Corrected Neutrophil Gelatinase-Associated Lipocalin (NGAL) Level Adjusted by the Scoring System of an Inflammation Index for Screening Renal Dysfunction in Patients with Systemic Inflammation.

This study investigated the use of corrected neutrophil gelatinase-associated lipocalin (cNGAL) values to screen renal dysfunction in patients with systemic inflammation. Plasma NGAL concentrations were measured using a fluorescent immunoassay in 259 patients with inflammatory diseases. An inflammation index was calculated using a scoring system based on high-sensitivity C-reactive protein (hsCRP) and corrected erythrocyte sedimentation rates. The uncorrected NGAL (uNGAL) concentration increased with the inflammation index, but cNGAL increased in parallel with serum creatinine (sCr) levels. After adjustment with the inflammation index, increased uNGAL concentrations returned to a level not significantly different from the control value. In a multivariate regression analysis, hsCRP was more closely associated with uNGAL than cNGAL [r=0.513 (p<0.001) vs. r=0.201 (p=0.017)], but the sCr level was more strongly linked to cNGAL than uNGAL (r=0.692 vs. r=0.583, respectively, p<0.001). In a receiver operating characteristics (ROC) curve analysis, the diagnostic accuracy of cNGAL, which identifies an increase of sCr ≥0.3 mg/dL within 48 hours, was found to be superior to that of uNGAL [0.72 (95% CI, 0.61-0.84) vs. 0.67 (95% CI, 0.56-0.81), p=0.038]. In conclusion, cNGAL more accurately reflects renal dysfunction than uNGAL under inflammatory conditions. A measurement of cNGAL may provide helpful information for assessing patients with renal impairment, particularly in association with systemic inflammation.