Comparison of Equations Based on Cystatin C versus Creatinine to Estimate Glomerular Filtration Rate in Renal Transplant Patients in the South of Iran

Background: Equations to estimate glomerular filtration rate (GFR) are available. The aim of this study was to identify the optimal equation that accurately estimates the GFR and the chronic kidney disease (CKD) stage in the renal transplant patients in the south of Iran.Material and Methods: This was a cross-sectional study of 58 renal transplant patients. Their venous samples were also obtained for serum creatinine and cystatin c determination which was used to calculate estimated GFR (eGFR). The mean difference of GFR between the equations was calculated with Bland-Altman analysis. We compared correlation, bias, imprecision and 10% and 30% accuracy between the eGFR cystatin c and creatinine. Concordance between both equations for CKD staging was performed. the classification of patients according to estimated renal function at the cut off of 60 ml/min/1.73m2 were investigated. Results: Bland-Altman plots and bias demonstrated that eGFR by Ab-MDRD was the most accurate compared with CKD-EPI cystatin c. After that, the CKD-EPI eGFR creatinine performed similarly. Referencing CKD-EPI cystatin c, the imprecision of the equations was approximately the similar that Ab-MDRD and CKD-EPI eGFR creatinine is still better than CG. Finally, our finding suggested that Ab-MDRD and CKD-EPI eGFR creatinine might be the best performing equation in the classification of the CKD stages in cut off 60ml/min/1.73m2. Conclusion: our findings indicate that due to the high cost and potential delay in measuring cystatin c, Ab-MDRD, after that CKD-EPI eGFR, creatinine measurement is a suitable alternative and facilitate rapid clinical decision making in the population of renal transplant patients.

کلیدواژه ها:

Glomerular fltration rate ، Renal transplant ، Cystatin c ، Creatinine ، CKD-EPI ، Cockcroft-Gault ، Ab-MDRD