The pathogenesis of rheumatic diseases is related to a variety of factors such as genetics, immune regulatory disorders and various trigger factors. Most patients have disorders of the immune system leading to antigen-antibody reactions, a large number of lymphocyte infiltrates at the lesion site, increased immunoglobulins and the presence of a large number of immune complexes, which leads to the idea of using anti-tumor drugs that inhibit cell deterioration and proliferation for the treatment of rheumatic diseases. This reduces the formation of immune complexes and decreases the abnormally increased immunity of the patient. The main antitumor drugs in this category are alkylating cytotoxic drugs (cyclophosphamide), which have a significant inhibitory effect on immune complex formation, and antimetabolic cytotoxic drugs (methotrexate), which specifically antagonize the corresponding metabolites within antibodies, ultimately hindering cell division and proliferation and reducing antibody production.