Objective To explore the application value of blood neutrophil gelatinase-associated lipocalin (NGAL) in diagnosing renal anemia and evaluating condition of disease.

Methods A total of 86 patients with chronic kidney disease (CKD) complicated with anemia were selected as research objects, and they were divided into mild group hemoglobin (Hb)≥90 g/L with 54 cases and moderate to severe group (Hb < 90 g/L) with 32 cases according to the degree of anemia. Another 36 CKD patients without anemia in the same period were selected as control group. The levels of red blood cell (RBC), hematocrit (HCT), Hb, blood NGAL, serum creatinine (Scr) and blood urea nitrogen (BUN) were compared among groups; the correlations between blood NGAL and various indexes were analyzed; the value of NGAL in diagnosis of renal anemia was analyzed by receiver operating characteristic (ROC) curve.

Results The levels of blood NGAL, Scr and BUN in the moderate to severe group were significantly higher than those in the mild group and the control group, and the levels of blood NGAL, Scr and BUN in the mild group were significantly higher than those in the control group (P < 0.05). Spearman correlation analysis showed that blood NGAL in CKD patients complicated with anemia was significantly negatively correlated with RBC, HCT and Hb (P < 0.05), and positively correlated with Scr and BUN (P < 0.05). ROC curve analysis showed that the area under the curve (AUC) of blood NGAL level in the diagnosis of renal anemia was 0.729, the sensitivity was 80.2% (95%CI, 70.6 to 87.3), the specificity was 61.1% (95%CI, 44.9 to 75.2), and the optimal cut-off value was 134.62ng/mL.

Conclusion The level of blood NGAL is closely related to the severity of renal anemia, and dynamic monitoring of blood NGAL level can provide reference for clinical diagnosis and disease evaluation of patients with renal anemia.