The Clinical Value Of Detecting Serum And Urine IL-6 On Patients With Severe Lupus Nephritis

Objective: To investigate the clinical value of detecting serum and urine IL-6 on patients with severe lupus nephritis (SLN).Methods: Serum and urine IL-6 levels were determined in 35 health controls and 43 cases of SLN patients by double antibody sandwich enzyme-linked immunosorbent assay (ELISA) before and after the double pulse therapy with MP and CTX. Anti-dsDNA antibody was detected by ELISA. Antinuclear antibody (ANA) was detected by indirect immune- fluorescence. Complement C3 and complement C4 were detected by rate nephelometry.Results: The levels of serum and urine IL-6 were significantly higher in SLN than those in normal control group (P<0.01) and they were positively correlated with the systemic lupus erythematosus disease activity index (SLEDAI) score, ANA, anti-dsDNA antibody ,erythrocyte sedimentation rate (ESR), 24-hour urinary proteninura, blood urea nitrogen (BUN) , serum creatinine (Scr) and cystatin C (Cyst C) (P<0.05 or P<0.01), and negatively correlated with complement C3, complement C4 and endogenous creatinine clearance rate (Ccr) (P<0.05 or P<0.01). There is no correlation between serum IL-6 level and urine IL-6 level (P>0.05). In patients with SLN treated with the double pulse therapy with MP and CTX, the levels of serum and urine IL-6 are obviously lower than those of pre-treatment (P<0.01).Conclusion: IL-6 takes part in the progress of SLN. The level of serum and urine IL-6, in some degree, indicates the level of renal damage and the extent of the disease with SLN. The dynamic observation of the level of serum and urine IL-6 contributes to judge SLN'S activity, treatment effectiveness and prognosis.