Serum cysteine proteases and their inhibitors in rheumatoid arthritis: relation to disease activity and radiographic progression.

This study aims to investigate the serum levels of cysteine proteases cathepsins B and H and their inhibitors stefin A, stefin B, and cystatin C, as well as traditional inflammatory markers such as C-reactive protein in patients with rheumatoid arthritis and to correlate these markers with scores of disease activity and radiographic progression. Seventy-two patients with rheumatoid arthritis were included from two previously described cohorts of patients with chronic polyarthritis. At inclusion, disease activity was assessed by a 28-joint count, patient global assessment, and serum C-reactive protein. Erosive status of hands and wrists was expressed by the Larsen score and recorded at inclusion and after 1 year. Serum levels of cathepsin B, cathepsin H, stefin A, stefin B, and cystatin C were determined by enzyme-linked immunosorbent assay. Neither cathepsin B nor cathepsin H serum levels were associated with disease activity, presence or progression of erosive disease. Number of swollen joints correlated with serum levels of stefin A and B and correlated negatively with cystatin C serum levels. Erosive disease was associated with high serum levels of C-reactive protein and stefin A and low serum levels of cystatin C. Progression of radiographic destruction was associated with high serum levels of C-reactive protein, stefin A and B, whereas serum levels of cystatin C were not associated with radiographic progression. The findings in this study support further investigation in the regulation of the activity of cathepsins and their inhibitors in erosive rheumatoid arthritis.

[B-, H- and L-cathepsin-like activity in blood plasma of patients with diseases of the thyroid, parathyroid and adrenal glands].

B-, H- and L-catepsine-like activity regarding Na-benzoyl-D,L-arginine-4-nitroanilide, L-leucine-4-nitroanilide and azocasein was studied in the blood plasma of patients with different diseases of thyroid, parathyroid and adrenal glands. It has been shown that the high H- catepsine-like activity confirming the activation of blood catepsin H secretion accompanied by the tissue growth under any pathology took place in the blood plasma of patients with all the above diseases. High B- catepsine-like activity in the blood plasma of patients with thyroid diseases was exceptionally fixed under the nodular forms of thyroid pathology, while the character of changes in L catepsine-like activity under these diseases was not so natural. In diaseses of the adrenal glands the changes in the B- and L-catepsine-like activity were only shown in the blood plasma of patients with cerebral layer tumors but not the gland cortex: B-catepsine-like activity increased in the blood plasma of patients with benign or malignant tumors, and L-catepsine-like activity decreased under benign tumor from chromaffin tissue. The established picture of changes in enzymatic activity in the blood plasma of patients does not allow to think that the determination of blood B- and L- catepsine-like activity can be recommended for obtaining additional information at diagnosis thyroid diseases.