Analysis of the Mechanisms of Complement Cold Activation of the Serum from C-type Hepatitis Patients

加入α - 2-纤溶酶抑制剂（PI）可以以剂量依赖的方式部分阻止c型肝炎患者血清补体（CA）的冷活化。氨甲环酸也表现出周效，而贝德林和尿司他丁则没有。这些患者血清中PI的内在活性明显低于正常人，并且正常血清中的PI活性因冷孵育而降低。患者与正常人之间的因子7活性无显著差异。采用凝胶过滤法制备CA阳性血清，加入高分子量组分（> ~ 100kd）诱导健康人血清中CA。超滤制备的高分子量组分对健康血清也有剂量依赖性的CA诱导作用，即使在CA发生后仍具有诱导CA的活性。从患者血清中获得的冷球蛋白可诱导CA，但部分冷球蛋白阴性血清也可显示CA，由此推测冷培养中固有纤溶酶抑制剂（如α 2- pi）的减少和纤溶酶样酶的激活是冷补体活化的因素之一。这也表明在这些患者的血清中存在着除冷球蛋白以外的CA诱导的高分子因子。

Cold activation of complement (CA) of the serum from patients with C-type hepatitis was partially prevented by adding alpha 2-plasmin inhibitor (PI) in a dose dependent manner. Tranexamic acid also showed week effect but bdelin and urinastatin did not. Intrinsic activities of PI in such patient sera were significantly lower than those of normals and the PI activities of normal sera were decreased by cold incubation. No significant difference was observed between the factor VII activity of patients and that of normals. CA was induced to healthy sera by the addition of high molecular weight fractions (>〜100kd) from CA positive sera prepared by gel filtration. High molecular weight fractions prepared by ultrafiltration also caused CA on healthy sera in the dose dependent manner and the CA inducing activity was remained even after CA occurred. Cryo-globurin obtained from patient sera induced CA but some cryo-globurin negative sera also showed CA.From these results it is speculated that the decrease of intrinsic plasmin inhibitors, like alpha2-PI, and the activation of plasmin like enzyme(s) in cold incubation is one of the factors of cold complement activation. It was also suggested that CA inducing high molecular factors other than cryo-globurin is present in such patient sera.