Changes Of Th17 Cells In The Systemic Lupus Erythematosus With Cardiac Involvement

BackgroundSystemic lupus erythematosus (SLE) is one of connective tissue diseases, and its features are generating many antoantibodies and formation of immune complexes which attack multi-system organs. In fact, cardiac involvement is the one of most important signs in SLE patients. Cardiac involvement in SLE include various parts of the heart, such as the pericardium and the myocardium, and transmits endocardial, coronary, then the detail mechanism of cardiac involvement is unclear. Currently, the heart damage is being considered the third reason cause SLE patient death. IL-17A is the most important cytokine from Th17 cells. The gene of nuclear receptors ror gammat is the key factor in differentiation of Th17 cells. Many evidences conform that Th17 cells and IL-17A mediate many kinds of autoimmune myocarditis and acute coronary syndrome, then involve in the pathogenesis of SLE. However, whether them mediated inflammatory response in heart damage with SLE, has not been reported. This article aims to explore the changes of Th17 cells and cardiac markers in the systemic lupus erythematosus with cardiac involvement.ObjectiveTo investigate the role of Th17 cells in the pathogenesis of SLE patients with cardiac involvement, and to understand the significancy of cardiac markers [brain natriuretic peptide (BNP), cardiac troponin I (cTnI), myocardial enzymes (aspartate aminotransferase, creatine kinase, creatine kinase-MB, lactate dehydrogenase,α-hydroxybutyric dehydrogenase)] in SLE patients with cardiac involvement.MethodsSerum IL-17A levels were measured by enzyme-linked immunosorbent assay in 47 SLE patients with cardiac involvement (Group I), 55 SLE patients without cardiac involvement (Group II) and 38 healthy controls (GroupⅢ). The ADVIA Centaur? XP Immunoassay analysis system was used to measure serum BNP and cTnI level, and OLYMPUS AU2700 automatic biochemical system was used to measure myocardial enzymes.Then Real time-quantitative polymerase chain reaction was used to measure of RORγt mRNA in 13 SLE patients with cardiac involvement, 14 SLE patients without cardiac involvement and 13 healthy controls. The age of SLE patients and course of diease, disease activity, clinical features were evaluated.Results1.Serum levels of IL-17A were markedly increased in Group I than Group II and GrouⅢ[27.98 (8.44~138.81) pg/ml VS 11.12 (3.64~22.30) pg/ml VS 5.77(2.22~9.60) pg/ml; both P﹤0.01].2.We found that Serum levels of BNP were significantly higher in Group I than Group II and GroupⅢ[49 (13.50~107.50) ng/ml VS 17 (9~26) ng/ml VS 7.50 (4.75~13) ng/ml; both P﹤0.001]; There was not significantly different among these groups with cTnI and myocardium enzymes spectrum (all P>0.05).3.Serum levels of IL-17A in SLE patients was positively correlated with C-reactive protein and creatinine (n=102, r=0.332, P﹤0.01; n=102, r=0.258, P﹤0.05). There was positive correlation between the serum levels of IL-17A and C-reactive protein in Group II SLE patients (n=55, r=0.443, P﹤0.05); then we found the serum levels of IL-17A was negative correlation with course of disease in Group I SLE patients (n=47, r=-0.294, P﹤0.05).4.We found that BNP was positively correlated with erythrocyte sedimentation rate (n=102, r=0.35, P﹤0.01); there was positive correlation between BNP and triglyeride in Group II SLE patients (n=55, r=0.649, P﹤0.01).5.We found that the age, course, SLEDAI were significantly higher in Group I SLE patients than Group II (P﹤0.01; P﹤0.01; P﹤0.05).6.The level of RORγt mRNA were significantly elevated in Group I as compared to Group II and GroupⅢ[2.2 (0.79~2.83) VS 0.72 (0.39~1.14) VS 0.19 (0.15~0.75); P﹤0.05; P﹤0.01].7.The level of RORγt mRNA was positively correlated with IL-17A (n=27, r=0.471, P﹤0.001); it was negative correlation with C3 levels (n=47, r=-0.457, P﹤0.05).Conclusion1.Th17 cells may contribute to the inflammation of heart in SLE. 2.The older age, longer course and higher activity of the SLE patients should be on guard against the cardiac involvement in SLE.3.Serum BNP may be as a useful indicator in SLE patients with heart involvement.