Serum neutrophil gelatinase-associated lipocalin correlates with kidney function in heart allograft recipients

The value of neutrophil gelatinase-associated lipocalin (NGAL) as a novel marker for early detection of acute renal failure has been highlighted recently. The aim of this study was to assess whether serum NGAL correlated with kidney function in heart allograft recipients. We evaluated serum NGAL, creatinine, and estimated glomerular filtration rate (GFR) in 164 heart allograft recipients on triple therapy. Heart transplant recipients showed significantly higher NGAL values than the control group. Kidney function was estimated using CKD-EPI, Modification of Diet in Renal Disease (MDRD), Cockcroft-Gault formula, 24-hour creatinine clearance, and serum creatinine. Kidney function was significantly impaired among heart transplant recipients compared with healthy volunteers. On univariate analysis serum NGAL strongly correlated with serum creatinine (r = .70, P < .001), estimated GFR (CKD-EPI, r = -.57, P < .001, MDRD r = .56, P < .001, Cockcroft-Gault, r = -.56, P < .001), 24-hour creatinine clearance (r = .43, P < .001), and cystatin C (r = .74, P < .001). In contrast, it was moderately correlated with red blood cell count (r = -.39, P < .01), hemoglobin level (r = -.42, P < .01), NT-proBNP (r = .25, P < .01), and only weakly with New York Heart Association class (r = .21, P < .05), time after transplantation (r = .21, P < .05), or age (r = .19, P < .05) upon multiple regression analysis, the best predictor of serum NGAL was estimated GFR (beta -0.87, P < .0001), explaining 89% of the NGAL concentrations. Even a successful heart transplantation is associated with kidney injury as reflected by elevated serum NGAL and reduced estimated GFR. Therefore, NGAL needs to be investigated as a potential early marker for impaired kidney function/injury, especially among patients with risk factors for renal damage, i.e., hypertension or diabetes, other than heart pathology.