Interleukin-32 increases in coronary arteries and plasma from patients with coronary artery disease

Background: Interleukin-32 (IL-32) is a cytokine associated with higher risk of cardiovascular diseases in inflammatory environments. This study aimed to investigate the IL-32 levels in coronary artery disease (CAD) patients. Methods: IL-32 expression in coronary arteries from both normal donors and CAD patients were analyzed. Plasma IL-32, IFN-gamma and IL-17 levels in stable angina pectoris (SAP, n = 80) patients, unstable angina pectoris (UAP, n = 96) patients, acute myocardial infarction (AMI, n = 72) patients and patients exhibiting chest pain unrelated to coronary artery disease (NCAD, n = 72) were measured. Additionally, whether plasma IL-32 levels were independent correlated with the presence of CAD was analyzed. Results: IL-32 was high expressed in atherosclerotic plaques of CAD patients when compared with normal coronary arteries, and macrophages were the major sources of IL-32. Compared with the NCAD group, IL-32, IFN-gamma and IL-17 levels were increased in the CAD group and gradually increased through the SAP, UAP and AMI groups. Plasma IL-32 levels were positively correlated with the Gensini score, IFN-gamma levels and IL-17 levels in CAD patients. The results of linear regression showed that IL-32 was independently associated with the occurrence of CAD. Conclusion: Both the coronary artery and circulating IL-32 levels were increased in CAD patients and IL-32 may be a marker of noninvasive diagnosis of CAD.