Liver Function Tests

Original Editor - Shwe Shwe U Marma Top Contributors - Shwe Shwe U Marma and Kim Jackson

Introduction

Groups of blood tests performed to know the condition of a liver of a patient are known as liver function tests (LFT) or liver panel or hepatic function panel or hepatic panel.[1]

Image showing liver

Components of Liver Function Tests

Alanine Transaminase (ALT); Normal value: 0-45 IU/L

Aspartate Transaminase (AST); Normal value: 0-35 IU/L[2]

Causes of raised transaminases:
Alkaline phosphatase (ALP); Normal value: 30–120 IU/l[2]
Causes of raised ALP:
  • Physiological
    • Women in the third trimester of pregnancy.
    • Adolescents.
    • Benign, familial (due to increased intestinal ALP).
  • Pathological
    • Bile duct obstruction.
    • Primary biliary cirrhosis.
    • Primary sclerosing cholangitis.
    • Drug induced cholestasis—for example, anabolic steroids.
    • Adult bile ductopenia.
    • Metastatic liver disease.
    • Bone disease.[3]
Gammaglutamyl transferase (GGT); Normal value: 0 to 30 IU/L[2]
Causes of raised GGT:
Bilirubin; Normal value: 2 to 17 micromoles/L[2]
Causes of isolated hyperbilirubinemia:
  • Unconjugated
    1. Increased bilirubin production.
      • Hemolysis.
      • Ineffective erythropoiesis.
      • Blood transfusion.
      • Resorption of hematomas.
    2. Decreased hepatic uptake.
    3. Decreased conjugation.
      • Gilbert’s syndrome.
      • Criggler-Najjar syndrome.
      • Physiological jaundice of the newborn.
  • Conjugated
    1. Dubin-Johnson syndrome.
    2. Rotor’s syndrome.[3]
Prothrombin time; Normal value: 10.9 to 12.5 seconds[2]
Causes of prolonged prothrombin time:
  • Vitamin K deficiency.
  • Warfarin therapy.
  • Liver disease.
  • Consumptive coagulopathy.[3]
Albumin; Normal value: 40 to 60 g/L[2]
With progressive liver disease serum albumin levels fall, reflecting decreased synthesis. Albumin levels are dependant on a number of other factors such as the nutritional status, catabolism, hormonal factors, and urinary and gastrointestinal losses.[3]
[4]

Resources

References

  1. Teshome G, Ambachew S, Fasil A, Abebe M. Prevalence of liver function test abnormality and associated factors in type 2 diabetes mellitus: a comparative cross-sectional study. Ejifcc. 2019 Oct;30(3):303.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Lala V, Goyal A, Bansal P, Minter D. Liver function tests. StatPearls. 2020 Apr 28.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Limdi JK, Hyde GM. Evaluation of abnormal liver function tests. Postgraduate medical journal. 2003 Jun 1;79(932):307-12.
  4. MedCram - Medical Lectures Explained CLEARLY. Liver Function Tests (LFTs) Explained Clearly by MedCram.com. Available from: https://www.youtube.com/watch?v=bFdTgty0T0I [Last accessed 29 November, 2020]