What is the scoring system used to assess the severity of liver disease in children?

Pediatric End-Stage Liver Disease (PELD) Score: Assessment of Liver Disease Severity in Children

The Pediatric End-Stage Liver Disease (PELD) score is the primary scoring system used to assess the severity of liver disease in children under 12 years of age, utilizing objective parameters including total serum bilirubin, INR, albumin, growth failure, and age less than 1 year to predict mortality risk and prioritize children for liver transplantation. 1

Components of the PELD Score

The PELD score incorporates five key objective parameters:

• Total serum bilirubin: Higher values indicate more severe disease 1
• International Normalized Ratio (INR): Measures coagulation status 1
• Serum albumin: Lower values indicate poorer synthetic function 1
• Growth failure: Defined as height or weight Z-score <-2 (more than 2 standard deviations below age and gender norms) 1, 2
• Age less than 1 year: Younger children have higher risk 1, 3

Clinical Application and Limitations

• PELD was developed from the Studies of Pediatric Liver Transplantation (SPLIT) database to predict mortality risk in children awaiting liver transplantation 1, 4
• The score is used for children under 12 years of age, while the Model for End-stage Liver Disease (MELD) is used for children 12 years and older 1
• Despite its implementation, studies have shown that just over 50% of children undergo liver transplantation with their calculated PELD score, with the remainder requiring exception points or Status 1 listing 1, 5
• Regional variations exist in PELD score utilization across transplant centers 1, 6

PELD Exceptions

When the calculated PELD score does not accurately reflect disease severity, exceptions can be requested:

• Appeal letters can be submitted to the Regional Review Board (RRB) 1
• Conditions warranting PELD adjustments include:
  • Failure to thrive 1
  • Intractable ascites 1
  • Pathologic bone fractures 1
  • Refractory pruritus 1
  • Hemorrhage due to portal hypertension complications 1

Special Considerations for Specific Conditions

• Children with urea cycle disorders or organic acidemia are automatically assigned a PELD score of 30 1
• If transplantation doesn't occur within 30 days, these children may be listed as Status 1B 1
• Similar policy exists for hepatoblastoma, though the 30-day waiting period at PELD 30 is no longer required 1
• Hospitalization is not required for Status 1B listing in these cases 1

Known Limitations and Concerns

• The growth failure threshold in PELD creates a "growth failure gap" where children with Z-scores <-2 may not meet PELD criteria, potentially losing 6-7 PELD points 2
• Children in this gap have higher waitlist mortality risk (adjusted SHR 1.78) and post-transplant mortality risk (adjusted HR 1.55) 2
• For children without exception points, waitlist mortality risk nearly triples for those in the growth failure gap 2
• The assigned 3-month mortality risk associated with PELD scores may be understated, necessitating exceptions when children compete with adults for donor organs 6

Clinical Implications

• Early referral to a pediatric liver transplant center is crucial for multidisciplinary care in children with liver failure 1
• Establishing the etiology of liver failure is important to identify conditions treatable without transplantation or contraindicated for transplantation 1
• The PELD system requires ongoing assessment and potential revision to address disparities and improve outcomes for children awaiting liver transplantation 5, 6, 2