CKD-EPI公式估算GFR评价狼疮肾炎患者早期肾功能损害

Application of estimated glomerular filtration rate to evaluating renal impairment in patients with lupus nephritis

目的:探讨基于胱抑素C(cystatin C,Cys C)、肌酐(creatinine,Cr)的2012年CKD-EPI公式估算GFR对评价狼疮肾炎早期肾功能损害的价值。方法:对369例系统性红斑狼疮患者病例资料进行回顾性分析。以2012年CKD-EPI公式计算每位患者分别基于Cr、Cys C和两者联合(Cr+Cys C)的估算肾小球滤过率(estimated glomerular filtration rate,e GFR)。以24 h尿蛋白定量将系统性红斑狼疮患者分为非狼疮肾炎组(非LN组)和狼疮肾炎组(LN组),比较两组间相关指标的差异;在LN组患者中分析Cr、Cys C及基于CKD-EPI公式计算的3种e GFR与狼疮肾炎指标间的相关性;以24 h尿蛋白定量水平将狼疮肾炎患者分为4个级别,比较每个尿蛋白级别对应的3种e GFR间的差异;比较Cr正常的LN组和非LN组患者间3种e GFR的差异。结果:血沉、补体C3、C4和抗ds-DNA抗体在非LN组和LN组间无显著差异(P>0.05),而两组在年龄、病程、24 h尿蛋白定量、Cys C、BUN、Cr、SLEDAI、renal-SLEDAI和e GFR间存在显著差异(P<0.01);在LN组中,Cr、Cys C及Cr-e GFR、Cys C-e GFR和(Cr+Cys C)-e GFR均与24 h尿蛋白定量及renal-SLEDAI具有相关性(P<0.01),而与抗ds-DNA抗体定量没有相关性(P>0.05);在LN组4个不同尿蛋白水平的Cys C-e GFR和(Cr+Cys C)-e GFR均低于Cr-e GFR(P<0.05),而前两者间无差异(P>0.05);在Cr正常的LN组和非LN组间Cr-e GFR无差异(P>0.05),而Cys C-e GFR和(Cr+Cys C)-e GFR间存在差异(P<0.01)。结论:基于Cys C或Cys C联合Cr的CKD-EPI公式估算GFR能够较好地反映LN患者早期肾脏功能损害。

Objective：To assess the value of the estimated glomernlar filtration rate to evaluation of early renal damage in patients with lupus nephritis. Methods： The clinical data were reviewed in 369 patients with systemic lupus erythematosus（ SLE）, and 2012 Chronic Kidney Disease Epidemiology Collaboration Equation （CKD-EPI） was used to calculate the estimated glomerular filtration rate （eGFR） for each patient based on the measured levels of creatinine（ Cr）, cystatin C（CysC） or combination of creatinine and cystatin C（ Cr ＋ CysC）, respectively. Then the patients with SLE were divided into non-lupus nephritis（nLN） group and lupus nephritis（LN） group for comparison of the difference of indicators. The correlation was analyzed between serum level of Cr and CysC and calculated eGFRs in patients with lupus nephritis. Based on the 24-hour urine protein, patients with lupus nephritis were furthered divided into four levels, where three median eGFRs were compared. Patients with normal serum Cr level were divide into nLN group and LN group, in which three eGFRs were compared. Results ：There was no difference concerning erythrecyte sedimentation rate, complement-3 and complement-4 and anti-ds-DNA antibody in nLN and LN groups（ P 〉 0.05 ）, yet the difference was significant regarding the ages, course of disease, 24-hour urine protein level, urea nitrogen, Cr, CrsC, SLEDAI, renal-SLEDAI and eGFR（P 〈0. O1 ）. Serum Cr, CysC, Cr-eGFR, CysC-eGFR and （Cr ＋ CysC）-eGFR were associated with 24-hour urine protein and renal-SLEDAI（ P 〈 0. 01 ）, whereas had no correlation with anti-ds-DNA antibody level（ P 〉 0.05 ）. Although CysC-eGFR and （ Cr ＋ CysC） -eGFR had no differences, the two indicators were both lower than Cr-eGFR among four different urine protein levels in patients with lupus nephritis（ P 〈 0.05 ）. There was significant difference between the two groups of patients with normal serum Cr on CysC-eGFR and （Cr ＋ CysC） -eGFR, yet no difference in Cr-eGFR. Conclusion ： CKD-EPI calculation, based on CysC or combined Cr with CysC, may best exhibit the early renal damage in patients with lupus nephritis.