Inhibition of IL-1 Ameliorates Cardiac Dysfunction and Arrhythmias in a Murine Model of Kawasaki Disease.

BACKGROUND

Kawasaki disease (KD) is an acute febrile illness and systemic vasculitis often associated with cardiac sequelae, including arrhythmias. Abundant evidence indicates a central role for IL (interleukin)-1 and TNFα (tumor necrosis factor-alpha) signaling in the formation of arterial lesions in KD. We aimed to investigate the mechanisms underlying the development of electrophysiological abnormalities in a murine model of KD vasculitis.

METHODS

Lactobacillus casei cell wall extract-induced KD vasculitis model was used to investigate the therapeutic efficacy of clinically relevant IL-1Ra (IL-1 receptor antagonist) and TNFα neutralization. Echocardiography, in vivo electrophysiology, whole-heart optical mapping, and imaging were performed.

RESULTS

KD vasculitis was associated with impaired ejection fraction, increased ventricular tachycardia, prolonged repolarization, and slowed conduction velocity. Since our transcriptomic analysis of human patients showed elevated levels of both IL-1β and TNFα, we asked whether either cytokine was linked to the development of myocardial dysfunction. Remarkably, only inhibition of IL-1 signaling by IL-1Ra but not TNFα neutralization was able to prevent changes in ejection fraction and arrhythmias, whereas both IL-1Ra and TNFα neutralization significantly improved vasculitis and heart vessel inflammation. The treatment of L casei cell wall extract-injected mice with IL-1Ra also restored conduction velocity and improved the organization of Cx43 (connexin 43) at the intercalated disk. In contrast, in mice with gain of function of the IL-1 signaling pathway, L casei cell wall extract induced spontaneous ventricular tachycardia and premature deaths.

CONCLUSIONS

Our results characterize the electrophysiological abnormalities associated with L casei cell wall extract-induced KD and show that IL-1Ra is more effective in preventing KD-induced myocardial dysfunction and arrhythmias than anti-TNFα therapy. These findings support the advancement of clinical trials using IL-1Ra in patients with KD.