Plasma neutrophil gelatinase-associated lipocalin (NGAL) is an indicator of interstitial damage and a predictor of kidney function worsening of chronic kidney disease in the early stage: a pilot study

The aim of this study was to examine whether plasma neutrophil gelatinase-associated lipocalin (NGAL) levels predict the outcome of kidney function and correlate with the severity of tubulointerstitial damages in patients with chronic kidney disease (CKD).

In this prospective 18-month cohort study of 112 patients with CKD between 2010 and 2011, associations between plasma NGAL levels and estimated glomerular filtration ratio (eGFR), further worsening of kidney function and histological lesion on kidney biopsy were investigated.

Serum levels of creatinine and eGFR before the study were 1.48 ± 0.65 mg/dl and 42.6 ± 22.0 ml/min/1.73 m². Median plasma NGAL level was 148.5 (83.75–248.25) ng/ml and showed no correlation with eGFR or age. 87 out of 112 patients were able to follow up for 18 months. Patients with higher levels of NGAL (>107.8 ng/ml) showed significantly more decrease in eGFR in CKD stage 1 or 2 than those with lower levels of NGAL (≦107.8 ng/ml), while there was no difference in change in eGFR in CKD stage 3–5 between patients with higher and lower levels of NGAL. In the kidney biopsy of 27 patients out of enrolled patients, plasma NGAL levels correlated significantly with the degree of interstitial cell infiltration and fibrosis, but did not correlate with that of glomerular sclerosis. In ROC analysis, plasma NGAL levels predicted tubulointerstitial cell infiltrations more accurately [AUC = 0.8300 than eGFR (AUC = 0.716)].

Plasma NGAL is a useful marker of interstitial lesions in patients with CKD and a predictor of further kidney worsening in the early CKD stage.