Cytokine inhibitors in patients with heart failure and impaired functional capacity

Cytokines are proteins with pleiotropic biological effects, but the pathophysiologic role of cytokine inhibitors in advanced cardiac disease remains unclear. We assessed the levels of tumor necrosis factor (TNF)-alpha and its soluble receptors I (sTNF-RI) and II (sTNF-RII), soluble interleukin-1 receptor antagonist (sIL-1 Ra), and interleukin-6 soluble receptor (IL-6 sR) in sera from 11 patients with severe chronic congestive heart failure (mean left ventricular ejection fraction 19 +/- 6%; mean symptom-limited oxygen consumption 13 +/- 4 ml/min per kg) and 11 healthy volunteers. The serum concentrations of TNF, sTNF-RI, and sIL-1 Ra, but not of sTNF-RII and IL-6 sR, were significantly increased in heart failure patients. Importantly, their symptom-limited oxygen consumption was strongly associated with both sTNF-RI (R = -0.68, p = 0.04) and sIL-1 Ra (R = -0.77, p = 0.01). These results suggest that cytokine inhibitors from different receptor families may be involved in functional disability, a characteristic feature in patients with severe congestive heart failure. Understanding the response of cytokine inhibitors to heart failure might have therapeutic value as interventions against cytokines become available.