Bladbjerg E M, Gram J, Jespersen J
Department of Thrombosis Research, University of Southern Denmark, Esbjerg.
Scand J Clin Lab Invest. 2000 May;60(3):161-8. doi: 10.1080/003655100750044802.
Ever since the coagulant activity of blood coagulation factor VII (FVII:C) was identified as a risk indicator of cardiac death, a large number of studies have measured FVII protein concentrations in plasma. FVII protein concentrations are either measured immunologically with an ELISA method (FVII:Ag) or estimated with an amidolytic method (FVII:Am). We have investigated whether FVII:Am is a valuable alternative to FVII:Ag. FVII:Ag and FVII:Am were measured in 147 plasma samples from blood donors, patients on oral anticoagulant therapy, postmenopausal women on hormone replacement therapy, in postprandial plasma, in cold activated plasma and in FVII deficient plasma. There was a positive correlation (r=0.96) between FVII:Ag and FVII:Am with slightly but significantly higher values for FVII:Ag (FVII:Ag= 106 U/ml and FVII:Am=100 U/ml; p <0.001). A significant correlation (r=0.93) was still observed after omitting the data from patients on oral anticoagulant therapy, with mean values of 113 U/ml for FVII:Ag and 110 U/ml for FVII:Am (p < 0.01). In a linear regression analysis, the intercept (alpha=-21.50) was different from zero (p < 0.0001) and the slope (beta=1.16) was different from 1.0 (p < 0.001). Only a few points (3.1%) in a difference plot were present outside the expected 95% interval calculated from the analytical imprecision of the two methods. Therefore, we consider the amidolytic method an acceptable alternative to the ELISA method when analysing citrated plasma samples containing only enzymatically functional FVII protein, but the results cannot be directly transferred from one method to the other.
自从凝血因子VII（FVII:C）的凝血活性被确定为心脏死亡的风险指标以来，大量研究已对血浆中的FVII蛋白浓度进行了测量。FVII蛋白浓度要么采用ELISA方法进行免疫测定（FVII:Ag），要么采用酰胺水解法进行估算（FVII:Am）。我们研究了FVII:Am是否是FVII:Ag的一种有价值的替代方法。对147份来自献血者、接受口服抗凝治疗的患者、接受激素替代治疗的绝经后女性、餐后血浆、冷激活血浆以及FVII缺乏血浆的样本进行了FVII:Ag和FVII:Am的测量。FVII:Ag与FVII:Am之间存在正相关（r = 0.96），FVII:Ag的值略高但显著高于FVII:Am（FVII:Ag = 106 U/ml，FVII:Am = 100 U/ml；p < 0.001）。在剔除接受口服抗凝治疗患者的数据后，仍观察到显著相关性（r = 0.93），FVII:Ag的平均值为113 U/ml，FVII:Am的平均值为110 U/ml（p < 0.01）。在线性回归分析中，截距（alpha = -21.50）不同于零（p < 0.0001），斜率（beta = 1.16）不同于1.0（p < 0.001）。在差异图中，只有少数点（3.1%）位于根据两种方法的分析不精密度计算出的预期95%区间之外。因此，当分析仅含有酶功能活性FVII蛋白的枸橼酸盐血浆样本时，我们认为酰胺水解法是ELISA法的一种可接受替代方法，但结果不能直接从一种方法转换到另一种方法。
