Jaundice: Types, Causes, Laboratory Diagnosis and Treatment

Clinical Chemistry

Jaundice: Types, Causes, Laboratory Diagnosis and Treatment

Jaundice or Icterus is a condition in which the skin, sclera (whites of the eye) and mucous membranes become yellow due to high levels of bilirubin which leaks from the leaver into the bloodstream, bilirubin is formed from the breakdown of red blood cells. it can affect newborns, adults and even children.

Causes of Jaundice

High unconjugated bilirubin may be due to excess red blood cell breakdown, large bruises, genetic conditions such as Gilbert’s syndrome, not eating for a prolonged period, newborn jaundice, or thyroid problems. High conjugated bilirubin may be due to liver diseases such as cirrhosis or hepatitis, infections, medications, or blockage of the bile duct.

Jaundice
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A jaundiced adult. (Photo Credits: Wikimedia Commons)

In the developed world, the cause is more often blockage of the bile duct or medications; in the developing world, it is more often infections such as viral hepatitis, leptospirosis, schistosomiasis, or malaria. Blockage of the bile duct may occur due to gallstones, cancer, or pancreatitis. Medical imaging such as ultrasound is useful for detecting bile duct blockage

Jaundice types

Jaundice can be caused within the three phases of bilirubin production giving the three types of jaundice namely Pre hepatic jaundice, hepatocellular Jaundice and post hepatic jaundice

Pre hepatic Jaundice

This is caused by anything that causes an increased rate of hemolysis (the breakdown of red blood cells). Unconjugated bilirubin comes from the breakdown of the heme pigment found in red blood cells’ hemoglobin.

The increased breakdown of red blood cells leads to an increase in the amount of unconjugated bilirubin present in the blood and deposition of this unconjugated bilirubin into various tissues can lead to a yellowish appearance.

In tropical countries, severe malaria can cause jaundice in this manner. Certain genetic diseases, such as sickle cell anemia, spherocytosis, thalassemia, pyruvate kinase deficiency, and glucose-6-phosphate dehydrogenase deficiency can lead to increased red cell lysis and therefore hemolytic jaundice. Commonly, diseases of the kidney, such as hemolytic-uremic syndrome, can also lead to coloration.

Due to hemolysis, the increased production of bilirubin leads to the increased production of urine-urobilinogen. Bilirubin is not usually found in the urine because unconjugated bilirubin is not water-soluble, so, the combination of increased urine-urobilinogen with no bilirubin in urine is suggestive of hemolytic jaundice.

Laboratory findings include:

  • Urine: no bilirubin present, urobilinogen > 2 units
  • Serum: increased unconjugated bilirubin.
  • Kernicterus is associated with increased unconjugated bilirubin not carried by albumin.

Hepatocellular Jaundice

This can be caused by acute or chronic hepatitis, hepatotoxicity, cirrhosis, drug-induced hepatitis, and alcoholic liver disease. Cell necrosis reduces the liver’s ability to metabolize and excrete bilirubin leading to a buildup of unconjugated bilirubin in the blood.

Other causes include primary biliary cirrhosis leading to an increase in plasma conjugated bilirubin because there is an impairment of excretion of conjugated bilirubin into the bile. The blood contains an abnormally raised amount of conjugated bilirubin and bile salts, which are excreted in the urine.

Laboratory findings:

  • Urine: Conjugated bilirubin present, urobilinogen > 2 units but variable (Except in children)
  • Plasma protein show characteristic changes.
  • Plasma albumin level is low, but plasma globulins are raised due to an increased formation of antibodies.

Post Hepatic Jaundice

Also called obstructive jaundice, is caused by an interruption to the drainage of bile containing conjugated bilirubin in the biliary system. The most common causes are gallstones in the common bile duct and pancreatic cancer in the head of the pancreas.

A group of parasites known as “liver flukes” can live in the common bile duct, causing obstructive jaundice. Other causes include strictures of the common bile duct, biliary atresia, cholangiocarcinoma, pancreatitis, cholestasis of pregnancy, and pancreatic pseudocysts. A rare cause of obstructive jaundice is Mirizzi’s syndrome.

Laboratory findings include:

  • Low urine urobilinogen.
  • Pale stools and dark urine.
  • Elevated serum cholesterol.
  • Severe itching or pruritis due to direct or indirect effects of pruritogen effects in the bile such as bile salts.

Treatment of Jaundice

Following the symptoms and the laboratory findings when tested for this abnormality, the underlying cause can be determined and treatment used more specific. The underlying causes in newborns, children or adults could be bile duct obstruction due to the formation of gallstones, liver cirrhosis, or any other related factors such as cancer.

The treatment regimen includes:

  • Antiretroviral therapy
  • Iron Supplementation for anemia caused Jaundice
  • Surgical removal of the obstruction
  • Change of medication for those caused by medication.

You’ve come this far. Test your Jaundice knowledge here

Stephen Otieno
Enthusiast, Lover and Friend
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