Munkvad S, Jespersen J, Sidelmann J, Gram J
Department of Clinical Chemistry, Ribe County Hospital, Esbjerg, Denmark.
Clin Chem. 1990 Jul;36(7):1305-11.
We present a new functional assay for the first complement component (C1) in plasma, based on its activation by inhibition of the C1-esterase inhibitor (C1-inh) when monospecific antiserum to C1-inh is added to the plasma. After maximal activation, we can determine the concentration of activated C1 by using an amidolytic rate assay with a chromogenic substrate. We have optimized the assay conditions with respect to incubation time, concentration of antiserum to C1-inh, ionic strength, and pH. Our method determines specifically the concentration in plasma of free activated C1, not complexes of activated C1 with C1-inh, and is not influenced by the concentration of C1-inh in the test sample. Concentrations of C1 correlated significantly with activities determined by a hemolytic assay (r = 0.55, t = 4.09, P less than 0.001). The estimated interassay CV was 5% and the intra-assay CV was 1%. The sensitivity, imprecision, and practical test performance of our assay are superior to those of conventionally used hemolytic assays.
我们提出了一种针对血浆中第一补体成分（C1）的新功能检测方法，该方法基于在血浆中加入抗C1酯酶抑制剂（C1-inh）单特异性抗血清时，通过抑制C1酯酶抑制剂来激活C1。在最大激活后，我们可以使用含显色底物的酰胺水解速率测定法来测定活化C1的浓度。我们在孵育时间、抗C1-inh抗血清浓度、离子强度和pH值方面优化了检测条件。我们的方法特异性地测定血浆中游离活化C1的浓度，而非活化C1与C1-inh的复合物，并且不受测试样品中C1-inh浓度的影响。C1的浓度与溶血测定法测定的活性显著相关（r = 0.55，t = 4.09，P小于0.001）。估计的批间变异系数为5%，批内变异系数为1%。我们检测方法的灵敏度、不精密度和实际检测性能优于传统使用的溶血测定法。
