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Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Nephrol. Jul 6, 2015; 4(3): 345-353
Published online Jul 6, 2015. doi: 10.5527/wjn.v4.i3.345
Estimating glomerular filtration rate in kidney transplantation: Still searching for the best marker
Josefina Santos, La Salete Martins
Josefina Santos, La Salete Martins, Nephrology and Transplant Department, Centro Hospitalar do Porto, Hospital de Santo António, 4099-001 Porto, Portugal
Author contributions: Both authors contributed equally to this article.
Conflict-of-interest statement: The authors have read and understood BPG policy on declaration of interests and declare that they have no competing interests.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Josefina Santos, MD, Nephrology and Transplant Department, Centro Hospitalar do Porto, Hospital de Santo António, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal. josefina.sts@gmail.com
Telephone: +351-22-2074685 Fax: +351-22-2033189
Received: January 26, 2015
Peer-review started: January 28, 2015
First decision: March 6, 2015
Revised: May 6, 2015
Accepted: May 7, 2015
Article in press: May 8, 2015
Published online: July 6, 2015
Processing time: 161 Days and 13 Hours
Abstract

Kidney transplantation is the treatment of choice for end-stage renal disease. The evaluation of graft function is mandatory in the management of renal transplant recipients. Glomerular filtration rate (GFR), is generally considered the best index of graft function and also a predictor of graft and patient survival. However GFR measurement using inulin clearance, the gold standard for its measurement and exogenous markers such as radiolabeled isotopes (51Cr EDTA, 99mTc DTPA or 125I Iothalamate) and non-radioactive contrast agents (Iothalamate or Iohexol), is laborious as well as expensive, being rarely used in clinical practice. Therefore, endogenous markers, such as serum creatinine or cystatin C, are used to estimate kidney function, and equations using these markers adjusted to other variables, mainly demographic, are an attempt to improve accuracy in estimation of GFR (eGFR). Nevertheless, there is some concern about the inability of the available eGFR equations to accurately identify changes in GFR, in kidney transplant recipients. This article will review and discuss the performance and limitations of these endogenous markers and their equations as estimators of GFR in the kidney transplant recipients, and their ability in predicting significant clinical outcomes.

Keywords: Glomerular filtration rate estimation; Creatinine; Cystatin C; Kidney transplantation; Clinical outcomes

Core tip: An accurate evaluation of allograft function is essential in the management of kidney transplant. Glomerular filtration rate (GFR), is generally considered the best index of graft function. Endogenous markers, such as serum creatinine or cystatin C, are used to estimate kidney function, and equations using these markers adjusted to other variables, are an attempt to improve accuracy in estimation of GFR. This article will review and discuss the performance and limitations of these endogenous markers and their equations as estimators of GFR in the kidney transplant recipients, and their ability in predicting clinical outcomes.