Cyclosporine: The Immune System

Cyclosporine

Transplantation is the act of transferring cells, tissues, or organs from one site to another. The malfunction of an organ system can be corrected with transplantation of an organ (eg, kidney, liver, heart, lung, or pancreas) from a donor. However, the immune system remains the most formidable barrier to transplantation as a routine medical treatment. As the immune system is responsible for the rejection of grafts understanding the mechanisms by which the immune system reject the graft helps in the treatment and development of drugs and ways that insure the success of the transplantation.

Types of Grafts:

The degree of immune response to a graft depends partly on the degree of genetic disparity between the grafted organ and

Class I molecules, these are normally expressed on all nucleated cells, whereas the class II molecules are expressed only on the professional antigen-presenting cells (APCs), such as dendritic cells, activated macrophages, and B cells. The physiological function of the MHC molecules is to present antigenic peptides to T cells, since the T lymphocytes only recognize antigen when presented in a complex with an MHC molecule. The class I molecules are responsible for presenting antigenic peptides from within the cell (eg, antigens from the intracellular viruses, tumor antigens, self-antigens) to CD8 T cells. The class II molecules present extracellular antigens such as extracellular bacteria to CD4 T

Hypertension occurs in ∼50% of renal transplant and almost all cardiac transplant patients. Hyperuricemia may lead to worsening of gout, increased P-glycoprotein activity, and hypercholesterolemia. Nephrotoxicity occurs in the majority of patients and is the major reason for cessation or modification of therapy. Combined use of calcineurin inhibitors and glucocorticoids is particularly diabetogenic. Especially at risk are obese patients, African-American or Hispanic transplant recipients, or those with a family history of type II diabetes or