Increased interleukin-18 expression in nonrheumatic aortic valve stenosis

Background It is unknown whether interleukin-18 (IL-18) participates in the pathophysiology of nonrheumatic aortic stenosis (NR-AS). Methods We examined IL-18 expression in human NR-AS valves by immunohistochemistry and Western blot analysis. Results Immunohistochemistry revealed that NR-AS valves showed increased IL-18 expression compared with controls. IL-18 receptor was also expressed in NR-AS valves. Western blot analysis showed that IL-18 was expressed as an active form in NR-AS valves. Furthermore, increased IL-18 expression was correlated with the advanced clinical severity of NR-AS. Conclusions IL-18 was expressed in the aortic valves and up-regulated in NR-AS valves. IL-18 may contribute to the pathophysiology of NR-AS.