[Cytokines--causes, players or bystanders in heart failure].

Background: Cytokines are important mediators of the immune system and are of pathophysiological relevance for different cardiac diseases. Currently, 18 cytokines carrying the name interleukin (IL) are known; they can be subdivided into pro- and anti-inflammatory interleukins.

Cardiac Cytokines: They partly act in a negative inotropic manner and cause destruction of cardiomyocytes resulting in myocardial fibrosis. The proinflammatory cytokine tumor necrosis factor (TNF-)alpha induces cardiodepressive effects and causes apoptosis. TNF-alpha, IL-6, soluble TNF-receptor-1 and -2 are independent predictors of increased mortality of patients with heart failure. Experimental and clinical evidence has shown that plasma and tissue levels of TNF-alpha were elevated to such extent as to explain at least some of the symptoms of heart failure due to the actions of this cytokine.

Clinical Trials: Two multicenter studies (RENAISSANCE, RECOVER), based on promising pilot studies, have disclosed no effect for the TNF-alpha antagonists (Etanercept) on mortality and morbidity. It is not possible, however, to draw the conclusion from the data of these studies that TNF-alpha plays no significant pathophysiological role in the etiology and progression of heart failure.