P0080INTERLEUKIN-17A GENE POLYMORPHISM (RS2275913G>A) IN SLE PATIENTS

Abstract

Abstract Background and Aims There are six IL-17-family ligands [IL-17A, IL-17B, IL-17C, IL-17D, IL-17E (IL-25) and IL-17F]. Interleukin-17A (IL-17A) also commonly called IL-17, is produced by the T helper17 (Th17) subset of CD4+ T cells.Interleukin-17 and other Th17 cytokines are linked to the pathogenesis of diverse autoimmune and inflammatory diseases. IL-17A is detected in synovial fluids and synovium from RA patients and induces proinflammatory cytokine production from synoviocytes, also expression of IL-17A was higher in SLE patients and its level positively correlated with the severity of lupus nephritis, because of its contribution to increasing anti-double-stranded DNA (dsDNA) antibody production in SLE. The aim of the present study is to determine the IL-17A gene polymorphism (rs2275913 G>A) frequency in patients with SLE and lupus nephritis, and to determine the association of this polymorphism with the disease activity. Method This cross-sectional, observational, case control study was carried out on 50 females patients, with their age ranged from 15 to 50 years (mean 25.67±9.29 years) with SLE attending Mansoura University Hospital .A control group of 50 healthy females of matched age were also included. The patient group was subdivided into patients with and those without lupus Nephritis (35 and 15 patients, respectively). Lupus nephritis was confirmed by renal biopsy. All patients were subjected to a thorough clinical evaluation and routine laboratory tests. SLEDAI score was calculated for all patients to determine the degree of lupus activity. DNA extraction was performed for all patients as well as controls, One SNPs of IL-17A (rs2275913G>A) was genotyped utilizing PCR- RFLP technique. Results The frequency of rs2275913 A allele was significantly higher in SLE patients than the control group (34.0% vs. 21.0%, respectively; p=0.04, OR =1.9, 95%CI =1.03-3.65). While G allele was significantly higher in control group, (P=0.04)). Moreover, AA genotype was significantly higher in the SLE patients than in the control group (8.0% vs. 0.0%, respectively; p=0.036) and associated with higher SLEDAI, ANA, and anti-dsDNA antibodies titer, (P=0.03, P=.039, P=0.047 respectively).on the other hand there was no significant difference in GG and GA genotypes in the SLE patients versus the control group. The frequency of both genotype GA and AA was higher in the SLE patients than the controls (60% vs. 42%, respectivley; OR=2.07, CI-95%=0.9-5.59); although the difference was not statistically significant (P= 0.07).Although A allele was numerically higher in lupus nephritis group versus non nephritis group(37.0% vs 27.0%, respectively), the Analysis of the frequency of IL-17A rs2275913 alleles and genotypes showed no statistical differences between the two groups. Moreover there was no statistical significance between different genotypes in cases of nephritis regard lupus nephritis class (P=0.9) and no statistical significance between different genotypes (GG-GA-AA) regarding activity indices (AI) or chronicity indices (CI) in lupus nephritis group (P=0.18, P=0.56 respectively). Conclusion We suggest that there was a significant association between IL-17A rs2275913 G>A polymorphism and SLE, as A allele and AA genotype were increased in SLE patients, lupus nephritis especially those with high activity