The fibrocyte in pulmonary hypertension: We seek him here, we seek him there

摘要

The fibrocyte is one of many populations of bone marrow-derived cells that can be detected in the peripheral blood and is considered to represent a mesenchymal progenitor cell [1]. The fibrocyte, as we currently understand this term, was originally described by Bucala et al. [2] in 1994 and is defined by the expression of a variety of cell surface antigens, including the stem cell marker CD34, the pan-leukocyte marker CD45, and monocyte markers CD14 and CD11. The fibroblast-like nature of these cells is evidenced by their expression of collagen I, collagen II and vimentin. In normal individuals, these cells comprise < 0.5% of circulating leukocytes [3]. In animal models employing surgically implanted wound chambers, it can be shown that approx16% of cells that accumulate over a number of days are putative blood-derived fibrocytes [4].