The Clinical Value Of Different GFR Methods In Renal Function Evaluation Of Polycystic Kidney Diseases

Objective:To investigate the application value of ^99mTc-DTPA renal dynamic imaging and blood creatinine estimation method for GFR detection in different stages of polycystic kidney diseases.Methods:Referring to the guidelines for clinical practice of chronic kidney disease and dialysis in the United States（NKF-K/DOQI）,59 polycystic kidney patients without dialysis were divided into 3 groups by the gold standard method of double plasma:Group A:GFR≥60ml/min·1.73m2)（including CKD1²,19 cases）;Group B:60ml/（min·1.73m2）>GFR≥30ml/（min·1.73m2）（including CKD3,23 cases）;Group C:GFR<30ml/（min·1.73m2）（including CKD4⁵,17 cases）.Firstly,the GFR（dGFR）measured by dual-plasma method(clearance rate of ^99mTc-DTPA)was used as the gold standard to compare the four GFR estimation equations based on serum creatinine in the renal function assessment of polycystic kidney disease;Bias,precision,accuracy within 30%ranges from the gold standard and agreements of each test were compared.Then the GFR values measured by the Gate’s method and the optimal serum creatinine estimation equation were respectively matched with the gold standard in the three groups for t-test and Pearson correlation analysis.Results:1.patients in general situation:there were 59 patients in total,19 in group A,23 in group B and 17 in group C,and there was no significant difference in age,sex and body surface area between 3 groups（P<0.05）.2.The Cockcroft-Gault equation（method B）had the highest accuracy（78%within30%the gold standard）with the least bias of only 3.76 ml/（min·1.73 m2）and the precision of only 11.24 ml/（min·1.73m2）.And it has the highest correlation with the gold standard（r=0.928,P<0.001）;The Bland-altman analysis obtained the confidence interval:Cockcroft-Gault<JSN-CKDI<MDRD<Chinese MDRD,the Cockcroft-Gault equation is the best.The method B showed no significant difference comparing with the gold standard method（method C）in group A,B and C（t=-1.462,-1.592,-1.791,all P>0.05）.In each group,the method B had a good correlation with method C（r=0.69,0.68,0.92,all P<0.05）;3.There was no significant difference between Gate’s method（method A）and method C in group A and group B（t=1.255,-0.061,all P>0.05）;There was a significant correlation between method A and method C in both groups（r=0.55,0.62,all P<0.05）;But in group C,there was a significant difference（t=-2.132,P<0.05）and no significant correlation（r=0.36,P>0.05）between them.The Gate’s method clearly overestimated the GFR.4.For group C（4-5 patients）,the Gate’s method was corrected by CT.The corrected GFR results were significantly improved with the gold standard.Conclusion:1.The CG equation can be used to evaluate renal function GFR commendably in patients with polycystic kidney disease（CKD1-5）.2.The Gate’s method can be used to evaluate renal function in the early and mid-term（CKD 1-3）stages of polycystic kidney disease（total GFR and per kidney GFR,renogram）,but the value in the late stage（CKD4-5）is limited.3.A correction technique of Gate’s method can improve the renal function in the late stage of polycystic kidney disease（CKD4-5 phase）（total GFR and per kidney GFR,renogram）...