Is dialysis membrane type responsible for increased circulating adhesion molecules during chronic hemodialysis?

Background: Patients with chronic renal failure under maintenance hemodialy sis (HD) present with numerous adverse effects including immunologic altera tions. Serious abnormalities of neutrophil function have been reported to b e associated with disturbed cell adhesiveness. These adhesion processes are mediated by cytokines and different adhesion molecules. Patients and metho ds: In this study, serum concentrations of the intercellular adhesion molec ule ICAM-1, vascular cell adhesion molecule VCAM-1 and endothelial leukocyt e adhesion molecule E-selectin were investigated during employment of diffe rent dialysis membranes (cuprophane: n = 23, cellulose: 8, polysulfone: 26, acrylonitrile: 7). These adhesion parameters from 64 patients before and a fter a hemodialysis session were investigated parallel to the serum levels of circulating cytokines and their inhibitors. Results: Circulating ICAM-1 levels were not elevated in low-flux membranes and most of the high-flux HD membranes, except for one high-flux polysulfone membrane, cVCAM-1 levels w ere significantly elevated both in low- and high-flux dialysis membranes, w hereas cE-selectin was not increased. cICAM-1 levels were not different bef ore and after hemodialysis in the entire study group. In contrast, cVCAM-1 and cE-selectin levels increased significantly during HD in the entire stud y group (both p < 0.001). Serum levels did not correlate with the duration of end-stage renal failure and hemodialysis. Levels of circulating cytokine antagonists/inhibitors (Il-1ra, Il-2R, TNFsRp55/75) were significantly inc reased in all patients before and after KD, whereas the serum concentration s of the corresponding circulating cytokines (Il-1 beta, Il-1, TNF-alpha) w ere within normal ranges. Conclusion: Increased levels of cVCAM-1 which sug gest an important role for immunological alterations in HD and cytokine-ind ependent changes during HD sessions in all membranes without alterations of cICAM-1 in most membranes and unchanged cE-selectin indicate that processe s such as uremia are responsible for these effects rather than membrane cha racteristics. The level of circulating adhesion molecules does not serve as an appropriate marker of membrane biocompatibility.