MELD and PELD
MELD, the Model for End-Stage Liver Disease, is a numeric scale, ranging from 6 (less ill) to 40 (gravely ill). Used for transplant candidates age 12 and older.
PELD, the Pediatric End-Stage Liver Disease, is a numeric scale for transplant candidates younger than 12. This score, recognizing children’s growth and development needs, may range higher and lower than MELD.
How is a patient’s medical urgency determined?
Liver function is essential to life. Unlike the kidney and pancreas, where other medical treatments can offset organ failure, there is no long-term treatment for liver failure other than a transplant.
Some people have a disease that reduces their liver function slowly over time. Some have a chronic liver disease that worsens quickly based on some complication. Other people suddenly develop life-threatening liver failure without having prior liver disease.
The liver transplant system strives to transplant people first whose condition is currently the most urgent. Given that the course of liver disease can be very different among transplant candidates, the system prioritizes people based on medical factors known to affect how long they may live without a transplant. Those candidates who are more medically urgent will be considered for available organs before other people who have a less immediate risk of dying without a transplant.
Status 1A and 1B
Some liver transplant candidates have a medical condition that is highly likely to lead to death very soon without a transplant. The very sickest candidates are listed either in a Status 1A or Status 1B category. They receive the highest priority for matching organs.
There are only a handful of Status 1A liver transplant candidates nationwide at any given time. They may be of any age, children or adults. They are expected to live less than seven days without a transplant, and they must meet very specific criteria outlined in OPTN policy. Examples of Status 1A conditions are having no functional liver (anhepatic), having a sudden and very severe onset of liver failure, or receiving a previous liver transplant that fails to function within seven days.
There may be a few dozen Status 1B liver transplant candidates nationwide at any given time. They are all younger than age 18, or were younger than 18 when listed for a transplant. They either have a specific diagnosis meeting requirements in OPTN policy or have a very high MELD or PELD score (see below) with severe complications.
MELD scores and PELD scores
For most liver transplant candidates, medical urgency is determined by a score that uses objective medical data. The Model for End-Stage Liver Disease (MELD) is used for transplant candidates age 12 and older. The Pediatric End-Stage Liver Disease (PELD) model is used for candidates younger than 12.
Each of these scores uses a formula that compares factors statistically proven to affect the risk of death in the short term without a liver transplant. A high MELD or PELD score means that the candidate is at higher risk than those with lower scores. MELD scores range from 6 (least sick) to 40 (most sick). PELD scores can range lower or higher than MELD scores.
MELD and PELD scores can change, higher or lower, over time based upon how the patient’s disease progresses. Candidates who remain listed a longer time for a transplant will have their score recalculated to ensure it reflects their current need. Those who are at higher levels of medical urgency will have their scores recalculated more frequently (every 30 days to every 7 days, depending on the most recent score).
Some transplant candidates have a medical condition, such as cancer or rare forms of chronic liver disease, where MELD or PELD will not accurately predict their short-term transplant need. If so, they may qualify for an “exception” score — a separately assigned score to be used instead of their calculated MELD or PELD in matching the person for available organ offers.