How are organ donors and recipients matched? Is it based solely on the blood type?

Question

Please state your source of information.

Answer 1

It has to do with blood types and also HLA antigens.

When the human body receives an organ or tissue from another person, the immune system recognizes that organ or tissue as being foreign, and tries to "reject" the organ. Fortuntely, today, doctors have powerful medications that prevent and treat rejection.

How does the body recognize a donated organ (such as a donated kidney) as being foreign? The answer lies in the types of proteins and carbohydrate molecules on the surfaces of the tiny cells that make up the organ. There are two types of important cell surface molecules that are responsible for rejection in humans: 1) carbohydrate molecules that determine blood types (either O, A, B, or AB) and 2) protein molecules called HLA antigens. Before a transplant, tests are performed to make sure that the recipient does not have immunity to the donors ABO blood type molecules and the donor's HLA antigens.

In a first step, doctors make sure that the donor and recipient have blood types that are compatible. If the blood types are not compatible, immediate rejection of the kidney is likely to occur. Most transplant centers around the world will not perform a kidney transplant if the blood types are not compatible.

In a second step, doctors perform a test called a crossmatch test. that determines whether the recipient has immunity to the donor's HLA antigens. So how does a person develop immunity to someone else's HLA antigens? The answer is simiple: immunity to HLA antigens may develop when a person's immune system comes in contact with another person's cells, tissues, or organs. This can occur with blood transfusions, organ or tissue transplants, or even pregnancy. Pregnancy is the most common cause of HLA immunity, because the baby has the HLA antigens of the father, which often come in contact with the mother's immune system.

So what happens if HLA immunity is present, and a transplant is performed? The answer is that there is a high risk of the recipient experiencing a very rapid rejection (within hours of the transplant), called hyperacute rejection.

If the donor and recipient have compatible blood types and the crossmatch test is negative (that is the recipient does not have immunity to the donor's HLA antigens) the transplant can be safely performed.

However, one of the most common reasons that a willing living donor cannot donate to their loved one is because they have the wrong blood type, or there is a positive crossmatch with the recipient. These donors and recipients may benefit from paired donation, which will allow the donor to donate and the recipient to receive a living donor kidney.

Answer 2

The blood type must be compatible or the antigens in the blood must match in order for the body not to reject the organ (6 of 6, 3 of 6, and zero match comes from that). anti rejection drugs allow someone with a 3 of 6 match to not reject the organ.

Answer 3

Autum, I had read an article on this very thing not too long ago. I find it very interesting. Some people even claim they crave food they never had a want of before. I don't think I have many talents to pass on. I would hope the person getting my blood or parts would not pick up my tendency to worry or pessimistic nature.

Answer 4

Programs for Donor/Recipient Pairs with Incompatible Blood Types

Kidney donors must have a compatible blood type with the recipient. In living donation, the following blood types are compatible:

Donors with blood type A... can donate to recipients with blood types A and AB
Donors with blood type B... can donate to recipients with blood types B and AB
Donors with blood type AB... can donate to recipients with blood type AB only
Donors with blood type O... can donate to recipients with blood types A, B, AB and O (O is the universal donor: donors with O blood are compatible with any other blood type)
So,

Recipients with blood type O... can receive a kidney from blood type O only
Recipients with blood type A... can receive a kidney from blood types A and O
Recipients with blood type B... can receive a kidney from blood types B and O
Recipients with blood type AB... can receive a kidney from blood types A, B, AB and O (AB is the universal recipient: recipients with AB blood are compatible with any other blood type)
Some programs are available to help donor/recipient pairs with blood types that are otherwise incompatible: paired exchange and plasmapheresis.

Paired Exchange

Sometimes a loved one may want to donate a kidney but their blood type is incompatible. Some transplant centers will help incompatible pairs of recipient/donors through a process called paired exchange, which involves two living donors and two recipients. If the recipient from one pair is compatible with the donor from the other pair, and vice versa— the transplant center may arrange for a “swap”—for two simultaneous transplants to take place. This allows two transplant candidates to receive organs and two donors to give organs though the original recipient/donor pairs were unable to do so with each other.

Again, both donors and candidates are carefully evaluated and tested medically and psychologically to assure that the benefits outweigh the risks. It is important for both surgeries to be scheduled for the same time in case either donor changes their mind at the time of surgery. Surgeries can take place at the same or different hospitals. It can be advantageous if the surgeries take place at the same hospital though this may mean extra costs of travel and housing for one couple.

Plasmapheresis

New protocols consisting of medications, spleen removal, and a form of blood filtering called plasmapheresis are allowing transplant candidates to receive kidneys from live donors with blood types that have traditionally been deemed incompatible.

Until now, a transplant patient could only receive an organ from someone with a compatible blood type. An organ from an incompatible blood type would be perceived as foreign and vulnerable to attack by the recipient's natural antibodies.

Now, through a process of immune conditioning, a recipient is able to receive a kidney from a donor of a different blood type. This new procedure is currently being provided at a limited number of transplant centers.

The new protocol involves testing the proposed recipient to assess the risk of rejection from harmful antibodies. Next the recipient undergoes plasmapheresis, a process involving the removal of the plasma portion of the blood that contains harmful antibodies and the administration of a medication to prevent their production. The patient is then ready to undergo transplant surgery where, in addition to receiving a donor organ, the patient's spleen is removed using minimally invasive surgical techniques. In some cases, spleen removal can be avoided through the use of a new drug that creates similar effects.

Post transplant, the patient undergoes additional plasmapheresis treatments before being discharged from the hospital. He or she will then take the same immunosuppression medications as patients receiving a compatible kidney.

Answer 5

Yes

Answer 6

No you have to match in a lot of different areas...