Vancomycin is used for the treatment of resistant staphylococcal and enterococcal infections but is associated with nephrotoxicity. Neutrophil gelatinase-associated lipocalin (NGAL) was recently identified as a sensitive biomarker for acute kidney injury. Here, we aimed to investigate the usefulness of serum NGAL in monitoring patients undergoing vancomycin therapy.Methods:
A total of 253 NGAL tests from 59 patients undergoing vancomycin therapy were evaluated. Patients with trough serum concentrations of vancomycin that exceeded 20 ug/mL were included. Serum NGAL was measured using a commercially available ELISA kit, and other biochemical indicators including creatinine, leukocyte count, eGFR and C-reactive protein were assessed.Results:
At the initiation of vancomycin treatment, serum creatinine level was 0.93 ± 0.40 (mean ± SD) mg/dL, NGAL was 341 ± 354 mg/dL, leukocyte count was 10,750 ± 7190 per uL and CRP level was high (10.8 ± 9.3 mg/dL). About 49% of patients had an elevated leukocyte count, and all patients showed a high CRP level. Basal serum NGAL concentration in the patients with elevated leukocyte level (10,000/uL or higher) was higher compared to that in patients with normal leukocyte levels (mean ± SD, 478 ± 449 mg/dL vs. 176 ± 101 mg/dL, p<0.001). A significant positive relationship was found between NGAL level and creatinine level in patients with normal basal leukocyte levels but not in those with higher leukocytes.Conclusion:
The clinical usefulness of serum NGAL should be interpreted carefully when evaluating renal impairment in patients undergoing vancomycin treatment.