organ transplantation

Examples of organ transplantation in the following topics:

• Organ Transplants

  • Organ transplantation involves moving organs between bodies (or from donor sites on patients' bodies) for the purpose of replacing recipients' damaged or absent organs.
  • Tissue transplants occur much more frequently than organ transplants.
  • Transplantation raises a number of bioethical issues, including the definition of death, when and how consent should be given for organ transplantation, and the possibility of payment for transplantation organs.
  • Some organs, such as the brain, cannot yet be transplanted in humans.
  • Organ transplants are not regulated by the FDA.

• Kidney Transplant

  • Kidney transplantation is the organ transplant of a kidney into a patient with end-stage renal disease.
  • Sometimes, people wait only a few days or weeks before receiving a donor organ.
  • Kidney transplantation, or renal transplantation, is the organ transplant of a kidney into a patient with end-stage renal disease.
  • Kidney transplantation is typically classified as either deceased-donor (formerly known as cadaveric) or living-donor transplantation, depending on the source of the donor organ.
  • The major barrier to organ transplants between genetically non-identical patients lay in the recipient's immune system, which would treat a transplanted kidney as a "non-self" and immediately or chronically reject it.

• Major Histocompatibility Complex Antigens (Self-Antigens)

  • MHC determines compatibility of donors for organ transplant as well as one's susceptibility to an autoimmune disease via crossreacting immunization.
  • Organ transplantation is a complex procedure that can potentially cure many chronic diseases or damaged conditions.
  • In nearly all cases, immunosuppressive chemotherapy is a requirement for successful organ transplantation.
  • These drugs are effective at stopping acute organ rejection after the procedure, but will not stop chronic organ rejection, in which gradual vascular lesions and endothelial thickening slowly kills the graft.
  • Additionally, if an organ donor has HLA similar to that of the recipient, the risk of organ rejection is reduced, however this isn't feasible for organ transplants of the heart, liver, or lungs, because there generally isn't enough time to find a matching organ donor to help a patient with diseases of these illnesses.

• Cytomegalovirus Infections

  • Major areas of risk of infection include prenatal or postnatal infants and immunocompromised individuals, such as organ transplant recipients, persons with leukemia, or those infected with human immunodeficiency virus (HIV).
  • HCMV infection is typically unnoticed in healthy people, but can be life-threatening for the immunocompromised, such as HIV-infected persons, organ transplant recipients, or newborn infants.
  • Transplant patients with CMV are also susceptible to pneumonia and hepatitis.

• Immunodeficiencies

  • As an anti-rejection protocol, transplant patients take medications to suppress their immune system, as do some patients suffering from an over-active immune system.
  • The treatment of primary immunodeficiencies depends on the nature of the defect, and may involve antibody infusions, long-term antibiotics, and (in some cases) stem cell transplantation.
  • Secondary immunodeficiencies, also known as acquired immunodeficiencies, can result from various immunosuppressive agents, for example, malnutrition, aging, and particular medications (e.g. chemotherapy, disease-modifying antirheumatic drugs, immunosuppressive drugs after organ transplants, and glucocorticoids).

• Secondary Immunodeficiency Diseases

  • Transplant patients take medications to suppress their immune system as an anti-rejection measure, as do some patients suffering from an over-active immune system.
  • The treatment of primary immunodeficiencies depends on the nature of the defect and may involve antibody infusions, long-term antibiotics, and (in some cases) stem cell transplantation.
  • Secondary immunodeficiencies, also known as acquired immunodeficiencies, can result from various immunosuppressive agents, for example, malnutrition, aging and particular medications (e.g., chemotherapy, disease-modifying antirheumatic drugs, immunosuppressive drugs after organ transplants, glucocorticoids).

• Graft Rejection and Tissue Typing

  • Transplant or graft rejection occurs when a transplanted tissue is rejected by the recipient's immune system.
  • Transplant (or graft) rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue.
  • Transplant rejection can also be limited by the use of immunosuppressant drugs after the transplant.
  • Very high magnification micrograph of a Masson body seen in lung transplant rejection.
  • Describe the role of tissue typing and graft rejection in transplantation

• Vertebrate Axis Formation

  • Through the expression patterns of different genes, the three axes of the body are established, aiding in tissue and organ development.
  • As the body forms, it must develop in such a way that cells, tissues, and organs are organized correctly along these axes.
  • In one of the most seminal experiments ever to be carried out in developmental biology, Spemann and Mangold took dorsal cells from one embryo and transplanted them into the belly region of another embryo.
  • They found that the transplanted embryo now had two notochords: one at the dorsal site from the original cells and another at the transplanted site.
  • Mutations in these genes leads to the loss of symmetry required for organism development.

• Type 1 Diabetes Mellitus

  • Pancreatic transplants have been used.
  • Pancreatic islet cell transplantation is experimental, though growing.
  • High blood sugar may lead to increased fatigue and can also result in long-term damage to organs.
  • Experimental replacement of beta cells (by transplant or from stem cells) is being investigated in several research programs.
  • Islet cell transplantation is less invasive than a pancreas transplant, which is currently the most commonly-used approach in humans.

• Burkitt's Lymphoma

  • Burkitt's lymphoma usually develops in the abdomen and spreads to other organs, including the brain.
  • Immunodeficiency-associated: Immunodeficiency-associated Burkitt lymphoma is usually associated with HIV infection or occurs in the setting of post-transplant patients who are taking immunosuppressive drugs.
  • Other treatments are immunotherapy, bone marrow transplants, stem cell transplant, surgery to remove the tumor, and radiotherapy.