The role of contaminated dialysate in hemodialysis-associated cytokine production

Cytokine Production by Human Peripheral Blood Mononuclear Cells Stimulated by a Pseudomonas Aeruginosa Culture Filtrate: Role of Plasma and Polymyxin B

The lack of consensus regarding the significance of transmembrane passage of bacterial products across hemodialysis membranes can be related to several methodological differences in the various studies, including the choice of circulating fluid in the blood compartment of the model, nature and concentration of the bacterial products employed to challenge the dialysate compartment and whether cytokine production by PMBC or the limulus amebocyte lysate (LAL) assay was used as the index of transfer and the cytokine used as the read-out. In this study, we examined the production of interleukin-1 alpha (IL-1α), interieukin-1 receptor antagonist (IL-1Ra) and interleukin-8 (IL-8) by peripheral blood mononuclear cells (PBMC) incubated with a Pseudomonas aeruginosa culture filtrate. Further, the effects of 10% autologous human plasma and Polymyxin B sulfate (PmB) on cytokine production by PBMC were also characterized. The results of our study indicate that the Ps. aeruginosa culture filtrate had both PmB suppressible and PmB non-suppressible components and that the addition of 10% human plasma significantly enhanced cytokine production by both PmB suppressible and PmB non-suppressible components. The enhancing effect of plasma was most evident at low concentrations of the filtrate. The inhibitory effect of PmB was most evident in samples cultured in the presence of 10% plasma. There was a direct correlation between the production of IL-1α and IL-1Ra suggesting that both pro-inflammatory cytokines and cytokine-specific inhibitory proteins are concurrently produced. There results have direct relevance to selection of study conditions for in vitro models used to study the transmembrane passage of bacterial products across hemodialysis membranes

The influence of ozonated autohemotherapy on oxidative stress in hemodialyzed patients with atherosclerotic ischemia of lower limbs

Ozonated autohemotherapy is used as a complementary medical approach in the treatment of vascular disorders. One of the greatest problems concerning an application of ozone in medicine is its induction of oxidative stress. The standards of ozonotherapy were elaborated recently making this treatment useful and probably non toxic. The aim of the present study was to investigate the influence of ozonated autohemotherapy on the oxidative stress extent in hemodialyzed patients, known to be particularly exposed to generation and deleterious effects of free radicals. Twelve continuously hemodialyzed subjects with atherosclerotic ischemia of the lower limbs were examined in a prospective, controlled, single blind study. Autohemotherapy with blood exposure to oxygen served as a control. The protein and lipid peroxidation products, the reduced glutathione level in red blood cells and free hemoglobin plasma concentration were measured. The study showed that ozonated autohemotherapy with ozone concentration 50 microg/ml per gram of blood induced a significant decrease in glutathione level after 9 sessions of this procedure. Therapy did not cause either the enhancement of protein and lipid peroxidation, or erythrocytes damage. It seems likely that the antioxidant defense system, part of which is glutathione, neutralizes oxidative properties of ozone in this concentration and protects against oxidative cell damage.