Brinkmann T, Dreier J, Diekmann J, Götting C, Klauke R, Schumann G, Kleesiek K
Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
Vox Sang. 2003 Oct;85(3):159-64. doi: 10.1046/j.1423-0410.2003.00347.x.
Serum alanine aminotransferase (ALT) determination is recommended, or even required by law, in the screening of blood donors in many countries, and donors with an increased catalytic activity of ALT are excluded from blood donation. In most countries, the ALT cut-off value for blood donor screening for men and women is twice the upper limit of the normal range. The introduction, in 2002, of the new International Federation of Clinical Chemistry (IFCC) reference method, performed at 37 degrees C, required new ALT reference values to be established for healthy individuals and a new cut-off point to be determined for blood donor screening.
We compared ALT values of donor blood units using the previous German standard method, which measures ALT values at 25 degrees C, and the new IFCC reference procedure, where ALT levels are measured at 37 degrees C.
We found a linear correlation between the ALT values obtained by the method at 25 degrees C and the new IFCC reference method (37 degrees C) (r = 0.983), and a gender- and age-independent ratio of 0.523. Using this ratio we calculated the new ALT cut-off for blood donations and now propose a new upper limit of 132 U/l (2.20 microkat/l) for men and 86 U/l (1.43 microkat/l) for women. Only 220 of 151 678 blood donations collected over a period of 5 years showed an ALT value higher than the cut-off. None were hepatitis C virus (HCV) positive in serological or nucleic acid amplification technology (NAT) assays. Only 0.006% of all blood donations were positive for antibody to HCV and thus excluded.
With the implementation of the new IFCC reference method for ALT determination at 37 degrees C, we propose a new ALT cut-off for blood donor screening, which, for men, is about three times the upper limit of the normal range and for women about 2.5 times. Our results show that a lower cut-off would probably not yield a higher safety of blood products in terms of detecting viral infections, but would result in a loss of approximately 0.75% of suitable blood donors.
在许多国家，血清丙氨酸氨基转移酶（ALT）测定在献血者筛查中被推荐，甚至是法律要求。ALT催化活性升高的献血者会被排除在献血之外。在大多数国家，男性和女性献血者筛查的ALT临界值是正常范围上限的两倍。2002年引入的新的国际临床化学联合会（IFCC）参考方法在37℃下进行，这就需要为健康个体建立新的ALT参考值，并为献血者筛查确定新的临界值。
我们比较了使用之前德国标准方法（在25℃下测量ALT值）和新的IFCC参考程序（在37℃下测量ALT水平）所测得的献血单位的ALT值。
我们发现25℃方法所获得的ALT值与新的IFCC参考方法（37℃）所获得的ALT值之间存在线性相关性（r = 0.983），且性别和年龄无关的比值为0.523。利用这个比值，我们计算了献血的新ALT临界值，现在建议男性的新上限为132 U/l（2.20微kat/l），女性为86 U/l（1.43微kat/l）。在5年期间采集的151678份献血中，只有220份的ALT值高于临界值。在血清学或核酸扩增技术（NAT）检测中，没有一份丙型肝炎病毒（HCV）呈阳性。所有献血中只有0.006%的抗HCV抗体呈阳性，因此被排除。
随着在37℃下测定ALT的新IFCC参考方法的实施，我们提出了献血者筛查的新ALT临界值，对于男性而言，该临界值约为正常范围上限的三倍，对于女性而言约为2.5倍。我们的结果表明，较低的临界值在检测病毒感染方面可能不会带来更高的血液制品安全性，反而会导致约0.75%的合适献血者流失。
