ABSTRACT
Therapeutic control of the immune system is the goal in a vast array of autoimmune diseases, which differ in their organ-specific involvement, pathogenetic cofactors, response to treatment, and prognosis. They range from diseases with "spontaneous" onset such as rheumatoid arthritis (RA) to rejection reactions after allograft organ transplantation. Nevertheless, a relatively similar group of medications has been used to control the immune response (I). This chapter will discuss a group of medications that may act through partial or complete inhibition of de novo synthesis of purine and/or pyrimidine nucleotides.
