Pecam-1 expression in patients with relapsing-remitting multiple sclerosis

PECAM-1 is an adhesion molecule - a member of the immunoglobulin superfamily - involved in the transendothelial migration of leukocytes. PECAM-1 is expressed on lymphocytes, monocytes and granulocytes. It is also found on endothelial cells and platelets. We present data showing that the cell-bound form of PECAM-1 expression on monocytes is increased in MS patients, compared to controls. We also show that PECAM-1 is significantly over-expressed on lymphocytes in patients with active MRI lesions, when compared to those without gadolinium-enhancing lesions. Our results suggest that the cell-bound form of PECAM-1 can be regarded as a marker of MS activity.