Gerhardt W, Nordin G, Herbert A K, Burzell B L, Isaksson A, Gustavsson E, Haglund S, Müller-Bardorff M, Katus H A
Department of Clinical Chemistry, Lasarettet, Helsingborg, Sweden.
Clin Chem. 2000 Jun;46(6 Pt 1):817-21.
Heparinized plasma samples allow more rapid analysis than serum samples, but preliminary studies showed lower cardiac troponin T (cTnT) results in plasma. We undertook a multicenter study to characterize this effect for cTnT and cardiac troponin I (cTnI).
Blood samples were collected with and without heparin at five hospitals. cTnT was measured by a "third generation" assay (Elecsys((R))), and cTnI was measured by a commercial immunoassay (IMMULITE((R))).
Mean cTnT was 15% lower in heparin sampling tubes than in serum. Measured concentrations of cardiac troponins also decreased with increasing heparin concentrations added to sera. Heparin-induced losses were greater in early than in late phases after onset of chest pain. Addition of heparin ( approximately 100 IU/mL) to serial samples from nine acute myocardial infarction patients produced mean cTnT losses of 33% at 1-12 h after onset of chest pain, 17% at 13-48 h, and 7% after 48 h. The changing heparin effects were seen for both cTnT and cTnI during time courses of individual patients with myocardial infarction.
We suggest that binding of heparin to troponins decreases immunoreactivity, especially in early phases of myocardial injury. The resulting losses may depend on the antibodies used in each troponin assay.
肝素化血浆样本比血清样本能进行更快速的分析，但初步研究显示血浆中的心肌肌钙蛋白T（cTnT）结果较低。我们开展了一项多中心研究来描述这种对cTnT和心肌肌钙蛋白I（cTnI）的影响。
在五家医院采集了使用和未使用肝素的血样。cTnT通过“第三代”检测法（Elecsys((R))）进行测量，cTnI通过商业免疫检测法（IMMULITE((R))）进行测量。
肝素采样管中的平均cTnT比血清中的低15%。随着向血清中添加的肝素浓度增加，测得的心肌肌钙蛋白浓度也降低。胸痛发作后早期肝素诱导的损失比晚期更大。向9例急性心肌梗死患者的系列样本中添加肝素（约100 IU/mL），在胸痛发作后1 - 12小时平均cTnT损失33%，13 - 48小时损失17%，48小时后损失7%。在心肌梗死个体患者的病程中，cTnT和cTnI均出现了肝素效应的变化。
我们认为肝素与肌钙蛋白的结合会降低免疫反应性，尤其是在心肌损伤的早期阶段。由此导致的损失可能取决于每种肌钙蛋白检测中使用的抗体。
