corticosteroid + mizoribine

This is a combination therapy consisting of a corticosteroid (a class of steroid hormones commonly used for their anti-inflammatory and immunosuppressive effects) and mizoribine, an immunosuppressive small molecule. Mizoribine is an imidazole nucleoside that selectively inhibits inosine monophosphate dehydrogenase and guanosine monophosphate synthetase, key enzymes in the de novo purine synthesis pathway. This inhibition suppresses the proliferation of T and B lymphocytes by blocking DNA synthesis in these cells without affecting other cell types that can use the salvage pathway for purine synthesis[6][8][10]. Corticosteroids act primarily by binding to glucocorticoid receptors, modulating gene expression to reduce inflammation and immune activity. The combination is used mainly as induction or maintenance therapy in autoimmune diseases such as lupus nephritis, juvenile systemic lupus erythematosus (SLE), refractory nephrotic syndrome, rheumatoid arthritis, and other renal or rheumatic conditions[1][3][9]. The regimen aims to enhance immunosuppression while potentially reducing corticosteroid dosage to minimize side effects.