Kidney Transplant: Blood Tests

What Is a Kidney Transplant?

A kidney transplant is a surgical procedure used to replace a damaged or diseased kidney with a healthy donor kidney. The kidney can come from a living donor or a deceased organ donor. It may be possible for family members or other suitable candidates to donate one of their kidneys. A live transplant is the name given to this kind of transplant. Donors of kidneys can lead normal lives with just one functioning kidney. If one suffers from end-stage renal disease (ESRD), they might require a kidney transplant. Kidney failure is a permanent disease.

What Blood Tests Are Required to Determine Whether a Patient and a Possible Kidney Donor Are Compatible?

Three primary blood tests can be performed to ascertain whether a patient and a possible donor are a kidney match. They are as follows.

1. Blood typing.

2. Tissue typing.

3. Crossmatching.

What Is Blood Typing?

The initial blood test to establish whether the blood type matches the possible donor's blood type is blood typing. This test quantifies blood antibodies that have varying blood group reactions.

The initial test determines the blood type (ABO). Everybody belongs to one of the four blood types—A, B, AB, or O—which are inherited groups. The donor and the recipient must share compatible or similar blood types. The Rh type (+, -) does not affect donor matching. The donor will take the following blood test (tissue typing) if their blood type matches them. The blood types listed below get along well:

• Blood type A and AB recipients can receive donations from blood type A donors.

• Blood type B and AB recipients can receive donations from blood type B donors.

• Only recipients with blood type AB can receive donations from donors with blood type AB.

• Blood types A, B, AB, and O recipients can receive donations from donors with blood type O (O is the universal donor; donors with blood type O are compatible with all the blood types).

Thus,

• Blood type O recipients are only eligible to receive kidneys from blood type O donors.

• A kidney can be given to recipients with blood type A from blood types A and O.

• A kidney of blood types B and O can be given to recipients with blood type B.

• Receivers with blood type AB are compatible with all other blood types, making them eligible to receive kidneys from recipients with blood types A, B, AB, and O.

Even if the blood types are incompatible, the donor might still be able to give the recipient blood directly if they can lessen the blood antibody levels with treatment. Furthermore, the donor might think about giving through a paired exchange program, enabling the recipient to get a kidney from a different donor in case the intended recipient is not a match.

What Is Tissue Typing?

The initial blood test aims to compare the tissue (HLA) types of the patient and the prospective donor to evaluate how closely they match. Except for identical twins, each person's tissues are often unique. The longer the transplant is successful, the better the HLA match. A parent and kid would have a minimum of a 50 percent probability of matching, siblings may have a zero to 100 percent match, and unrelated donors would be less likely to match at all due to the way chromosomes and Deoxyribonucleic acid (DNA) are transmitted or passed down in a family. A full match is ideal for the receiver. If the patient has a highly common HLA type, then all indicators may match, even with an unrelated deceased donor organ.

The second blood test is performed only on the patient. It is repeated (sometimes monthly, but less frequently depending on the transplant program policy) to assess antibodies to human leukocyte antigens (HLA). HLA antibodies need to be tested before transplant surgery, throughout the waiting period for a transplant, and after the transplant since they can be detrimental to the donated organ and can fluctuate over time. Finding a donor with human leukocyte antigens (HLA) types that do not match the HLA antibodies in the patient's blood is the best course of action if the patient has HLA antibodies in their blood, as they are deemed HLA "sensitized." It is important to inform the transplant team about any occurrences that may have affected the HLA antibody levels, such as blood transfusions, miscarriages, minor surgeries (such as dental work or fistula replacement), or serious infections.

What Is Percent Reactive Antibody (PRA)?

One might develop an antibody to distinct HLA proteins if exposed to alien tissues, which could happen from a previous transplant, blood transfusion, or pregnancy. Patients are deemed "sensitized," the panel reactive antibody (PRA) percentage will be higher than 0 if they test positive for HLA antibodies. The blood's proportion of PRA increases with the amount of HLA antibodies present. It is crucial to have these HLA antibodies tested before transplant. Finding a suitable kidney for the recipient could be more challenging if the level of HLA antibodies is high. On the other hand, fresh methods and therapies are being created to lower the blood's antibody levels. As previously indicated, changes in HLA antibodies can affect the percentage of PRA over time.

What Is Crossmatching?

The body produces antibodies throughout life, which work to eliminate foreign objects. The body may produce antibodies every time one has an illness, becomes pregnant, receives blood transfusions, or has a kidney transplant. If an individual has antibodies to the donor's kidney, the body will destroy the kidney. That is why tests are performed to make sure one does not already have antibodies against the donor when a kidney is available for them. This test is referred to as a crossmatch.

To perform a crossmatch, the blood is combined with donor cells. An individual should not get this specific kidney if the crossmatch is positive, which indicates that the recipient has antibodies against the donor. The recipients are eligible to get this kidney if the crossmatch test is negative, indicating they do not have any antibodies against the donor.

Several crossmatches are acquired in the lead-up to a living-related donor transplant, especially if donor-specific blood transfusions are being used. Within 48 hours of the transplant, a final crossmatch is also carried out.

What Are the Other Things Included in the Blood Tests for Kidney Transplants?

• Metabolic Panel: The whole metabolic panel assesses 14 distinct chemicals in the blood and indicates renal function.

• Liver Function Panel: The liver function panel examines the liver for damage, infection, or illness.

• Lipid Panel: Assesses the risk of cardiovascular disease and cholesterol levels.

• Hemoglobin: Hemoglobin A1c is a blood sugar measurement.

• Complete Blood Count: A test that assesses general health and looks for conditions like leukemia, anemia, and infections.

• Blood Clotting: It is measured by PT/PTT/INR (partial thromboplastin/partial thromboplastin time/international normalized ratio).

• Testing for viruses, such as hepatitis, tuberculosis, EBV, syphilis, CMV, HIV, and West Nile virus.

Conclusion:

To find out if one is a suitable kidney match for the recipient they wish to donate, one will need to undergo testing. The biological compatibility of a possible transplant recipient and a living kidney donor is called a "match." There are three different kinds of tests that can be used to find compatibility. Special blood tests are required to identify the type of blood and tissue they have, irrespective of the type of kidney transplant one can receive—cadaveric or alive. These test findings aid in matching the body to a kidney donor.