Clinical relevance of cytokine production in hemodialysis

Blood-dialyzer interaction in hemodialysis has the potential to activate mo nonuclear cells leading to the production of inflammatory cytokines. The ex tent of activation is dependent on the dialyzer material used and is consid ered an index of biocompatibility. Cytokines. such as interleukin-1 beta (I L-1 eta), tumor necrosis factor-alpha (TNF-alpha), and IL-6, may induce an inflammatory state and are believed to play a significant role in dialysis- related morbidity. The interleukin hypothesis suggests that the release of proinflammatory cytokines acts as an underlying pathophysiologic event in h emodialysis-related acute manifestations, such as fever and hypotension. Ne vertheless, a cytokine overproduction may alter sleep pattern in chronic he modialyzed patients, thus explaining the presence of sleep disorders in the se patients. A potential role of cytokines in chronic-related morbidity has also been suggested. High levels of some inflammatory cytokines are often associated with anemia caused by hyporesponsiveness to erythropoietin. Cyto kine production may also play a relevant role in bone remodeling by regulat ing osteoblast/osteoclast cell functions and parathyroid hormone (PTH). Fin ally, cytokine release may have a long-term deleterious effect on mortality of uremic patients by altering immune response and increasing susceptibili ty to infections. Bioincompatibility of dialytic membranes may also contrib ute to malnutrition in dialysis patients by increasing the monocyte release of catabolic cytokines such as TNF-alpha and IL-6. Bioincompatible dialyti c treatment may induce an inappropriate monocyte activation and cytokine pr oduction, which, in turn, may mediate some of the immune and metabolic dysf unction associated with hemodialysis. The use of biocompatible dialytic mem branes appears to reduce the monocyte activation and to improve the surviva l of hemodialysis patients.