title: Effect of picric acid and enzymatic creatinine on the efficiency of the glomerular filtration rate predicator formula.
abstract: BACKGROUND
  To investigate the impact of serum creatinine measurement on the applicability of glomerular filtration rate (GFR) evaluation equations.
  
  
  METHODS
  99mTc-DTPA plasma clearance rate was used as GFR reference (rGFR) in patients with chronic kidney disease (CKD). Serum creatinine was measureded using enzymatic or picric acid creatinine reagent. The GFR of the patients were estimated using the Cockcroft-Gault equation corrected for body surface area, simplified Modification of Diet in Renal Disease (MDRD) equation, simplified MDRD equation corrected to isotopes dilution mass spectrometry, the CKD epidemiology collaborative research equation, and two Chinese simplified MDRD equations.
  
  
  RESULTS
  Significant differences in the eGFR results estimated through enzymatic and picric acid methods were observed for the same evaluation equation. The intraclass correlation coefficient (ICC) of eGFR when the creatinine was measured by the picric acid method was significantly lower than that of the enzymatic method. The assessment accuracy of every equation using the enzymatic method to measure creatinine was significantly higher than that measured by the picric acid method when rGFR was > or = 60 mL/min/1.73m2.
  
  
  CONCLUSIONS
  A significant difference was demonstrated in the same GFR evaluation equation using the picric acid and enzymatic methods. The enzymatic creatinine method was better than the picric acid method.
authors.affiliation: Department of Laboratory Medicine, Peking Union Medical College Hospital, Beijing 100730, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Qiu
authors.forename: Xiuzhi
authors.initials: X
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhu
authors.forename: Weilin
authors.initials: W
authors.lastname: Shou
authors.forename: Mengchun
authors.initials: M
authors.lastname: Gong
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Huijuan
authors.initials: H
authors.lastname: Han
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Quan
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.forename: Hang
authors.initials: H
authors.lastname: Li
authors.forename: Xuewang
authors.initials: X
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China; D003404:Creatinine / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology; D007677:Kidney Function Tests / Q000379:methods* / Q000592:standards; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D010851:Picrates / Q000737:chemistry*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000097:blood; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D016284:Technetium Tc 99m Pentetate / Q000097:blood
chemical_list: D010851:Picrates; D019275:Radiopharmaceuticals; C005858:picric acid; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate