不同肌酐测定方法对MDRD方程在IgA肾病患者中适用性的评价

Effect of Different Creatinine Assayed Methods on the Validity in MDRD Equation

目的:探讨不同的肌酐测定方法对适用不同MDRD公式估算肾小球滤过率(GFR)的影响。方法:回顾性分析1987年以来的IgA肾病患者数据库资料,获得完整数据2204例。根据肌酐测定方法的不同,分为A、B两组,A组采用比色法测定血肌酐,B组采用酶法测定血肌酐,分别采用简化MDRD公式和2005年IDMS-肌酐重新表述的MDRD公式计算GFR。采用Bland-Altman分析两者之间的偏差,并进一步探讨偏差和肌酐值之间的相关性。结果:在A组,与简化的MDRD公式相比,将比色法测定肌酐带入2005年MDRD公式所得GFR存在低估,平均差异-5.1ml.min-1.1.73m-2(95%CI-9.9～-0.3);在B组,与2005年MDRD公式相比,将酶法测定结果带入简化MDRD公式后造成对GFR的高估,平均相差5.1ml.min-1.1.73m-2(95%CI01～10.6)。相关分析和趋势检验显示随着肌酐的增加偏差减小。结论:不同肌酐测定方法适用不同的MDRD公式将出现偏差,在临床工作中需要根据肌酐测定方法选择不同的MDRD公式。

Objective： To evaluate the effect of diffement creatinine assayed methods on the vaidity of GFR estimated equations in patients with IgA nephropathy. Methods： IgA database was analysed retrospectivdy, and 2 204 patients were selceted. The abbreviated Modification of Diet in Renal Disease （MDRD） and isotopic dilution mass spectrometry（IDMS） MDRD equations were used to estimated GFR from serum creatinine levels. Bland-Altman blot was used to analysis the bias of different methods. The correlation between serum creatinine level and the difference of the two equation was analysed with Spearman correlation. Results： A- mong 2 204 patients with IgA nephropathy, 1319 were male and 885 were female. In group A, the mean defferenee between abbre- vated MDRD and IDMS MDRD equation was - 5.1（95 % CI-9.9 -- - 0.3） ml·min^-1·1.73 m^- 2 ; While the mean doifference between abbrevated MDRD and IDMS MDRD equation was 5.1（95 % CI 0.1--10. 6）ml·min^-1·1.73 m^-2. Correlation analysis and tendency test showed that the difference decline with the serum creatinine level increasing. Conclusion： Bias occurs when creatinine measured from different methods is applied into same MDRD equation,so creatinine assayed with different methods should apply to different MDRD equation.