1 Immunosuppressants are drugs that reduce the body's ability to attack foreign material and thus are used to prevent organ rejection after organ transplantation. This ability to attack foreign material is provided by the body's immune system, and is comprised of white blood cells known as lymphocytes. These lymphocytes are further classified as B and T lymphocytes. B lymphocytes are cells that make antibodies which help to protect the body against infections and foreign substances. When T lymphocytes are activated, they produce an increase in the production and release of substances known as cytokines.
Cytokines are chemical messengers that play a role in the immune system.
These cytokines increase the sensitivity of T lymphocytes to rid the body of foreign substances. Tacrolimus suppresses this process by decreasing the production and release of cytokines. When an organ such as a kidney or liver is transplanted from one individual to another, the recipient is treated with immunosuppressants such as tacrolimus. As a result the recipient's immune system is unable to recognize the transplanted organ as foreign and unable to attack and reject the organ. Atopic dermatitis includes an immune component wherein the skin's immune system is over-reactive.