Ab0024 association of Il6 Rs1800795 but Not Il6r Rs2228145, Rs4845618 and Stat4 Rs7574865 Polymorphisms With Chlamydia-Associated Rheumatoid Arthritis

Abstract

Background:Rheumatoid arthritis (RA), associated with Chlamydial Infection, has some clinical and immunological particulars that interfere with the early diagnosis and require significant changes in treatment strategy [1].Objectives:To estimate the distribution of some non-HLA genetic markers such as STAT4 rs7574865, IL6 rs1800795, IL6R rs2228145 and rs4845618 in Chlamydia positive and negative RA patients and healthy controls.Methods:We examined 380 healthy blood donors and 187 RA patients classified according to the ACR/EULAR 2010 criteria for RA [2]. Twenty-three of the RA patients were positive for Chlamidia trachomatis (n=17) or Chlamidia pneumonia (n=6) persistence. DNA from peripheral blood samples was extracted by phenol-chloroform method. SNPs were genotyped by the real-time PCR with fluorescent probes. Statistical significance of SNPs’ frequency was estimated by two-way Fisher exact test (F, p2-t) with Bonferroni correction for multiple comparisons (pcor). Moreover, diagnostic odds ratio (dOR), the likelihood ratio of positive (LR+) and negative (LR–) tests and corresponding confidence intervals (CI) were calculated.Results:We revealed statistically significant increase of genotype СС frequency (IL6 rs1800795) in Chlamydia-associated RA (60.9%) vs healthy donors (20.7%): p2-t=0.000065; pcor=0.00026; dOR=5.95 (CI95%2.53-13.94); LR+=2.94 (CI95%1.90-3.29); LR–=0.49 (CI95%0.28-0.75) as well as in Chlamydia-associated RA (60.9%) vs Chlamydia-negative RA (23.9%): p2-t=0.00051; pcor=0.002; dOR=4.99 (CI95%2.04-12.16); LR+=2.56 (CI95%1.60-3.57); LR–=0.51 (CI95%0.29-0.78). Significant differences in STAT4 rs7574865, IL6R rs2228145 and IL6R rs4845618 distribution between studied groups were not found.Conclusion:Our data suggest the association between СС genotype of IL6 rs1800795 and Chlamydia-associated RA.References:[1]Soroka N.F. Rheumatoid Arthritis, associated with Chlamydial infection // Healthcare 2009; 1: 5-9.[2]Aletaha D. et al. 2010 Rheumatoid arthritis classification criteria// Arthritis Rheum 2010; 62 (9): 2569-81.Disclosure of Interests:Tatiana Zybalova: None declared, Viktor Yagur: None declared, Roza Goncharova: None declared, Nikolaj Soroka Grant/research support from: JSC BIOCAD, Natalia Dostanko: None declared, Valery Apanasovich: None declared, Anastasiya Tushina: None declared