CD31 expression on leukocytes is downregulated in vivo during hemodialysis

Background/Aim: CD31 on leukocytes is the adhesion molecule involved in the leukocyte extravasation in inflammatory conditions. During hemodialysis wi th cellulosic membranes, it is considered that activated leukocytes adhere to endothelium, but do not show extravasation. However, it is not elucidate d why activated leukocytes do not show endothelial transmigration during he modialysis with cellulosic membranes. Methods: In the present study, change s in the expressions of Mac-1 and CD31 on granulocytes and monocytes were a nalyzed by flow cytometry during hemodialysis in 7 patients treated with re generated-cellulose (RC) membranes and next with polysulfone (PS) membranes . Results: During dialysis with RC, Mac-1 expressions on granulocytes and m onocytes both significantly increased as compared with predialysis values a nd across the dialyzer. During dialysis with RC, the CD31 expression on gra nulocytes and monocytes significantly de-creased as compared with predialys is values. During dialysis with PS, changes in Mac-1 and CD31 expressions o n granulocytes and monocytes were smaller than those during dialysis with R C. Conclusions: Decreased CD31 expression on leukocytes may affect leukocyt e function more in patients chronically hemodialyzed with RC than in those hemodialyzed with PS, since CD31 is important in leukocyte transendothelial migration in inflammatory conditions. Copyright (C) 2001 S. Karger AG, Bas el.