Serum liver-type fatty acid-binding protein predicts recovery of graft function after kidney transplantation from donors after cardiac death

Kidneys procured by donation after cardiac death (DCD) may increase the donor pool but are associated with high incidence of delayed graft function (DGF). Urinary liver-type fatty acid-binding protein (L-FABP) level is an early biomarker of renal injury after kidney transplantation (KTx); however, its utility is limited in DGF cases owing to urine sample unavailability. We examined whether serum L-FABP level predicts functional recovery of transplanted DCD kidneys. Consecutive patients undergoing KTx from living related donors (LD), brain-dead donors (BD), or DCD were retrospectively enrolled. Serum L-FABP levels were measured from samples collected before and after KTx. Serum L-FABP decreased rapidly in patients with immediate function, slowly in DGF patients, and somewhat increased in DGF patients requiring hemodialysis (HD) for >1 wk. Receiver-operating characteristic curve analysis demonstrated that DGF was predicted with 84% sensitivity (SE) and 86% specificity (SP) at cutoff of 9.0 ng/mL on post-operative day (POD) 1 and 68% SE and 90% SP at 6.0 on POD 2. DGF >7 d was predicted with 83% SE and 78% SP at 11.0 on POD 1 and 67% SE and 78% SP at 6.5 on POD 2. Serum L-FABP levels may predict graft recovery and need for HD after DCD KTx.