Bilirubin, the byproduct of hemoprotein breakdown, particularly hemoglobin, is a critical marker in diagnosing, prognosing, and managing liver diseases. This review delves into bilirubin's multifaceted roles, not only as a diagnostic marker but also as a molecule with antioxidant and immunomodulatory properties. In both acute and chronic liver conditions, such as viral hepatitis, alcohol-related liver disease, and autoimmune liver disease, bilirubin offers insight into disease severity and progression, as well as potential therapeutic implications.
Bilirubin metabolism The metabolism of bilirubin begins with its production from heme in the spleen and bone marrow, followed by transportation to the liver, where it undergoes enzymatic conversion. The liver plays a key role in bilirubin conjugation and excretion. Any disruption in this process-;whether in the production, metabolism, or excretion of bilirubin-;leads to conditions such as hyperbilirubinemia.
Elevated levels can signify liver dysfunction or blockages within the hepatic or extrahepatic bile ducts. Molecular mechanisms in liver diseases In liver diseases, bilirubin metabolism can be altered in multiple stages. Overproduction, faulty conjugation, or defective excretion mechanisms are common in conditions like cirrhosis or genetic disorders, such as Gilbert's or Crigler-Najjar syndromes.
Genetic mutations affecting enzymes and transporters responsible for bilirubin processing lead to these disorders. Furthermore, choles.