Cirrhosis and Liver Diseases Revision Notes
Nonalcoholic Fatty Liver Disease (NAFLD)
Definition
- NAFLD encompasses a range of liver conditions:
- Steatosis (NAFL): Fat accumulation without inflammation.
- Steatohepatitis (NASH): Fat accumulation with inflammation and hepatocyte injury.
- Cirrhosis: Advanced scarring of the liver.
Epidemiology
- Most common cause of liver test elevation globally.
- Affects ~30% of the US population; 15%-20% risk progression to cirrhosis.
- Projected 100 million US citizens affected by 2030.
- Associated with obesity, type 2 diabetes, and cardiovascular diseases.
Histopathology
- Similar to Alcoholic Liver Disease (ALD) but with distinctions.
- Features:
- Steatosis: Mainly macrovesicular.
- Hepatocyte ballooning.
- Lobular inflammation: Mild, may include neutrophils.
- Perisinusoidal fibrosis.
- Small lipogranulomas.
- Mallory-Denk bodies:
- May be absent or poorly formed.
- Restricted to ballooned hepatocytes in NASH.
- Fibrosis progression:
- Begins in pericentral perisinusoidal spaces.
- Extends to portal and periportal fibrosis.
- May lead to bridging fibrosis and cirrhosis.
- Grading and Staging:
- Based on steatosis, ballooning, inflammation, and fibrosis.
- NASH Clinical Research Network system widely used.
Differential Diagnosis
- Marked portal inflammation with lymphoid aggregates or plasma cells suggests:
- Chronic viral hepatitis.
- Autoimmune hepatitis (AIH).
- Cholestasis and broad septa are rare in NASH but common in ALD.
Cirrhosis in NASH
- Histologic features may disappear as fibrosis progresses.
- Cryptogenic cirrhosis requires prior biopsy evidence of NASH for diagnosis.
Chronic Hepatitis C
Epidemiology
- High cirrhosis rate before interferon-sparing therapies.
- Risk factors for progression:
- Long infection duration.
- Alcohol consumption.
- Coinfection with HBV or HIV.
- Nonresponse to antiviral therapy.
- Male gender.
- Post-cure fibrosis progression occurs in some patients.
Histopathology
- Cirrhosis patterns:
- Macronodular or mixed nodularity.
- Fibrovascular septa vary in width.
- Portal inflammation:
- Mononuclear cells: Lymphocytes, plasma cells, eosinophils.
- Lymphoid aggregates with germinal centers (characteristic).
- Bile duct damage (Poulsen lesion) may be mild.
- Interface hepatitis may be present.
- Lobular inflammation:
- Spotty and mild.
- May include acidophilic bodies.
- Subendothelial inflammation in portal veins (endotheliitis).
Chronic Hepatitis B
Epidemiology
- Common cause of cirrhosis.
Histopathology
- Severe necroinflammation, especially during exacerbations.
- Bridging necrosis with lobular collapse.
- Ground-glass inclusions:
- Pale or eosinophilic hepatocyte cytoplasm.
- Due to hepatitis B surface antigen accumulation.
- Confirmed with orcein or Victoria blue stains or immunohistochemistry.
- Coinfection with HDV:
- More severe damage.
- Accelerated cirrhosis.
- Diagnosed via immunohistochemical detection of HDV antigen.
Autoimmune Hepatitis (AIH)
Diagnosis
- Based on clinical, laboratory, and histopathologic findings.
- Liver biopsy confirms and excludes other causes.
Histopathology
- Dense mononuclear infiltrate: Portal, septal, lobular areas.
- Marked interface hepatitis.
- Plasma cells are prominent.
- Hepatic rosettes: Pseudoacinar formations.
- Severe cases: Confluent or bridging necrosis.
- Centilobular necrosis with mild portal inflammation can occur.
- Rapid fibrosis progression if untreated.
- In cirrhosis, plasma cells and rosettes may diminish.
Burned-out AIH
- May cause cryptogenic cirrhosis.
- Features may be absent in advanced stages.
Primary Biliary Cholangitis (PBC)
Definition
- Autoimmune destruction of intrahepatic bile ducts.
- Predominantly affects women during or after childbearing years.
Pathogenesis
- Multifactorial and poorly understood.
Histopathology
- Florid duct lesion (pathognomonic):
- Lymphocytic or granulomatous bile duct infiltration.
- Portal inflammation: Mixed infiltrate with lymphocytes, plasma cells, eosinophils.
- Ductular reaction, interface hepatitis, and periportal changes.
- Cholate stasis: Foamy hepatocyte changes due to bile salts.
- Copper deposition in hepatocytes.
- Ductopenia in advanced stages.
- Canalicular cholestasis with bile plugs in late stages.
Diagnosis
- Positive anti-mitochondrial antibody (AMA).
- Presence of florid duct lesion is diagnostic.
Overlap Syndrome
- Features of AIH may occur with or precede PBC.
- Treatment guided by dominant histopathologic process.
Complications
- Hepatocellular carcinoma (HCC) risk similar to cirrhotic HCV.
- Non-response to ursodeoxycholic acid (URSO) increases risk.
Primary Sclerosing Cholangitis (PSC)
Definition
- Idiopathic inflammation and fibrosis of bile ducts.
- Affects both extrahepatic and intrahepatic ducts.
Epidemiology
- Associated with inflammatory bowel disease (especially ulcerative colitis).
- More common in young men.
Histopathology
- Onion-skin periductal fibrosis:
- Concentric fibrosis around bile ducts.
- Indicates chronic biliary obstruction.
- Duct atrophy and degeneration.
- Fibro-obliterative scars replacing ducts.
- Ductopenia and chronic cholestasis features.
Diagnosis
- Based on characteristic imaging findings.
- Liver biopsy less useful due to disease inhomogeneity.
Complications
- Cholangiocarcinoma (CCA):
- 400- to 1500-fold increased risk.
- Often occurs within first year of PSC diagnosis.
- Increased risk of colorectal carcinoma, gallbladder carcinoma, and HCC.
Hereditary Hemochromatosis (HH)
Definition
- Autosomal recessive disorder causing iron overload.
Genetics
- Commonly due to homozygous C282Y mutation in the HFE gene.
- Results in abnormal expression of hepcidin.
Histopathology
- Iron deposition:
- Begins in zone 1 (periportal) hepatocytes.
- Decreases toward centrilobular areas.
- Prussian blue stain shows iron granules.
- Progression:
- Iron throughout lobule in hepatocytes, Kupffer cells, bile duct cells, portal macrophages.
- Siderotic nodules (Kupffer cell clusters).
- Minimal portal/lobular inflammation.
- Fibrosis:
- Portal-based.
- Cirrhosis is typically micronodular.
- Iron-loaded hepatocytes in cirrhotic nodules.
Diagnosis
- Confirmed by genetic testing.
- Hepatic iron index via chemical quantitation.
Differential Diagnosis
- Secondary iron overload in chronic HCV, HBV, ALD, NASH.
- Mild iron deposition; higher scores may indicate HH.
Complications
- Increased risk of HCC in C282Y homozygous patients.
Wilson Disease
Definition
- Autosomal recessive disorder of copper metabolism.
- Mutation in ATP7B gene.
Clinical Presentation
- Young to middle-aged patients with unexplained liver disease.
- Neuropsychiatric symptoms common.
- Hemolytic anemia may occur.
Histopathology
- Variable features:
- Portal lymphocytic infiltration with interface hepatitis.
- Steatosis, necrosis, anisocytosis, anisonucleosis.
- Lipofuscin accumulation.
- Canalicular cholestasis.
- Iron accumulation.
- Cirrhosis is usually micronodular.
Diagnosis
- Copper stains (rhodanine, rubeanic acid, orcein, Victoria blue):
- May be negative in early stages.
- Detect copper in advanced stages.
- Hepatic copper concentration assay:
- 250 μg/g dry weight is diagnostic.
- Genetic testing is complex due to multiple mutations.
Differential Diagnosis
- Chronic hepatitis, steatohepatitis, PBC, PSC, iron overload, non-Wilson copper toxicosis.
α1-Antitrypsin Deficiency
Definition
- Genetic disorder due to retention of mutant α1-antitrypsin protein.
- Leads to hepatocyte injury and death.
Genetics
- Caused by mutations in the SERPINA1 gene.
- PiZZ genotype (homozygous) commonly associated with liver disease.
- PiMZ genotype (heterozygous) may predispose to other liver injuries.
Histopathology
- Eosinophilic globules in zone 1 hepatocytes:
- Contain misfolded α1-antitrypsin.
- Best seen with PAS-diastase (PAS-d) stain.
- Confirmed by immunohistochemistry.
Clinical Implications
- Cirrhosis patterns vary: micronodular, macronodular, biliary, or mixed.
- HCC may develop in cirrhotic livers.
- Exclude other causes like HCV or alcohol.
Cryptogenic Cirrhosis
Definition
- Cirrhosis with no identifiable cause.
- Accounts for 10%-15% of cases.
Possible Etiologies
- Burned-out NASH:
- Advanced fibrosis may lack NASH features.
- Associated with type 2 diabetes and obesity.
- Common post-transplant recurrence.
- Autoimmune Hepatitis (AIH):
- May be seronegative in advanced stages.
- Primary Sclerosing Cholangitis (PSC).
- Alcoholic Cirrhosis.
- Budd-Chiari Syndrome.
- Genetic mutations in keratins or transporter proteins.
Diagnosis
- Requires careful review of prior liver biopsies.
- Exclude other possible causes.