Studies of human coronary plaque specimens have shown that T lymphocytes and macrophages are present in all types of lesions, from fatty streaks to advanced plaques. There is growing evidence for a pathogenic role for immune response in progression of atherosclerosis. This study was designed to investigate cytokine production by mononuclear leukocytes from patients with myocardial infarction.

We measured the kinetics of secretion of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) by mononuclear leukocytes from 8 control subjects and 12 patients with acute myocardial infarction. Mononuclear leukocytes were isolated and incubated with plant lectin mitogen concanavalin-A for 24 and 48 hours. TNF-α and IFN-γ secretions were measured by ELISA.

There were no significant differences between TNF-α and IFN-γ secretions by mononuclear leukocytes at and before 24 hours of incubation from both patients and control subjects, but TNF-α and IFN-γ secretions at 48 hours of incubation were higher (p<0.005, p<0.05) in patients when compared with control subjects. TNF-α and IFN-γ secretions by mononuclear leukocytes after incubation correlated with the peak level of creatine phosphokinase (CK) and CK-MB.

Increased cytokine secretory capacity of mononuclear leukocytes may be due to the acute inflammatory response of myocardial infarction. Further trials may be needed to determined the effects of increase in secretory capacity of mononuclear leukocytes before myocardial infarction.