Levels of interleukin-33 and interleukin-6 in patients with acute coronary syndrome or stable angina.

PURPOSE The purpose of this study was to investigate the levels of interleukin-33 (IL-33) and interleukin-6 (IL-6) in patients with acute coronary syndrome or stable angina. METHODS Serum IL-33 and IL-6 were measured with Enzyme Linked Immuosorbent Assay (ELISA) in patients with acute coronary syndrome (ACS, n=40), and stable angina pectoris (SAP, n=43). IL-33 and IL-6 were also determined in 30 healthy subjects (control group). RESULTS The serum level of IL-33 in the ACS group (78.60±44.84 ng/L) was lower than in the SAP (102.58±37.21 ng/L, P<0.01) or control groups (130.24±10.17 ng/L, P<0.01). The serum level of IL-6 in the ACS group (39.90±12.64 ng/L) was higher than in the SAP (18.68±11.89 ng/L, P<0.05) or control groups (6.28±17.72 ng/L, P<0.05). There were no differences in serum levels of IL-33 and IL-6 among the single-, double- and triple-vessel lesion groups. IL-33 and IL-6 levels were negatively correlated with each other in the ACS (r=-0.871, P<0.01) and SAP groups (r=-0.788, P<0.01). CONCLUSION The serum level of IL-33 was lower in patients with ACS or SAP and was negatively correlated with the serum level of IL-6. Thus, IL-33 and IL-6 may be used as biomarkers for evaluating inflammatory response and severity of coronary heart disease in patients with ACS or SAP.