Organ transplantation was a major miracle and breakthrough in the medical field. Heart, lung and liver transplants are life saving procedures apart from this there is kidney and pancreas transplantation and some of these enhance a patient's quality of life. The use of organs from human organ donors, and their transplantation into patients having an organ failure has lead to successful allotransplantations (allo-other). The use of human organs for transplantation was not feasible as there was an acute shortage of the organs and the people who wanted transplants had to wait for years and die in this process. The mortality rate is high and in order to overcome this problem organ from other species was thought as an option. This is called as xenotransplantation (xeno-foreign). Use of xenogenic cells is a key to bridge the gap between organ supply and demand. The first attempt to conduct a xenotransplant (XTs) was in the 1960s where a chimpanzee's kidney was transplanted.
Transplantation is not always a success, if the transplantation done is not accepted then there is graft rejection. Prior to any transplantation, tests have to be conducted. First and foremost performing a physical exam and checking the medical history of the donor is essential.
Blood tests: These are done to check if the donor has any transmittable diaseases/malignant tumours/latency infections.
Electocardiogram and echocardiogram: Used to check the function of stability is important before any organ transplantation. Echocardiagram takes pictures created by sound waves bounced off by heart. An electrocardiogram measures electrical activity in heart.
CT scans: Here one can view the detailed anatomy of the liver and e donor kidneys.
Aeteriogram: X-ray where a dye is injected to study the arteries going into the kidneys via a small tube placed through the groin.
Viral testing: It is important to know if the donor is exposed to virus, hepatitis or AIDS before a transplant.
Tissue typing: Done on WBCs. The WBCs have special markers that tell you the tissue type you have.
Pannel reactive antibody: Anyone is a donor HLA type against many HLA types and if one has antibodies against the common ones the transplant is tough. This is called %PRA. This shows how active our immune system is.
Cross matching: This is the final pre transplant immunologic screening step. The types are complement-dependent cytotoxicity crossmatch (CDC), B cell crossmatch and flow cytometry crossmatch. CDC seeks to identify clinically significant donor specific HLA antibody mediated responses for a given recipient. Donor lymphocytes are isolated and segregated into T and B cells. The serum from the recipient is extracted and mixed with the lymphocytes in a multi-well plate. Complement which is derived from rabbit serum is added. If donor-specific antibody is present and binds to donor cells, the complement cascade will be activated via the classical pathway and destroy the lymph. Grading is done to determine strength of crossmatch.
B cell crossmatch is a part of CDC crossmatch. B-cell crossmatches are often performed as part of the immunologic assessment before live donor transplantation when there is more time to determine the significance of the result.
Flow cytometry crossmatching is performed using the same donor lymphocytes and recipient serum as CDC and was first described in 1983. Antibody binding is allowed to occur and after washing, fluoresceinated antihuman globulin (AHG) is added to bind attached donor-specific antibodies (DSAbs) and hence allow detection by flow cytometry. The read-out may be reported as positive or negative or can be further quantitated. Although a positive lymphocytotoxic crossmatch is a contraindication to kidney transplantation, the place of flow cytometry cross match is still controversial, this test can detect very low levels of circulating antibodies.
There are many ethical issues involved in organ transplantation and they are tightly regulated worldwide. Transplants from dead or deceased have concerns which include respect for dead and their wishes, respecting family's wishes. In this light if people do want to donate their organs after their death may wish o specify their limits. Transplants between the living and recipient raise questions whether it is ethical to mutilate one living person for the benefit of another. No one can be forced to donate an organ or a part of it only the individual living has the right to take decisions. In case of a mentally related patient/child the guardian can take the decision for that person. There is a debate to take tissues/organs from the fetuses to benefit others. However this is considered gravely immoral by some sections of the world. Ethical issues regarding the recipient are widely accepted. The recipient should be well informed regarding the benefits, risks, burdens and costs of transplant. Recipients must avoid any unethical cooperation in any abuses for instance procuring the organs illegally. Consent forms are finally the most important in any transplantation procedure. If there is xeno transplant where there is transfer of organs from different species then there is a need to brief the patient about this as some are very dicey about the whole scenario.
However, even with all these drawbacks transplantation has saved the life of many and will continue to save many more in the future.
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