Serum and urinary neutrophil gelatinase-associated lipocalin levels in children with chronic renal diseases.

BACKGROUND: Recent studies showed that serum and urinary neutrophil gelatinase-associated lipocalin (NGAL) represents a novel, sensitive, specific biomarker for early detection of acute kidney injury. However, the clinical significance of measuring serum and urinary NGAL on chronic renal diseases remains unclear.

METHODS: In this study, we measured serum and urinary NGAL levels in patients with several common pediatric renal diseases such as renal dysfunction (estimated glomerular filtration rate < 90 mL/min/1.73 m(2)), proliferative glomerulonephritis, steroid-resistant and steroid-sensitive nephrotic syndrome, and tubular dysfunction.

RESULTS: Urinary NGAL level was significantly increased compared with the control in all of these disease groups except in patients with a remission stage of steroid-sensitive nephrotic syndrome, although a significant increase in serum NGAL level was observed in the renal dysfunction group only. Both serum and urinary NGAL levels showed significant inverse correlations with an estimated glomerular filtration rate in the analysis with total subjects, and also in the analysis with the renal dysfunction group in urinary NGAL. In proteinuric patients, the extent of proteinuria significantly correlated with urinary NGAL level. In patients with tubular dysfunction, the increase of urinary NGAL level was remarkable compared with the other disease groups.

CONCLUSION: These results indicated that urinary NGAL level is a better biomarker for chronic renal diseases in children than serum NGAL level, although multiple pathological mechanisms should be considered in evaluating these NGAL values.