Objectives: The purpose of this study was to examine the role of tumor necrosis factor-alpha and tetrahydrobiopterin and superoxide anion release from neutrophils in severe chronic heart failure.
Background: Previous studies have demonstrated elevated production of tumor necrosis factor-alpha and free radical-induced endothelial cell damage in severe heart failure.
Methods: Plasma and serum levels of immunoreactive interleukin-1, interleukin-6, interferon-gamma, neopterin and tumor necrosis factor-alpha and the release of superoxide anions from circulating neutrophils both at basal conditions and after triggering with f-Met-Leu-Phe or phorbol 12-myristate 13-acetate were measured in 16 patients with severe heart failure and in 11 healthy control subjects.
Results: Circulating levels of tumor necrosis factor-alpha and neopterin were elevated in patients with heart failure compared with values in control subjects. A significant correlation between the two was found. Basal and phorbolester-triggered release of oxygen radicals from neutrophils was not affected in patients with heart failure. However, formylpeptide-stimulated release of oxygen radicals by neutrophils was significantly reduced.
Conclusions: Suppressed neutrophil function in patients with heart failure exhibiting elevated levels of tumor necrosis-alpha factor may indicate self-protection against the deleterious effects of neutrophil-derived oxygen radicals. Through induction of tetrahydrobiopterin synthesis (as reflected by increased neopterin), tumor necrosis factor-alpha may affect nitric oxide synthesis.