Clearance of cardiac troponin T with and without kidney function
Clearance of cardiac troponin T with and without kidney function
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DOI：
10.1016/j.clinbiochem.2017.02.007
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发表时间：
2017-06-01
影响因子：
2.8
通讯作者：
Hammarsten, Ola
中科院分区：
文献类型：
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作者：
Friden, Vincent;Starnberg, Karin;Hammarsten, Ola
目的：心脏损伤生物标志物心肌肌钙蛋白 T (cTnT) 的肾脏依赖性清除程度尚不清楚。方法和结果：我们检查了在有或没有夹闭肾血管的大鼠中注射心脏提取物后 cTnT 的清除情况。在人类受试者中检查了 cTnT 降解为能够通过肾小球膜的片段的程度以及 cTnT 的肾脏提取指数。推注大鼠心脏提取物后，模拟大面积心肌梗塞，无论有无肾功能，cTnT 清除率均无显着差异。然而，在清除过程后期，cTnT 水平较低时，观察到清除速度较慢。当以恒定速率输注低水平的大鼠心脏提取物至稳态时，肾血管的夹紧导致 cTnT 清除率显着降低 2 倍。在人类受试者中测得的 cTnT 中，超过 60% 的分子量低于 17 kDa，预计可以相对自由地通过肾小球膜。 3例接受肾静脉置管的心力衰竭患者的cTnT提取指数为8-19%。肾功能调整后的 cTnT 水平增加了急诊室队列中 cTnT 分析诊断心肌梗死的 ROC 曲线下面积。结论：在高浓度时（通常在大面积心肌梗塞后发现），cTnT 的肾外清除占主导地位。在 cTnT 水平较低时（常见于 cTnT 稳定升高的患者），肾脏清除率也有助于 cTnT 的清除。这可能解释了为什么肾功能低下的患者稳定的 cTnT 水平往往更高。 (C) 2017 年由 Elsevier Inc. 代表加拿大临床化学家协会出版。
Objective: The extent of kidney-dependent clearance of the cardiac damage biomarker cardiac troponin T (cTnT) is not known.Methods and results: We examined clearance of cTnT after injection of heart extracts in rats with or without clamped kidney vessels. The extent of degradation of cTnT to fragments able to pass the glomerular membrane and the kidney extraction index of cTnT was examined in human subjects. After a bolus injection of rat cardiac extract, simulating a large myocardial infarction, there was no significant difference in clearance of cTnT with or without kidney function. However, a slower clearance was observed late in the clearance process, when cTnT levels were low. When low levels of rat cardiac extract were infused at a constant rate to steady state, clamping of the renal vessels resulted in significant 2-fold reduction in clearance of cTnT. Over 60% of the measured cTnT in human subjects had a molecular weight below 17 kDa, expected to have a relatively free passage over the glomerular membrane. The extraction index of cTnT in three heart failure patients undergoing renal vein catheterization was 8-19%. Kidney function adjusted cTnT levels increased the area under the ROC curve for diagnosis of myocardial infarction of the cTnT analysis in an emergency room cohort.Conclusions: At high concentrations, often found after a large myocardial infarction, extrarenal clearance of cTnT dominates. At low levels of cTnT, often found in patients with stable cTnT elevations, renal clearance also contribute to the clearance of cTnT. This potentially explains why stable cTnT levels tend to be higher in patients with low kidney function. (C) 2017 Published by Elsevier Inc. on behalf of The Canadian Society of Clinical Chemists.