Association of tumor necrosis factor-α (TNF-α) −308A/G (rs1800629) gene polymorphism with carotid artery atherosclerosis in rheumatoid arthritis patients

BackgroundIncreased coronary artery atherosclerosis in rheumatoid arthritis (RA) may cause significant mortality. Tumor necrosis factor (TNF) is a potent proinflammatory cytokine that has been involved in RA pathogenesis and atherosclerosis.Aim of the workTo determine the association between TNF-α rs1800629 polymorphism and carotid atherosclerosis in RA patients.Patients and methodsThis study was carried out on 50 RA patients and 40 age and sex matched healthy control. All patients were subjected to full history taking, thorough clinical examination, and assessment of disease activity score (DAS28). Carotid artery intima–media thickness (IMT) was measured by Doppler ultrasonography. TNF-α −308A/G (rs1800629) polymorphism was assessed.ResultsThe mean age of patients was 41.2 ± 13.2 years with disease duration of 6.1 ± 4.5 years. The mean DAS28 was 4.1 ± 0.8 and Larsen score 2.1 ± 0.9. The mean IMT was significantly higher in patients (0.78 ± 0.47 mm) compared to the control (0.44 ± 0.16 mm) (p < 0.001). Carotid plaques and calcifications were present in 2 and 3 patients respectively. Regarding the TNF-α polymorphism, there was a significantly higher frequency of GG (60%) followed by GA (24%) and AA (16%) (p < 0.0001). All control had GG genotype except 1 patient had GA. The G allele was significantly increased (72%) compared to the A allele (28%) (p < 0.0001). The mean carotid IMT was significantly higher in AA genotype (1.2 ± 0.4 mm) compared to GA (1.02 ± 0.5 mm) and GG (0.5 ± 0.3 mm) (p < 0.001).ConclusionRheumatoid arthritis and atherosclerosis are strictly linked to each other; TNF-α −308A/G polymorphism might increase atherosclerotic susceptibility in RA patients through increased risk of inflammation with subsequent abnormal lipid profile.