Changes in Mac-1 and CD14 expression on monocytes and serum soluble CD14 level during push/pull hemodiafiltration

BACKGROUND/AIM: Employment of treated dialysate as replacement fluid raises concerns about exposure of patients to pyrogenic substances. This study was undertaken to evaluate the safety of treated dialysate as the replacement fluid for push/pull hemodiafiltration. METHODS: In the present study, changes in the expressions of Mac-1 and CD14 on monocytes, which are upregulated by monocyte activation, were analyzed by flow cytometry, and the serum level of sCD14 which elevates by monocyte activation was measured by enzyme-linked immunosorbent assay (ELISA) during treatment in 7 patients on hemodialysis with regenerated cellulose (RC) membrane, polysulfone (PS) membranes and by push/pull hemodiafiltration (HDF) with PS membranes in a cross-over fashion. RESULTS: During hemodialysis with RC, hemodialysis with PS or push/pull hemodiafiltration with PS, both Mac-1 and CD14 expressions on monocytes significantly increased by passing through the artificial kidneys, and, accordingly, the respective values downstream of the artificial kidneys were significantly higher than the predialysis values, even when the lipopolysaccharide level in dialysate was not detectable by Limulus assay. There was no significant variation in serum sCD14 levels during any of the hemodialysis with RC, hemodialysis with PS or push/pull hemodiafiltration. However, during hemodialysis with PS or push/pull hemodiafiltration with PS, changes in Mac-1 and CD14 expression on monocytes were significantly smaller than those during hemodialysis with RC. CONCLUSION: Monocytes are activated to a greater extent during hemodialysis with RC membranes than during push/pull HDF with PS membranes. We consider that push/pull HDF may be safer than hemodialysis with RC membrane and that it is as safe as hemodialysis with the PS membrane in terms of monocyte activation, when pyrogen-free dialysate is employed.