Bilirubin in Urine

First of all, what exactly is bilirubin? Bilirubin is the byproduct of red blood cells, specifically hemoglobin. When no longer useful to the body or the cells become damaged, the liver or spleen breaks down the portions of the hemoglobin of the red. If the heme portion of the hemoglobin is broken down in the spleen, it is called indirect or unconjugated bilirubin and is insoluble in water; meaning it cannot be dissolved. It is then sent to the liver bound to another blood product called albumin for further processing to make it dissolvable in water. If the heme is processed directly in the liver, it is termed direct or conjugated bilirubin and is soluble, or dissolvable in water.

But how does bilirubin get in the urine and what does it mean? Bilirubin that is conjugated or dissolvable can be passed in the urine. If not, the bilirubin circulates the body via red blood cells instead. The bilirubin is excreted as a component of bile, and gives rise to the color of urine and feces through further processing in the small intestine to a component called urobilinogen. The urobilinogen is then exported back to the liver and then circulates the blood to be finally excreted in the urine. That which remains to circulate in the blood before final excretion gives to the coloring of bruises and also the yellowing of the eyes and skin seen in those who are jaundiced. As a product itself, bilirubin in urine is generally not present, as it should be converted to urobilinogen. However trace amounts are not unheard of nor should be of great concern.

Disease and Conditions with Increased Levels of Bilirubin in Urine

The official medical term for elevated levels of bilirubin in urine is bilirubinuria. Generally, bilirubin in urine relates to problems occurring in liver or the gallbladder in either obstructive (cancerous or otherwise) or inflammatory processes. In some individuals, inherited conditions may also give rise to higher than normal levels of bilirubin in urine.

Inherited Conditions (Bilrubin in Urine)

• Dubin-Johnson Syndrome is a rare inherited condition that prevents the liver from conjugating bilirubin, which results marked levels of bilirubin in urine as one of the symptoms. This disease is usually diagnosed during infancy with the main symptom of jaundice.

• Rotor’s Syndrome is similar to Dubin-Johnson Syndrome, but considered more rare. It is also known as Floretin and Manahan Syndrome. It also has marked levels of bilirubin in urine but differs in the pigmentation of liver cells and in the minuscule chemical components of bilirubin.

Hepatitis due to Bilrubin in urine

Hepatitis, or inflammation of the liver which can produce detectable levels of bilirubin in urine can lead to liver cirrhosis and may have several origins including:

• Viral hepatitis types A, B, C, D, and E, bacteria, and parasites

• Inflammation of the liver secondary to an autoimmune disorder originating outside the liver or bile duct system including type 1 diabetes; Graves disease, the main cause of an overactive thyroid; Rheumatoid Arthritis an autoimmune disorder which affects the joints and the heart; Sjogren’s Syndrome which causes a particular type of anemia; ulcerative colitis causing inflammation and ulcers in the large colon and rectum

• Alcohol, drug, or medically (usually medications) induced toxic hepatitis

Gallbladder Conditions Resulting in Bilirubin in Urine

The gallbladder receives bile produced by the liver and shunts it to the intestinal tract through the common bile duct. When bile is not able to utilized by the intestinal tract, it is exported back to liver and raises the level of bilirubin that can be detected in urine.

• Most often, problems associated with the gallbladder or the common bile duct is the development of stones, or solidified components of bile salts, which blocks the passage of bile.

• Biliary strictures, a narrowing of the bile duct often a result of surgical procedures

Other Potential Symptoms Associated with Bilirubin in Urine

Bilirubin in urine, when greater than trace amounts, is a symptom that something else is going on in your body. Symptoms that may accompany higher than normal levels of bilirubin in urine may include:

• Yellowing of the skin and whites of the eyes

• Itchy skin

• Dark urine

• Nausea and vomiting

• Fatigue or general weakness

• Abdominal pain

• Abdominal swelling

• Light or clay colored feces

• Fever

 Additional Tests to Diagnose Bilrubin in Urine

Much like symptoms, additional tests will be needed to make a diagnosis related to the cause of the elevation in urine bilirubin. Some examinations may include:

• Additional blood tests including liver function tests, and hepatitis viral cultures

• Abdominal ultrasound

• Abdominal CAT scan

• Surgical biopsy of the liver or fluid analysis of the abdominal cavity

• Endoscopic Retrograde Cholangeopancreatography. A small camera is inserted orally while under sedation to visualize the gallbladder and pancreas using specialized xray techniques

Treatment Considerations

Depending on the type of condition associated with an increased of bilirubin in urine, treatment can vary. Antibiotics and antivirals are the recommended initial treatments for hepatitis; however, there are cases where such treatments will not be successful. In such cases, a liver transplant may be considered. If the cause of increased bilirubin in urine due to gallstones, medications may be given in attempt to dissolve and pass the stones naturally.

Lithotripsy, a special type of ultrasound treatment used to obliterate the stones, has the intention of passing the sediments through the body, and may also be considered. Lastly, surgery is most often considered as it has a high rate of success in alleviating symptoms associated with gallstones thereby indirectly reducing the amount of bilirubin present in urine.