Immune inhibitor

An immunosuppressant is a drug that reduces the immune response. It can selectively act on certain immune reaction links and immune cells required for inhibition. Immunity refers to the body's response to various pathogenic substances. Some of these reactions are beneficial to the body and can enhance the body's disease resistance. Some are unfavorable to the body and can cause physiological disorders or tissue damage (allergy). Therefore, the immune response of the body is reduced by applying an immunosuppressive agent to an allergic reaction to the body to affect the immune process. In order to treat various immune diseases and to attenuate tissue incompatibility, various immunosuppressive agents have been developed, some of which have been widely used in the clinic. There are many kinds of immunosuppressive agents. Commonly used immunosuppressive agents are glucocorticoids (prednisone, prednisolone, etc.), alkylating agents (nitrogen oxide mustard, cyclophosphamide, thiotepa, busulfan, etc.). Antimetabolites (6-mercaptopurine, azathioprine, methotrexate, etc.). 1. Glucocorticoids: commonly used cortisone, hydrocortisone and semi-synthetic prednisone (prednisone), prednisolone (prednisolone), dexamethasone (dexamethasone) Wait. The anti-inflammatory and immunosuppressive effects of these hormones are similar. The mechanism of immunosuppressive effects of glucocorticoids is mainly: 1 inhibits the phagocytic function of the mononuclear phagocytic system and interferes with the function of macrophages. 2 has a destructive effect on lymphoid tissue, the most sensitive part is the germinal center of the lymph nodes. However, after stimulation with allogeneic antigens, the usual dose inhibits the synthesis of antibodies is not obvious, but has a significant inhibitory effect on the production of autoantibodies. The clinical application of glucocorticoids is very broad, mainly including the following three aspects: 1 autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, nodular arteritis, dermatomyositis, scleroderma, nephropathy 2, etc.; 2 tissue and organ transplantation; 3 allergic diseases such as bronchial asthma, anaphylactic shock, angioedema, etc. 2. Azathioprine: Inhibition of killer cells and T cell-mediated immune responses (mixed lymphocyte reaction, allograft rejection and delayed type hypersensitivity, etc.). At high doses, antibody formation is inhibited. The inhibition of the primary response is much stronger than for the secondary reaction. Strong inhibition of the production of macrophage precursors, monocytes, leads to inhibition of phagocytosis. It can also change the recirculation of lymphocytes. It is commonly used in kidney transplant patients. No humoral immunosuppression is observed during the administration. It is often combined with corticosteroids to treat autoimmune diseases. 3. Cyclophosphamide: Cyclophosphamide selectively inhibits B cells, inhibits antibody synthesis induced by various antigens (including primary and secondary immune responses), and induces tolerance to antigens. The humoral immunosuppressive effect of cyclophosphamide is mainly achieved by lysing lymphocytes. One injection can drastically reduce the number of cells in the lymphoid tissues such as the spleen and lymph nodes and the number of lymphocytes in the blood. Cyclophosphamide acts mainly on immature cells and inhibits their ability to proliferate. Mature antibody-forming cells are not sensitive to cyclophosphamide. In recent years, cyclophosphamide has been found to have a strong inhibitory effect on certain subsets of T cells. Larger doses can inhibit graft versus host response and delayed type hypersensitivity. However, if administered prior to sensitization, delayed type hypersensitivity is promoted. Cyclophosphamide is ineffective in vitro and only works after metabolism in the body. It is clinically used to treat a variety of autoimmune diseases in which corticosteroids are ineffective and reduce autoantibody titers. It also prolongs the survival time of transplanted organs.