NGAL as Biomarker of Clinical and Subclinical Damage of Kidney Function after Coronary Angiography

Abstract

Contrast-induced acute kidney injury (CI-AKI) is a serious complication after angiographic examinations in cardiology. Diagnosis may be delayed based on standard serum creatinine, and subclinical forms of kidney damage may not be detected at all. In our study we investigate the clinical use in these directions of a “damage” type biomarker - Neutrophil Gelatinase-Associated Lipocalin (NGAL). Among patients with a high-risk profile undergoing scheduled coronary angiography and/or angioplasty, plasmsa NGAL was determined at baseline, at 4 and 24 hours after contrast administration. In the CI-AKI group, NGAL increased significantly at the 4th hour (132.33±72.83 ng/ml versus 111.48±65.06 ng/ml, p=0.006) and at the 24th hour (212 .93±276.61 ng/ml, p=0.008). In patients with subclinical CI-AKI, NGAL also increased significantly at the 4th hour (128.18±99 ng/ml, p=0.002) and reached levels close to those in patients with CI-AKI. Unlike new biomarker, however, serum creatinine did not change significantly in this group. The diagnostic power of NGAL is extremely good - AUC 0.847 (95% CI: 0.677-1.000; p=0.001) in CI-AKI and AUC 0.731 (95% CI: 0.539 – 0.924; p=0.024) in subclinical CI-AKI. NGAL may be a reliable biomarker for early diagnosis of clinical and subclinical forms of renal injury after contrast angiographic studies.