A comparison of four established GFR formulas to estimate measured GFR and changes in GFR in adult kidney transplant recipients

Abstract

The accurate assessment of glomerular filtration rate (GFR) is important in the follow-up of kidney transplant recipients in order to identify graft dysfunction. A number of formulas have been proposed to calculate GFR from endogenous plasma markers such as creatinine or cystatin C since measuring GFR using exogenous markers is troublesome. This study compares and evaluates the ability of four different GFR formulas to estimate kidney graft function and to detect changes in GFR in kidney transplant recipients. The study included patients from the prospective, multicenter CONTEXT trial in kidney transplant recipients. GFR was measured using plasma clearance of ⁵¹Cr-EDTA and estimated using the MDRD, CKD-EPI Creatinine, CKD-EPI Cystatin C and CKD-EPI Cystatin C + Creatinine equations at three (n = 83) and twelve (n = 65) months post-transplantation. For each formula mean bias, precision, and accuracy were evaluated. The MDRD equation had the lowest mean bias (0.2 ml/min/1.73 m²), whereas the CKD-EPI Cystatin C + Creatinine equation had the highest precision (8 ml/min/1.73 m²). Accuracy at three months were similar for all equations (P30 > 80%) except for the CKD-EPI Cystatin C equation, which performed poorer (P30 = 55%). None of the formulas evaluated avoided misclassification of changes in GFR. The most optimal combination of precision and accuracy suggests the use of CKD-EPI Creatinine + Cystatin C equation in kidney transplant recipients.

Keywords:

• Kidney
• glomerular filtration rate
• kidney transplantation
• cystatin c
• creatinine

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Correction

Correction Statement

This article was originally published with errors, which have now been corrected in the online version. Please see Correction (http://dx.doi.org/10.1080/00365513.2023.2183000)

Acknowledgements

The authors acknowledge additional members of the CONTEXT-study group (G. J. Nieuwenhuijs-Moeke, Department of Anaestesiology, University Center Groningen, the Netherlands and F. J. M. F. Dor, Division of HPB & Transplant Surgery, Department of Surgery, Erasmus MC, University Medical Center, Rotterdam, the Netherlands) for collection and preparation of patient samples included in the CONTEXT study population. Authors like to thank and Bo Martin Bibby, Department of Biostatistics, Aarhus University for statistical assistance.

Disclosure statement

All authors declare no conflicts of interest.

Data availability statement

Data can unfortunately not be made publicly available due to ethical concerns, as it is not possible to anonymise data sufficient for public access. Data is available on request to the CONTEXT Data Access Committee ([email protected])

Additional information

Funding

Lundbeck Foundation, The Danish Council for Independent Research Medical Sciences; the Novo Nordic Foundation; the Danish Nephrology Society; the Swedish Medical Association; A. P. Møller og hustru Chastine Mc-Kinney Møllers Fond til Almene Formaal; Aarhus University Hospital; Aarhus University.