**8. Conclusions**

Although many publications (Shinmei et al. 1992; Lohmander et al. 1995; Saxne & Heinegard 1995; Myers 1999; Ortutay et al. 2003) have described increased release of markers of cartilage, bone, and synovial metabolism into joint fluid, serum, and urine in rheumatoid arthritis, the significance of several of these markers remains elusive. Up to now, no markers have yet been formally validated to monitor rheumatoid diseases of the joints. We hypothesize that determining HEX activity in the synovial fluid of patients with suspected idiopatic juvenile arthritis has diagnostic value. Elevation of HEX activity in synovial fluid to greater than 10 µkat/kg of protein, suggests rheumatoid disease.

Despite its huge public health impact, the conservative treatment of joint diseases, particularly of OA, is limited to a few types of medication which provide primarily symptomatic relief. Inhibition of hexosaminidase activity may represent a potentially novel strategy for treating RA and OA. Liu et al. (2001) have synthesized and investigated a series of iminocyclitols designed as transition-state analogue inhibitors of extracellular human hexosaminidase. Our team (Olszewski et al. 2010) is focusing on pyrimethamine which contributes to the regulation of HEX gene expression in synovial cells.
