[Cellular Composition of Calcified Bioprosthetic Heart Valves].

With the aim to assess the mechanisms of the structural dysfunctions associated with xenograft tissue calcification, we investigated the cellular composition of the explanted xenoaortic epoxy-treated bioprosthetic heart valves. In the leaflets, we revealed multiple cells with retained internal structure. Most of them located on the leaflet surface, at the areas of collagen destruction, and near calcium deposits. Monocytes were the predominant cell fraction on the leaflet surface whilst immune (macrophages, multinucleated giant cells, plasma cells, neutrophils) and connective tissue (fibroblasts, fibrocytes, endothelial, and smooth muscle cells) cells prevailed at the areas of collagen destruction and near calcium deposits. Calcification of the leaflets was accompanied by cellular infiltration, therefore suggesting that pathological mineralization may be associated with cell-mediated processes.