Ceresa Erik, Brouwers Els, Peeters Miet, Jern Christina, Declerck Paul J, Gils Ann
Laboratory for Pharmaceutical Biology and Phytopharmacology, Faculty of Pharmaceutical Sciences, Katholieke Universiteit Leuven, Belgium.
Arterioscler Thromb Vasc Biol. 2006 Feb;26(2):423-8. doi: 10.1161/01.ATV.0000199246.08616.98. Epub 2005 Dec 8.
To date, quantitation of TAFI antigen levels has been mainly focused on "total" antigen levels and has been shown to yield ambiguous results because of the existence of different isoforms and various degrees of activation. Our objective was to develop assays that allow measuring the extent of TAFI activation.
A variety of enzyme-linked immunosorbent assays (ELISAs) were evaluated for their preferential reactivity toward TAFI before and after activation, and toward the recombinantly expressed activation peptide. Three ELISAs with distinct reactivities were selected: recognizing either exclusively nonactivated TAFI, the released activation peptide, or exclusively TAFIa (activated TAFI). Evaluation of TAFI activation during clot lysis revealed that decreases of TAFI levels are associated with increases of the released activation peptide and TAFIa levels. In addition, antigenic measurement of TAFIa parallels activity measured by chromogenic assay. Analyzing plasma samples revealed that subjects with hyperlipidemia had significantly higher plasma levels of both the activation peptide (109.2 versus 95.5; P<0.001) and TAFIa (112.1 versus 103.3; P=0.03), and not of TAFI antigen (92.5 versus 87.9; P=0.07) (results in % of plasma pooled from normolipidemic subjects).
ELISAs that allow to measure the extent of TAFI activation were developed. These ELISAs constitute more sensitive markers in studies on the relationship between TAFI and cardiovascular diseases.
迄今为止，凝血酶激活的纤溶抑制物（TAFI）抗原水平的定量主要集中在“总”抗原水平上，并且由于存在不同的同工型和不同程度的激活，已显示会产生不明确的结果。我们的目标是开发能够测量TAFI激活程度的检测方法。
评估了多种酶联免疫吸附测定（ELISA）对激活前后TAFI以及重组表达的激活肽的优先反应性。选择了三种具有不同反应性的ELISA：分别专门识别未激活的TAFI、释放的激活肽或专门识别激活的TAFI（TAFIa）。对凝血溶解过程中TAFI激活的评估表明，TAFI水平的降低与释放的激活肽和TAFIa水平的增加相关。此外，TAFIa的抗原性测量与显色测定法测得的活性平行。分析血浆样本显示，高脂血症患者血浆中激活肽（109.2对95.5；P<0.001）和TAFIa（112.1对103.3；P=0.03）的水平均显著升高，而TAFI抗原水平未升高（92.5对87.9；P=0.07）（结果以正常血脂受试者混合血浆的百分比表示）。
开发了能够测量TAFI激活程度的ELISA。这些ELISA在TAFI与心血管疾病关系的研究中构成了更敏感的标志物。
