功能性组织因子途径抑制物抗原测定的研究

目的：试图建立功能性组织因子途径抑制物的抗原（fTFPI:Ag）测定法，方法：用组织凝血活酶（含磷脂与组织因子）包板后，加入凝血酶原复合物（PCC）及经过加热处理的含TFPI的待测血浆或TFPI标准品，然后加入抗TFPI单抗，最后加入HRP标记的IgG及相关的底物，根据显色的深浅来反映TFPI的含量，待测样本的含量从标准曲线上换算出来，结果：（1）用本法测得全长的TFPI线性关系好（r=0.974)，而TFPI1-161线性差（r=0.582)。（2）抗TFPI多抗能以剂量依赖性降低fTFPI:Ag测定值，但非特异性IgG对fTFPI:Ag测定值无影响。（3)fTFPI:Ag与BerrettiniTFPI活性法及TFPI抗凝活性法相关性较好，但与酰解终点法无明显相关。（4）fTFPI:Ag与总TFPI、含K3的TFPI、截短的TFPI测定值相关性无显著性意义。（5）与对照成人相比，急性心肌梗死患者的fTFPI增高，急性缺血性脑卒患者较正常对照组低；注入肝素引起fTFPI显著升高。结论：（1）本法实际是反映全长的TFPI。（2）本法可以反映体内具有抗凝活性的TFPI抗原含量变化。

Studies on an Assay for Functional Tissue Factor Pathway Inhibitor Antigen

Objective: To establish an immunoenzymatic assay for tissue factor pathway inhibitor antigen (fTFPI:Ag) in plasma. Methods: After rabbit thromboplastin was immobilized on microtiter plates, the appropriate amount of prothrombin complex concentrate and of heated plasma or recombinant TFPI was then added to the wells. TFPI was detected using a monoclonal antibody recognizing TFPI K1 and subsequently bound with HRP labelled second antibody. The levels of TFPI were calculated from HRP-substrate reaction. Results: (1)The full length TFPI had a significantly linear correlation with fTFPI : Ag (r = 0. 974), but the truncated TFPI1-161 did not (r = 0.582). (2)Polyclonal antibody specific for TFPI decreased the amount of fTFPI: Ag in dose-dependent manner while unspecific antibody did not affect it. (3)fTFPI: Ag was related to the thromboplastin-immobilized chromogenic assay and the diluted thromboplastin. clotting time, but not to amidolytic end point assay. (4) There were no significant correlations among fTFPI: Ag and total TFPI, TFPI containing K3 and truncated TFPI. (5) Compared with healthy adults. fTFPI: Ag in the patients with ischemic stroke was lower and it in patients with accute myocardiac infarction was higher. Heparin infusion induced remarkable increment of fTFPI: Ag in plasma. Conclusion: (1) fTFPI : Ag represents the antigen amount of full length TFPI. (2) fTFPI: Ag can reflect the changes in vivo of TFPI possessing anticoagulant activity.