Cambridge G, Williams M, Leaker B, Corbett M, Smith C R
Department of Immunology, University College London Medical School, United Kingdom.
Ann Rheum Dis. 1994 Jan;53(1):24-9. doi: 10.1136/ard.53.1.24.
To determine the prevalence and clinical associations of autoantibodies to myeloperoxidase (MPO) in an unselected series of well-characterised outpatients with rheumatoid arthritis (RA) and to compare the distribution of IgG subclasses of anti-MPO antibodies in these patients with that in patients with systemic vasculitis.
A study was made of 97 patients with RA, who have been seen regularly in this department for up to 20 years, and 29 patients with anti-neutrophil cytoplasmic antibody (ANCA) positive systemic vasculitis. Anti-MPO antibodies were detected using a direct-binding enzyme-linked immunosorbent assay (ELISA) with MPO from human granulocytes as antigen. The IgG subclass of anti-MPO antibodies was determined by ELISA using isotype specific monoclonal antibodies.
Anti-MPO antibodies were detected in 12% of patients with RA. Six sera contained IgG anti-MPO antibodies only, 1 IgM only and 5 antibodies of both classes. In the patients with RA the predominant subclasses were IgG1 and IgG3: only 2 sera contained detectable IgG4 antibodies. This was in contrast to patients with vasculitis, in whom most sera contained IgG1, IgG3 and IgG4 anti-MPO antibodies. Anti-MPO antibodies in sera from both patient groups bound only to the native protein. None of the patients studied with RA had evidence of vasculitis affecting the nerves or kidney: three patients (1 positive for anti-MPO antibodies and 2 negative) had cutaneous vasculitis. In the patients with RA, positivity for anti-MPO antibodies was associated with nodules and number of active joints. Three patients with anti-MPO antibodies, and none without, had pulmonary fibrosis.
Twelve per cent of a group of unselected outpatients with RA, but without evidence of major systemic vasculitis, had anti-MPO antibodies in their serum. Positivity for anti-MPO antibodies was more common in patients with nodular disease and lung involvement but not in patients with cutaneous vasculitis. IgG4 sub-class anti-MPO antibodies were present in 90% of sera from patients with ANCA-positive vasculitis and only 2/11 (18%) of anti-MPO antibody containing sera from patients with RA.
确定在一系列未经挑选的、特征明确的类风湿关节炎（RA）门诊患者中髓过氧化物酶（MPO）自身抗体的患病率及临床相关性，并比较这些患者与系统性血管炎患者中抗MPO抗体IgG亚类的分布情况。
对97例在本科室定期就诊长达20年的RA患者以及29例抗中性粒细胞胞浆抗体（ANCA）阳性的系统性血管炎患者进行了研究。使用以人粒细胞来源的MPO为抗原的直接结合酶联免疫吸附测定（ELISA）检测抗MPO抗体。采用同种型特异性单克隆抗体通过ELISA法测定抗MPO抗体的IgG亚类。
在12%的RA患者中检测到抗MPO抗体。6份血清仅含有IgG抗MPO抗体，1份仅含IgM抗体，5份血清同时含有这两类抗体。在RA患者中，主要的亚类为IgG1和IgG3：仅有2份血清含有可检测到的IgG4抗体。这与血管炎患者不同，血管炎患者的大多数血清含有IgG1、IgG3和IgG4抗MPO抗体。两组患者血清中的抗MPO抗体仅与天然蛋白结合。研究的RA患者中无一例有影响神经或肾脏的血管炎证据：3例患者（1例抗MPO抗体阳性，2例阴性）有皮肤血管炎。在RA患者中，抗MPO抗体阳性与结节及活动关节数量相关。3例抗MPO抗体阳性患者有肺纤维化，而抗体阴性患者无此情况。
在一组未经挑选的无主要系统性血管炎证据的RA门诊患者中，12%的患者血清中有抗MPO抗体。抗MPO抗体阳性在有结节病和肺部受累的患者中更常见，但在皮肤血管炎患者中并非如此。ANCA阳性血管炎患者90%的血清中有IgG4亚类抗MPO抗体，而RA患者含抗MPO抗体的血清中仅有2/11（18%）含有该抗体。
