Approach to the Patient with Liver Disease¶
Chapter 347 | Part 10: Disorders of the Gastrointestinal System
KEY CLINICAL POINTS¶
- Liver structure and function are critical for diagnosing liver disease, including synthesis of proteins, bile production, and metabolism of nutrients.
- Clinical evaluation must integrate history, physical exam, laboratory tests, imaging, and liver biopsy to determine etiology, severity, and stage.
- Noninvasive methods (e.g., elastography, FibroTest) are increasingly used for fibrosis staging, reducing the need for biopsy.
- Fatigue is the most common symptom, while jaundice is a hallmark of severe liver dysfunction.
- Liver biopsy remains the gold standard for grading activity and staging fibrosis in chronic disease.
1. DEFINITION & OVERVIEW¶
Liver disease encompasses a wide range of conditions affecting hepatic structure and function. Diagnosis requires integration of clinical history, physical examination, laboratory tests, imaging, and liver biopsy. The liver's dual blood supply (hepatic artery and portal vein) and unique cellular architecture (hepatocytes, Kupffer cells, stellate cells) underpin its role in metabolism, detoxification, and immune function.
Table 347-1 Liver Diseases¶
| DISEASE | CLINICAL FEATURES |
|---|---|
| Inherited hyperbilirubinemia | Gilbert syndrome, Crigler-Najjar, Dubin-Johnson, Rotor syndrome |
| Viral hepatitis | Hepatitis A–E, Epstein-Barr, CMV, HBV, HCV |
| Autoimmune liver diseases | Primary biliary cholangitis, autoimmune hepatitis, sclerosing cholangitis |
| Alcohol-related liver disease | Alcoholic hepatitis, cirrhosis |
| Metabolic disorders | a1-antitrypsin deficiency, hemochromatosis, Wilson disease |
| Drug-induced liver injury | Isoniazid, acetaminophen, sulfonamides |
| Cholestatic syndromes | Biliary atresia, Caroli disease, cryptosporidiosis |
| Mass lesions | Hepatocellular carcinoma, metastases, abscesses |
1.1 Liver Structure and Function¶
The liver is the largest visceral organ, weighing 1–1.5 kg, with a dual blood supply (20% hepatic artery, 80% portal vein). Hepatocytes (2/3 of mass) perform metabolic, synthetic, and detoxifying functions. Kupffer cells (macrophages) and stellate cells (collagen producers) are critical in immune and fibrotic responses.
1.2 Classification of Liver Disease¶
Liver diseases are classified as hepatocellular (e.g., viral hepatitis), cholestatic (e.g., primary biliary cholangitis), or mixed (e.g., drug-induced injury). Staging (fibrosis severity) and grading (inflammation activity) guide management.
2. EPIDEMIOLOGY¶
Liver disease prevalence is influenced by risk factors including alcohol use, viral hepatitis (HBV, HCV), obesity, and metabolic syndrome. Chronic hepatitis C is the most common cause of cirrhosis in many regions. Hepatitis B is more prevalent in endemic areas, while hepatitis E is common in Asia and Africa. Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent in Western populations.
2.1 Risk Factors¶
Alcohol consumption (>2 drinks/day in women, >3 in men), viral hepatitis exposure, obesity, diabetes, metabolic syndrome, and drug use (e.g., acetaminophen, methotrexate) are major risk factors. Travel to endemic regions and injection drug use increase hepatitis risk.
2.2 Demographics¶
Hepatitis B and C are more common in men, while alcoholic liver disease is prevalent in middle-aged males. Wilson disease and hemochromatosis often present in adults, while pediatric cholestatic diseases (e.g., biliary atresia) are more common in infants.
3. ETIOLOGY & PATHOPHYSIOLOGY¶
Liver disease arises from viral, metabolic, autoimmune, toxic, or structural causes. Viral hepatitis (HBV, HCV) causes inflammation and fibrosis. Alcohol-induced steatosis progresses to steatohepatitis and cirrhosis. Autoimmune diseases (e.g., primary biliary cholangitis) involve immune-mediated destruction of bile ducts. Genetic disorders (e.g., hemochromatosis) lead to iron overload and parenchymal damage.
3.1 Viral Hepatitis¶
HBV and HCV are leading causes of chronic liver disease. HCV is more likely to progress to cirrhosis, while HBV can cause fulminant hepatitis. Hepatitis E is common in endemic regions and can be severe in immunocompromised patients.
3.2 Metabolic and Genetic Causes¶
Nonalcoholic fatty liver disease (NAFLD) is linked to insulin resistance and obesity. Hemochromatosis (iron overload) and Wilson disease (copper accumulation) cause parenchymal damage. α 1-antitrypsin deficiency leads to early-onset cirrhosis.
4. CLINICAL FEATURES¶
Symptoms include fatigue, jaundice, pruritus, and right upper quadrant pain. Physical findings may reveal hepatomegaly, splenomegaly, spider angiomas, palmar erythema, and ascites. Advanced disease presents with muscle wasting, hepatic encephalopathy, and portal hypertension.
4.1 Symptomatology¶
Fatigue is the most common symptom, often worsening with activity. Jaundice (icterus) is a hallmark of severe dysfunction. Pruritus occurs in cholestatic disease, while abdominal pain is common in cholangitis or biliary obstruction.
4.2 Physical Findings¶
Hepatomegaly is variable in size and shape. Splenomegaly indicates portal hypertension. Spider angiomas and palmar erythema suggest chronic liver disease. Ascites and peripheral edema are signs of advanced cirrhosis.
5. DIFFERENTIAL DIAGNOSIS¶
Differential diagnosis includes hepatocellular vs. cholestatic patterns. Hepatocellular injury (e.g., viral hepatitis) presents with elevated ALT/AST, while cholestatic disease (e.g., PBC) shows elevated alkaline phosphatase. Drug-induced injury may mimic viral hepatitis or autoimmune disease.
5.1 Hepatocellular vs. Cholestatic Patterns¶
Hepatocellular injury (ALT/AST > ALP) is seen in viral hepatitis, alcohol, or drug-induced injury. Cholestatic patterns (ALP > ALT) occur in biliary obstruction, PBC, or drug-induced cholestasis.
5.2 Common Mimics¶
Hepatic encephalopathy may mimic psychiatric disorders. Ascites can resemble heart failure or nephrotic syndrome. Pruritus may be confused with dermatological conditions.
6. INVESTIGATIONS & DIAGNOSIS¶
Liver function tests (ALT, AST, ALP, bilirubin, albumin, prothrombin time) and imaging (US, CT, MRI) are essential. Liver biopsy remains the gold standard for staging fibrosis. Noninvasive tests (e.g., FibroTest, TE) are increasingly used for fibrosis assessment.
Table 347-3 Important Diagnostic Tests in Common Liver Diseases¶
| DISEASE | DIAGNOSTIC TEST |
|---|---|
| Hepatitis A | Anti-HAV IgM |
| Hepatitis B | HBsAg, anti-HBc IgM (acute), HBV DNA (chronic) |
| Hepatitis C | Anti-HCV, HCV RNA |
| Autoimmune hepatitis | ANA, SMA, elevated IgG |
| Primary biliary cholangitis | Antimitochondrial antibody, elevated IgM |
| Wilson disease | Decreased ceruloplasmin, increased urinary copper |
| Hemochromatosis | Elevated iron saturation, serum ferritin |
| Alcoholic liver disease | History of excessive alcohol use, compatible histology |
6.1 Laboratory Tests¶
Serum bilirubin (direct/indirect), albumin, and prothrombin time assess synthetic function. ALT/AST reflect hepatocellular injury. ALP and γ GT are elevated in cholestatic disease. Iron studies and ceruloplasmin help diagnose hemochromatosis and Wilson disease.
6.2 Imaging¶
Ultrasound is first-line for detecting fatty liver, biliary obstruction, or masses. CT/MRI are used for staging tumors and assessing vascular anatomy. MRCP is preferred for biliary tree visualization.
6.3 Algorithm for Evaluation¶
- Initial tests: ALT, AST, ALP, bilirubin, albumin, prothrombin time.
- Viral hepatitis screening (anti-HAV, HBsAg, anti-HCV, etc.).
- Imaging for masses or biliary obstruction.
- Liver biopsy if diagnosis remains unclear.
7. MANAGEMENT & TREATMENT¶
Management depends on etiology: antiviral therapy for hepatitis, abstinence from alcohol, weight loss for NAFLD, and cholangiography for biliary obstruction. Liver transplantation is indicated for end-stage disease. Nonalcoholic steatohepatitis (NASH) requires lifestyle modification and emerging pharmacotherapies.
7.1 Pharmacologic Therapy¶
Antivirals (e.g., tenofovir for HBV, direct-acting antivirals for HCV). Ursodeoxycholic acid for cholestasis. Corticosteroids for autoimmune hepatitis. Zinc acetate for Wilson disease. Iron chelation for hemochromatosis.
7.2 Non-Pharmacologic Interventions¶
Alcohol abstinence, weight loss, dietary modification, and exercise for NAFLD. Avoidance of hepatotoxic drugs. Management of comorbidities (e.g., diabetes, obesity).
7.3 Surgical and Interventional Options¶
Portocaval shunts for refractory ascites. Liver transplantation for end-stage disease. Percutaneous drainage for abscesses. ERCP for biliary obstruction.
8. PROGNOSIS & COMPLICATIONS¶
Prognosis depends on etiology and stage. Cirrhosis carries a 5-year survival rate of ~50% without treatment. Complications include hepatic encephalopathy, ascites, spontaneous bacterial peritonitis, and hepatocellular carcinoma. Early intervention improves outcomes.
8.1 Complications of Cirrhosis¶
Ascites, portal hypertension, hepatic encephalopathy, and spontaneous bacterial peritonitis are common. Hepatocellular carcinoma risk increases with cirrhosis duration.
8.2 Prognostic Scores¶
Child-Pugh and MELD scores predict survival in cirrhosis. MELD-Na incorporates sodium levels for better risk stratification.
9. SPECIAL CONSIDERATIONS¶
Pregnancy may complicate liver disease (e.g., cholestasis of pregnancy). Pediatric liver disease often presents with cholestatic syndromes (e.g., biliary atresia). Elderly patients may have atypical presentations. HIV-positive patients require antiretroviral therapy adjustments for liver disease.
9.1 Pregnancy¶
Cholestasis of pregnancy is common in the third trimester. Hepatitis B and C can be transmitted vertically, but prevention is possible with immunization.
9.2 Pediatric Considerations¶
Infants with jaundice may have biliary atresia or metabolic disorders. Neonatal cholestasis requires urgent evaluation.
9.3 HIV and Immunosuppression¶
HIV-positive patients are at higher risk for HBV and HCV coinfection. Immunosuppressed patients (e.g., transplant recipients) are prone to hepatitis E and opportunistic infections.
10. KEY POINTS & CLINICAL PEARLS¶
- Fatigue is the most common symptom of liver disease, often worsening with activity.
- Jaundice is a hallmark of severe liver dysfunction, with bilirubin levels >2.5 mg/dL indicating significant conjugation impairment.
- Noninvasive tests (e.g., FibroTest, TE) are increasingly used for fibrosis staging.
- Liver biopsy remains the gold standard for grading activity and staging fibrosis.
- Early intervention for viral hepatitis, alcohol cessation, and weight loss can prevent progression to cirrhosis.