Serum Concentrations of Interleukin-33 and its Soluble Receptor sST2 in Patients with Persistent Atrial Fibrillation

Objectives: Interleukin-33 (IL-33) is a new member of the IL-1 cytokine family, which is thought to be involved in the pathogenesis of various inflammatory diseases, through its soluble receptor ST2. There is increasing evidence that inflammation is a relevant player in structural atrial remodeling that represents the main mechanism for atrial fibrillation (AF) persistence. This study was designed to investigate the state of IL-33/ST2 axis serum concentrations in patients with persistent AF. Design and Methods: We investigated the concentrations of IL-33, its soluble ST2 receptors, and high-sensitivity C-reactive protein levels (hsCRP) in the sera of 92 patients with persistent atrial fibrillation, and 68 controls. Results: Serum concentrations of IL-33, sST2, and hsCRP were all significantly elevated in patients with persistent AF compared to controls (P <0.0001 for all). Moreover, serum IL-33 concentrations was positively correlated with the inflammatory marker hsCRP (r=0.606, P =0.002). Conclusion: These preliminary results may support the role of inflammation in AF pathogenesis and IL-33/sST2 axis may be involved in the inflammatory process in AF.