Serum IL-17 And IL-35 Levels In Patients With Systemic Lupus Erythematosus And Their Correlations With Renal Damage

Objectives:To detect the serum IL-17 and IL-35 levels from patients with systemic lupus erythematosus(SLE)and healthy controls,and preliminarily investigate the role and correlations with each other of IL-17 and IL-35 in SLE and their correlations with renal damage?Methods:55 hospitalized SLE patients diagnosed from August 2017 to May 2018 in the Department of Rheumatology and Immunology of Tianjin Medical University General Hospital and 25 sex-and age-matched healthy volunteers were recruited.According to SLEDAI scores,55 patients with SLE were classified into the 27 cases of active SLE group(>10 scores)and the 28 cases of inactive SLE group(<10 scores).According to the diagnostic criteria for lupus nephritis(LN),55 patients with SLE were divided into LN group(n=30)and non-LN group(n=25).Serum IL-17 and IL-35 levels in 55 subjects were detected by ELISA.Serum levels of the two cytokines in SLE patients and controls,active and inactive SLE group,and LN and non-LN patients were compared,respectively.The correlations between serum IL-17,IL-35 levels and disease activity in SLE patients,serum IL-17 and IL-35 levels in SLE patients and healthy controls,and serum IL-17,IL-35 levels and renal damage in LN patients were analyzed.Results:(1)Compared with healthy controls,SLE patients had higher serum IL-17 levels(144.05± 18.00 pg/mL vs.122.25±14.61 pg/mL,P<0.01),and IL-35 levels were observably lower(54.15±6.66 pg/mL vs.61.73±5.05 pg/mL,P<0.01)(2)Compared with inactive SLE patients,semm IL-17 levels were higher in active SLE patients(153.81 ± 13.61 pg/mL vs.134.63±16.80 pg/mL,P<0.01),and serum IL-35 levels were decreased(50.92±5.21 pg/mL vs.57.27±6.49 pg/mL,P<0.01)(3)Serum IL-17 levels were positively correlated with SLEDAI scores(r=0.59,P<0.05),and a negative correlation was observed between serum IL-35 levels and SLEDAI scores(r=-0.50,P<0.05)in SLE patients.(4)Serum anti-dsDNA antibody and IgG levels in SLE patients are positively correlated with IL-17 levels(r=0.51,p<0.01;r=0.67,p<0.01),and negatively correlated with IL-35 levels(r=-0.41,P<0.01;r=-0.44,P<0.01),There were no significant correlations between serum IL-17?IL-35 levels and C3?C4 levels.(5)Serum IL-17 levels were negatively correlated with IL-35 in SLE patients and healthy controls(r=-0.78,P<0.05;r=-0.47,P<0.05)(6)Serum IL-17 levels were higher and serun IL-35 levels were lower in patients with LN than that in patients without LN(148.89±17.87 pg/mL vs.138.24±16.69 pg/mL,52.33±7.10 pg/mL vs.56.34±5.46 pg/mL)(7)In LN patients,serum IL-17 levels were correlated with 24-h proteinuria(r=0.76,P<0.01)and eGFR(r=-0.44,P<0.05),not with Scr.And serum IL-35 levels were correlated with 24-h proteinuria(r=-0.69,P<0.01),not with eGFR and Scr.Conclusions:(1)Serum IL-17 levels were higher and serum IL-35 levels were lower in SLE patients than controls,and serum IL-17 levels were negatively correlated with IL-35 in SLE patients and controls,as a pair of pro-inflammatory and anti-inflammatory factors,IL-17 and IL-35 are both involved in the pathogenesis of SLE.(2)Serum IL-17 levels were higher and serum IL-35 levels were lower in the active SLE group than the inactive group.SLEDAI scores were positively correlated with serum IL-17 levels and negatively correlated with IL-35,suggesting that IL-17 and IL-35 are correlated with activity,which can be used as indicators of SLE activity.(3)Serum IL-17 levels were increased and positively correlated with 24-h proteinuria,While serum IL-35 levels were reversed in LN patients,IL-17 and IL-35 may be involved in renal damage in SLE.