Yamaguchi Tsuyoshi, Higashihara Eiji, Okegawa Takatsugu, Miyazaki Isao, Nutahara Kikuo
Department of Urology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
Department of ADPKD Research, Kyorin University School of Medicine, Tokyo, Japan.
Clin Exp Nephrol. 2018 Oct;22(5):1213-1223. doi: 10.1007/s10157-018-1574-2. Epub 2018 May 22.
The reliability of various equations for estimating the GFR in ADPKD patients and the influence of tolvaptan on the resulting estimates have not been examined when GFR is calculated on the basis of inulin clearance.
We obtained baseline and on-tolvaptan measured GFRs (mGFRs), calculated on the basis of inulin clearance, in 114 ADPKD, and these mGFRs were compared with eGFRs calculated according to four basic equations: the MDRD, CKD-EPI, and JSN-CKDI equations and the Cockcroft-Gault formula, as well as the influence of tolvaptan and of inclusion of cystatin C on accuracy of the results. Accuracy of each of the seven total equations was evaluated on the basis of the percentage of eGFR values within mGFR ± 30% (P).
mGFRs were distributed throughout CKD stages 1-5. Regardless of the CKD stage, Ps of the MDRD, CKD-EPI, and JSN-CKDI equations did not differ significantly between baseline values and on-tolvaptan values. In CKD 1-2 patients, P of the CKD-EPI equation was 100.0%, whether or not the patient was on-tolvaptan. In CKD 3-5 patients, Ps of the MDRD, CKD-EPI, and JSN-CKDI equations were similar. For all four equations, regression coefficients and intercepts did not differ significantly between baseline and on-tolvaptan values, but accuracy of the Cockcroft-Gault formula was inferior to that of the other three equations. Incorporation of serum cystatin C reduced accuracy.
The CKD-EPI equation is most reliable, regardless of the severity of CKD. Tolvaptain intake has minimal influence and cystatin C incorporation does not improve accuracy.
当基于菊粉清除率计算肾小球滤过率（GFR）时，尚未研究用于估计常染色体显性多囊肾病（ADPKD）患者GFR的各种公式的可靠性以及托伐普坦对所得估计值的影响。
我们获取了114例ADPKD患者基于菊粉清除率测得的基线GFR和服用托伐普坦后的GFR（mGFR），并将这些mGFR与根据四个基本公式计算的估算肾小球滤过率（eGFR）进行比较：肾脏病饮食改良（MDRD）公式、慢性肾脏病流行病学合作（CKD-EPI）公式、日本肾脏病学会慢性肾脏病公式（JSN-CKDI）以及Cockcroft-Gault公式，同时还研究了托伐普坦以及纳入胱抑素C对结果准确性的影响。基于eGFR值在mGFR±30%范围内的百分比（P）评估七个总公式中每个公式的准确性。
mGFR分布于慢性肾脏病（CKD）1 - 5期。无论CKD处于何阶段，MDRD、CKD-EPI和JSN-CKDI公式的P值在基线值和服用托伐普坦后的值之间无显著差异。在CKD 1 - 2期患者中，无论是否服用托伐普坦，CKD-EPI公式的P值均为100.0%。在CKD 3 - 5期患者中，MDRD、CKD-EPI和JSN-CKDI公式的P值相似。对于所有四个公式，基线值和服用托伐普坦后的值之间的回归系数和截距无显著差异，但Cockcroft-Gault公式的准确性低于其他三个公式。纳入血清胱抑素C会降低准确性。
无论CKD的严重程度如何，CKD-EPI公式最为可靠。服用托伐普坦的影响最小，纳入胱抑素C并不能提高准确性。
