Cystatin C-based formula is superior to MDRD, Cockcroft-Gault and Nankivell formulae in estimating the glomerular filtration rate in renal allografts.
OBJECTIVE
There are conflicting reports on the reliability of the various glomerular filtration rate formula in renal allografts, to assess the performance of various glomerular filtration rate formula in estimating renal function of renal allografts.


METHODS
Glomerular filtration rate was measured using an isotope Tc99m DTPA in 97 renal transplant patients and estimated using modification of diet in renal disease, Cockroft-Gault formula, Nankivell, and a cystatin C-based formula. The overall performance of these formula was evaluated by calculating bias, accuracy and precision.


RESULTS
Mean age was 39.8 years (-/+ 12.7), body mass index was 26.9 (-/+ 6.3) and serum creatinine was 114.5 micromol/L (-/+ 39.3). The mean measured glomerular filtration rate was 58.1 mL/min (-/+ 25.6). The bias with modification of diet in renal disease was 7.7 (P = .03), with Cockroft-Gault formula it was 3.2 (P = .3), with Nankivell it was 10.3 (P = .0002), and with cystatin C it was 0.31 (P = .9) The precisions (r) for modification of diet in renal disease, Cockroft-Gault formula, Nankivell, and cystatin C were 0.26 (P = .01), 0.26 (P = .01), 0.42 (P = .0001), and 0.60 (P < .0001), respectively. We also investigated the impact of sex, age, body mass index, and glomerular filtration rate on the performance of these 4 formula.


CONCLUSIONS
The best correlation, highest precision, accuracy, and least bias were seen when using cystatin C. The largest bias was seen when using Nankivell and modification of diet in renal disease formula.
Qutb
Ammar
A
King Saud Bin Abdulaziz University for Health Sciences, Kingdom of Saudi Arabia.
Syed
Ghulam
G
Tamim
Hani M
HM
Al Jondeby
Mohammad
M
Jaradat
Maha
M
Tamimi
Waleed
W
Al Ghamdi
Ghormullah
G
Al Qurashi
Salem
S
Flaiw
Ahmed
A
Hejaili
Fayez
F
Al Sayyari
Abdulla A
AA
D000328:Adult; D015982:Bias; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006305:Health Status Indicators; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D016030:Kidney Transplantation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D016284:Technetium Tc 99m Pentetate; D014184:Transplantation, Homologous; D016896:Treatment Outcome
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D019275:Radiopharmaceuticals; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate