Levels of plasma cysteine-proteinase activity in bladder cancer patients

Plasma activity of a Cathepsin B like (CB) cystine protease was evaluated employing a chromogenic assay in citrated plasma samples of 21 patients with transitional bladder cancer (TBC), and 36 healthy blood donors. The median value of total CB activity was significantly higher in the group of patients bearing bladder carcinoma (103.4 mU/ml) as compared to the control group (77.7 mU/ml). 57% of patients showed high values of total CB while only 25% of the controls showed values over the cut-off levels (97.0 mU/ml). When the proenzyme (pro-CB) was analyzed, the median value was also significantly higher in the TBC patients (42.2 mU/ml) as compared to the control group (20.6 mU/ml). While 62% of TBC group showed values over pro-CB cut-off level (35.0 mU/ml) only 31% of controls did so. Total CB median value from other 29 patients succesfully treated from TBC without evidence of disease at the moment of blood colection was near the cut-off (97.6 mU/ml) while pro-CB median values were lower than the cut-off levels (33.2 mU/ml).