From the Guidelines
Elevated bilirubin levels can indicate a range of underlying conditions, including liver disease, bile duct obstruction, or hemolytic anemia, and it is essential to consult a healthcare provider for proper evaluation and diagnosis. The implications of elevated bilirubin levels can be significant, and understanding the causes and consequences is crucial for effective management.
Causes of Elevated Bilirubin
- Unconjugated hyperbilirubinaemia is usually due to haemolysis or impaired conjugation, whereas conjugated hyperbilirubinaemia is typically due to parenchymal liver disease or obstruction of the biliary system, as stated in the guidelines on the management of abnormal liver blood tests 1.
- The most common cause of an isolated elevated bilirubin concentration is Gilbert’s syndrome, which is an inherited disorder of metabolism and leads to impaired conjugation via reduced activity of the enzyme glucuronyltransferase 1.
Diagnosis and Evaluation
- Most laboratories will routinely report total bilirubin, which comprises unconjugated and conjugated fractions, and elevations of either fraction will lead to a rise in the measured bilirubin concentration 1.
- Except in the neonatal period, the majority of measurable bilirubin should be conjugated, even in individuals with significant liver disease, and if the majority of the elevated bilirubin comprises the unconjugated fraction, then the cause, in the absence of haemolysis, is virtually always Gilbert’s syndrome 1.
Management and Treatment
- Treatment depends entirely on the underlying cause, and it is essential to identify the cause of elevated bilirubin levels to provide effective management, as stated in the guidelines on the management of abnormal liver blood tests 1.
- In neonates and infants, referral to a paediatrician for urgent assessment of possible liver disease is essential if the conjugated bilirubin is >25 μmol/L 1.
Prognosis and Quality of Life
- Elevated bilirubin levels can cause jaundice, which can lead to yellowing of the skin and eyes, and in severe cases, it can cause kernicterus, a condition that can lead to brain damage and death 1.
- It is essential to manage elevated bilirubin levels effectively to prevent long-term complications and improve quality of life, and this can be achieved by consulting a healthcare provider for proper evaluation and diagnosis, and following the recommended treatment plan 1.
From the Research
Implications of Elevated Bilirubin Levels
Elevated bilirubin levels can have significant implications for individuals, particularly in terms of liver function and overall health. Some of the key implications include:
- Neurotoxicity: Very high levels of unconjugated bilirubin can be neurotoxic, as noted in a study on neonatal jaundice 2.
- Underlying disease: An elevated level of bilirubin almost always indicates the presence of an underlying disease state, such as liver disease or biliary tract issues 3.
- Increased risk of kernicterus: Infants with rapidly rising bilirubin levels are at risk of kernicterus, a serious condition that can cause brain damage 2.
- Indicator of liver function: Bilirubin levels can be used as an indicator of liver function, with high levels of conjugated bilirubin potentially indicating biliary atresia or other liver problems 2, 4.
- Impact on drug metabolism: The UGT1A1*28 promoter polymorphism, which can cause elevated bilirubin levels, has been linked to drug tolerance and multifactorial diseases such as cancer 5.
Diagnostic Evaluation
The diagnostic evaluation of elevated bilirubin levels typically involves a combination of laboratory tests and imaging studies, including:
- Measurement of bilirubin levels (total and fractionated) 4
- Complete blood cell count 4
- Liver function tests (e.g. aspartate transaminase, alanine transaminase) 4
- Imaging studies (e.g. ultrasonography, computed tomography, magnetic resonance cholangiopancreatography) 4
- Liver biopsy (in some cases) 4
Management and Treatment
The management and treatment of elevated bilirubin levels depend on the underlying cause and severity of the condition. Some possible treatments include:
- Phototherapy: A simple and effective way to reduce bilirubin levels in infants with neonatal jaundice 2.
- Exchange transfusions: May be necessary in severe cases of hyperbilirubinemia 2, 6.
- Intravenous immunoglobulin (IVIG) therapy: May be used to treat hemolytic disease of the newborn 6.
- Medical treatment of underlying conditions: Such as liver disease or biliary tract issues 3, 4.