降主动脉与髂动脉）（P = 0.0007）。线性回归显示动脉瘤表面积与平均血浆IL - 6之间存在正相关（Spearman相关性，P = 0.003）。TA的平均表面积为0.07 m²（四分位间距[IQR]，0.06至0.09），高于AAA的平均表面积0.03 m²（IQR，0.02至0.04；P = 0.002）。高敏CRP在正常范围内，AAA组与对照组之间未发现显著差异。
动脉瘤患者主动脉内循环的IL - 6升高，且与动脉瘤位置相对应。此外，动脉瘤表面积与平均血浆IL - 6相关。在没有hs - CRP升高形式的任何全身炎症证据的情况下，这些数据支持动脉瘤向循环中分泌IL - 6的假设。这可能导致动脉瘤患者中观察到的高心血管死亡率。
