Bilirubin in Urine

Medically the condition of bilirubin found in urine is termed as bilirubinuria. This condition is developed due to liver or gallbladder related disorder. Obstruction in the bile passage occurs due to inflammatory condition in the liver, stone or malignant tissue formation in the gallbladder. In some cases genetically elevated bilirubin level also causes bilirubinuria.

Image 1: Bilirubin in Urine

Bilirubin production in the body is normal and occurs when red blood cells break down in the liver. Red blood cells contain haemoglobin which is metabolised and produces bilirubin. Normally a small quantity of bilirubin is found in the blood serum. Total values of bilirubin found in the serum volume are 0.2-1 mg/dL (3.4-17.1 µmol/L). Two types of bilirubin found in the body.

• Unconjugated which bind with other proteins
• Conjugated which are free and passed in different parts of the body via the blood stream and ultimately accumulates in the liver.

Conjugated bilirubin is passed to the small intestine and ultimately reached into large intestines which give stool colouration. Very small quality of this can reach in the kidney which excreted via urine and provide straw colour.

If the blood serum contains more than the normal range of bilirubin due to liver is not functioning properly and un-conjugated bilirubin is increased then jaundice progresses, the usual symptoms are

• Dark yellow coloration of urine
• Yellow coloration of all visible and invisible parts of the body including skin, eye, nail beds etc.
• Nausea
• Vomiting
• Fatigues

Image 2: Bilirubin Crystal

Bilirubin in Urine Causes

The following conditions may increase the limits of bilirubin and more than normal value of bilirubin found in urine.

• Hepatitis is the inflammatory condition of the liver and causes increased the bilirubin value. Hepatitis can develop due to viral, bacterial or parasitic attacks. There are different types of viral hepatitis which include Hepatitis A, B, C, D and E. Inflammatory condition of liver cause liver cirrhosis in advanced stage. Other than this, autoimmune disorders are also caused inflammation in the liver, such as type 1 diabetes; Graves disease, an overactive thyroid; Rheumatoid Arthritis, Sjogren’s Syndrome. These diseases are developed outside the liver or bile duct, but hamper the liver activity.
• Ulcerative colitis also increase the bilirubin amount, as it is not smoothly passed out via stool due to inflammation and ulcers in the large colon and rectum.
• Gallbladder obstruction due to stone formation causes bilirubin in urine, as the stored bile from gall bladder cannot move to small intestine. It is reversed back to liver and increase the bilirubin amount and excretes via urine.
• Narrowing of the bile duct due to surgical process or any other inflammatory condition reduces the flow of bile from the gall bladder to the intestine which also increases the bilirubin amount.

Image 3: Mechanism of Bilirubin in urine

• Alcohol consumption, hepatic toxic drugs or other chemicals also increase the bilirubin amount.
• Inherited disease like Dubin-Johnson Syndrome and Rotor’s Syndrome causes prevention of bilirubin conjugation and increased the level of bilirubin in urine.
• Sickle cell anaemia accelerates the haemoglobin breakdown and increases the bilirubin production.
• Septicemia or blood poisoning causes infection in the bloodstream and arterial hypotension occurs. Septic shock increases the bilirubin production by increasing the inflammatory agent cytokine synthesis.

What does it mean?

Bilirubin in urine is also termed as hyperbilirubinemia.  Hyperbilirubinemia is the condition when the bilirubin is secreted via urine and dark yellow coloured urine is passed. Bilirubin is normally conjugated in the liver and become water soluble, un-conjugated bilirubin is unable to get soluble in the water. Unconjugated bilirubin is unable to filter in the kidney as it binds with albumin. The presence of bilirubin in the urine signifies the existence of conjugated hyperbilirubinemia.

In case of biliary obstruction which occurs due to impairment of the passage of the bile into the large intestine or in case of hepatitis where reduction of bilirubin secretion into the bile cause conjugated hyperbilirubinemia. In case of septic shock bile production is increased as inflammatory cytokine production is high.

Treatment

The cause of increased bilirubin is differ and treatment is totally depends upon the underlying cause.

• In the initial stage of hepatitis, often doctors prescribed antibiotics or antiviral drugs to control the infection.
• In case of liver cirrhosis or permanent damage in the liver, then liver transplantation is the only available treatment.
• Gallstone is also increased the bilirubin in the urine. Some medications or therapy claim to dissolve the stone, but there is no assurance about the effectiveness of this type of treatment. Lithotripsy, is advanced treatment, in which stones are destroyed by ultrasound treatment, without incision. Otherwise, the typical surgical procedure is available and 100% effective result is obtained in case of gallstone and associated symptoms are rid of including bilirubin in urine.
• Consumption of alcohol and hepatotoxic drugs are strictly restricted in bilirubinuria.

References

1. Bilirubin Test results, risks, procedure at https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=167&ContentID=bilirubin_direct
2. http://www.nlm.nih.gov/medlineplus/ency/article/003595.htm
3. Conjugated Hyperbilirubinemia Pathophysiology, etiology and Prognosis at http://emedicine.medscape.com/article/178757-overview#a4
4. Bilirubin in Urine Symptoms & Treatment at http://symptomstreatment.org/bilirubin-in-urine/