The relationship between production of IL-1beta and TNFalpha by peripheral blood mononuclear cells (PBMC) of hemodialysis (HD) patients and clinical disorders characteristic for HD patients was examined. The study included 28 HD patients divided in the 4 groups: group 1--6 patients with malnutrition; group 2--6 patients with secondary hyperparathyroidism; group 3--6 patients with eosinophilia; group 4--10 stable HD patients without clinical complication. The control group consisted of 9 healthy volunteers. All patients were dialyzed with cuprophane membrane more than one years. Blood samples were taken immediately before the beginning of hemodialysis and PBMC were isolated by centrifugation on the density gradient. Concentrations of IL-1beta and TNFalpha were measured in the supernatants of the cultures by ELISA tests. The results showed marked individual differences in cytokine production both in healthy controls and in HD patients. Spontaneous and LPS stimulated production of IL-1beta by PBMC of HD patients was significantly higher compared to PBMC of healthy controls. There were no significant differences between group of patients with different clinical complications in cytokine production. However, a positive correlation was found between IL-1beta concentration and body mass index for patients with malnutrition and between concentration of IL-1alpha and parathyroid hormone (PTH) for patients with secondary hyperparathyroidism. The results suggest that PBMC of HD patients are chronically stimulated to produce IL-1beta, which may contribute to the development of particular chronic complications.