The relation between interleukin-6 and different categories of acute coronary syndrome

Background Inflammation is now recognized to play a key role in the pathogenesis of atherosclerotic cardiovascular disease. Two circulating markers of inflammation, C-reactive protein (CRP) and interleukin (IL)-6, have emerged as predictors of future cardiovascular pathology and mortality in epidemiologic studies of (middle aged women) midlife healthy men and women, postmenopausal women, and older adults. The aim of the present study was to study the changes in IL-6 in acute coronary syndrome (ACS) and to clarify whether IL-6 release is a factor initiating the inflammatory process in ACS or whether it is predominantly a response to this clinical condition, and to assess its correlation with CRP, cardiac biomarkers troponin I, and CK-MB for risk prediction in ACS. Patients and methods The study included 60 patients admitted by ACS who were categorized randomly into three groups: group I included 20 patients admitted for unstable angina, group II included 20 patients admitted for ST-segment elevation myocardial infarction with successful thrombolytic therapy, and group III included 20 patients admitted for ST-segment elevation myocardial infarction with failed thrombolytic therapy. The study also included 12 healthy control patients matched for age and sex (group IV). Blood levels of IL-6, CRP, and cardiac troponin I were measured; all samples of groups II and III were obtained after thrombolytic therapy whereas samples of group I were obtained on admission. Results IL-6 was significantly higher in group II, with a mean of 87.10, and ranged from 3.0 to 550.0; on exclusion of two patients who had an IL-6 level of 220 and 550 we obtained a mean of 54. In group III, the mean level was 52.36, ranging from 5.0 to 120.0, compared with control group IV, in which it ranged from 3.0 to 5.0, mean 3.67 (P Conclusion Atherosclerosis is currently considered a systemic inflammatory disease and IL-6 is an inflammatory cytokine. The IL-6 serum level was significantly increased in patients with ACS and in patients with successful thrombolytic therapy. There was a statistically significant positive correlation between IL-6 and CRP in ACS patients with failed thrombolytic therapy; IL-6 serum levels did not correlate with cardiac troponin levels in any of the ACS patient groups.