紫癜性肾炎病儿转谷氨酰胺酶-2的表达及其意义

EXPRESSION AND SIGNIFICANCE OF TRANSGLUTAMINASE-2 IN CHILDREN WITH HENOCH-SCH NLEIN PURPURA NEPHRITIS

目的探讨转谷氨酰胺酶-2(TG2)在紫癜性肾炎(HSPN)病儿中的表达及其意义。方法选取过敏性紫癜(HSP)病儿91例作为研究对象,根据是否并发肾脏损伤,分为HSPN组(39例)和非HSPN组(NHSPN组,52例);另选取同期体检的30例健康儿童作为正常对照组。采用酶联免疫吸附试验法检测各组儿童血清及尿液中TG2的水平,并对HSPN组病儿尿液TG2水平与血清TG2水平、24 h尿蛋白定量进行相关性分析;利用受试者工作特征(ROC)曲线评估尿液TG2水平对HSPN的诊断效能。结果HSPN组、NHSPN组及对照组儿童血清TG2水平差异无显著性(P>0.05),HSPN组病儿尿液TG2水平明显低于对照组及NHSPN组(t=4.906、6.944,P<0.01);HSPN组病儿尿液TG2水平与24 h尿蛋白定量呈负相关(r=-0.89,P<0.05)。ROC曲线分析显示,尿液TG2水平诊断HSPN的曲线下面积为0.857,95%置信区间为0.767~0.948;HSP病儿尿液TG2诊断HSPN的最佳阈值为0.32μg/L,此时其诊断灵敏度为0.795,特异度为0.892。结论HSPN病儿尿液TG2水平明显降低,且与24 h尿蛋白定量呈负相关;尿液TG2可作为早期诊断和预测HSP并发肾损伤的有效指标。

Objective To investigate the expression and significance of transglutaminase-2(TG2)in children with Henoch-Sch nlein purpura nephritis(HSPN).Methods A total of 91 children with Henoch-Sch nlein purpura(HSP)were enrolled as subjects and divided into HSPN group(n=39)and non-HSPN group(NHSPN group,n=52)according to the presence or absence of renal damage.Thirty healthy children who underwent physical examination during the same period of time were enrolled as control group.The levels of TG2 in serum and urine were determined by enzyme linked immunosorbent assay.The correlation of urinary TG2 levels with serum TG2 levels and 24 h urine protein in the HSPN group was analyzed.Meanwhile,the diagnostic potency of urinary TG2 levels for HSPN was evaluated by the receiver operating characteristic(ROC)curve.Results There was no significant difference in serum level of TG2 between the HSPN,NHSPN,and control groups(P>0.05).The urinary level of TG2 in the HSPN group was significantly lower than that in the control and NHSPN groups(t=4.906,6.944,P<0.01).There was a negative correlation between the urinary TG2 level and 24 h urine protein in the HSPN group(r=-0.89,P<0.05).By ROC curve analysis,the area under the curve of urinary TG2 level for diagnosis of HSPN was 0.857,and the 95%CI was 0.767-0.948.The optimal cutoff value for urinary TG2 in children with HSP was specified as 0.32μg/L to predict HSPN,and the diagnostic sensitivity and specificity were 0.795 and 0.892,respectively.Conclusion The urinary TG2 level in children with HSPN is significantly reduced and negatively correlated with 24 h urine protein.Urinary TG2 can be used as an effective indicator for early diagnosis and prediction of HSP with renal damage.