Serum And Urine Neutrophil Gelatinase-associated Lipocalin As A Biomarker Of Lupus Nephritis:Relation To Disease Activity

Objective: To investigate the expression level of serum and urinary neutrophil gelatinase-associated lipoclin(NGAL)in lupus nephritis(LN)and its relationship with renal activity.Methods:This study included 71 cases of SLE patients as well as 46 healthy subjects.It was divided into 4 groups: group A was comprised of 24 patients with active LN;group B included 11 patients with non active LN;group C was consisted of 36 SLE patients without LN and group D included47 matched controls.Serum and urinary NGAL were measured by latex enhanced immunoturbidimetry,and other correlative biochemical and immune indexes were collected.SLEDAI score and renal SLEDAI(R-SLEDAI)score were calculated to identify disease activity.The SPSS21 software is used for statistical analysis。Results: Patients with active LN had an elevated serum NGAL level as compared to those of inactive LN group,SLE non LN group and controls.However,no significant difference was shown in serum NGAL level among the three groups of inactive LN 、 SLE non lupus nephritis and controls.Patients with SLE non lupus nephritis,active and non-active LN all had higher urinary NGAL levels than the controls.But there was no significant difference among the three groups.Serum NGAL of patients with active LN had a positive correlation with renal SLEDAI(R-SLEDAI),but no correlation with SLEDAI score.Urinary NGAL of patients with active LN had no correlation with either R-SLEDAI or SLEDAI.The sensitivity of serum NGAL for evaluating LN activity was 66.7%,and the specificity was 83.9%.Conclusion: Serum but not urinary NGAL can be used as a biomaker to evaluate the activity of lupus nephritis.