Increased plasma concentrations of interleukin 35 in patients with coronary artery disease

Introduction: Atherosclerosis leading to coronary artery disease (CAD) is a chronic inflammatory condition. Interleukin 35 (IL-35) released by regulatory T cells (Tregs) has been found to be associated with CAD in the Chinese population. However, nothing is known about the relation between IL-35 concentrations and cholesterol levels. The aim of the study was to assess the levels of IL-35 in CAD patients and healthy subjects from a Caucasian population, and to analyze the relationship between IL-35 and the levels of total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, left ventricular ejection fraction (LVEF), sex and postmenopausal status.

Material and methods: Thirty-one patients with CAD and 30 healthy controls were included in the study. Levels of plasma IL-35 were analyzed by ELISA. The LVEF was assessed by transthoracic echocardiographic examination. Plasma levels of cholesterol fractions and C-reactive protein (CRP) were assessed by immunoenzymatic methods.

Results: The CAD patients had higher levels of IL-35 as compared to healthy controls (58.1 ±16.6 pg/ml vs. 5.35 ±3.35 pg/ml; p < 0.001). IL-35 levels negatively correlated with total and LDL cholesterol concentrations (R = -0.31, p < 0.01) and positively correlated with HDL cholesterol in men (R = 0.53, p < 0.01). In women, IL-35 levels negatively correlated with LVEF (R = -0.29, p < 0.05) and positively with the duration of postmenopausal status (R = 0.55, p < 0.01).

Conclusions: These results suggest a possible association between high levels of IL-35 and CAD.