THE ROLE OF NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN (NGAL) FOR EARLY DETECTION OF ACUTE KIDNEY INJURY IN PATIENTS UNDERGOING CORONARY ANGIOGRAPHY

With escalating use of radiographic contrast media in clinical practice contrast-induced acute kidney injury (CIAKI) is widely recognized as a significant source of morbidity and mortality. One of the new promising biomarkers for early detection of CIAKI is Neutrophil Gelatinase-Associated Lipocalin (NGAL). The aim of our study was to assess the relationship between serum NGAL and the "gold standards" for estimating of kidney function as serum creatinine (sCr) and GFR in patients undergoing percutaneous coronary angiography. The study enrolled 45 patients with arterial hypertension, diabetes mellitus and preserved kidney function with established or suspected coronary artery disease. Blood samples for serum NGAL and sCr were collected baseline at the day before, at the 4th and 24th hour after contrast administration. Out of the total enrolled patients 9 have developed CIAKI (20%) and 16 (35.6%) patients served as controls. The remaining patients (n = 20, 44.4%) had minimal change of serum creatinine and positive NGAL results and were defined as "NGAL-P" group. The results of the study demonstrated that sCr, GFR and serum NGAL had no significant change before and after contrast investigation in control group. In the CIAKI group sCr increased and GFR decreased statistically significantly at the 24th hour. At the same time the level of serum NGAL increased statistically significantly still 4 hours after contrast administration and this elevation was observed also in the period between the 4th and 24th hour. The baseline and 4th hour values of NGAL correlated strongly with decreased GFR at the 4th hour in this group. In the "NGAL+" group sCr and GFR changed minimally but serum NGAL increased significantly at the 4th hour. ROC analysis was also corresponding to this result as it showed 70% sensitivity and 75% specificity for serum NGAL at the 4th hour to detect initial kidney injury. In conclusion our study demonstrates that NGAL increases early after contrast administration in patients who developed CIAKI later as well as in patients with subclinical acute kidney injury. The new biomarker correlates perfectly with changes in GFR and can be used for early detection of acute kidney injury.