Integrin expression at the bone/biomaterial interface.

The aim of this study was to visualize integrin expression by cells in interface tissue in relation to their ligands. Tissue samples were obtained from 25 patients undergoing revision of aseptically loose total joint replacements. Serial sections were immunolabeled for the integrins alpha(2)beta(1), alpha(v)beta(3), alpha(4)beta(1), alpha(L)beta(2) (CD11a), alpha(M)beta(2) (CD11b), and alpha(X)beta(2) (CD11c), and the ligands fibronectin, laminin, vitronectin, intercellular adhesion molecule-1, and vascular adhesion molecule-1. Most cells were found to express alpha(2)beta(1), most macrophages and giant cells expressed CD11b, and the majority of CD11a was found on perivascular T lymphocytes. From the small amount of alpha(4)beta(1) and vascular adhesion molecule-1 expression in the interface tissue and the combination of CD11a, CD11b, and intercellular adhesion molecule-1 expression, it would seem that macrophages use beta(2) integrins to transmigrate.