CheatSheet: Hepatology

1. Viral Hepatitis

1.1 Hepatitis A (HAV)

1.2 Hepatitis B (HBV)

1.2.1 HBV Serology Patterns

1.2.2 HBV Treatment Indications

• HBeAg positive: HBV DNA >20,000 IU/mL + ALT >2× ULN or significant fibrosis
• HBeAg negative: HBV DNA >2,000 IU/mL + ALT >2× ULN or significant fibrosis
• First-line drugs: Entecavir, Tenofovir (high barrier to resistance)
• Interferon-α: 48 weeks for HBeAg positive, contraindicated in decompensated cirrhosis
• Prophylaxis in pregnancy: Tenofovir if HBV DNA >200,000 IU/mL from 28-32 weeks

1.3 Hepatitis C (HCV)

1.4 Hepatitis D (HDV)

• Defective RNA virus requiring HBsAg for replication
• Coinfection with HBV: acute hepatitis, resolves with HBV
• Superinfection in chronic HBV: severe chronic hepatitis, high cirrhosis risk
• Diagnosis: Anti-HDV IgM, HDV RNA
• Treatment: Pegylated interferon-α for 48 weeks

1.5 Hepatitis E (HEV)

2. Cirrhosis

2.1 Definitions and Classification

2.1.1 Child-Pugh Classification

• Class A: 5-6 points (1-year survival 100%, 2-year survival 85%)
• Class B: 7-9 points (1-year survival 80%, 2-year survival 60%)
• Class C: 10-15 points (1-year survival 45%, 2-year survival 35%)

2.2 Common Etiologies

• Alcohol (most common in Western countries, macronodular)
• Chronic HBV and HCV (most common worldwide)
• NASH (Non-Alcoholic Steatohepatitis)
• Autoimmune hepatitis
• Primary biliary cholangitis (AMA positive)
• Primary sclerosing cholangitis (pANCA positive, associated with IBD)
• Wilson disease (Kayser-Fleischer rings, low ceruloplasmin)
• Hemochromatosis (increased ferritin, transferrin saturation >45%)
• α1-antitrypsin deficiency (PAS-positive globules)
• Budd-Chiari syndrome (hepatic vein thrombosis)

2.3 Complications

2.3.1 Portal Hypertension

2.3.2 Esophageal Varices

• Develop when HVPG >10 mmHg, bleed when >12 mmHg
• Primary prophylaxis: Non-selective beta-blockers (propranolol, carvedilol) or EVL if high-risk varices
• Acute bleed management: Resuscitation, vasoactive drugs (terlipressin/octreotide), EVL, antibiotics (ceftriaxone)
• Salvage therapy: TIPS (Transjugular Intrahepatic Portosystemic Shunt) if refractory
• Secondary prophylaxis: Beta-blockers + EVL

2.3.3 Ascites

2.3.4 Spontaneous Bacterial Peritonitis (SBP)

2.3.5 Hepatic Encephalopathy (HE)

• Precipitants: GI bleed, infection, constipation, hypokalemia, diuretics, sedatives, high protein diet
• Pathophysiology: Ammonia accumulation, GABA receptor alterations
• Treatment: Lactulose (20-30g TDS to achieve 2-3 soft stools/day), Rifaximin 550mg BD
• Acute management: Identify precipitant, lactulose enema, correct electrolytes

2.3.6 Hepatorenal Syndrome (HRS)

2.3.7 Hepatopulmonary Syndrome (HPS)

• Triad: Liver disease + intrapulmonary vascular dilatations + arterial hypoxemia (PaO₂ <80mmhg or="" a-a="" gradient="">
• Clinical features: Platypnea (dyspnea worse in upright position), orthodeoxia (hypoxemia worse upright)
• Diagnosis: Contrast-enhanced echocardiography (bubbles appear in left atrium after 3-6 beats)
• Treatment: Oxygen, liver transplant (only definitive treatment)

2.3.8 Portopulmonary Hypertension

• Mean pulmonary artery pressure >25mmHg with pulmonary vascular resistance >240 dynes·sec·cm⁻⁵
• Contraindication to transplant if mean PAP >45mmHg
• Treatment: Prostacyclin analogues, endothelin receptor antagonists, phosphodiesterase-5 inhibitors

3. Acute Liver Failure

3.1 Definition and Classification

3.2 Common Etiologies

• Viral: HAV, HBV, HEV (pregnant women), HSV, CMV
• Drugs: Paracetamol (most common in West), anti-TB drugs, NSAIDs, valproate
• Toxins: Amanita phalloides (mushroom), CCl₄
• Vascular: Budd-Chiari syndrome, ischemic hepatitis
• Metabolic: Wilson disease, acute fatty liver of pregnancy
• Autoimmune hepatitis

3.3 King's College Criteria for Transplant

3.3.1 Paracetamol-Induced ALF

• Arterial pH <7.3 after="" resuscitation="">
• All three: INR >6.5, creatinine >3.4mg/dL, Grade III-IV encephalopathy

3.3.2 Non-Paracetamol ALF

• INR >6.5 OR
• Any three of: Age <10 or="">40 years, etiology (non-A non-B hepatitis, drug), jaundice to encephalopathy >7 days, INR >3.5, bilirubin >17.5mg/dL

3.4 Management

• ICU admission, monitor vitals and mental status
• N-acetylcysteine if paracetamol toxicity (loading 150mg/kg over 1h, then 50mg/kg over 4h, then 100mg/kg over 16h)
• Correct coagulopathy only if active bleeding (not prophylactic FFP)
• Lactulose for encephalopathy, avoid sedatives
• Hypoglycemia monitoring and correction (10% dextrose)
• Infection surveillance (broad-spectrum antibiotics if suspected)
• Liver transplantation (definitive treatment if criteria met)

4. Alcoholic Liver Disease

4.1 Spectrum

4.2 Alcoholic Hepatitis Severity

4.2.1 Maddrey Discriminant Function (MDF)

• MDF = 4.6 × (PT patient - PT control) + Bilirubin (mg/dL)
• MDF ≥32: Severe, consider corticosteroids (prednisolone 40mg/day for 28 days)
• Lille score at day 7: <0.45 (continue="" steroids),="">0.45 (stop steroids, poor responder)

4.2.2 MELD Score

• MELD ≥21: Consider corticosteroids

4.3 Management

• Abstinence (most important), nutritional support (high-calorie, high-protein diet)
• Thiamine, folic acid, multivitamins
• Prednisolone 40mg/day for 28 days if severe (MDF ≥32)
• Pentoxifylline 400mg TDS (alternative if steroids contraindicated)
• N-acetylcysteine may be added to steroids
• Liver transplant: Minimum 6 months abstinence required

5. Non-Alcoholic Fatty Liver Disease (NAFLD)

5.1 Definitions

5.2 Risk Factors

• Metabolic syndrome (obesity, T2DM, hypertension, dyslipidemia)
• Insulin resistance (central pathophysiologic mechanism)
• PCOS, hypothyroidism, obstructive sleep apnea

5.3 Diagnosis

• USG: Increased echogenicity (bright liver)
• AST:ALT <1 (unlike="" alcoholic="" liver="">
• Liver biopsy: Gold standard for NASH diagnosis
• Non-invasive: FibroScan (transient elastography), NAFLD fibrosis score

5.4 Management

• Weight loss (7-10% target), exercise, dietary modification
• Tight control of diabetes, hypertension, dyslipidemia
• Vitamin E 800 IU/day (non-diabetic NASH with fibrosis)
• Pioglitazone (NASH with fibrosis, diabetic or non-diabetic)
• Avoid hepatotoxic drugs and alcohol
• No FDA-approved specific pharmacotherapy

6. Autoimmune Liver Diseases

6.1 Autoimmune Hepatitis (AIH)

• Clinical: Young-middle aged females, insidious or acute hepatitis, hypergammaglobulinemia (IgG elevation)
• Histology: Interface hepatitis (piecemeal necrosis), plasma cell infiltration
• Treatment: Prednisolone + azathioprine (steroid-sparing), remission in 65-80%
• Maintenance: Continue until remission (normal transaminases, IgG, histology), minimum 2-3 years
• Transplant indication if decompensated cirrhosis or treatment failure

6.2 Primary Biliary Cholangitis (PBC)

6.3 Primary Sclerosing Cholangitis (PSC)

7. Metabolic Liver Diseases

7.1 Wilson Disease

7.2 Hereditary Hemochromatosis

7.3 α1-Antitrypsin Deficiency

• Autosomal recessive, SERPINA1 gene (chromosome 14), PiZZ genotype (most severe)
• Liver: Neonatal cholestasis, chronic hepatitis, cirrhosis, HCC
• Lungs: Early-onset emphysema (panacinar, lower lobes), exacerbated by smoking
• Diagnosis: Low serum α1-antitrypsin level, phenotyping, liver biopsy (PAS-positive diastase-resistant globules)
• Treatment: Smoking cessation, α1-antitrypsin replacement (emphysema), liver transplant (definitive for liver disease)

8. Drug-Induced Liver Injury (DILI)

8.1 Patterns

8.2 Common Hepatotoxic Drugs

8.3 Management

• Discontinue offending drug (most important)
• N-acetylcysteine for paracetamol toxicity
• Supportive care, monitor liver function
• Corticosteroids if autoimmune-like DILI
• Liver transplant if acute liver failure

9. Hepatocellular Carcinoma (HCC)

9.1 Risk Factors

• Cirrhosis (80-90% of HCC), especially HBV, HCV, alcoholic, hemochromatosis
• Chronic HBV (even without cirrhosis), HCV
• Aflatoxin B1 exposure (Aspergillus flavus contamination)
• NAFLD/NASH
• Genetic: Hemochromatosis, α1-antitrypsin deficiency, Wilson disease, tyrosinemia

9.2 Surveillance

• High-risk patients: Cirrhosis (any cause), chronic HBV (Asian males >40 years, Asian females >50 years, family history HCC, Africans >20 years)
• Method: USG abdomen + AFP every 6 months
• AFP >400 ng/mL is highly suggestive of HCC

9.3 Diagnosis

9.4 Barcelona Clinic Liver Cancer (BCLC) Staging

9.5 Milan Criteria for Liver Transplant

• Single tumor ≤5 cm OR
• Up to 3 tumors, each ≤3 cm
• No macrovascular invasion, no extrahepatic metastases
• 5-year survival >70% if within Milan criteria

9.6 Treatment Options

• Surgical resection: Solitary tumor, Child A, adequate liver reserve
• Liver transplant: Best for small HCC with cirrhosis (Milan criteria)
• Radiofrequency ablation (RFA): Tumors <3cm, not="" near="">
• TACE: Intermediate stage, multinodular without vascular invasion
• Sorafenib: Advanced HCC, portal vein thrombosis, extrahepatic spread

10. Liver Abscess

10.1 Pyogenic Liver Abscess

10.2 Amoebic Liver Abscess

10.3 Differentiation

11. Miscellaneous Liver Disorders

11.1 Budd-Chiari Syndrome

11.2 Acute Fatty Liver of Pregnancy (AFLP)

• Rare, 3rd trimester complication, microvesicular steatosis
• Clinical: Nausea, vomiting, jaundice, abdominal pain, may progress to ALF
• Labs: Hypoglycemia, elevated transaminases, low platelets, coagulopathy, elevated uric acid
• Treatment: Immediate delivery (definitive), supportive care
• Differentiate from HELLP syndrome (hemolysis, elevated liver enzymes, low platelets)

11.3 Gilbert Syndrome

11.4 Crigler-Najjar Syndrome

11.5 Dubin-Johnson Syndrome

• Autosomal recessive, defective MRP2 (canalicular transport protein)
• Conjugated hyperbilirubinemia, black liver (melanin-like pigment)
• Benign, no treatment required

11.6 Rotor Syndrome

• Autosomal recessive, defective hepatic uptake and storage
• Conjugated hyperbilirubinemia, normal liver color
• Benign, no treatment required

11.7 Ischemic Hepatitis (Shock Liver)

• Acute hepatocyte injury due to hypoperfusion (shock, cardiac failure, sepsis)
• Massive transaminase elevation (ALT/AST >1000 IU/L, often >3000)
• Rapid rise and fall (peak 1-3 days, normalize in 7-10 days)
• Treatment: Address underlying cause, supportive care