尿液中铁调素在系统性红斑狼疮中的临床意义

Clinical significance of urine hepcidin in lupus nephritis

目的通过检测尿液中铁调素在系统性红斑狼疮(systemic lupus erythematosus,SLE)肾脏受累患者中的表达水平,分析其与狼疮肾炎(lupus nephritis,LN)肾脏受累的关系,进一步探讨尿液中铁调素与LN活动性的关系。方法本实验共纳入38例健康对照者(女性29例,男性9例)和54例SLE患者(女性46例,男性8例),根据其肾脏是否受累将入组的54例SLE患者进一步分为SLE无肾炎组(12例)和LN组(42例),用酶联免疫吸附测定法(enzyme-linked immunosorbent assay,ELISA)检测入组者尿液中铁调素的表达水平。将42例LN患者根据肾脏SLEDAI评分(R-SLEDAI)将其分为静止期LN患者组(10例)和活动期LN患者组(32例),比较其尿液中铁调素的表达水平,进一步分析尿液中铁调素与R-SLEDAI评分的相关性。同时根据测得的铁调素值对LN的活动性进行预测,通过受试者工作特征曲线(ROC曲线)分析其敏感性和特异性。结果尿液铁调素在LN患者组中的表达水平明显高于SLE无肾炎组和健康对照组(P<0.01);尿液铁调素在活动期LN患者组中表达水平显著高于静止期LN组(P<0.01)。LN患者的尿液铁调素与R-SLEDAI评分呈正相关关系(r=0.313,P=0.043),与SLEDAI和肾外RSLEDAI评分均无相关性(P>0.05);尿液铁调素的ROC曲线截值点为7.483 ng/ml(敏感度90.62%,特异度80%),曲线下面积为0.897,大于补体C3、补体C4、血清肌酐和抗ds-DNA抗体的曲线下面积,但小于24h尿蛋白定量的曲线下面积。结论尿液中铁调素在SLE肾脏受累的患者中表达水平增高,可能是一种新的反映LN活动性的指标。

Objective To test the level of urine hepcidin（ Hepc） in systemic lupus erythematosus（ SLE） patients with renal damage,study the relationship between the level of urine Hepc and lupus nephritis（ LN）,and to further investigate the relationship between urine Hepc and active LN. Methods This experiment included 38 healthy subjects（ 29 females and 9 males） and 54 cases of SLE（ 46 females and 8males）. According to the renal damage,all SLE patients were divided into SLE non-LN group（ 12 cases）and SEL LN group（ 42 cases）. The enzyme-linked immunosorbent assay（ ELISA） was used to measure the level of urine Hepc. Forty-two cases of LN were divided into inactive LN group（ 10 cases） and active LN group（ 32 cases） according to Renal-Systemic Lupus Erythematosus Disease Activity Index（ R-SLEDAI）.The level of urine Hepc was compared between inactive LN group and active LN group,and the relationship between the R-SLEDAI and urinary Hepc was analyzed. At the same time,the activity of LN was predicted according to the Hepc values,and the sensitivity and specificity were analyzed by receiver operating characteristic curve（ ROC curve）. Results The level of urine Hepc in SLE LN group was significantly higher than SLE non-LN group and healthy control group（ both P〈0. 01）. The level of urine Hepc in active LN groupwas significantly higher than that in inactive LN group（ P〈0. 001）. The urine Hepc in LN patients was positively correlated with the R-SLEDAI score（ r = 0. 313,P = 0. 043）,and there was no correlation between SLEDAI and renal RSLEDAI score（ P〉0. 05）. Cut-off in urine Hepc was 7. 483 ng/ml（ 90. 62%for sensitivity,and 80% for specificity）. The area under the ROC curve was 0. 897,greater than that of complement C3,C4,serum creatinine and serum anti ds-DNA antibody,but less than that of 24-h urinary protein quantity. Conclusions The expression level of urine Hepc in the SLE patients with renal involvement may be a new indicator of LN activity.