BACKGROUND: Kidney diseases are characterized by deterioration of the function of this organ, often leading to irreversible failure, where transplantation is the only alternative to permanent dialysis. Proteolytic enzymes, including cathepsins B, cleave the peptide bond by hydrolysis reaction. They are also involved in pathological processes such as carcinogenesis and inflammatory processes. The aim of this study was to determine the activity of cathepsin B in the serum of patients after kidney transplantation and to assess the correlation with glucocorticosteroids treatment.

MATERIAL AND METHODS: In the study, blood samples of 100 renal transplant recipients were used. The subjects were divided into groups according to the time elapsed since transplantation and the use of steroids in the current and primary treatment. Enzyme activity was measured  by spectrofluorometric technique.

RESULTS: The study showed significant correlations of cathepsin B with the time since renal transplantation (p<0.05) and steroid used in the primary and current treatment. Steroid treatment is associated with a decrease of the activity of cathepsin B in serum.

CONCLUSIONS: The obtained results show decreasing activity of cathepsin B with longer time elapsed since transplantation. We have shown that steroids decrease activity of cathepsin B after renal transplantation. A significant increase in cathepsin B activity is observed mainly in cancer and atherosclerosis. Decreased activity of cathepsin B is probably due to the stabilizing action of steroids on the lysosomal membrane. The impact of steroid therapy for patients with these diseases appears to be significant.

Keywords: cathepsin B, Enzymes, Glucocorticoids, Kidney Transplantation