ACLF Grading System
ACLF is classified into four distinct grades (No ACLF, Grade 1a, Grade 1b, Grade 2, and Grade 3) based on the number and type of organ failures, with 28-day mortality ranging from <5% in patients without ACLF to 78% in Grade 3 ACLF. 1
Grading Classification
The EASL-CLIF grading system stratifies patients with acute decompensation of cirrhosis based on organ failure patterns assessed by the CLIF-SOFA score: 1
No ACLF
- No organ failure present 1
- Single non-kidney organ failure with creatinine <1.5 mg/dl and no hepatic encephalopathy 1
- 28-day mortality: <5% 1
ACLF Grade 1a
ACLF Grade 1b
- Single non-kidney organ failure (liver, coagulation, circulation, or lungs) combined with creatinine 1.5-1.9 mg/dl and/or hepatic encephalopathy grade 1-2 1
- Cerebral failure combined with mild renal dysfunction (creatinine 1.5-1.9 mg/dl) 1
- 28-day mortality: approximately 23% 2
ACLF Grade 2
ACLF Grade 3
- Three or more organ failures 1
- 28-day mortality: 78% 1
- Patients with ≥4 organ failures or CLIF-C ACLF score >64 at days 3-7 who do not undergo liver transplantation have 100% mortality by 28 days 3
Organ Failure Definitions
The CLIF-SOFA score defines organ failures across six systems: 1
- Liver failure: Bilirubin ≥12 mg/dl 1
- Kidney failure: Creatinine ≥2 mg/dl 1
- Cerebral failure: Hepatic encephalopathy grade III-IV 1
- Coagulation failure: INR ≥2.5 or platelet count ≤20,000/mm³ 1
- Circulatory failure: Use of vasopressors (dopamine >5 μg/kg/min or any dose of epinephrine/norepinephrine) 1
- Respiratory failure: PaO₂/FiO₂ ≤200 or SpO₂/FiO₂ ≤214 1
Clinical Significance
The kidney and brain receive special attention in ACLF grading because even mild dysfunction in these organs (creatinine 1.5-1.9 mg/dl or hepatic encephalopathy grade 1-2) combined with another organ failure significantly increases short-term mortality to ≥15% at 28 days. 1
The grading system is dynamic—approximately 81% of patients reach their final ACLF grade within 1 week, making assessment at days 3-7 critical for accurate prognostication and determining need for liver transplantation versus futility of care. 3 ACLF can resolve or improve in 49.2% of patients, remain steady or fluctuate in 30.4%, and worsen in 20.4%. 3
Prognostic Tools
The CLIF-C ACLF score incorporates the CLIF-C Organ Failure score, age, and white blood cell count, providing superior prognostic accuracy compared to MELD or MELD-Na for patients with ACLF. 4, 5 Sequential CLIF-SOFA evaluations provide more accurate prognostic information than single assessments. 5