Significance of Neutrophil Gelatinase-Associated Lipocalin Level-to-Serum Creatinine Ratio for Assessing Severity of Inflammation in Patients with Renal Dysfunction

The aim of this study was to assess the significance of the neutrophil gelatinase-associated lipocalin/serum creatinine ratio (NGAL/sCr ratio) in patients with renal dysfunction. The percent difference between plasma NGAL level and the NGAL/sCr ratio was 36.7% (95% CI, 18.4-83.7%) in patients with sCr level ≥ 1.2 mg/dL. In a multivariate analysis, high sensitivity C-reactive protein (hsCRP) was significantly associated with the NGAL/sCr ratio and plasma NGAL level (r = 0.526 and r = 0.453, resp., P < 0.001). In a receiver operating characteristics curve, the diagnostic ability of the NGAL/sCr ratio to identify hsCRP > 4.0 mg/dL was superior to that of NGAL [0.783 (95% CI, 0.674-0.892) versus 0.733 (95% CI, 0.615-0.852), P = 0.032]. The area under the curve of the NGAL/sCr ratio was larger than that of hsCRP to detect corrected erythrocyte sedimentation rate > 25 mm/h and the neutrophil-to-lymphocyte ratio >4.5 in renal dysfunction. In short, the NGAL/sCr ratio may offer useful information when screening patients with both systemic inflammation and renal dysfunction.