title: Clinical Assessment of Follow-Up Cystatin C-Based eGFR in Live Kidney Donors.
abstract: OBJECTIVE
  We aimed to compare the cystatin C-based estimated glomerular filtration rate (eGFR) and the serum creatinine-based eGFR and to investigate the clinical roles of the cystatin C-based eGFR in assessing the follow-up renal function of kidney donors.
  
  
  METHODS
  We enrolled 121 healthy kidney donors who underwent live donor nephrectomy between October 2009 and December 2010 in a prospective manner. Serum creatinine and cystatin C were measured preoperatively and were followed after the surgery (1st, 4th, and 7th postoperative day and 1st, 3rd, 6th, and 12th postoperative month). We also compared the sensitivity and specificity of each eGFR method for predicting the development of chronic kidney disease (CKD) after donor nephrectomy.
  
  
  RESULTS
  For those who had a Modification of Diet in Renal Disease postoperative day 4 eGFR of less than 60 ml/min/1.73 m(2), the probability of developing CKD was 89.0% (Chronic Kidney Disease Epidemiology Collaboration eGFR, 66.0%; Cockcroft-Gault eGFR, 74.0%; cystatin C eGFR, 57.1%). A cystatin C eGFR of below 60 ml/min/1.73 m(2) at postoperative day 4 predicted CKD at 6 months with a specificity of 90.3%, which was the highest among the estimation methods used. Cystatin C eGFRs were generally higher than the creatinine-based eGFRs.
  
  
  CONCLUSIONS
  We conclude that cystatin C-based estimations of the GFR are helpful for predicting the recovery of renal function in kidney donors and could be added to the follow-up protocol of kidney donors who may develop CKD, especially patients whose immediate postoperative renal function is marginal.
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyun Ho
authors.initials: HH
authors.lastname: Han
authors.forename: Kyung Hwa
authors.initials: KH
authors.lastname: Choi
authors.forename: Seung Choul
authors.initials: SC
authors.lastname: Yang
authors.forename: Woong Kyu
authors.initials: WK
authors.lastname: Han
keywords: Kidney function tests; Kidney transplantation; Living donors; Nephrectomy