Stanford Neurocritical Care Program, Stanford Stroke Center, Department of Neurology and Neurological Sciences, Stanford University Medical Center, Stanford, CA, USA.
Neurocrit Care. 2013 Oct;19(2):161-6. doi: 10.1007/s12028-013-9867-5.
In comatose post-cardiac arrest patients, a serum neuron-specific enolase (NSE) level of >33 μg/L within 72 h was identified as a reliable marker for poor outcome in a large Dutch study (PROPAC), and this level was subsequently adopted in an American Academy of Neurology practice parameter. Later studies reported that NSE >33 μg/L is not a reliable predictor of poor prognosis. To test whether different clinical laboratories contribute to this variability, we compared NSE levels from the laboratory used in the PROPAC study (DLM-Nijmegen) with those of our hospital's laboratory (ARUP) using paired blood samples.
We prospectively enrolled cardiac arrest patients who remained comatose after resuscitation. During the first 3 days, paired blood samples for serum NSE were drawn at a median of 10 min apart. After standard preparation for each lab, one sample was sent to ARUP laboratories and the other to DLM-Nijmegen.
Fifty-four paired serum samples from 33 patients were included. Although the serum NSE measurements correlated well between laboratories (R = 0.91), the results from ARUP were approximately 30% lower than those from DLM-Nijmegen. Therapeutic hypothermia did not affect this relationship. Two patients had favorable outcomes after hypothermia despite NSE levels measured by DLM-Nijmegen as >33 μg/L.
Absolute serum NSE levels of comatose cardiac arrest patients differ between laboratories. Any specific absolute cut-off levels proposed to prognosticate poor outcome should not be used without detailed data on how neurologic outcomes correspond to a particular laboratory's method, and even then only in conjunction with other prognostic variables.
在荷兰一项大型研究（PROPAC）中，33μg/L 是神经元特异性烯醇化酶（NSE）在 72 小时内的血清水平的一个可靠标志物，被鉴定为心脏骤停后昏迷患者预后不良的标志物，这一水平随后被美国神经病学学会的实践参数所采用。后来的研究报告称，NSE＞33μg/L 并不能可靠预测不良预后。为了测试不同的临床实验室是否对此有影响，我们使用配对血样比较了用于 PROPAC 研究的实验室（DLM-Nijmegen）和我们医院实验室（ARUP）的 NSE 水平。
我们前瞻性纳入了心脏骤停复苏后仍昏迷的患者。在最初的 3 天内，以中位数 10 分钟的时间间隔抽取配对的血清 NSE 血样。在为每个实验室进行标准准备后，一份样本被送到 ARUP 实验室，另一份送到 DLM-Nijmegen。
33 名患者的 54 对配对血清样本被纳入研究。尽管实验室之间的血清 NSE 测量结果相关性良好（R = 0.91），但 ARUP 的结果比 DLM-Nijmegen 低约 30%。亚低温治疗并不影响这种关系。尽管 DLM-Nijmegen 测量的 NSE 水平＞33μg/L，但在亚低温治疗后，仍有 2 名患者有良好的预后。
昏迷心脏骤停患者的血清 NSE 绝对水平在不同实验室之间存在差异。任何特定的绝对截断值，用于预测不良预后，都不应该在没有详细数据说明特定实验室方法与特定神经结局之间的对应关系的情况下使用，即使在这种情况下，也只能与其他预后变量结合使用。
