Chronic Liver Disease

Definition/diagnostic criteria

Chronic liver disease (CLD) encompasses a spectrum of diseases that affect the liver over a long period, typically more than six months. It includes conditions such as cirrhosis, chronic hepatitis, and fatty liver disease. The diagnosis is often based on a combination of history, physical examination, and characteristic abnormalities in liver function tests, imaging, and sometimes liver biopsy results. According to NICE guidelines, the presence of persistent abnormalities in liver function tests (LFTs) for over six months necessitates further evaluation for CLD.

Epidemiology

In the UK, CLD is a significant health concern, with rising incidence and mortality rates. The most common causes include alcohol-related liver disease, non-alcoholic fatty liver disease (NAFLD), and chronic viral hepatitis. The obesity epidemic has resulted in NAFLD becoming the most common liver disorder in Western countries.

Diagnosis

Clinical features

Early stages of CLD may be asymptomatic or present with non-specific symptoms such as fatigue and malaise. As the disease progresses, more specific signs such as jaundice, spider naevi, palmar erythema, and ascites may develop. A detailed history including alcohol consumption, medication use, and risk factors for viral hepatitis is crucial.

Investigations

The investigation of CLD aims to determine the cause, severity, and presence of complications. A systematic approach includes:

1. Liver Function Tests (LFTs):
   LFTs are a routine first step and may reveal elevated transaminases (ALT and AST), alkaline phosphatase, and bilirubin. These abnormalities prompt further investigation.
2. Serological Tests:
   Screening for underlying causes such as viral hepatitis, autoimmune liver disease, or hemochromatosis is essential. Tests include hepatitis B and C serologies, autoimmune markers (e.g., ANA, SMA), and iron studies.
3. Non-Invasive Scoring Systems (FIB-4 Index):
   The FIB-4 index is a simple, non-invasive tool widely used to assess liver fibrosis. It combines readily available clinical data, including patient age, platelet count, ALT, and AST. FIB-4 is especially useful in identifying individuals with significant fibrosis, which may guide the need for additional investigations such as imaging or liver biopsy.
   • A low FIB-4 score (<1.3) suggests minimal fibrosis and may reduce the need for invasive procedures.
   • A high FIB-4 score (>2.67) indicates significant fibrosis or cirrhosis, prompting further assessment with imaging or elastography.
4. Imaging:
   • Ultrasound: First-line imaging modality for assessing liver size, structure, and the presence of fatty liver, fibrosis, or cirrhosis.
   • Transient Elastography (FibroScan): Increasingly used to non-invasively assess liver stiffness, which correlates with fibrosis severity.
   • Advanced Imaging (CT/MRI): Utilized in cases of suspected complications such as hepatocellular carcinoma or portal hypertension.
5. Liver Biopsy:
   Although increasingly replaced by non-invasive tools, liver biopsy remains the gold standard for confirming the diagnosis, determining the cause, and staging liver disease. It is particularly helpful in cases where other modalities are inconclusive.

Treatment

Management of CLD involves treating the underlying cause, preventing disease progression, and managing complications.

• Lifestyle Modifications:
  • Alcohol cessation for alcohol-related liver disease.
  • Weight loss and dietary changes for NAFLD.
• Pharmacological Treatments:
  • Antiviral medications for chronic hepatitis B or C.
  • Corticosteroids for autoimmune hepatitis.
• Management of Complications:
  • Variceal bleeding, ascites, and hepatic encephalopathy require specific interventions, such as endoscopic banding, diuretics, or lactulose.
• Advanced Therapies:
  Liver transplantation is an option for patients with end-stage liver disease or decompensated cirrhosis.

Monitoring and Follow-Up of Fatty Liver Disease

Fatty liver disease, which encompasses non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease, is one of the most common causes of CLD. Due to its potential progression to fibrosis, cirrhosis, or hepatocellular carcinoma, regular monitoring and follow-up are critical.

1. Risk Stratification:
   Patients with NAFLD are stratified based on fibrosis risk using tools such as the FIB-4 index or transient elastography. Those with advanced fibrosis or cirrhosis require more intensive follow-up.
2. Lifestyle Monitoring:
   • Weight loss goals should aim for a reduction of 5-10% of total body weight, as this has been shown to improve liver histology.
   • Regular assessment of metabolic comorbidities such as diabetes, dyslipidemia, and hypertension is necessary.
3. Imaging and Laboratory Follow-Up:
   • LFTs and non-invasive fibrosis markers (e.g., FIB-4 or FibroScan) should be periodically re-evaluated to assess progression or improvement.
4. Patient Education:
   Ongoing education about lifestyle changes, the importance of adherence to medical therapy, and recognizing signs of decompensation (e.g., jaundice, confusion, ascites) is crucial.

Prognosis

The prognosis of CLD is highly variable, depending on the cause, stage at diagnosis, and presence of liver cirrhosis. Early diagnosis and intervention can significantly improve outcomes. The development of cirrhosis is associated with a higher risk of liver failure and hepatocellular carcinoma, markedly affecting survival rates. Regular monitoring and management of complications are crucial for improving quality of life and survival.