Allotransplantation
Encyclopedia
Allotransplantation is the transplantation
of cells
, tissues
, or organs
, sourced from a genetically non-identical member of the same species as the recipient. The transplant is called an allograft or allogeneic transplant or homograft. Most human tissue and organ transplant
s are allografts.
In contrast, a transplant from another species is called a xenograft. A transplanted organ or tissue from a genetically identical donor, i.e., an identical twin, is termed an isograft
. Finally, when a tissue is transplanted from one site to another on the same patient, it is termed an autograft. In bone marrow transplantation, the term for a genetically identical graft is syngeneic, whereas the equivalent of an autograft is termed autologous transplantation.
When a host mounts an immune response against an allograft or xenograft, the process is termed rejection
. An allogenic bone marrow transplant can result in an immune attack against recipient, termed Graft-versus-host disease.
tissue from his or her body for the purpose of transplant to another who is in need. This may be accomplished through self-registration on a donor registry. Additionally, consent for donation may be given by the donor's Legal Next of Kin
if the donor did not specify his or her wishes before death. Consent is obtained shortly after death, generally in-person at a hospital or through a recorded telephonic conversation.
After consent is obtained, potential donors are thoroughly screened for risk factors and medical conditions that would rule out donation, such as pathology
to the organs/tissues to be donated, or risk for relevant communicable diseases such as HIV
and Hepatitis B and C
. This screening includes interviews with family members and/or the donor's primary care physician
, evaluation of medical, hospital and coroner records, a physical assessment of the donor, and recovery of blood, spleen and/or lymph nodes for infectious disease testing. Recovery of the tissue is performed with respect for the donor using surgical techniques.
Personnel from tissue recovery agencies remove the tissue from the donor. These agencies are under the regulation of the Food and Drug Administration
and must abide by the Current Good Tissue Practices
rule. Once the tissue is removed, it is sent to tissue banks for processing and distribution. Each year, AATB-accredited tissue banks distribute 1.5 million bone and tissue allografts. These banks are also regulated by the Food and Drug Administration to ensure the quality of the tissue being distributed.
can be used for allografts. These include:
Bone and tissue allografts have many uses for patients, but overall they save lives, repair limbs, and enhance the quality of a patient’s life. Allografts may be used to replace damaged heart valves and skin; however, they are more frequently used in orthopedic surgery to replace tendons or bones as necessary.
Another choice surgeons have is an autograft, which takes tissue from one part of your body for transplantation to another part. Using an allograft eliminates the need for a second surgery site — avoiding additional pain, risk and possible longer hospital stay.
Further options may include a transplant from another species (a xenograft
), or a transplanted organ or tissue from a genetically identical donor, i.e., an identical twin (an isograft
).
Organ transplant
Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
of cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
, tissues
Biological tissue
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
, or organs
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
, sourced from a genetically non-identical member of the same species as the recipient. The transplant is called an allograft or allogeneic transplant or homograft. Most human tissue and organ transplant
Organ transplant
Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
s are allografts.
In contrast, a transplant from another species is called a xenograft. A transplanted organ or tissue from a genetically identical donor, i.e., an identical twin, is termed an isograft
Isograft
An Isograft is a graft of tissue between two individuals who are genetically identical . Transplant rejection between two such individuals virtually never occurs....
. Finally, when a tissue is transplanted from one site to another on the same patient, it is termed an autograft. In bone marrow transplantation, the term for a genetically identical graft is syngeneic, whereas the equivalent of an autograft is termed autologous transplantation.
When a host mounts an immune response against an allograft or xenograft, the process is termed rejection
Transplant rejection
Transplant rejection occurs when transplanted tissue is rejected by the recipient's immune system, which destroys the transplanted tissue. Transplant rejection can be lessened by determining the molecular similitude between donor and recipient and by use of immunosuppressant drugs after...
. An allogenic bone marrow transplant can result in an immune attack against recipient, termed Graft-versus-host disease.
Procedure
For any number of reasons, before death, a person may have decided to donateOrgan donation
Organ donation is the donation of biological tissue or an organ of the human body, from a living or dead person to a living recipient in need of a transplantation. Transplantable organs and tissues are removed in a surgical procedure following a determination, based on the donor's medical and...
tissue from his or her body for the purpose of transplant to another who is in need. This may be accomplished through self-registration on a donor registry. Additionally, consent for donation may be given by the donor's Legal Next of Kin
Next of kin
Next of kin is a term with many interpretations depending on the jurisdiction being referred to. In some jurisdictions, such as the United States, it is used to describe a person's closest living blood relative or relatives...
if the donor did not specify his or her wishes before death. Consent is obtained shortly after death, generally in-person at a hospital or through a recorded telephonic conversation.
After consent is obtained, potential donors are thoroughly screened for risk factors and medical conditions that would rule out donation, such as pathology
Pathology
Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....
to the organs/tissues to be donated, or risk for relevant communicable diseases such as HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
and Hepatitis B and C
Viral hepatitis
Viral hepatitis is liver inflammation due to a viral infection. It may present in acute or chronic forms. The most common causes of viral hepatitis are the five unrelated hepatotropic viruses Hepatitis A, Hepatitis B, Hepatitis C, Hepatitis D, and Hepatitis E...
. This screening includes interviews with family members and/or the donor's primary care physician
Primary care physician
A primary care physician, or PCP, is a physician/medical doctor who provides both the first contact for a person with an undiagnosed health concern as well as continuing care of varied medical conditions, not limited by cause, organ system, or diagnosis....
, evaluation of medical, hospital and coroner records, a physical assessment of the donor, and recovery of blood, spleen and/or lymph nodes for infectious disease testing. Recovery of the tissue is performed with respect for the donor using surgical techniques.
Personnel from tissue recovery agencies remove the tissue from the donor. These agencies are under the regulation of the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
and must abide by the Current Good Tissue Practices
Current Good Tissue Practices
Current Good Tissue Practice , also known as Good Tissue Practice , is a term that is one of the "GxP" requirements derived from cGMP. The rule was written and is enforced by the U.S. Food and Drug Administration , specifically the Center for Biologics Evaluation and Research...
rule. Once the tissue is removed, it is sent to tissue banks for processing and distribution. Each year, AATB-accredited tissue banks distribute 1.5 million bone and tissue allografts. These banks are also regulated by the Food and Drug Administration to ensure the quality of the tissue being distributed.
Examples of organs and tissues
A variety of transplantable organs and tissuesTransplantable organs and tissues
Transplantable organs and tissues may both refer to organs and tissues that are relatively often or routinely transplanted , as well as relatively seldom transplanted organs and tissues and ones on the experimental stage....
can be used for allografts. These include:
- Anterior cruciate ligamentAnterior cruciate ligamentThe anterior cruciate ligament is a cruciate ligament which is one of the four major ligaments of the human knee. In the quadruped stifle , based on its anatomical position, it is referred to as the cranial cruciate ligament.The ACL originates from deep within the notch of the distal femur...
(ACL) repair - Joint reconstruction in the kneeKnee replacementKnee replacement, or knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve the pain and disability of osteoarthritis. It may be performed for other knee diseases such as rheumatoid arthritis and psoriatic arthritis...
and ankleAnkle replacementAnkle replacement, or ankle arthroplasty, is a surgical procedure to replace the damaged articular surfaces of the human ankle joint with prosthetic components. This procedure is becoming the treatment of choice for patients, replacing the conventional use of arthrodesis, i.e. fusion of the bones... - Meniscal replacement
- Reconstruction due to cancer or trauma
- Ridge augmentation in dental procedures
- Shoulder repairShoulder surgeryAs the shoulder is the most complex and unstable joint in the body, it can get injured easily. Many surgeries have been developed to repair the muscles, connective tissue or damaged joints that can arise from traumatic or overuse injuries to the shoulder....
- Spinal fusionSpinal fusionSpinal fusion, also known as spondylodesis or spondylosyndesis, is a surgical technique used to join two or more vertebrae. Supplementary bone tissue, either from the patient or a donor , is used in conjunction with the body's natural bone growth processes to fuse the vertebrae.Fusing of the...
- Urological proceduresUrologyUrology is the medical and surgical specialty that focuses on the urinary tracts of males and females, and on the reproductive system of males. Medical professionals specializing in the field of urology are called urologists and are trained to diagnose, treat, and manage patients with urological...
- skinSkin-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
transplants - corneaCorneaThe cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
l transplants - heart transplantsHeart transplantationA heart transplant, or a cardiac transplantation, is a surgical transplant procedure performed on patients with end-stage heart failure or severe coronary artery disease. As of 2007 the most common procedure was to take a working heart from a recently deceased organ donor and implant it into the...
- heart valves
- lung transplantation
- Intestinal transplantation (Isolated Small Bowel, Intestine & Liver, Multivisceral)
- liver transplantsLiver transplantationLiver transplantation or hepatic transplantation is the replacement of a diseased liver with a healthy liver allograft. The most commonly used technique is orthotopic transplantation, in which the native liver is removed and replaced by the donor organ in the same anatomic location as the original...
- kidney transplantsKidney transplantationKidney 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 deceased-donor or living-donor transplantation depending on the source of the donor organ...
- bone marrow transplantBone marrow transplantHematopoietic stem cell transplantation is the transplantation of multipotent hematopoietic stem cell or blood, usually derived from bone marrow, peripheral blood stem cells, or umbilical cord blood...
s - boneBoneBones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
allograft - ligamentLigamentIn anatomy, the term ligament is used to denote any of three types of structures. Most commonly, it refers to fibrous tissue that connects bones to other bones and is also known as articular ligament, articular larua, fibrous ligament, or true ligament.Ligament can also refer to:* Peritoneal...
or tendonTendonA tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...
allograft
Bone and tissue allografts have many uses for patients, but overall they save lives, repair limbs, and enhance the quality of a patient’s life. Allografts may be used to replace damaged heart valves and skin; however, they are more frequently used in orthopedic surgery to replace tendons or bones as necessary.
Laws & regulations
Since 1993, the Food and Drug Administration (FDA) has regulated human tissue intended for transplants. As of May 2005, there are three new regulations that address the manufacturing activities associated with human cells, tissues, and cellular and tissue-based products (HCT/Ps). The first regulation requires companies to register with the FDA if they intend to produce and distribute HCT/Ps. The second regulation, called the “Donor Eligibility” rule, concerns the donor’s ability to meet certain criteria in order to be eligible to donate tissue. Finally, the third rule, referred to as the “Current Good Tissue Practices” rule, oversees the overall processing and distribution practices of each company. As a whole, these rules are implemented to ensure the quality of the tissue and reduce the risk of contamination or disease transmission.Other options
Allografts are a natural alternative to synthetic and metal implants. However, unlike synthetic or metal implants, allografts incorporate into your body.Another choice surgeons have is an autograft, which takes tissue from one part of your body for transplantation to another part. Using an allograft eliminates the need for a second surgery site — avoiding additional pain, risk and possible longer hospital stay.
Further options may include a transplant from another species (a xenograft
Xenotransplantation
Xenotransplantation , is the transplantation of living cells, tissues or organs from one species to another. Such cells, tissues or organs are called xenografts or xenotransplants...
), or a transplanted organ or tissue from a genetically identical donor, i.e., an identical twin (an isograft
Isograft
An Isograft is a graft of tissue between two individuals who are genetically identical . Transplant rejection between two such individuals virtually never occurs....
).
External links
- http://www.aatb.org/files/safetyoftissuetransplants.pdf
- http://www.cdc.gov/ncidod/dhqp/tissueTransplantsFAQ.html#top
- http://www.fda.gov/BiologicsBloodVaccines/TissueTissueProducts/default.htm
- http://www.organdonor.gov/donor/registry.shtm (How to register to be a donor in the USA)