Key Differences Between APASL and EASL Definitions of Acute-on-Chronic Liver Failure (ACLF)
The APASL and EASL definitions of ACLF differ significantly in their underlying philosophy, patient population, precipitating events, and organ failure criteria, leading to different prognostic implications and management approaches.
Core Conceptual Differences
APASL defines ACLF as an early-stage disease characterized by acute liver dysfunction triggered primarily by intrahepatic precipitants, while EASL-CLIF defines it as a more advanced condition with both hepatic and extrahepatic organ failures 1
APASL criteria are more sensitive but less specific, identifying patients at an earlier stage with lower 28-day mortality, while EASL criteria identify patients at intermediate to late stages with higher mortality 1
APASL focuses primarily on liver failure parameters, while EASL incorporates a multi-organ failure assessment system 1
Differences in Underlying Chronic Liver Disease
APASL definition applies to both patients with cirrhosis without prior decompensation and those with non-cirrhotic chronic liver disease 1
EASL definition applies only to patients with cirrhosis, including those with previous decompensation 1
This fundamental difference reflects the regional variation in liver disease etiology, with viral hepatitis (especially HBV) being more common in Asia 2, 3
Differences in Precipitating Events
APASL does not consider bacterial infections, gastrointestinal bleeding, or surgery as potential precipitating events for ACLF 1
EASL recognizes both intrahepatic and extrahepatic insults (including bacterial infections, GI bleeding, and surgery) as potential precipitants 1
This distinction significantly impacts patient identification and management approaches 3, 4
Organ Failure Assessment
APASL primarily focuses on liver failure parameters (bilirubin and coagulopathy) without systematically incorporating extrahepatic organ failures 1, 5
EASL uses the CLIF-SOFA scoring system to evaluate six major organ systems: liver (bilirubin), coagulation (INR), brain (encephalopathy), kidney (creatinine), circulation (blood pressure/vasopressors), and respiration (PaO2/FiO2 ratio) 1
EASL grades ACLF severity based on the number of organ failures (ACLF-1, ACLF-2, ACLF-3), which directly correlates with mortality risk 1
Mortality Prediction
Patients meeting only APASL criteria have significantly better survival rates compared to those meeting both APASL and EASL criteria 5, 4
EASL criteria better predict short-term mortality, with 28-day mortality rates of approximately 37.6% compared to 41.9% for APASL criteria 6, 5
The 90-day mortality rates are 50.4% for EASL ACLF and 56.1% for APASL ACLF 6
Clinical Implications
The discordance between definitions leads to different patient populations being identified, with one study showing only 62.8% of patients meeting both criteria 4
EASL criteria identify patients with more severe disease requiring intensive care management and potential organ support 1
APASL criteria may identify patients earlier in their disease course, potentially allowing for more preventive interventions 1
Harmonization Efforts
The World Gastroenterology Organization has proposed a working definition to bridge the gap between these regional definitions 3
Recent efforts are focused on harmonizing the definitions to improve research consistency and clinical care 2
The American Association for the Study of Liver Diseases (AASLD) acknowledges these differences and suggests that any definition of ACLF should include both hepatic dysfunction and extrahepatic organ failure 1
Common Pitfalls in Application
Applying the wrong regional criteria may lead to inappropriate risk stratification and management decisions 3, 4
Failure to recognize that APASL and EASL criteria identify different patient populations can lead to misinterpretation of research findings 6, 5
Over-reliance on a single definition may miss patients who would benefit from early intervention (EASL) or unnecessarily escalate care (APASL) 2, 3