Lymphangiogenesis is increased in heart valve endocarditis

Background: Inflammation-associated lymphangiogenesis (IAL) has been identified as part of several acute and chronic inflammation. Sparse data exist on lymphatics during endocarditis. Materials and methods: Fifty-two patients with surgically resected valves were included. Endocarditis was present in 18 aortic and 10 mitral valves. Controls consisted of 15 degenerative aortic and 9 degenerative mitral valves. There were 22 males with endocarditis and 17 males in controls. The mean age was 58 (SD 15) years with endocarditis vs. 62 (SD 13) years for controls. Lymphatics were detected by podoplanin antibody immunohistochemistry and morphometrical analysis was performed. Results: The lymphatic density in endocarditiswas 833 (SD 529) vessels/mm(2) (range 0-1707) as compared with 39 (SD 60) vessels/mm(2) (range 0-250) in controls (p = 0.000). In endocarditis, the mean lymphatic size was 153 (SD 372) mu m(2) ranging from1 to 2034 mu m(2), whereas itwas 30 (SD 29) mu m(2), with maximum 90 mu m(2) and minimum 2 mu m(2) in controls (p = 0.000). Conclusions: IAL is increased in valves with endocarditis as compared with controls. Lymphatics in heart valves may provide a novel means for treatment strategies against endocarditis. (C) 2016 Elsevier Ireland Ltd. All rights reserved.