Q: What is FIB-4 and how is it interpreted?

FIB-4 (Fibrosis-4 Index) = (Age × AST) ÷ (Platelets × √ALT). It estimates hepatic fibrosis non-invasively. In patients aged 35–65: FIB-4 <1.30 = low risk (F0–F1, rules out advanced fibrosis with NPV ~90%); 1.30–2.67 = indeterminate (requires further evaluation with elastography or biopsy); >2.67 = high risk for advanced fibrosis (F3–F4). FIB-4 is now recommended by AASLD as the first-line non-invasive test for liver fibrosis in NAFLD/MASLD.

Q: What does the AST/ALT ratio indicate?

An AST/ALT ratio >2:1 is characteristic of alcoholic liver disease (due to pyridoxal phosphate deficiency impairing ALT synthesis). A ratio >3:1 strongly suggests alcohol as the cause. In viral hepatitis, non-alcoholic fatty liver disease, and most other causes, ALT typically exceeds AST (ratio <1). An elevated ratio in known cirrhosis may suggest progression regardless of etiology. The ratio should always be interpreted alongside clinical context and absolute transaminase levels.

Question 1

When should I use the Rockall score vs Glasgow-Blatchford score?

Accepted Answer

Use the Glasgow-Blatchford score (GBS) pre-endoscopy to identify patients who need intervention — a GBS of 0 is safe for outpatient management with sensitivity near 99% for avoiding intervention. Use the complete Rockall score post-endoscopy (after seeing the lesion) to predict re-bleeding and mortality. GBS is the preferred triage tool; Rockall guides post-procedure risk stratification. AIMS65 is an alternative pre-endoscopy tool that predicts inpatient mortality.

Question 2

How is the MELD score used for liver transplant prioritization?

Accepted Answer

MELD (Model for End-Stage Liver Disease) uses bilirubin, INR, creatinine, and sodium (MELD-Na) to predict 90-day mortality in cirrhosis. UNOS uses MELD-Na for organ allocation — higher scores receive priority. MELD <10: low priority; 10–18: moderate; 19–24: high; ≥25: very high. MELD ≥15 is the threshold where transplant survival benefit typically exceeds surgical risk. MELD 3.0 (2022) incorporates sex-based adjustments to reduce gender disparity.

Question 3

What is FIB-4 and how is it interpreted?

Accepted Answer

FIB-4 (Fibrosis-4 Index) = (Age × AST) ÷ (Platelets × √ALT). It estimates hepatic fibrosis non-invasively. In patients aged 35–65: FIB-4 <1.30 = low risk (F0–F1, rules out advanced fibrosis with NPV ~90%); 1.30–2.67 = indeterminate (requires further evaluation with elastography or biopsy); >2.67 = high risk for advanced fibrosis (F3–F4). FIB-4 is now recommended by AASLD as the first-line non-invasive test for liver fibrosis in NAFLD/MASLD.

Question 4

How is Child-Pugh classification used clinically?

Accepted Answer

Child-Pugh scores bilirubin, albumin, PT/INR, ascites, and hepatic encephalopathy (5 variables, 1–3 points each). Class A (5–6): well-compensated cirrhosis, good surgical candidate; Class B (7–9): significant functional compromise; Class C (10–15): decompensated, poor prognosis. Child-Pugh C predicts 1-year survival of approximately 45%. It guides surgical risk assessment, TIPS candidacy, and identifies patients needing transplant evaluation — though MELD is now preferred for transplant listing.

Question 5

What BISAP score predicts severe pancreatitis?

Accepted Answer

BISAP (Blood urea nitrogen >25, Impaired mental status, SIRS criteria, Age >60, Pleural effusion) is scored at 24 hours. Score 0–1: low risk (<1% mortality); 2: ~2%; 3: ~5–6%; 4–5: ~15–20%. BISAP ≥3 suggests severe acute pancreatitis warranting ICU-level monitoring. It is simpler than Ranson's criteria (which requires 48-hour data) and comparable in predictive accuracy. Early aggressive IV fluid resuscitation remains the cornerstone of pancreatitis management regardless of score.

Question 6

What does the AST/ALT ratio indicate?

Accepted Answer

An AST/ALT ratio >2:1 is characteristic of alcoholic liver disease (due to pyridoxal phosphate deficiency impairing ALT synthesis). A ratio >3:1 strongly suggests alcohol as the cause. In viral hepatitis, non-alcoholic fatty liver disease, and most other causes, ALT typically exceeds AST (ratio <1). An elevated ratio in known cirrhosis may suggest progression regardless of etiology. The ratio should always be interpreted alongside clinical context and absolute transaminase levels.

Gastroenterology and Hepatology Calculators

Curated Tools for Gastroenterology & Hepatology (12)

MELD Score

Child-Pugh Score

Rockall Score

Glasgow-Blatchford

AIMS65

FIB-4

APRI Score

NAFLD Fibrosis Score

BISAP Score

AST/ALT Ratio

Anion Gap

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