系统性红斑狼疮血清抗核小体抗体水平及意义的探讨

Anti-nucleosome antibodies in systemic lupus erythematosus

目的研究抗核小体抗体(AnuA)在系统性红斑狼疮(systemiclupuserythematosus,SLE)患者血清中的水平及其相关影响因素,探讨AnuA在SLE诊治中的作用和意义。方法采用酶联免疫吸附法(ELISA)测定120例初诊SLE患者、55例其他风湿性疾病和30名健康对照血清中AnuA水平。同时记录各种临床表现,检测并分析其治疗前的其他自身抗体和实验室指标。结果自身抗体在SLE及其他风湿病对照组的阳性率分别为AnuA56%和7%,抗dsDNA抗体35%和1%,抗Sm抗体24%和0。AnuA与SLE患者性别、年龄、病程无相关性,对SLE的诊断敏感性和特异性分别为55.8%、95.3%,对狼疮肾炎(lupusnephritis,LN)的诊断敏感性和特异性分别为77.6%、64.5%。AnuA与肝脏损害和疾病活动呈线性相关(t=3.152,2.171,P<0.05)。AnuA分别与抗dsDNA、抗Sm联合检测对SLE诊断敏感性提高27%、40%(字值2分别为38.930、18.161,P<0.01)。结论AnuA在SLE血清中水平显著增高,AnuA测定是SLE诊断和治疗监测中有价值的新的实验室检测指标之一,与抗dsDNA抗体联合检测可提高诊断SLE、LN的敏感性和特异性。

Objective Antinucleosome antibody (AnuA) has recently been described in patients with systemic lupus erythematosus (SLE) and it has been suggested that its presence is associated with lupus nephritis (LN). Methods The groups included 120 consecutive patients with SLE (four or more ACR criteria), 30 healthy blood donors and 55 patients with 7 other connective tissue disease (CTD). Disease activity was assessed using systemic lupus erythematosus disease activity index (SLEDAI). The groups were evaluated for AnuA by enzyme-linked immunosorbent assay (ELISA) and for clinical, humoral parameters and other autoantibodies. Results The prevalence of AnuA in SLE patients and controls was 55.8% and 4.7% respectively, 35% and 1.2% for anti-dsDNA, and 24.2% and 0 for anti-Sm antibody. AnuA had a sensitivity of 55.8% and specificity of 95.3% for SLE diagnosis. AnuA showed the highest correlation with disease activity, especially in patients negative for anti-dsDNA antibodies. The level of AnuA strongly correlated with SLEDAI (t=2.171, P<0.05), but inversely correlated with serum complement (C3, C4) levels. AnuA also showed strong association with renal and liver damage. Conclusion The measurement of AnuA appears to be a useful addition to the laboratory tests that can help the diagnosis and treatment of SLE, especially in patients who are negative for anti-dsDNA antibody. The data suggest that the AnuA may be a sensitive and specific for SLE, but isn′t a marker for an increased risk of lupus nephritis. Simultaneous detection of AnuA, anti-dsDNA antibody, anti-Sm antibody and antibody to nuclear antigens (ANA) can notably improve the sensitivity and specificity of SLE diagnosis.