Cystatin and glomerular filtration rate equations in old renal transplant donors

Abstract

IntroductionEarly detection of renal dysfunction in live kidney donors is important and needs easy reliable tools. The aim of the study is to evaluate the cystatin level and cystatin-based equation in assessment of renal function in old healthy kidney donors.Participants and methodsA total of 27 living kidney donors were selected in the study, where serum creatinine and cystatin C were measured. Measured glomerular filtration rate (GFR) was done by DTPA renal scintigraphy, and it was estimated by the following equations: Cockroft–Gault, Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology Collaboration-based creatinine, cystatin, and creatinine–cystatin formulae.ResultsA total of 27 kidney donors comprised 12 (44.4%) males and 15 (55.6%) females. The mean±SD age was 61±0.14 years, and mean±SD age at the time of donation was 56.9±1.7 years. The mean of cystatin level was 1.28±0.44. Serum cystatin was negatively correlated with measured filtration rate by renal scintigraphy and estimating GFR by cystatin and creatinine–cystatin formulae. The performance of Cockroft–Gault equation was better, with the highest sensitivity (70%). Serum cystatin and cystatin-based equation had higher specificity (70%) at criterion of 1.4 and 48, respectively. Area under the curve was 0.204 and 0.839, respectively, and significance level was 0.002 and 0.009, respectively.ConclusionSerum cystatin and cystatin-based formulae could outperform as surrogate tools to monitor the renal function and estimating GFR in healthy older kidney donors. Chronic Kidney Disease Epidemiology Collaboration-based cystatin has better specificity, whereas Cockroft–Gault equation has better sensitivity with the best accuracy.