尿β痕迹蛋白检测在2型糖尿病肾损伤诊断中的应用

目的探讨尿β痕迹蛋白（beta-trace protein，βTP）检测在2型糖尿病（T2DM）肾损伤中的诊断价值。方法临床确诊T2DM 174例，按照尿白蛋白（Alb）与肌酐（Cr）比值（Alb／Cr）将其分为糖尿病无肾损伤组（A组）和糖尿病肾损伤组（B组），另设健康对照组（C组）70名。采用胶乳增强散射免疫比浊法原理检测尿液BTP、α1微球蛋白（α1 microglobulin，α1MG），免疫比浊法测定尿Alb，碱性苦味酸法测定Cr，测定结果以与Cr比值表示。比较各组尿βTP水平，并行ROC曲线分析，同时对尿βTP与α1 MG及其他指标作相关分析。结果B组尿βTP／Cr中位数为9．1mg／gCr，显著高于A组的3．1mg／gCr和C组的2．0mg／gCr，差异有统计学意义（H=45．5，P〈0．01）。B组其他指标Alb／Cr、α1MG／Cr、血Cr（SCr）结果均高于A、C组（H值分别为110．9、38．3、11．4，P值均〈0．01）。相关分析结果表明，尿βTP／Cr与尿α1MG/Cr与显著正相关，相关系数为r=0．894（P〈0．01），与SCr、糖化血红蛋白A1（HbA1C）、收缩压、病程呈正相关，r分别为0．367（P〈0．05）、0．242（P〈0．05）、0．162（P〈0．05）、0．251（P〈0．05）；与舒张压、空腹血糖（FBG）、体重指数（BMI）无相关性。ROC曲线分析结果表明，尿βTP／Cr与α1MG／Cr曲线下面积分别为0．86（95％C10．78～0．93）、0．76（95％C10．67～0．85）。尿βTP／Cr最佳判断水平为4．1mg／gCr，诊断敏感性为68．5％，特异性为89．8％；尿α1MG／Cr最佳判断水平为10．9mg／gCr，诊断敏感性为59．7％，特异性为80．3％，两者差异有统计学意义（P〈0．05）。结论尿βTP对T2DM肾损伤有诊断价值，可敏感地反映肾小管功能损伤，诊断价值优于尿α1MG，可作为评价肾小管损伤的一个新的生物标志物。

The urinary beta-trace protein in the diagnosis of type 2 diabetic renal injury

Objective To study the potential use of the urinary beta-trace protein （βTP） for diagnosis of type 2 diabetic renal injury. Methods 174 patients with type 2 diabetic mellitus （T2DM） were classified into 2 groups according to the ratio of urinary albumin to creatinine （Alb/Cr） ： diabetes without renal injury group （group A） and diabetes with renal injury group （group B）. 70 healthy subjects served as normal control group （ group C ）. The level of urinary ~3TP and al mieroglobulin （oH MG） was measured by latex particle enhanced im- munoturbidimetry assay. The urinary Alb and Cr were determined by nephelometry and Jaffe method respectively. The level of urinary βTP among all groups was compared and ROC curve analysis was performed. The relevant a- nalysis on urinary βTP, urinary c~l MG and other related indexes was made. Results The median level of urinary βTP/Cr in group B was 9. 1 mg/g Cr, significantly higher than 3.1 mg/g Cr of group A and 2. 0mg/g Cr of group C. The difference had statistical significance （ H =45.5, P 〈0. 01 ）. The other indexes （Alb/Cr,cHMG/Cr, SCr） were all higher in group B than in the other 2 groups （ H = 110. 9, 38.3, 11.4 respectively, P 〈 0. 01 ）. The relevant analysis showed that urinary βTP/Cr was positively correlated with urinary ctlMG/Cr （r = 0. 894, P〈0.01）, SCr （r=0.367, P〈0.05）,HbAIC （r=0.242, P〈0.05）, systolic pressure （r=0.162, P〈 0. 05 ）, and the course of the disease （ r = 0. 251, P 〈 0. 05 ）. No correlation was found between urinary βTP/Cr and diastolic pressure, fasting blood glucose （FBG） or BMI. ROC curve analysis showed the area under thecurve （AUC） was 0. 86 （95%CI, 0. 78-0. 93） for urinary βTP/Cr and 0. 76 （95% CI, 0. 67- 0. 85） for urinary cdMG/Cr. The best cut-off value of urinary βTP/Cr and cdMG/Cr was 4. 1 mg/g Cr vs 10. 9mg/g Cr, the sensitivitywas 68.5% vs 59.7% , and the specificity was 89. 8% vs 80. 3%. The difference had statistical significance （ P 〈 0. 05）. Conclusions Urinary βTP has better diagnostic value for type 2 diabetic patients with renal injury than urinary cdMG. It can sensitively reflect renal tubular injury and can be used as a novel available biomarker to evaluate the renal tubular injury in clinic.