Allotransplant (''allo-'' meaning "other" in

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

) is the transplantation of cells, tissues, or

organs In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a f ...

to a recipient from a genetically non-identical donor of the same species. The transplant is called an allograft, allogeneic transplant, or homograft. Most human tissue and

organ transplant Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transpo ...

s are allografts. It is contrasted with autotransplantation (from one part of the body to another in the same person),

syngenic The word "syngenic" or "syngeneic" (from the Greek word for a relative) means genetically identical, or sufficiently identical and immunologically compatible as to allow for transplantation. For example, it may be used for something transplanted fr ...

transplantation of isografts (grafts transplanted between two genetically identical individuals) and

xenotransplantation Xenotransplantation (''xenos-'' from the Greek meaning "foreign" or strange), or heterologous transplant, is the transplantation of living cells, tissues or organs from one species to another. Such cells, tissues or organs are called xenograft ...

(from other species). Allografts can be referred to as "homostatic" if they are biologically inert when transplanted, such as bone and

cartilage Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck an ...

. An immune response against an allograft or

xenograft Xenotransplantation (''xenos-'' from the Greek meaning "foreign" or strange), or heterologous transplant, is the transplantation of living cells, tissues or organs from one species to another. Such cells, tissues or organs are called xenograft ...

is termed rejection. An allogenic bone marrow transplant can result in an immune attack on the recipient, called

graft-versus-host disease Graft-versus-host disease (GvHD) is a syndrome, characterized by inflammation in different organs. GvHD is commonly associated with bone marrow transplants and stem cell transplants. White blood cells of the donor's immune system which remain wit ...

Procedure

Material is obtained from a donor who is a living person, or a deceased person's body receiving mechanical support or ventilation, or a deceased person's body whose heart stopped beating. Screening for pathology and risk factors for communicable diseases such as

HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...

and Hepatitis B and C is then conducted. In the US, donor tissue must be recovered and processed adhering to the

Current Good Tissue Practices Good tissue practice (GTP) is one of the "GxP" requirements derived from good manufacturing practice. The rule was written and is enforced by the U.S. Food and Drug Administration (FDA), specifically the Center for Biologics Evaluation and Research ...

rule. In most cases, it is sent to tissue banks for processing and distribution. Each year,

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

regulated and American Association of Tissue Banks-accredited tissue banks distribute 1.5 million bone and tissue allografts.

Transplantable organs and tissues

A variety of organs and tissues can be used for allografts, including: *

Anterior cruciate ligament The anterior cruciate ligament (ACL) is one of a pair of cruciate ligaments (the other being the posterior cruciate ligament) in the human knee. The two ligaments are also called "cruciform" ligaments, as they are arranged in a crossed formation ...

(ACL) repair * Joint reconstruction in the

knee In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...

and

ankle The ankle, or the talocrural region, or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular join ...

* Meniscal replacement * Reconstruction due to cancer or trauma * Ridge augmentation in dental procedures * Shoulder repair *

Spinal fusion Spinal fusion, also called spondylodesis or spondylosyndesis, is a neurosurgical or orthopedic surgical technique that joins two or more vertebrae. This procedure can be performed at any level in the spine (cervical, thoracic, or lumbar) and pre ...

* Urological procedures *

Skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...

transplants *

Cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...

l transplants * Heart transplants *

Heart valve A heart valve is a one-way valve that allows blood to flow in one direction through the chambers of the heart. Four valves are usually present in a mammalian heart and together they determine the pathway of blood flow through the heart. A heart v ...

s * Lung transplantation * Intestinal transplantation (isolated small bowel, intestine & liver, multivisceral) * Liver transplants *

Kidney transplants Kidney transplant or renal transplant is the organ transplant of a kidney into a patient with end-stage kidney disease (ESRD). Kidney transplant is typically classified as deceased-donor (formerly known as cadaveric) or living-donor transplantati ...

Pancreas transplantation A pancreas transplant is an organ transplant that involves implanting a healthy pancreas (one that can produce insulin) into a person who usually has diabetes. Overview Because the pancreas is a vital organ, performing functions necessary in the ...

Islet cell transplantation Islet transplantation is the transplantation of isolated islets from a donor pancreas into another person. It is an experimental treatment for type 1 diabetes mellitus. Once transplanted, the islets begin to produce insulin, actively regulating th ...

Bone marrow transplant Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood in order to replicate inside of a patient and to produce ...

s *

Bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

allograft *

Ligament A ligament is the fibrous connective tissue that connects bones to other bones. It is also known as ''articular ligament'', ''articular larua'', ''fibrous ligament'', or ''true ligament''. Other ligaments in the body include the: * Peritoneal li ...

tendon A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...

allograft

Laws and regulations

United States

In the US, the

(FDA) has regulated human tissue intended for transplants since 1993. In order to ensure the quality of donor tissue and reduce contamination and disease transmission risks, three regulations addressing manufacturing activities associated with human cells, tissues, and cellular and tissue-based products (HCT/Ps) were promulgated in May 2005: * companies producing and distributing HCT/Ps must register with the FDA. * "Donor Eligibility" rule: prescribes criteria for donor eligibility. * "Current Good Tissue Practices" rule: oversees overall processing and distribution practices of each company.

Other transplant options

Autograft Autotransplantation is the transplantation of organs, tissues, or even particular proteins from one part of the body to another in the same person ('' auto-'' meaning "self" in Greek). The autologous tissue (also called autogenous, autogene ...

, tissue transplanted from one site to another on the same patient. An autograft reduces the risk of rejection but requires a second surgery site, adding pain, risk and possible longer aftercare. *

Xenograft Xenotransplantation (''xenos-'' from the Greek meaning "foreign" or strange), or heterologous transplant, is the transplantation of living cells, tissues or organs from one species to another. Such cells, tissues or organs are called xenograft ...

, a transplant from another species *

Isograft An Isograft is a graft of tissue between two individuals who are genetically identical (i.e. monozygotic twins). Transplant rejection between two such individuals virtually never occurs, making isografts particularly relevant to organ transplanati ...

, a transplant from a genetically identical donor, such as an identical twin. * Synthetic and metal implants. Unlike allografts, such grafts do not corporate into the body.

Risks

As with many operations, allotransplantation risks some side effects. A limiting factor in tissue allotransplantation for reconstructive surgery deals with the side effects of

immunosuppression Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse react ...

(metabolic disorders, malignancies, opportunistic infections) which is a predominant issue. The risk of transmitting infection is high.

References

External links

* https://web.archive.org/web/20160303183943/http://www.aatb.org/files/safetyoftissuetransplants.pdf * https://www.cdc.gov/ncidod/dhqp/tissueTransplantsFAQ.html#top * https://www.fda.gov/BiologicsBloodVaccines/TissueTissueProducts/default.htm * https://web.archive.org/web/20101126080809/http://organdonor.gov/donor/registry.shtm (How to register to be a donor in the USA)
Allogeneic stem cell transplantation
entry in the public domain NCI Dictionary of Cancer Terms
Allogeneic bone marrow transplantation
entry in the public domain NCI Dictionary of Cancer Terms {{Organ transplantation Transplantation medicine Immunology