尿N-乙酰-β-D-氨基葡萄糖苷酶对原发性肾病综合征并发急性肾损伤的诊断价值

Diagnostic Value of Urinary N-acetyl-β-(D)-glucosaminidase in Idiopathic Nephrotic Syndrome Complicated by Acute Kidney Injury

目的探讨原发性肾病综合征(primary nephrotic syndrome,PNS)并发急性肾损伤(acute kidney injury,AKI)的危险因素及尿N-乙酰-β-D-氨基葡萄糖苷酶(NAG)在PNS并发AKI中的预测价值。方法 PNS患者78例,其中PNS并发AKI患者(AKI组)21例,PNS未并发AKI(非AKI组)患者57例。对2组患者记录年龄、性别、有无感染、有无使用血管紧张素转换酶抑制剂和(或)血管紧张素受体拮抗剂(ACEI/ARB)及非甾体类抗炎药(NSAIDS),记录入院后的血压[收缩压(SBP)、舒张压(DBP)],测定2组患者血尿素氮(BUN)、血尿酸(BUA)、血肌酐(SCr)、外周血白细胞计数(WBC计数)、血红蛋白(Hb)、血总胆固醇(TC)、血三酰甘油(TG)、血纤维蛋白原(Fbg)和血清C-反应蛋白(CRP)、血浆白蛋白(Alb)及NAG、尿β2-微球蛋白(β2-MG)、24h尿蛋白定量的水平。结果 PNS并AKI的发生率为26.9%(21/78),AKI组男性发病率较非AKI组高,差异有统计学意义(P<0.05)。AKI组患者血BuN、血BUA、血Fbg、尿NAG、尿β2-MG、24h尿蛋白定量水平均明显高于非AKI组(P<0.05或P<0.01),AKI组患者血浆Alb水平明显低于非AKI组(P<0.05)。单因素Logistic回归分析结果显示:男性、血BUA、血浆Fbg、尿NAG、24h尿蛋白定量水平高是PNS并发AKI的危险因素。多因素Logistic回归分析结果显示:尿NAG升高是PNS并发AKI的独立危险因素[OR1.059、OR(95%CI)1.005～1.115、P<0.01]。尿NAG升高诊断PNS并发AKI特征曲线下面积(AUCROC)为0.903(95%CI 0.826～0.979);尿NAG诊断PNS并发AKI的阳性参考值为>83U.L-1,敏感性为0.789,特异性为0.936。结论尿NAG是早期发现、早期诊断PNS并发AKI的理想生物学标记物。

Objective To investigate the risk factors for primary nephrotic syndrome（PNS） complicated by acute kidney injury（AKI）,and to explore the predictive value of urinary N-acetyl-β-（D）-glucosaminidase（NAG） in patients with AKI and PNS.Methods Seventy-eight PNS patients with AKI（AKI group,n=21） or without AKI（non-AKI group,n=57） were enrolled in this study.The age,gender,infection and applications of angiotensin-converting-enzyme inhibitors（ACEI）/angiotensin receptor antagonists（ARB） and non-steroid anti-inflammatory drugs（NSAIDS） were recorded in both groups.In addition,blood urea nitrogen（BUN）,blood uric acid（BUA）,serum creatinine（SCr）,peripheral white blood cell（WBC） count,hemoglobin（Hb）,serum albumin（Alb）,serum total cholesterol（TC）,serum triacylglycerol（TG）,serum C-reactive protein（CRP）,plasmic fibrinogen（Fbg）,urinary N-acetyl-β-（D）-glucosaminidase（NAG）,urinaryβ2-microglobulin（β2-MG） and 24-hour urine protein excretion were determined.Results Among the 78 patients,PNS was complicated by in 21（26.9%）.Furthermore,the incidence of AKI in male PNS patients was significantly higher than that in female PNS patients（P0.05）.Compared with non-AKI group,AKI significantly increased the levels of BUN,BUA,plasma Fbg,urinary NAG,urinaryβ2-MG and 24-hour urine protein excretion,but obviously decreased the levels of serum Alb（P0.05 or P0.01）.from univariate logistic regression models showed that male and high levels of blood BUA,plasma Fbg,urinary NAG and 24-hour urine protein excretion were the risk factors for PNS complicated by AKI.from multiple logistic regression models showed that urinary NAG increase was the independent predictor of PNS complicated by AKI [OR 1.059,OR（95%CI）1.005~1.115、P0.01].The area under the receiver operating characteristic curve（AUCROC） for urinary NAG was 0.903（95% CI 0.826~0.936）,with a positive value of 83 U·L-1,a diagnostic sensitivity of 0.789 and a diagnostic specificity of 0.979 for PNS complicated by AKI.Conclusion Urinary NAG is a sensitive and specific biomarker for early detection of AKI in INS patients.