Aillaud M F, Pouymayou K, Brunet D, Parrot G, Alessi M C, Amiral J, Juhan-Vague I
Laboratory of Hematology, CHU Timone, Marseille, France.
Thromb Haemost. 1996 Feb;75(2):283-5.
Congenital deficiencies of protein S (PS) are associated with thrombophilia. Their characterization and classification have been hampered by the complex physiology of the protein C-protein S system and the poor standardization and reliability of laboratory assays. The free active form of protein S is usually determined by immunoassay using polyclonal antibodies in the plasma supernate after polyethyleneglycol (PEG) precipitation. A new one step ELISA using two monoclonal antibodies specific for distinct epitopes of the free form of protein S has been developed for the direct measurement of free PS in untreated plasma. We have tested two ELISA assays for free PS. One assay was based on the PEG precipitation (Asserachrom PS, Stago, Asnières, France) whereas the other was a one step ELISA assay (Asserachrom free PS, Stago). Values were obtained in 35 PS deficient patients recruited among 500 consecutive patients evaluated by the laboratory for diagnosis of congenital disorders of coagulation. Values were compared to those obtained in 50 patients with no PS deficiency matched for age and sex with the PS deficient patients as well as in 33 normal subjects and in 12 pregnant women. Strong correlation was found between the two tests (r = 0.81, p < 10(-5)) in the entire population (n = 130), as well as in the separate groups. The new one step ELISA was more accurate than the PEG free PS determination. Determination of PS activity and antigens allowed us to separate quantitative and qualitative deficiencies. Among the qualitative deficiencies, isolated decrease in PS activity was the most frequent defect observed (66%). This fact questions the substitution of PS activity assays by the one step antigenic free PS ELISA assay.
蛋白S（PS）先天性缺陷与血栓形成倾向有关。蛋白C-蛋白S系统复杂的生理学特性以及实验室检测方法标准化程度低和可靠性差，阻碍了对其特征的描述和分类。游离活性形式的蛋白S通常通过在聚乙二醇（PEG）沉淀后的血浆上清液中使用多克隆抗体的免疫测定来确定。一种新的一步酶联免疫吸附测定法（ELISA）已被开发出来，该方法使用两种针对游离形式蛋白S不同表位的单克隆抗体，用于直接测量未经处理血浆中的游离PS。我们测试了两种游离PS的ELISA检测方法。一种检测方法基于PEG沉淀（Asserachrom PS，法国阿斯尼埃的Stago公司），而另一种是一步ELISA检测法（Asserachrom游离PS，Stago公司）。在实验室为诊断先天性凝血障碍而评估的500例连续患者中招募了35例PS缺陷患者，并获得了检测值。将这些值与50例年龄和性别与PS缺陷患者相匹配的无PS缺陷患者、33例正常受试者以及12例孕妇所获得的值进行比较。在整个人群（n = 130）以及各个单独的组中，两种检测方法之间均发现有很强的相关性（r = 0.81，p < 10⁻⁵）。新的一步ELISA比PEG游离PS测定更准确。PS活性和抗原的测定使我们能够区分定量和定性缺陷。在定性缺陷中，观察到最常见的缺陷是PS活性单独降低（66%）。这一事实对用一步抗原性游离PS ELISA检测法替代PS活性检测提出了质疑。
