健康人群和慢性肾病患者基于血清CysC水平估算肾小球滤过率公式的适用性评价

目的 评价基于血清胱抑素C(Cys C)的估算肾小球滤过率(eGFR)公式在健康人群和慢性肾病(CKD)患者中的适用性。方法 选取2 495例健康人和805例CKD患者作为研究对象,测定其血清Cys C和肌酐(Cr),使用改善全球肾脏病预后组织(KDIGO)慢性肾脏病评估与管理临床实践指南推荐的公式(2012 CKD-EPIcr-cysc,2012CKD-EPIcysc)和笔者实验室建立的基于Cys C的公式(eGFRcysc)分别计算研究对象的eGFR。以KDIGO推荐的公式为参考,用偏倚、偏倚的四分位数间距(IQR)和P30评价eGFRcysc的性能。结果 健康人群的Cys C和Cr的M(P25,P75)分别为0.76(0.67,0.86)mg/L和64.1(53.8,75.6)μmol/L。CKD患者的Cys C和Cr的M(P25,P75)分别为4.18(1.99,5.93)mg/L和385.4(152.1,704.5)μmol/L。在健康人群和CKD的1～4期患者中,eGFRcysc与2012 CKD-EPIcr-cysc的偏倚均小于2012CKD-EPIcysc的偏倚。在所有研究对象中,IQR是较低的(2.0～13.3)。在健康人群和CKD的1～2期患者中,P30均达到90%以上。Bland-Altman分析结果显示,在所有研究对象中,偏倚的一致限在-30～30范围内,一致限内的比例均大于90%。在CKD分期方面,eGFRcysc与2012 CKD-EPIcr-cysc具有中等的一致性(κ=0.487)。结论 在评价健康人群、1期CKD患者和2期CKD患者的GFR时,eGFRcysc与2012 CKD-EPIcr-cysc具有较好的一致性。在评价3～5期CKD患者的GFR时,与2012 CKD-EPIcr-cysc比较,eGFRcysc会高估GFR。在1～3期CKD患者中,eGFRcysc与2012 CKD-EPIcr-cysc具有较好的分期一致性,在4～5期CKD患者中,分期一致性较差。

Evaluating of the Applicability of Estimated Glomerular Filtration Rate Formula Based on Cystatin C in Healthy Population and Chronic Kidney Disease Patients

Abstract:Objective To evaluate the applicability of estimated glomerular filtration rate(eGFR)formula based on cystatin C(Cys C)inhealthy population and chronic kidney disease(CKD)patients.MethodsThe serum Cys C and creatinine(Cr)were measured in 2 495 healthypopulation and 805 CKD patients.The eGFR were calculated with two 2012 ChronicKidney Disease Epidemiology Collaboration(CKD-EPI)equations(2012CKD-EPIcr-cysc and 2012CKD-EPIcysc)and eGFRcysc equation based on CysC,respectively.Taking 2012CKD-EPI equation as a reference,the performance of eGFRcysc was evaluated with bias, interquartile range(IQR)and P30.Results The median(P25,P75)of Cys C and Cr in healthy population were 0.76(0.67,0.86)mg/L and 64.1(53.8,75.6)μmol/L,respectively.The median(P25,P75)of Cys C and Cr in CKD patients were 4.18(1.99,5.93)mg/L and 385.4(152.1,704.5)μmol/L,respectively.In healthy population and 1～4 phase of CKDpatients,the bias of eGFRcysc and 2012 CKD-EPIcr-cysc was less than that of2012CKD-EPIcysc.Of all the subjects,IQR was lower(the lowest 2.0,the highest 13.3).P30 were more than 90% in healthy population and 1～2 phase of CKD patients.The results of Bland-Altman analysis showed that in all the subjects,the limit of the bias was within the range of -30 to 30,and the proportion within the agreement limit was more than 90%.In CKD staging,eGFRcysc and 2012 CKD-EPIcr-cysc had moderate consistency(kappa=0.487).Conclusion The eGFRcysc equation had good consistency with 2012CKD-EPIcr-cysc in evaluating the GFR of healthy population,1 phase CKD patients and 2 phase CKD patients.In evaluating the GFR of 3～5 phase of CKD patients,eGFRcysc would overestimate GFR compared with 2012CKD-EPIcr-cysc.There was a better consistency between eGFRcysc and 2012CKD-EPIcr-cysc in 1～3 phase of CKD patients,and waspoor in the 4～5 phase CKD patients on the CKD staging.