Comparison of serum creatinine, cystatin c, and neutrophil gelatinase-associated lipocalin for acute kidney injury occurrence according to risk, injury, failure, loss, and end-stage criteria classification system in early after living kidney donation

To evaluate the kidney function after living kidney donation, we measured serum creatinine (SCr), cystatin C, and neutrophil gelatinase-associated lipocalin (NGAL) of 42 living donors before uninephrectomy and in three immediate days after it. We also evaluated the prevalence of the occurrence of the different stages of acute kidney injury (AKI) classified according to risk, injury, failure, loss, and end-stage (RIFLE) criteria, and accuracy of each of these three biomarkers for predicting them were evaluated. Significant serum NGAL (s-NGAL) changes were limited to the 1 st day after donation, whereas SCr and cystatin C changes continued to the third day after donation. s-NGAL level in the 1 st day and serum cystatin C in the 3 rd day after donation, respectively, had the largest area under curve and best sensitivity and specificity for Stage 1 (risk) AKI prediction. During the immediate three days after donation, about half of patients suffered from AKI; mostly Stage 1 (injury). The sequence of the emergence of s-NGAL and s-cystatin C in the 1 st and 3 rd days as biomarkers with highest accuracy and power for RIFLE criteria defined AKI stage discrimination in our study was comparable to previous studies. We conclude that our study suggests that AKI was best detected in the 1 st day after uninephrectomy by the s-NGAL levels, whereas cystatin C was the best in the 3 rd day after donation for detection of AKI.