Who is a candidate for a liver transplant?
To determine who is in the most critical need of a liver transplant, the United Network for Organ Sharing (UNOS) uses a system in the US that includes the Model for End-Stage Liver Disease (MELD) scoring system for adults and the Pediatric End-Stage Liver Disease (PELD) scoring system for children under 18 years of age. These scoring methods were set up so that donor livers could be distributed to those who need them most urgently, not just who had been on the waiting list the
longest.
In early 2002, UNOS enacted a major modification to the way in which people were assigned the need for a liver transplant. Previously, patients awaiting livers were ranked as status 1, 2A, 2B, and 3, according to the severity of their current disease. Although the status 1 listing has remained, all other patients are now classified using the Model for End-Stage Liver Disease (MELD) scoring system if they are aged 18 years or older, or the Pediatric End-Stage Liver Disease (PELD) scoring system if they are younger than 18 years. These scoring methods were set up so that donor livers could be distributed to those who need them most urgently.
Status 1 (acute severe disease) is defined as a patient with only recent development of liver disease who is in the intensive care unit of the hospital with a life expectancy without a liver transplant of fewer than 7 days.
MELD scoring: This system is based on the risk or probability of death within 3 months if the patient does not receive a transplant. The MELD score is calculated based only on laboratory data in order to be as objective as possible. The laboratory values used are a patient’s creatinine, bilirubin, and international normalized ratio, or INR (a measure of blood-clotting time). A patient’s score can range from 6 to 40. In the event of a liver becoming available to 2 patients with the same MELD score and blood type, time on the waiting list becomes the deciding factor.
PELD scoring: This system is based on the risk or probability of death within 3 months if the patient does not receive a transplant. The PELD score is calculated based on laboratory data and growth parameters. The laboratory values used are a patient’s albumin, bilirubin, and INR (measure of blood-clotting capability). These values are used together with the patient’s degree of growth failure to determine a score that can range from 6 to 40. As with the adult system, if a liver were to become available to two similarly sized patients with the same PELD score and blood type, the child who has been on the waiting list the longest will get the liver.
Based on this system, livers are first offered locally to status 1 patients, then according to patients with the highest MELD or PELD scores. Next, if there are no local recipients, the liver is offered regionally, in the same order, and finally, on a national level.
Status 7 (inactive) is defined as patients who are considered to be temporarily unsuitable for transplantation. |
