Aim: To investigate the possible association between genes polymorphisms of the interlukin 1- β (IL-1 β) and IL-1 receptor antagonist (IL-1 ra) and susceptibility to carotid atherosclerosis in rheumatoid arthritis.
Subjects and methods: The study included two groups. Group I: 120 premenopausal female patients who fulfilled the American College of Rheumatology classification criteria for rheumatoid arthritis (RA) and Group II: 120 premenopausal female's apparently healthy subjects were selected as control group. Cases and controls symptomatic for atherosclerosis or having traditional risk factors for atherosclerosis were excluded. Blood was obtained for DNA determination of IL-1 β gene and IL-1 Ra gene polymorphisms from both cases and controls.They were subjected to carotid ultrasound examination to measure carotid inimal medial thickness (CIMT) in addition to detailed history and physical examination and
Results: It was found that RA patients who had the IL 1-β allele 1 showed an increased risk to develop atherosclerosis with CIMT ≥ 0.9mm (OR = 13.2, P = 0.000) compared with RA patients with IL 1-β allele 2 (OR = 11.3, P = 0.000). While in control there was no risk to develop atherosclerosis with IL1- β alleles. Also, It was found that RA patients who had the IL1-ra allele 1 showed an increased risk to develop atherosclerosis with CIMT ≥ 0.9mm (OR = 39, P = 0.000) compared with RA patients with other alleles of IL1-ra (OR = 14.3, P = 0.000) .While in control there were no risk to develop atherosclerosis with IL1-ra alleles.
Conclusion: These data suggest that allele 1 of the IL-1 β gene and allele 1 of the IL-1ra gene represent a susceptibility factor in the development of carotid atherosclerosis in RA patients.