PELD Score

PELD score explained

The Pediatric End-stage Liver Disease stratifies the severity of liver disease in pediatric patients that are listed for hepatic transplant.

The model is used by the United Network for Organ Sharing (UNOS) and is addressed to children below the age of 12, while the adult equivalents of the score are MELD and MELD-Na.

There are five patient variables taken into account. Patient age is considered to exclude patients over 12 years old and to offer provision in the study for patients listed for transplant during the first year of life.

Bilirubin and albumin, both blood determinations of liver function, are considered in the calculation.

The INR, International Normalized Ratio for prothrombin time shows the existence of a coagulopathy due to liver failure.

In case history of growth failure is present, a factor of 0.667 is added to the formula. This takes account of the weight and height development of the patient.

The PELD score is therefore based on the following formula:

PELD Score = 10 x (0.480 x ln(bilirubin) + 1.857 x ln(INR) - 0.687 x ln(albumin) + 0.436 (if patient under 12 months) + 0.667 (if history of growth failure positive).

Higher scores are correlated with more critical conditions therefore, the higher the PELD score, the higher the mortality risk.

About the study

The original study conducted by McDiarmid involved data from the Studies of Pediatric Liver Transplantation (SPLIT) and was aimed at creating a score that can use verifiable and objective parameters in order to prioritize pediatric patients suffering from chronic liver disease.

Initially, 17 factors were taken in consideration, from which 6 remained. In the end, glomerular filtration rate, which was the sixth, was also excluded as not significant enough.

The score’s functionality was also compared against the MELD score.

A subsequent validation study evaluated the PELD score as a severity index on a cohort of 104 patients with biliary atresia.

This has shown that PELD profiling is a useful scoring system for patients with severe liver dysfunction caused by biliary atresia, however, the model was not validated in long term complications.

Cirrhosis staging

The first stage of liver damage is inflammation (usually hepatitis), fatty deposits called steatosis and scaring of the liver (known as fibrosis).

The following stage is cirrhosis which is also graded from A to C, from relatively mild to severe.

Cirrhosis can be compensated or decompensated. In the latter, the liver is uncappable of fulfilling its function and this can lead to complications and comorbidities such as portal hypertension, ascites or encephalopathy.

Original study

McDiarmid SV, Anand R, Lindblad AS; Principal Investigators and Institutions of the Studies of Pediatric Liver Transplantation (SPLIT) Research Group. Development of a pediatric end-stage liver disease score to predict poor outcome in children awaiting liver transplantation. Transplantation. 2002; 74(2):173-81.

Validation

Shinkai M, Ohhama Y, Take H, Fukuzato Y, Fujita S, Nishi T. Evaluation of the PELD risk score as a severity index of biliary atresia. J Pediatr Surg. 2003; 38(7):1001-4.

Other references

1. Barshes NR, Lee TC, Udell IW, O'mahoney CA, Karpen SJ, Carter BA, Goss JA. The pediatric end-stage liver disease (PELD) model as a predictor of survival benefit and posttransplant survival in pediatric liver transplant recipients. Liver Transpl. 2006; 12(3):475-80.

2. Shneider BL, Neimark E, Frankenberg T, Arnott L, Suchy FJ, Emre S. Critical analysis of the pediatric end-stage liver disease scoring system: a single center experience. Liver Transpl. 2005; 11(7):788-95.