[Side effects in immunosuppressive therapy]

61 patients with rheumatoid arthritis received a total of 80 courses of immunosuppressive therapy with one or more of the following substances: azathioprine, chlorambucil, mannitolmustard, cyclophosphamide, procarbazine. The overall results were excellent or good in 50% of the patients. There was a significant correlation between the efficacy of the different substances and the rate of side effects. Azathioprine was best tolerated, but gave only medium results whereas procarbazine, as a very potent drug, had the highest rate of side effects (especially depression of bone marrow, infections, gastrointestinal manifestations etc.). Serious immediate side effects of the immunosuppressive therapy according to our experience and in literature are infections and leucopenia, whereas the most important late risk is the possibility of an occurrence of malignancy. In our series, which had been followed up to five years, no malignancies have been thus far detected. Also, in the literature, there are only very few patients with malignancies published. Therefore the risk of immunosuppressive therapy in rheumatoid arthritis with regards the incidence of malignancies, seems to be relatively small in contrast to the findings in patients with kidney transplants.