Liver Function Tests (LFTs)

Liver Function Tests (LFTs)

LFTs are a group of clinical chemistry tests used to assess liver function and detect liver damage or disease.

Types of Liver Function Tests

1. Enzyme Tests

• Alanine Transaminase (ALT): also known as Serum Glutamic Pyruvic Transaminase (SGPT)
  • Normal range: 7-56 IU/L
  • Elevated in: hepatitis, liver damage, liver disease
• Aspartate Transaminase (AST): also known as Serum Glutamic Oxaloacetic Transaminase (SGOT)
  • Normal range: 8-48 IU/L
  • Elevated in: liver damage, liver disease, muscle damage
• Gamma-Glutamyl Transferase (GGT):
  • Normal range: 5-55 IU/L
  • Elevated in: liver disease, bile duct obstruction, alcohol abuse

2. Synthetic Function Tests

• Albumin:
  • Normal range: 3.5-5.5 g/dL
  • Decreased in: liver disease, malnutrition, inflammation
• Prothrombin Time (PT):
  • Normal range: 11-13.5 seconds
  • Prolonged in: liver disease, vitamin K deficiency, warfarin therapy

3. Excretory Function Tests

• Bilirubin:
  • Normal range: 0.2-1.2 mg/dL
  • Elevated in: liver disease, bile duct obstruction, hemolysis
• Alkaline Phosphatase (ALP):
  • Normal range: 30-120 IU/L
  • Elevated in: liver disease, bone disease, pregnancy

Interpretation of Liver Function Tests

• Elevated enzyme tests (ALT, AST, GGT) indicate liver damage or disease.
• Decreased synthetic function tests (albumin, PT) indicate liver disease or dysfunction.
• Elevated excretory function tests (bilirubin, ALP) indicate liver disease, bile duct obstruction, or bone disease.
• Combination of elevated LFTs and physical examination findings can help diagnose liver disease, such as cirrhosis or hepatitis.

Liver Function Tests (LFTs)

• LFTs are used to assess liver function and detect liver damage or disease.

Types of Liver Function Tests

Enzyme Tests

• Alanine Transaminase (ALT) is also known as Serum Glutamic Pyruvic Transaminase (SGPT).
• Normal ALT range: 7-56 IU/L.
• Elevated ALT levels are seen in hepatitis, liver damage, and liver disease.
• Aspartate Transaminase (AST) is also known as Serum Glutamic Oxaloacetic Transaminase (SGOT).
• Normal AST range: 8-48 IU/L.
• Elevated AST levels are seen in liver damage, liver disease, and muscle damage.
• Gamma-Glutamyl Transferase (GGT) has a normal range of 5-55 IU/L.
• Elevated GGT levels are seen in liver disease, bile duct obstruction, and alcohol abuse.

Synthetic Function Tests

• Albumin has a normal range of 3.5-5.5 g/dL.
• Decreased albumin levels are seen in liver disease, malnutrition, and inflammation.
• Prothrombin Time (PT) has a normal range of 11-13.5 seconds.
• Prolonged PT is seen in liver disease, vitamin K deficiency, and warfarin therapy.

Excretory Function Tests

• Bilirubin has a normal range of 0.2-1.2 mg/dL.
• Elevated bilirubin levels are seen in liver disease, bile duct obstruction, and hemolysis.
• Alkaline Phosphatase (ALP) has a normal range of 30-120 IU/L.
• Elevated ALP levels are seen in liver disease, bone disease, and pregnancy.

Interpretation of Liver Function Tests

• Elevated enzyme tests indicate liver damage or disease.
• Decreased synthetic function tests indicate liver disease or dysfunction.
• Elevated excretory function tests indicate liver disease, bile duct obstruction, or bone disease.
• Combination of elevated LFTs and physical examination findings can help diagnose liver disease, such as cirrhosis or hepatitis.