Donor used in organ transplantation and compatibility conditions

Time is very important in organ transplantation as viability and post transplant functions of the graft is highly determinated by the time the organ is not supplied by circulation (ischemic time).

Cadaveric donor

Because of the organ damage caused by a prolonged ischemia, organs are procured from cadaveric donors whose heart is still beating, i.e. who died of brain death. Brain death rarely occurs and is usually observed only in intensive cares. Usually, all the functional organs are procured (multiorgan procurement) from a brain dead donor.

Organ procurement from cadaveric donors responds to standardized legal criteria (view Switzerland policies) and is done according to the agreement of the family or the previous consent of the patient.

Cadaveric vs living donors

Prior to brain death legislation, organs were routinely retrieved from donors when irreversible heart function occurs as the only organ resource. Although ischemic time may be critic, Non Heart Beating Donor (NHBD) are for now gaining acceptance as a method of donor pool expansion, particularly for kidney donation.

Living donor

Faced with cadaveric organ shortage, number of kidney living donors has significantly increased for the last decade. Living donors are also considered in liver (liver split); and, less frequently, in lung, pancreas, and small intestine transplantation. Advantages of living-donor transplantation include selection of an ideal donor, maximal time to prepare the recipient, and relatively short cold ischemia time. Living donors follow a physiological and psychiatric evaluation to ensure that they are emotionally prepared for the transplant and aftercare regimen.

Allocation of cadaveric organ

Allocation of cadaveric organs referred to the management, distribution and choice of recipient. Because the determination of the more suitable recipient have to be taken quickly, allocation is an essential link in transplantation. Allocation is coordinated by a transplantation coordination center, which is Swiss transplant in Switzerland.

Compatibility conditions and organ matching

Compatibility criteria between donor and patient has varying influence on survival rates according to the organ transplanted. However, compatibility criteria are essential but balance with the availability of organs.

ABO blood group compatibility is a prerequisite to every organ transplantation. ABO group is determinated by ABO grouping. However new protocols of ABO incompatibilities for kidney and liver are under investigations.
Mismatch for HLA antigens may be tolerated depending on the organ transplanted. Influence of the degree of HLA compatibility (histocompatibility) on transplantation success depends on the type of organ transplanted. The degree of matching is determined by a series of histocompatibility tests referred to as HLA typing.
Size matching
Infectious status (HIV, Hepatitis B / C) could exclude a suitable donor
In kidney transplantation (heart and lung in specific situations), the presence of preformed antibodies against HLA may lead to hyperacute rejection. A cross match test is performed just before the transplant procedure.