Understanding MELD Scores for Liver Transplantation

In the United States, thousands of people are currently on the waiting list to receive a liver. The national transplant candidate waiting list for all organs is managed by the United Network for Organ Sharing (UNOS). UNOS also operates a 24/7 electronic matching system accessible to every organ procurement organization (OPO) and transplant center in the country.

The private non-profit organization serves as the Organ Procurement and Transplantation Network (OPTN) under contract with the Health Resources and Services Administration of the U.S. Department of Health and Human Services.

How are patients prioritized on the liver transplant wait list?

In 2002 the Model for End-Stage Liver Disease (MELD) system was adopted by UNOS as the system for assessing the severity of patients’ liver disease in order to prioritize organ allocation for liver transplantation. Every transplant center in the country follows the MELD system.

What is a MELD score?

MELD is a numerical scale ranging from six to 40 and is used for liver transplant candidates age 12 and older. Pediatric End-Stage Liver Disease (PELD) is a similar model used for patients younger than 12.

How is your MELD score calculated?

The scores are calculated using a mathematical formula based on lab results which determine how urgently a patient needs a transplant in the next three months. The higher the score, the more gravely ill a patient is. In January 2016, the MELD score was updated and may now be referred to as the MELD-Na score.

Which lab results determine your MELD score?

The lab test results that inform the MELD-Na score are:

• Total bilirubin, which measures how effectively the liver excretes bile;
• International Normalized Ratio (INR), which measures the liver's ability to make blood clotting factors; and
• Creatinine, which measures kidney function;
• Serum sodium, which measures the severity of conditions such as portal hypertension which can be caused by cirrhosis.

How does the MELD score work for children?

Pediatric End-Stage Liver Disease (PELD) is a similar model used for patients younger than 12. PELD scores use similar lab results as the MELD score but include an additional serum albumin test and weigh factors such as growth, development and age of the child.

How often is your MELD score updated?

Once a patient is placed on the liver transplant list, clinicians will order these lab tests on a regular basis. Patients with greater liver disease severity (i.e., higher MELD scores) have their MELD scores updated more frequently compared with patients with less severe liver disease.

Can patients receive additional points to the calculated MELD score?

UNOS awards extra points for certain diagnoses treatable by liver transplantation not accounted for by the MELD score. A UNOS National Liver Review Board functions to award defined additional points for specific diagnoses. Established exception points are awarded for following diagnoses:

• Hepatocellular carcinoma tumors meeting specific criteria including size
• Hilar cholangiocarcinoma tumors that have met size and treatment criteria
• Hepatopulmonary syndrome
• Metabolic diseases
• Portopulmonary hypertension

Transplant programs apply for these additional points and appeal processes exist for additional diagnoses.

Are there exceptions to the MELD score?

There is an exception to the MELD system when a patient is categorized as Status 1A and 1B.

• Status 1A patients have sudden and severe onset liver failure and a life expectancy of hours to a few days without a liver transplant.
• Status 1B patients are chronically ill pediatric patients.
• Less than 1% of all liver transplant candidates, adult and pediatric, are in these categories at one time.