Serum interleukin-18 and its relationship with subclinical atherosclerosis in systemic lupus erythematosus

BACKGROUND: Interleukin-18 (IL-18) is a pro-inflammatory and pro-atherogenic factor, and its blood level has shown a direct correlation with atherosclerosis. We aimed to evaluate the serum IL-18 level in patients with systemic lupus erythematosus (SLE) and its relationship with the intima-media thickness (IMT) of the carotid artery in these patients, as an indicator of atherosclerosis. METHODS: In this cross-sectional study, 60 patients as the patient group and 30 healthy volunteers as the control group matched sex, age, and body mass index (BMI) were selected, and their disease status and general data were gathered using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) form. A blood sample was also obtained from all participants to determine the serum level of IL-18 and other metrics, including high-sensitivity C-reactive protein (hs-CRP), cholesterol, triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), anti-double stranded deoxyribonucleic acid (anti-dsDNA), complement 3 (C3), and C4. The IMT of the carotid artery was calculated in both groups. We also evaluated the clinical cardiovascular manifestations. RESULTS: The serum IL-18 levels in patients were significantly higher than in the control group (P � 0.005). It had no significant correlation with disease activity (P = 0.10). The patients with SLE with high IL-18 serum levels (> 280 pg/ml) had higher SLEDAI-2K (P = 0.02) than the patients with a low level (< 280), where 280 was the median of the IL-18 levels. The serum IL18 level had no significant correlation with the carotid artery IMT. CONCLUSION: A high level of IL-18 reflects the disease activity, but it was not significantly correlated with subclinical atherosclerosis, denoted by the carotid artery IMT. © 2022, Isfahan University of Medical Sciences(IUMS). All rights reserved