Patients are prioritized on the waiting list based on a MELD (Model for End-stage Liver Disease) score. The goal with the MELD score is to have the sickest patient transplanted first. It is a predictor of patient’s likelihood of death with liver disease. It is a numerical score from 6 (healthier) to 40 (sicker). It is derived form 3 lab values bilirubin, creatinine, and INR. Patients with the highest MELD score is considered first for the liver. A patient’s MELD can vary from month to month based on lab work.
BILIRUBIN
Bilirubin is produced by the normal breakdown of red blood cells. It’s the substance that gives bile its yellow-green color. Normally, bilirubin passes through the liver and is eventually excreted through the body. But if that’s not happening as it should because of a liver disease or other health problem, bilirubin levels can rise. When high bilirubin levels accumulate in the blood, the skin can take on the yellow discoloration known as jaundice.
CREATININE
A chemical waste molecule that is generated from muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles. Approximately 2% of the body’s creatine is converted to creatinine every day. Creatinine is transported through the bloodstream to the kidneys. The kidneys filter out most of the creatinine and dispose of it in the urine.
Although it is a waste, creatinine serves a vital diagnostic function. Creatinine has been found to be a fairly reliable indicator of kidney function. As the kidneys become impaired the creatinine will rise. Abnormally high levels of creatinine thus warn of possible malfunction or failure of the kidneys, sometimes even before a patient reports any symptoms. It is for this reason that standard blood and urine tests routinely check the amount of creatinine in the blood.
INR
International normalized ratio, a system established by the World Health Organization (WHO) and the International Committee on Thrombosis and Hemostasis for reporting the results of blood coagulation (clotting) tests. All results are standardized using the international sensitivity index for the particular thromboplastin reagent and instrument combination utilized to perform the test.
For example, a person taking the anticoagulant (“blood thinner”) warfarin (brand name: Coumadin) might optimally maintain a prothrombin time (a “pro time” or PT) of 2 to 3 INR. No matter what laboratory checks the prothrombin time, the result should be the same even if different thromboplastins and instruments are used. This international standardization permits the patient on warfarin to travel and still obtain comparable test results.
