Clinical immunology Essay Example | Topics and Well Written Essays - 500 words

Clinical immunology - Essay Example n recipients of any organ transplant, in whom the prevalence of morbidities such as systemic hypertension, diabetes mellitus, renal insufficiency, and malignancy remain high as compared with the general population. The barriers to short and long-term success of transplant procedures are predominantly the result of incompatibility between donor and recipient, acute and chronic rejection, and complications of long-term pharmacologic immune suppression. This is the reason why clinicians need to consider several factors prior to transplantation. Examples of conditions to be studied include, but are not limited to: 6. Susceptibility to and prevention of the adverse consequences (e.g., nephropathy, systemic hypertension, diabetes mellitus, malignancy) of current post-transplant immunosuppressive regimens (Department of Health and Human Services, 2003). In many cases of transplantation the histocompatibility barrier between recipient and donor remains a problem in that it will activate immune responses leading to graft rejection. Because HLA plays such a dominant role in transplant immunity, pre-transplant histocompatibility testing seems important for organ transplantation. In order to appreciate the role of Human Leukocyte Antigen (HLA) in transplantation, we must first consider the structural and functional aspects of HLA molecules. HLA antigens are controlled by a series of highly polymorphic genes on the short arm of chromosome 6, referred to as the human MHC. These genes have been classified into major categories. HLA-A, HLA-B and HLA-C encode for Class I molecules consisting of a 45kD glycopeptide chain complexed to a 12kD ï  ¢2-microglobulin chain encoded by a nonpolymorphic gene on chromosome 15. The genes in the HLA-DR, HLA-DQ and HLA-DP regions encode for Class II molecules consisting of a ~30kD ï  ¡-chain and a ~28k D ï  ¢-chain. These HLA class I and class II alloantigens can induce transplant immunity at both humoral (antibody) and cellular (T lymphocyte)