Lymphangiogenesis is increased in heart valve endocarditis

•Inflammation-associated lymphangiogenesis was found in heart valve endocarditis•Lymphatic vasculature is increased in valves with endocarditis as compared with degenerative valves•Lymphatics in heart valves may provide a novel means for treatment strategies against endocarditis

BackgroundInflammation-associated lymphangiogenesis (IAL) has been identified as part of several acute and chronic inflammation. Sparse data exist on lymphatics during endocarditis.Materials and methodsFifty-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.ResultsThe lymphatic density in endocarditis was 833 (SD 529) vessels/mm2 (range 0-1707) as compared with 39 (SD 60) vessels/mm2 (range 0-250) in controls (p = 0.000). In endocarditis, the mean lymphatic size was 153 (SD 372) μm2 ranging from 1 to 2034 μm2, whereas it was 30 (SD 29) μm2, with maximum 90 μm2 and minimum 2 μm2 in controls (p = 0.000).ConclusionsIAL is increased in valves with endocarditis as compared with controls. Lymphatics in heart valves may provide a novel means for treatment strategies against endocarditis.

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