The Levels And Significance Of Serum And Urinary TWEAK In Patients With Lupus Nephritis

Objective:To study the levels and clinical significance of serum and urinary TWEAK in patients with lupus nephritis(LN).Methods:There were 29 selected patients with LN in total, including 1 male, 28 females, aged from 18 to 60 years, the average age was ( 37.52±12.55 ) years. The patients were divided into different groups according to the renal SLE disease activity index ( rSLEDAI ) score, and anti-dsDNA antibody: 19 patients with active LN ( rSLEDAI≥4 ) and 10 patients with non-active LN ( rSLEDAI≥4 ); 19 patients with positive anti-dsDNA antibody and 10 patients with negative anti-dsDNA antibody. Twenty sex- and age-matched healthy Chinese volunteers were recruited as normal controls, moreover, 14 patients with non-LN SLE were recruited as disease controls. Concentrations of TWEAK in serum and urinary were measured by Enzyme linked immunosorbent essay ( ELISA ). And the clinical and laboratory data of the patients were collected.Results:1. Serum TWEAK levels had no significant difference among the LN group, the non-LN SLE group and the control group ( P > 0.05 ).2. Levels of serum TWEAK in patients with LN didn't correlate with the total SLEDAI score, the rSLEDAI score, and only the non-renal components of the index score( P > 0.05 ).3. Urinary TWEAK levels of patients with LN were significantly higher than the non-LN SLE and normal controls ( P < 0.001 ), but urinary TWEAK levels had no significant difference between the non-LN SLE group and the control group ( P > 0.05 ).4. Urinary TWEAK levels were higher in patients with active LN as compared to non-active LN ( P < 0.01 ); levels of urinary TWEAK correlated with the rSLEDAI score ( r = 0.61, P < 0.001 ), urinary TWEAK levels also displayed significant correlation with the total SLEDAI score ( r = 0.49, P = 0.007 ), however, this correlation was no longer significant when only the non-renal components of the index were correlated with urinary TWEAK ( P > 0.05 ).5. In LN patients, urinary TWEAK levels negatively correlated with serum complement 3 ( r = -0.85, P < 0.001 ), serum complement 4 ( r = -0.78, P < 0.001 ), respectively.6. No significant differences were observed for serum TWEAK levels between LN patients with positive anti-dsDNA antibody and LN patients with negative anti-dsDNA antibody ( P > 0.05 ). And there were also no statistic differences for levels of urinary TWEAK between LN patients with positive anti-dsDNA antibody and LN patients with negative anti-dsDNA antibody( P > 0.05 ).Conclusions:The levels of urinary TWEAK are significantly elevated in patients with LN, and the levels of urinary TWEAK positively correlate with SLEDAI scores, rSLEDAI score, respectively, and negatively correlate with complement 3, complement 4, respectively, suggesting that: TWEAK may be involved in the pathogenesis of LN, and may reflect nephritis activity of LN patients. However, serum TWEAK levels don't correlate with LN and the disease activity of LN cases.