Seelen M A, Trouw L A, van der Hoorn J W A, Fallaux-van den Houten F C, Huizinga T W J, Daha M R, Roos A
Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands.
Clin Exp Immunol. 2003 Nov;134(2):335-43. doi: 10.1046/j.1365-2249.2003.02274.x.
In systemic lupus erythematosus (SLE), autoantibodies directed against complement components of the classical pathway, especially against C1q, are associated with severe disease and are of prognostic value for flares of lupus nephritis. Mannose-binding lectin (MBL), the recognition unit of the MBL pathway of complement activation, has structural similarities to C1q. Deficiencies of MBL have been shown to predispose to the development of SLE and to influence the course of the disease. We hypothesized that the presence of autoantibodies to MBL, analogous to autoantibodies to C1q in patients with SLE, may contribute to disease development. The occurrence of anti-MBL autoantibodies was assessed by enzyme-linked immunosorbent assay (ELISA) of 68 serum samples from 20 patients with SLE and in serum from 70 healthy controls. Levels of antibodies directed against MBL were significantly higher in patients with SLE compared to healthy subjects. No significant difference was found between patients with active disease compared to those with inactive disease. While the occurrence of anti-C1q autoantibodies was associated with renal involvement, no such relationship was found for anti-MBL autoantibodies. A significant correlation was found between anti-MBL and anti-C1q antibody levels. The level of anti-MBL antibodies was negatively correlated with MBL-complex activity of circulating MBL. Anti-MBL autoantibodies were of the immunoglobulin G (IgG) isotype and the binding site of IgG anti-MBL was located in the F(ab')2 portion. We conclude that anti-MBL are present in sera from SLE patients and influence the functional activity of MBL.
在系统性红斑狼疮（SLE）中，针对经典途径补体成分的自身抗体，尤其是针对C1q的自身抗体，与严重疾病相关，并且对狼疮性肾炎的发作具有预后价值。甘露糖结合凝集素（MBL）是补体激活MBL途径的识别单位，与C1q具有结构相似性。已表明MBL缺乏易导致SLE的发生并影响疾病进程。我们推测，与SLE患者中针对C1q的自身抗体类似，针对MBL的自身抗体可能有助于疾病发展。通过酶联免疫吸附测定（ELISA）评估了20例SLE患者的68份血清样本以及70名健康对照者血清中抗MBL自身抗体的发生情况。与健康受试者相比，SLE患者中针对MBL的抗体水平显著更高。活动期疾病患者与非活动期疾病患者之间未发现显著差异。虽然抗C1q自身抗体的出现与肾脏受累相关，但抗MBL自身抗体未发现此类关系。抗MBL和抗C1q抗体水平之间存在显著相关性。抗MBL抗体水平与循环MBL的MBL复合物活性呈负相关。抗MBL自身抗体属于免疫球蛋白G（IgG）同种型，IgG抗MBL的结合位点位于F(ab')2部分。我们得出结论，抗MBL存在于SLE患者的血清中，并影响MBL的功能活性。
