Neutrophil gelatinase-associated lipocalin as emerging biomarker of acute renal failure in renal transplant patient after coronary artery bypass surgery.

Acute renal injury (AKI) is a serious complication, which increases the risk of death after cardiac surgery. Although serum Cre is typically used for diagnosis of AKI, there are disadvantages in its use as renal marker. Neutrophil gelatinase-associated lipocalin (NGAL) is a protein of the lipocalin family and is expressed by neutrophils and other epithelial cells including segments of proximal collecting tubule (PCT). It is introduced as an excellent renal biomarker, for the early diagnosis of AKI in children and adults undergoing renal transplantation and cardiac surgery. According to literature data NGAL is detected in the very first urine sample within two hours following ischemia. It is one of the earliest and most robustly induced proteins in kidneys following ischemic and nephrotoxic insults. We present an interesting case of renal transplant patient under long-term immunosuppressive therapy. He had already renal impairment of the transplant kidney (GFR 29.3 mL/min/1.73 m(2)). He suffered from coronary artery disease without history of myocardial infraction and underwent elective coronary artery bypass grafting (CABG). Renal function was monitored also with NAGL, in order to avoid potential renal graft failure postoperatively.