[Acid lysosomal hydrolase activity in the serum and synovial fluid of rheumatoid arthritis patients].

Five acid lysosome hydrolases were studied in 20 patients with rheumatoid arthritis (RA), active stage in serum (S) and synovial fluid (SF) in parallel, obtained from the knee joint. The enzyme activity was fluorimetrically determined, making use of substrates specific for each enzyme, derivatives of 4-methyl-umbelliferone. The serum lysosome activity of the patients with RA, compared with that of a referent group of healthy subjects, showed a significant increase in three of the hydrolases studied. With the juxtaposition of enzyme activity between SF and serum of the patients with RA, the activity of all acid hydrolases in the synovial fluid studied proved to be several times higher and with high statistical significance (p less than 0.01-0.001). Our data support the valuable informative value of the study on acid lysosome hydrolases in the synovial fluid. A sensitive indicator of the activity of the joint process in RA is the coefficient of lysosome enzymatic activity SF/S, substantially surpassing 1.0.