Mair J
Institut für Medizinische Chemie and Biochemie, University of Innsbruck, Austria.
Crit Rev Clin Lab Sci. 1997;34(1):1-66. doi: 10.3109/10408369709038215.
New clinical requirements for triaging chest pain patients challenge the abilities of the current cardiac markers. Serial measurements of myoglobin, creatine kinase (CK) isoenzyme MB (CKMB) mass, or CK isoforms in emergency rooms help to rapidly rule out acute myocardial infarction (AMI). However, within the first 3 to 4 h from chest pain onset, their sensitivities are too low to contribute significantly to AMI diagnosis during this period. CKMB and lactate dehydrogenase (LDH) isoenzyme 1 are not heart-specific, which hampers reliable diagnosis in patients with concomitant skeletal muscle damage. By contrast, the regulatory proteins troponin I and troponin T are expressed in three different isoforms: one for slow-twitch skeletal muscle fibers, one for fast-twitch skeletal muscle fibers, and one for cardiac muscle (cTnI, cTnT); cardiac-specific cTnI and cTnT assays are already available for routine use. cTnT and cTnI are the most promising markers for risk stratification in patients with unstable angina pectoris. Recent reports on increased cTnT in patients with renal failure or myopathy without evidence of myocardial injury and undetectable cTnI suggest that cTnT could be reexpressed similar to CKMB and LDH-1 in chronically damaged human skeletal muscle. Therefore, cTnI is probably the most heart-specific marker. Among the recently proposed new markers for early AMI diagnosis: glycogen phosphorylase isoenzyme BB (GPBB), fatty acid binding protein, phosphoglyceric acid mutase isoenzyme MB, enolase isoenzyme alpha beta, S100a0, and annexin V, GPBB is the most promising because it increases as early as 1 to 4 h from chest pain onset and its early release appears to be essentially dependent on ischemic myocardial injury.
胸痛患者分诊的新临床需求对当前心脏标志物的能力提出了挑战。在急诊室对肌红蛋白、肌酸激酶（CK）同工酶MB（CKMB）质量或CK同工型进行连续测量有助于快速排除急性心肌梗死（AMI）。然而，在胸痛发作后的最初3至4小时内，它们的敏感性过低，无法在此期间对AMI诊断做出显著贡献。CKMB和乳酸脱氢酶（LDH）同工酶1并非心脏特异性的，这妨碍了对伴有骨骼肌损伤患者的可靠诊断。相比之下，调节蛋白肌钙蛋白I和肌钙蛋白T以三种不同的同工型表达：一种用于慢肌纤维骨骼肌，一种用于快肌纤维骨骼肌，一种用于心肌（cTnI、cTnT）；心脏特异性的cTnI和cTnT检测方法已可用于常规使用。cTnT和cTnI是不稳定型心绞痛患者危险分层最有前景的标志物。最近有报告称，在没有心肌损伤证据的肾衰竭或肌病患者中cTnT升高，而cTnI检测不到，这表明cTnT可能会像CKMB和LDH - 1一样在慢性受损的人类骨骼肌中重新表达。因此，cTnI可能是最具心脏特异性的标志物。在最近提出的用于早期AMI诊断的新标志物中：糖原磷酸化酶同工酶BB（GPBB）、脂肪酸结合蛋白、磷酸甘油酸变位酶同工酶MB、烯醇化酶同工酶αβ、S100a0和膜联蛋白V，GPBB最有前景，因为它在胸痛发作后1至4小时就开始升高，其早期释放似乎主要依赖于缺血性心肌损伤。
