血清胱抑素C评价肾小球滤过率的临床意义

目的探讨应用血清胱抑素C(CysC)判断肾小球滤率的价值。方法对235例患者分别用乳胶增强免疫透射比浊法测定血清CysC的浓度及使用苦味酸速率法和酶学传导速率法测定血清肌酐(Scr)、尿素氮(BUN),以99Tcm-DTPA清除率测得的GFR作为评价的标准,分析CysC、Scr、BUN和GFR之间的相关性;按照GFR值将患者分4组:A组GFR≥90 ml(/min.1.73 m2),B组60~89 ml/(min.1.73 m2),C组30~59 ml(/min.1.73 m2),D组<30 ml(/min.1.73 m2),依据单侧肾小球滤过率GFR<40 ml/min(60岁以上<35 ml/min)为肾滤过功能减退依据,比较CysC、Scr、BUN 3指标诊断各组分肾GFR下降敏感度与特异度。结果 235例患者,随着GFR下降,血清CysC、BUN、Scr均逐渐升高(P<0.01),血清CysC与GFR之间呈负相关(r=-0.649,P<0.01),血清CysC与Scr、BUN之间呈正相关(r=0.850、r=0.874,P<0.01)。A、B、C组患者血清CysC诊断分肾滤过功能下降敏感度分别为58.82%、76.56%和95.51%,均优于Sc(rP<0.01)、BUN(P<0.05);A、B组患者血清CysC诊断分肾滤过功能下降特异度低于Scr、BUN(P<0.05)。结论测定血清胱抑素C的浓度用来评价肾小球滤过功能是一种可行、敏感的指标,测定方法简便,对预测早期肾损害迅速灵敏,值得临床推广应用。

The clinical significance of serum Cystatin-C in evaluating glomerular filtration rate

Objective To investigate the value of Cystatin-C(CysC)in evaluating GFR.Methods Blood samples of 235 patients were collected,the concentration of serum CysC was detected by latex enhanced immunoturbidimetric method.Scr was determined by alkaline kinetic method,BUN was detected by Utease Conductivity Rate method,GFR was estimated by the plasma clearance of 99Tcm-DTPA,and the correlation analysis among CysC,Scr,BUN and GFR was carried out.A total of 235 patients were divided into A,B,C,and D group according to the level of GFR,with a standard for impairment of unilateral GFR<40 ml/min(or GFR<35 ml/min on patients above 60 years old)to compare the sensitivity and specificity of CysC,Scr,and BUN in diagnosing renal impairment among A,B,C,and D group.Results The serum mean levels of CysC,BUN,and Scr increased gradually when GFR decreased(P <0.05).The serum level of CysC was negatively correlated with GFR(r=-0.649,P <0.01),but positively correlated with Scr and BUN levels(r=0.850,P <0.01;r=0.874,P <0.01).Among group A,B,and C,the sensitivity for the diagnosis of renal impairment calculated by the concentration of serum CysC was 58.82%,76.56% and 93.59% respectively,which was more sensitive than by the concentration of Sc(r P <0.01)and BUN(P <0.05);in group A and B,the specificity for the diagnosis of renal impairment calculated by the concentration of serum CysC was much less than by that of Scr and BUN(P <0.05).Conclusion The detection of serum level of CysC is a convenient,feasible,reliable and sensitive method,which could be applied to the evaluation of glomerular filtration function.The detection of CysC could evaluate the inchoate damages in renal function quickly.It is worth clinical popularization and application.