Decrease in disease activity and concomitant increase in the percentage of peripheral blood suppressor T-cells in rheumatoid arthritis by a newly synthesized slow-acting anti-rheumatic drug (Bucillamine).

Bucillamine: N-(2-mercapto-2-methyl-propanoyl)-L-cysteine, is a newly synthesized slow-acting anti-rheumatic drug with two SH-bonds in its chemical structure. Eleven patients with rheumatoid arthritis (RA) were treated with Bucillamine, and both Lansbury's activity index and the percentage of suppressor T-cells (Leu 2a+ Leu 15+) were serially monitored for 10 weeks. The percentage of suppressor T-cells, which was depressed in the active disease state, reached normal levels with clinical improvement according to Lansbury's index. Bucillamine may have an immunomodulating activity and may be a useful drug for the treatment of RA.