Neutrophil gelatinase-associated lipocalin as a biomarker of disease activity in pediatric lupus nephritis.
We hypothesized that neutrophil gelatinase-associated lipocalin (NGAL) is an early predictive biomarker of disease activity in lupus nephritis. NGAL in serial plasma (PNGAL) and urine (UNGAL) samples was measured by enzyme-linked immunosorbent assay (ELISA) in 85 participants with pediatric systemic lupus erythematosus (pSLE), healthy children (n = 50), and children with juvenile idiopathic arthritis (JIA) (n = 30). Disease activity was measured by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Plasma and urinary NGAL were significantly increased in subjects with pSLE compared with those with JIA or with healthy controls (all p < 0.03), and unrelated to subjects' age, weight, or height. Plasma and urinary NGAL were stable in pSLE subjects with unchanged disease activity. The pSLE subjects with worsening global or renal disease activity had a mean +/- standard error (SE) increase of UNGAL (in ng/ml) of 11.5 +/- 6.4 or 36.6 +/- 12.1 (p < 0.01), corresponding to a 156% or 380% increase, respectively. PNGAL increased with worsening disease but to a much lesser degree than UNGAL [global disease activity (mean +/- SE): 7.3 +/- 6.2 or 21%; renal disease activity: 20.2 +/- 6.0 or 51%; both p = not significant]. In conclusion, NGAL in urine but not in plasma represents a novel biomarker for renal disease activity in pSLE.
Suzuki
Michiko
M
Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
Wiers
Kristina M
KM
Klein-Gitelman
Marisa S
MS
Haines
Kathleen A
KA
Olson
Judyann
J
Onel
Karen B
KB
O'Neil
Kathleen
K
Passo
Murray H
MH
Singer
Nora G
NG
Tucker
Lori
L
Ying
Jun
J
Devarajan
Prasad
P
Brunner
Hermine I
HI
D000209:Acute-Phase Proteins / Q000652:urine*; D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D002648:Child; D005260:Female; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood* / Q000652:urine*; D008181:Lupus Nephritis / Q000097:blood* / Q000652:urine*; D008297:Male; D011518:Proto-Oncogene Proteins / Q000097:blood* / Q000652:urine*
D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins