中文摘要：

目的：本实验旨在研究用亲和层析提取的显微镜下型多血管炎（MPA）患者抗髓过氧化物酶（MPO）抗体对MPO氧化活性的抑制作用，并进一步研究MPO、铜蓝蛋白和抗MPO抗体之间的关系。方法：应用蛋白G亲和层析纯化11名抗MPO抗体阳性的显微镜下型多血管炎患者血浆及12名健康志愿者的血清中免疫球蛋白G（IgG）成分。进一步应用MPO亲和层析柱从患者IgG成分中提取抗MPO抗体。应用经典的MPO氧化活性测定方法分别测定在不同浓度的患者抗MPO抗体、不同浓度的铜蓝蛋白和正常人IgG存在条件下MPO酶的氧化活性，并应用酶联免疫吸附法测定铜蓝蛋白、MPO和抗MPO抗体之间的相互作用。结果：11名MPA患者中有7名患者的抗MPO抗体能够以非竞争性抑制的方式剂量依赖性地抑制MPO的活性。铜蓝蛋白能够以竞争性抑制的方式剂量依赖性和时间依赖性的抑制MPO的活性。抗MPO抗体能够抑制MPO和铜蓝蛋白之间的结合，最大可达到（75.4±11.6）%。结论：大多数MPA患者的抗MPO抗体能够抑制MPO的氧化活性；抗MPO抗体可以干扰MPO和铜蓝蛋白的结合。

英文摘要：

Objective： To investigate the inhibitory effects on myeloperoxidase （MPO） oxidation activity by affinity-purified anti-MPO antibodies from patients with microscopic polyangiitis （MPA） and to further investigate the interaction between MPO, ceruloplasmin and anti-MPO antibodies. Methods： Human IgG fractions were purified from plasma of 11 patients with anti-MPO antibody positive MPA and sera of 12 normal controls. Anti-MPO antibodies were further purified from anti-MPO antibody containing IgG fractions using MPO affinity chromatography. The enzyme activity of MPO was measured, in the presence of anti-MPO antibodies and normal IgG preparations, using a classical MPO oxidation assay. Interaction between ceruloplasmin, MPO and anti-MPO antibodies was further investigated using ELISA. Results： Anti-MPO antibodies from 7/11 patients with MPA could inhibit the MPO activity as non-competitive inhibitors in a dose-dependent manner. Ceruloplasmin could competitively inhibit the oxidation activity of MPO in a dose-dependent and time-dependent manner. Anti-MPO antibodies could inhibit the binding between MPO and ceruloplasmin to a maximum of （75. 4 ± 11. 6 ）%. Conclusion： Anti-MPO antibodies, from the majority of patients with MPA, could inhibit the oxidation activity of MPO and interfere with the binding between MPO and ceruloplasmin.