酶法与碱性苦味酸法测定肌酐清除值的差异情况研究

目的研究酶法和碱性苦味酸法测定肌酐清除值（CrCl）的差异,探讨酶法CrCl采用国外参考区间是否合适。方法分别用肌氨酸氧化酶法（简称酶法）和碱性苦味酸速率法（简称苦味酸法）测定266名患者的血肌酐、尿肌酐以及CrCl,并以苦味酸法CrCl水平分为4组,第1-4组CrCl分别为〈25、26-50、51-80和〉81 mL/min。分析两法测定血肌酐、尿肌酐和CrCl结果的差异以及各组两法差异的变化。结果酶法血肌酐值和尿肌酐值低于苦味酸法（P〈0.001）,酶法CrCl除第1组外均高于苦味酸法（P〈0.001）。第1组两法血肌酐相对差值较小,且与两法尿肌酐相对差值接近,使CrCl在两法间无差异;第2-4组血肌酐相对差值逐渐增大,尿肌酐相对差值基本不变,导致CrCl在两法间出现差异且差异越来越大（P〈0.001）。结论CrCl〈25 mL/min时,两法CrCl没有差异;CrCl〉26 mL/min时,两法CrCl出现差异且差值逐渐增大;CrCl正常组两法差值很大,酶法CrCl采用国外参考区间不合适。

Study on the difference between enzymic method and Jaffe kinetic creatinine assay for the determination of creatinine clearance

Objective To compare the enzymic method and Jaffe kinetic creatinine assay for the determination of creatinine clearance（CrCl） and discuss whether using foreign CrCl reference interval is appropriate.Methods The levels of serum creatinine,urine creatinine and CrCl were determined in 266 patients by sarcosine oxidase enzymic method and Jaffe kinetic creatinine assay.The results were divided into 4 groups by the CrCl level of Jaffe kinetic creatinine assay.Their CrCl levels were 25,26-50,51-80 and 81 mL/min in Group 1-4 respectively.The two methods′ results of serum creatinine,urine creatinine and CrCl and their difference were analyzed statistically.Results The creatinine concentrations in serum and urine determined by the enzymic method were significantly lower than those determined by Jaffe kinetic creatinine assay（P0.001）.However,the CrCl（except Group 1） determined by the enzymic method was much higher than that by Jaffe kinetic creatinine assay（P0.001）.The relative deviation of serum creatinine between the two methods was small and was close to the relative deviation of urine creatinine in Group 1,so that CrCl values by both methods had no significant difference.The relative deviation of serum creatinine gradually increased in Group 2-4,however,the relative deviation of urine creatinine almost unchanged.The deviation of CrCl between the two methods would be larger and larger（P0.001）.Conclusions When CrCl 25 mL/min,CrCl by the two methods has no difference.On the contrary,when CrCl 26 mL/min,the difference of CrCl appears and will be growing.The deviation of CrCl in normal group is large,so it is unappropriate to use foreign CrCl reference interval.