[Application of NGAL and Cys c in predicting graft function during early period after kidney transplantation]

To assess the diagnostic values of novel biomarkers, such as neutrophil gelatinase-associated lipocalin (NGAL) and cystatin c (Cys c), in the diagnosis of delayed graft function (DGF).

A total of 114 patients undergoing kidney transplantation from deceased donors from October 2012 to October 2013 were enrolled. Recipients on dialysis during the first postoperative week were included into DGF group while those without DGF into early graft function (EGF) group. sNGAL, sCys c and serum creatinine (sCr) were measured pre-operation, as well as at 4, 12, 24, 72 and 168 h post-operation. Furthermore, uNGAL leveks were measured at 4, 12 and 24 h post-transplantation. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the predictive value of DGF.

Among 114 recipients enrolled, 23 presented DGF and 91 EGF. In EGF group, within 4 h post-transplantation sNGAL and sCys c decreased more significantly than sCr (51.31% (40.30%, 62.31%), 56.39% (50.02%, 68.40%) vs 21.40% (6.77%, 27.44%), P = 0.009 and 0.029 respectively). Between two groups, differences of sequential decrease were observed earlier in sNGAL and sCys c than uNGAL and sCr. It demonstrated better performance in predicting DGF. The AUC of sCr was between uNGAL and sNGAL, sCys c. Combination of both sNGAL and sCys c yielded a ROC-AUC of 1.000.

sNGAL and sCys are ideal for predicting the recovery of graft function during early period after kidney transplantation. And a combination of both biomarkers may dramatically improve the specificity and sensitivity of diagnosing DGF.