Enhanced secretion of tumour necrosis factor in patients with myocardial infarction

Recent evidence suggests that leukocyte infiltration of myocardial tissue may extend the area of necrosis during the acute phase of myocardial infarction. Since the activation of leukocytes depends on the action of cytokines, mainly tumour necrosis factor (TNF), we evaluated TNF secretion during myocardial infarction.

The study included 12 patients with acute myocardial infarction as diagnosed on the basis of enzymatic and ECG criteria. Patients were admitted within 3 hours from onset of chest pain. Serum levels of TNF were measured by immunoradiometric assay on venous blood samples collected at time 0, and at 6, 12 and 18 hours and 1, 2, 4 and 7 days following myocardial infarction. Plasma levels of atrial natriuretic peptide-alpha (ANP) were also measured on the same samples.

Mean TNF levels significantly increased during the myocardial infarction, with a peak within the first 24 hours (p < 0.01). They remained significantly elevated until day 4 (p < 0.05). The rise in TNF was positively correlated with creatinine kinase levels. ANP was also significantly increased with a delayed peak after that of TNF (p < 0.01).

Even though limited to a small number of cases, this study shows that acute myocardial infarction is associated with increased TNF secretion. Because of its capacity of stimulating leukocyte infiltration in myocardial tissue, the increased levels of TNF might potentially have a negative prognostic significance.