C3d及荷C3d免疫复合物的测定与意义

Detection of C3d and C3dfearing immune complexes and its clinical significance

目的：探讨Ｃ３ｄ与Ｃ３ｄ－ＩＣ的测定方法及其与临床疾病的关系。方法：用抗人Ｃ３和抗人ＩｇＧγ－球蛋白组份作为固相反应物，建立了检测Ｃ３ｄ及Ｃ３ｄ－ＩＣ的ＥＬＩＳＡ法，并对临床各类疾病患者血清Ｃ３ｄ与Ｃ３ｄ－ＩＣ的水平进行了测定。结果：发现慢性肾炎、全身性红斑狼疮（ＳＬＥ）、慢性乙型肝炎及肺炎患者血清中Ｃ３ｄ总体水平均较对照组显著增高，分别有５８．５％～７２．２％的患者Ｃ３ｄ含量高于正常上限（Ｐ＜０．０１），且该类患者亦有较高的Ｃ３ｄ－ＩＣ阳性检出率（肺炎患者除外）。本研究表明，Ｃ３ｄ－ＩＣ阳性者，其血清Ｃ３ｄ含量均高于正常水平，二者具有显著的相关性。结论：Ｃ３ｄ－ＩＣ与补体的起始激活有直接关系，因而Ｃ３ｄ－ＩＣ与Ｃ３ｄ可以看作是疾病或组织损伤及补体活化反应的重要参考指标。

Objectives:To investigate the associations between C3d and C3dIC as well as clinical diseases. Methods:Using antihuman C3 and antihuman IgGγ globulin as solid phase reagents,an enzyme linked immunosorbent assay(ELISA) for C3d and C3dIC was developed,and was used to evaluate sera from patients with variety of clinical diseases,for the levels of C3d and C3dIC. Results:The total levels of sera of C3d which from patients with chronic nephritis,SLE,chronic HBV hepatitis and pneumonia was significantly elevated than control.It was 58.5%~72.2% of patients that sera C3d concentrations exceeded the upper limit of normal respectively(P<0.01),and the positive rate of C3dIC was also higher than control(except pneumonia).In this study,all of C3dIC positive cases had a higher levels of C3d,and both of them had significant associations. Conclusions:C3dIC was directly related to the activation of complement cascade.Therefore,C3dIC and C3d could serve as important index causing diseases and tissue damage as well as activation of complement reflection.