血清抗C1q抗体与狼疮肾炎活动性及病理改变的相关性

目的 探讨血清抗C1q抗体与狼疮肾炎(LN)肾组织病理改变的相关性,以及对LN的活动性的评价.方法 用酶联免疫吸附法(ELISA)检测活动期LN患者60例和非LN患者60例血清中的抗C1q抗体,分析这一抗体与LN肾组织病理改变、活动指数及其他实验室参数的相关性.结果 LN患者血清抗C1q抗体水平(89±26)U/ml较非LN患者(57±23)U/ml高(P＜0.01);60例LN患者有同期肾活检病理资料,按世界卫生组织(WHO)分型,Ⅱ型12例,Ⅲ型14例,Ⅳ型18例,Ⅴ型16例.经方差分析显示,各病理类型问抗C1q抗体水平差异有统计学意义,其中以Ⅳ型LN的抗C1q抗体水平显著高于其他病理类型(P＜0.01);C1q在肾组织的沉积与血清抗C1q抗体水平相关;血清抗C1q抗体水平与肾脏病变的活动指数(AI)及尿蛋白含量呈正相关(P＜0.01),与补体C3、C4水平呈负相关(P＜0.01);抗双链DNA(dsDNA)抗体阳性的SLE患者,血清抗C1q抗体水平高于抗dsDNA抗体阴性者(P＜0.01).结论 血清抗C1q抗体水平在一定程度上反映LN肾脏的病理改变,并与肾脏病变活动指数有相关性,检测血清抗C1q抗体对评价LN病情及指导治疗有临床实用价值.

Correlation between serum anti-C1q antibodies and renal pathological characteristic in patients with lupus nephritis

Objective To analyze the correlation between serum anti-C1q antibody (anti-C1q Ab)and renal pathological characteristic,disease activity as well as some laboratory tests in patients with lupus nephritis (LN).Methods Serum anti-C1q antibodies were detected by enzyme-linked immunosorbant assay ELISA) in 120 patients with systemic lupus nephritis (SLE),which included 60 LN patients and 60 non-LN patients.Renal biopsy was conduted in all LN patients.The relationships between serum anti-C1q Ab level and renal pathohistology,lupus nephritis activity,as well as some laboratory parameters were analyzed.Results The mean level of serum anti-C1q Ab in LN patients was (89+26) U/ml,significantly higher than that of nonLN patients (57±23) U/ml (P＜0.01).Twelve cases of renal biopsies were classified as WHO Class Ⅱ,fourteen cases Class Ⅲ,eighteen cases Class Ⅳ,and sixteen cases Class Ⅴ.Significant difference of serum anti-C1q Ab level between each class was found by ANOVA test,and serum anti-C1q Ab level of Class Ⅳ was the highest (P＜0.01).Renal biopsies showed a positive correlation between serum anti-C1q Ab level and activity index of renal pathohistology (P＜0.01).Renal deposition of C1q was related with the level of serum anti-C1q Ab.Serum anti-C1q Ab level was positively correlated with proteinuria (P＜0.01),and negatively correlated with levels of C3 and C4 (P＜0.01).Mean level of serum anti-C1q antibody in SLE patients with positive antidsDNA was higher than that in the patients with negative anti-dsDNA (P＜0.01).Conclusion Serum antiC1q Ab level is significantly associated with lupus nephritis activity and renal pathohistology.It is a useful marker to predict renal lesion and disease activity in lupus nephritis.