What is the process of kidney transplantation?

Answer 1

Evaluation of Potential Recipients After thinking about the advantages and disadvantages, the next step is the decision by your physicians as to whether or not a transplant is a good choice for you. The decision will be based upon a thorough medical history and physical examination. It will include a chest x-ray, an EKG or ECG, abdominal ultrasound, and echocardiogram. Bladder tests may be done in order to see how well your bladder functions. Additional testing will be scheduled based on your individual medical needs. Your own kidneys may need to be removed only if medically necessary. A psychiatric evaluation may be done in order to determine your understanding of the benefits and risks as they were explained to you. It also helps to look at how you might react to the transplanted kidney or the medications. Tissue typing is done during the evaluation. This involves taking a sample of blood and analyzing it for markers on the white blood cells (antigens) that are used to match a donated kidney with a potential recipient. Evaluation for transplant includes a discussion about the patient's family and whether or not there is a person (related or not) who could donate a kidney. This is called a living donor kidney transplant. The other source of a kidney is a person who has recently died and whose family has consented to kidney donation. This is called a cadaver kidney transplant. Tissue typing and matching for both types of transplants will be discussed in a later section. Evaluation of the patient's support system is also done. It is important that transplant patients have reliable transportation at the time of transplantation, as well as for clinic follow-ups. Also, family or other support systems may be necessary to ensure the proper taking of medications, home testing, or other situations which may arise post-operatively. You can see or print a copy of our [http://www.utmb.edu/renaltx/quest.htm "Questionnaire for Transplant Evaluation."] Tissue TypingTissue typing, also called HLA typing, is a process of identifying genetic markers (antigens) on white blood cells. In the laboratory, these markers can be specifically identified. Each person inherits his antigens from his or her parents. Certain antigens are used in choosing potential recipients and donated kidneys. In order to carry out tissue typing, a blood sample is drawn and the genetic markers on the blood cells are identified. Each marker has a letter and number in its name. For example, two common antigens are known as HLA-A1 and HLA-B8. Over 100 of these antigens have been identified. Some of the antigens are more common than others. In a family with the same mother and father, children can inherit various combinations of antigens from the parents. Each child inherits 1/2 of his/her antigens from each parent. Four combinations of inherited antigens are possible. This means there is a one out of four, or a 25%, chance for an identical match between brothers and sisters as well as a 25% chance for no match at all. There is a two out of four, or 50%, chance that there will be a 3 antigen match between brothers and sisters. A 6 antigen match is the best possible match for kidney transplants, but lesser matches are used and have successful outcomes. If a potential transplant candidate has someone interested in donating a kidney, tissue typing is done to see how closely his/her antigens match the recipient. Other blood tests (including the cross-match) will be done to determine if the pair is compatible. If the transplant candidate does not have someone able to donate a kidney, the antigens identified in the recipient are used to match with a donated cadaver kidney. However, it must be clearly understood that drawing blood for tissue typing and obtaining blood samples routinely for antibody screens does not mean that someone is automatically placed on the list for a cadaver kidney. No one's name is placed on the list in the computer unless it is known that he/she is ready to become an active candidate and have his/her name placed on the list. At that time, it is necessary to talk with the transplant coordinator and give her the necessary phone numbers. When on the list, it is necessary to let the coordinators know if you are treated for any infections or are hospitalized for any reason. A transplnat cannot be performed under these conditions and we would need to put your name on hold until you are well again. Blood Type Compatibility In addition to matching donated kidneys to recipients by tissue typing, blood types must also be compatible. Blood types are identified as A, B, AB, and O. The most common type is O. Fifty percent of the population has blood type O. The next most common is blood type A with 40% of the population having this type. Only a small percent of the population has blood types B or AB. It can be seen from the diagram of blood type compatibility that a kidney from an O donor can be transplanted into a person with any blood type. A kidney from an AB donor can only go to an AB recipient. The person with AB blood can receive a kidney from a person with any blood type. Various other combinations are possible for persons with A or B blood. It is not necessary to match the positive and negative signs that are a part of a person's blood type. However, there are federal regulations that govern matching for cadaver kidneys that outline the combinations that can be used. These regulations do not apply to living donor transplants. {| border="4" cellspacing="2" | BLOOD TYPE COMPATIBILITY {| border="4" cellspacing="2" | |- valign="middle" | Donor can be type: | If the blood type of the recipient is: | |}

|- valign="middle" | O | O or A or B or AB |} {| |- valign="middle" | A | A or AB |} {| |- valign="middle" | B | B or AB |} {| |- valign="middle" | AB | AB |}

Matching Kidneys to Recipients Matching donated kidneys to recipients is based entirely upon blood group compatibility and antigen matching, not upon age, race or sex. Because of many variables involved in receiving a kidney, it is possible that some people may wait for a kidney a short time after going on the list, while others may wait a long time. Because the time it takes to obtain a cadaver kidney for a recipient is unpredictable, hemodialysis or peritoneal dialysis may be necessary during the waiting time. Even though a living donor transplant may be planned, dialysis may still be needed. Transplant and dialysis are options that work together to treat end-stage kidney disease.