Background: Urine neutrophil gelatinase-associated lipocalin (uNGAL) has been proposed as a potential biomarker for lupus nephritis (LN) activity. We determined the association between uNGAL with LN activity in systemic lupus erythematosus (SLE) patients compared to the current standard markers of SLE.
Methods: A total of 100 SLE patients with biopsy-proven LN were recruited-47 with active and 53 inactive LN. uNGAL levels were measured. Renal function test, urinary parameters, lupus serology and calculated renal SLE Disease Activity Index-2K (renal SLEDAI-2K) were analyzed to determine their associations with uNGAL.
Results: Normalized uNGAL levels (ng/mg creatinine) were significantly higher in patients with active LN compared to those with inactive disease (p=0.01). uNGAL and renal SLEDAI-2K were associated (r=0.32, p=0.001). Multiple logistic regression showed that only serum creatinine and renal SLEDAI-2K were independent predictors of uNGAL levels (p=0.03 and 0.02 respectively). Analysis of the receiver operating characteristic (ROC) curve showed that uNGAL was a potential biomarker for LN.
Conclusions: uNGAL was increased in active LN especially in LN flares. Serial measurements of uNGAL levels may be of value in monitoring response of LN to treatment and for predicting LN flares.
Keywords: Lupus nephritis; Renal disease activity; Urine neutrophil gelatinase–associated lipocalin.
© 2013 Elsevier B.V. All rights reserved.