SLE患者抗载脂蛋白A-I抗体的检测及其对细胞内胆固醇外流的影响

Prevalence of anti-ApoA-I autoantibody in patients with SLE and its role in the pathogenesis of atherosclerosis

研究系统性红斑狼疮(SLE)患者血中抗载脂蛋白A-I(Apo A-I)抗体的阳性率及其可能的致动脉粥样硬化的机制。采用酶联免疫吸附法(ELISA)检测175例SLE患者抗Apo A-I抗体,以64例正常人为对照;用抑制试验研究Apo A-I aa74- 105肽段能否抑制抗ApoA-I多抗和单抗IS4与Apo A-I的结合;并观察抗Apo A-I多抗和单抗对细胞内胆固醇流出的影响。结果显示,在SLE患者中存在抗Apo A-I抗体,阳性率为16.6%;肽段aa74-105能够抑制抗Apo A-I抗体与Apo A-I的结合;抗Apo A-I抗体在体外能抑制细胞内胆固醇的流出。实验表明,SLE患者的抗Apo A-I抗体可能通过和Apo A-I功能区中的部分氨基酸结合,影响Apo A-I的功能而抑制细胞胆固醇流出,促进SLE患者动脉粥样硬化的发生。

This study is aimed to investigate the prevalence of the anti-apolipoprotein A-I （Apo A-I） autoantibody in SLE patients and its role in the pathogenesis of atherosclerosis. Sera of 175 SLE patients and 64 normal controls were tested for antibody to Apo A-I by enzyme linked immunosorbent assay （ELISA）. An inhibition assay was used to study whether ApoA-I amino acid residues 74-105 which was related with cellular cholesterol efflux could inhibit the binding of anti-ApoA-I antibody to Apo A-I. We also examined the effect of anti-ApoA-I antibody on cellular cholesterol efflux. It was found that 16.6 % SLE patients was positive for anti-Apo A-I antibody. Peptide 74-105 could inhibit the binding of anti-Apo A-I antibody to Apo A-I, and the anti-Apo A-I antibody can inhibit cellular cholesterol efflux from THP-1 cells in vitro. Our study indicated that the anti-Apo A-I antibody might bind to the functional domain of Apo A-I, thus inhibiting the efflux of cellular cholesterol efflux and inducing the development of atherosclerosis in SLE.