A Critical Review of MELD as a Reliable Tool for Transplant Prioritization

Abstract

In a context of global organ shortage, the Model for End-Stage Liver Disease (MELD) score seems to be a fair prioritization tool, with a paradigm: “sickest first.” Since its introduction in the United States in 2002, it has been rapidly adopted by transplant centers and organ sharing agencies around the world. The MELD score showed its effectiveness with a 12% reduction in waiting list mortality in the United States. Its success is linked to its simplicity, the use of basic variables (serum creatinine, serum bilirubin, and international normalized ratio [INR]), and its ability to predict short-term mortality, particularly on the transplant waiting list. However, this score is not perfect: its variables may have disadvantages for some patients, especially women, with serum creatinine and interlaboratory variability of the INR. The MELD score does not take into account some variables associated with poor short-term prognosis in cirrhotic patients. In addition, it is currently capped at 40, which results in the exclusion of sicker patients who could greatly benefit from transplantation. Finally, the MELD score does not accurately reflect the prognosis of several conditions, requiring a MELD exception system. Some solutions have been suggested such as MELD-Na or MELD uncapping, but it has not yet been fully accepted by all transplant centers.

Sarco‐Model: A score to predict the dropout risk in the perspective of organ allocation in patients awaiting liver transplantation

“…This phenomenon was already observed in previous experiences in which combining sarcopenia and liver‐function models improved the diagnostic ability in patients with low MELD points 10,24 . In fact, it is well known that MELD and MELDNa outperform the other scores in patients with severe liver disease, but their ability declines in LT candidates with milder hepatic conditions 5,6 …”

“…MELD and MELDNa have shown the best usefulness among the ‘urgency’ models, namely the models able to prioritize in the list the ‘sickest‐first’ candidates 4 . However, both the MELD and MELDNa score present some limitation, and some cirrhotic patients may be misclassified, mainly in their low classes 5,6 …”

Artificial intelligence to predict overall survivals of patients with cirrhosis and outcomes of variceal bleeding

“…[7] The MELD score was first proposed about 20 years ago to measure mortality risk and select candidates for a transjugular intrahepatic portosystemic shunt. [8] The MELD score circumvented many drawbacks of the CTP with objective variables, no ceiling effect, and the incorporation of widely available laboratory tests and measures of renal function, as well as ease of use and strong validation. Nonetheless, the MELD score also has weaknesses: There are disparities based on gender and race, several conditions still require exceptions, INR values can vary between laboratories, and since the creatinine level is dependent on muscle mass, it is less valuable in cases of cirrhosis.…”

The Inside-Out of End-Stage Liver Disease: Hepatocytes are the Keystone

“…The MELD score ranges from 6 to 40 and is currently used to determine how urgently a patient may need LT. Later iterations have suggested adding sodium measurements (MELD-Na) or removing the 40-point max score as potential changes to improve the clinical capabilities; however, neither has yet to be fully accepted by the transplant community. 54 Clinical manifestations in patients with ESLD are directly related to specific alternated metabolic pathways in failing hepatocytes and these pathways are regulated by specific genes and transcription factors. Current knowledge regarding control of cellular gene expression programs has had an important impact on our understanding of misregulation of gene expression in disease.…”