Decentralized glomerular filtration rate (GFR) estimates in healthy kidney donors show poor correlation and demonstrate the need for improvement in quality and standardization of GFR measurements in Sweden

Objective. Glomerular filtration rate (GFR) is generally accepted as the best overall index of renal function. Thus, all potential live kidney donors are tested to ensure that they have a normal GFR before they are eligible for kidney transplantation. The choice of GFR test is very much dependent on local traditions and may include iohexol, 51Cr-EDTA, inulin, or creatinine clearance based on urine collection, and creatinine clearance calculated from the Cockcroft-Gault or Modification of Diet in Renal Disease (MDRD) equation as well as cystatin C. The aim of this study was to compare the results of GFR measurements performed in all actual live kidney donors who have undergone live donor nephrectomy at the University Hospital in Uppsala, Sweden, between the years 2000 and 2004. Material and methods. The patients were selected from all parts of Sweden and the measurements were performed at their local hospital. Results. We found large discrepancies between repeated iohexol measurements in these presumably healthy individuals. There was also a poor correlation between iohexol clearance and calculated creatinine clearance using the Cockcroft-Gault (R2 = 0.046) or MDRD formula (R2 = 0.045). Conclusions.The study shows that the standardization and quality of GFR measurements in Sweden have to be improved.