Lysosomal cathepsins B and L and Stefin A blood levels in patients with hepatocellular carcinoma and/or liver cirrhosis: potential clinical implications.

The serum levels of lysosomal cathepsin B and L and Stefin A, an intracellular inhibitor of these proteolytic enzymes, were determined in patients with hepatocellular carcinoma (HCC) and/or liver cirrhosis (LC) and correlated with some clinical and biochemical parameters of these diseases. Cathepsin B serum levels were increased in HCC and in LC patients as compared to normal subjects (p < 0.001). However no difference was observed between HCC and LC groups. Interestingly, a significant relationship was evidenced between cathepsin B serum content and the grade of severity of cirrhosis (r = 0.41; p < 0.001). Cathepsin L was significantly elevated only in sera of cancer patients as compared to normal subjects or LC patients (p < 0.001) and significantly correlated with the number of malignant lesions (r = 0.49; p = 0.001). Stefin A serum levels were increased in HCC and LC patients as compared to healthy subjects (p < 0.02). However, these levels were significantly higher in the LC group as compared to the HCC group (p < 0.05). In cancer patients, a significant relationship was observed between Stefin A serum content and tumor size (r = 0.35; p < 0.05), number of neoplastic lesions (r = 0.556; p < 0.001) and serum alpha-fetoprotein (r = 0.38; p < 0.01). These data suggest that cathepsin B and L and Stefin A may be potentially useful as additional biochemical parameters to monitor the therapeutic response of these diseases to clinical treatments and to identify patients with cirrhosis developing precancerous lesions.