Adu D, Williams D G
Clin Exp Immunol. 1984 Mar;55(3):495-501.
Complement activation in vitro by cryoglobulins isolated from the sera of 28 patients with systemic lupus erythematosus (SLE) was examined by incubating the cryoglobulin with normal human serum and performing crossed-immunoelectrophoresis of the mixture to detect C3 conversion. Eighteen of the 28 SLE cryoglobulins activated complement; eight by the classical pathway, four by the alternative pathway exclusively, and six by both pathways. In contrast only two out of 20 cryoglobulins isolated from the sera of normal subjects activated complement and both did so by the classical pathway. Twenty-three of the 28 SLE sera activated complement and complement activating cryoglobulins were isolated from 15 of these 23 sera. The parent sera of cryoglobulins activating complement had lower C4 and C3 concentrations than sera whose cryoglobulins did not split complement but these differences were not significant. The ability of SLE cryoglobulins to activate complement in vitro suggests that these immune complexes activate complement in vivo and thus may contribute to tissue damage in this disease. The activation of both classical and alternative complement pathways is in keeping with other evidence that both pathways are involved in SLE.
通过将28例系统性红斑狼疮（SLE）患者血清中分离出的冷球蛋白与正常人血清孵育，并对混合物进行交叉免疫电泳以检测C3转化，来研究体外补体激活情况。28份SLE冷球蛋白中有18份激活补体；8份通过经典途径激活，4份仅通过替代途径激活，6份通过两种途径激活。相比之下，从正常受试者血清中分离出的20份冷球蛋白中只有2份激活补体，且均通过经典途径激活。28份SLE血清中有23份激活补体，且从这23份血清中的15份中分离出了补体激活冷球蛋白。激活补体的冷球蛋白的原始血清的C4和C3浓度低于其冷球蛋白不裂解补体的血清，但这些差异不显著。SLE冷球蛋白在体外激活补体的能力表明，这些免疫复合物在体内激活补体，因此可能导致该疾病的组织损伤。经典和替代补体途径的激活与其他证据一致，即两种途径都参与SLE。
