Sabah Alharazy, Norella C.T. Kong, Marlyn Mohammad, Shamsul A. Shah, Halim Gafor and Arbaiyah Báin
الملخص الانجليزي
Introduction and Aims: Several small studies have indicated a role for urine
neutrophil gelatinase – associated lipocalin (uNGAL) and urine monocyte
chemoattractant protein-1 (uMCP-1) as markers of lupus nephritis (LN) disease
activity.We therefore compared the urinary levels of these two biomarkers in SLE
patients with biopsy-proven LN.
Methods: This was a prospective, cross-sectional observational study in which
consecutive SLE patients with biopsy-proven LN attending the Nephrology/SLE Clinic
were recruited. Two x10 ml samples of early morning urine were collected for
urinalysis, urine protein creatinine ratio and for both uNGAL (ng/mg of urinary
creatinine) and uMCP-1 ( pg/mg of urinary creatinine). The last two were measured
from frozen stored urine at end visit using an enzyme-linked immunosorbent assay
(ELISA). Their renal function test, serum albumin, urinary parameters, lupus serology
and renal SLEDAI-2K (global, renal, extra-renal) were also measured.
Results: Of the 100 patients recruited, 47 had active and 53 inactive LN. uNGAL levels
(ng/mg creatinine) and uMCP-1 levels ( pg/mg creatinine) were significantly higher in
patients with active LN compared to those with inactive renal disease (p = 0.01* and p
< 0.001** respectively). Both uNGAL and uMCP-1 levels were highly associated with
SLEDAI-2K (renal) (uNGAL: rsp= 0.32, p = 0.001**; uMCP-1: rsp= 0.39, p = 0.001**).
Both biomarker levels also correlated with SLEDAI-2K (global) (uNGAL: rsp= 0.19, p
= 0.05*; uMCP-1: rsp= 0.28, p = 0.006*
). However, there were no associations between
uNGAL and uMCP-1 with SLEDAI-2K (extra-renal). Using receiver operating
characteristic (ROC) curve, the area under the curve (AUC) for uNGAL was 0.83 (95%
CI = 0.74 – 0.92, p = 0.001**). With a cut-off value at 91.25 ng/ mg creatinine, uNGAL
had a sensitivity of 0.89 and specificity of 0.67 for prediction of LN activity. Whereas,
the AUC of uMCP-1 was 0.84 (95% CI = 0.75 – 0.92, p = 0.001**). With a cut-off value
at 4247 pg/ mg creatinine, uMCP-1 had a sensitivity of 0.89 and specificity of 0.61 for
early diagnosis of LN activity.
Conclusions: Both uNGAL and uMCP-1 were highly correlated with LN activity. Since
renal flares portend a worse prognosis for the renal outcome, serial measurements of
one or both these noninvasive urinary biomarkers may be of great clinical value in
predicting early flares of LN thus permitting earlier intervention.
تاريخ النشر
01/05/2013
الناشر
Nephrol Dial. Transplant, Published by Oxford University Press on behalf of ERA-EDTA
د. صباح محمد الحرازي | Sabah Mohamed Alharazy | 3029