What is Bilirubinuria?
Bilirubinuria is when there’s bilirubin, a substance that gives bile and stool their typical color, in your urine. This can be found during a common urine test, known as a urinalysis, which is done in hospitals around the world. However, finding bilirubin in the urine isn’t normal, as it usually needs to be able to dissolve in water to be removed from your body through the kidneys.
Bilirubin can exist in two forms in your body: conjugated/direct or unconjugated/indirect. Unconjugated bilirubin can dissolve in fat, but not in water, so it can’t be excreted or detected in the urine. If you have a high level of unconjugated bilirubin, your urine won’t turn dark, but you might experience a condition known as acholuric jaundice.
In contrast, conjugated bilirubin can dissolve in water and therefore can be removed through your urine. When this happens, it may cause your urine to turn a tea or cola color if you have jaundice (yellowing of the skin or eyes) and a high amount of conjugated bilirubin. This type of bilirubin usually increases in the body due to liver or bile duct disease.
In a healthy person with proper liver function and bile duct structure, bilirubin shouldn’t be found in the urine. So, if it’s detected, it can be an early sign of liver or bile duct disease, signaling a condition known as conjugated hyperbilirubinemia, which is an abnormally high amount of bilirubin in the blood.
What Causes Bilirubinuria?
Your body processes a substance called bilirubin in three steps. First, it prepares the bilirubin for processing – this is what we call the “prehepatic” phase. Then, it processes the bilirubin inside the liver, turning it into a form that can dissolve in water. This is the “intrahepatic” phase. Finally, the bilirubin leaves the liver and either gets stored in the gallbladder or passes through a part of your gut called the duodenum. If there’s a disease that prevents the liver from processing bilirubin or blocks the bilirubin from leaving the liver, you can end up with too much bilirubin in your body, which doctors call “conjugated hyperbilirubinemia.”
There are several things that can cause too much bilirubin to build up in your liver. Diseases like viral hepatitis, alcoholic liver disease, autoimmune hepatitis, and Wilson’s disease can all lead to this issue. Certain inherited conditions like Dubin-Johnson syndrome and Rotor syndrome can also cause it. Other factors, such as preeclampsia in pregnancy, a blood condition called sarcoidosis, or an injury caused by a drug can also lead to too much bilirubin in the liver.
Besides these, some conditions can block the bilirubin from leaving your liver, causing it to build up. Obstructions in the liver’s ducts such as gallstones, strictures or narrowings, choledochal cysts, cholangitis (inflammation of the bile ducts), and cholangiocarcinoma (bile duct cancer) are examples. Even malignancies in other parts of the body, like lymphoma and pancreatic cancer, or chronic inflammation in the pancreas can lead to a buildup of bilirubin in your body.
Risk Factors and Frequency for Bilirubinuria
Bilirubinuria, a condition detected in a lab test and associated with various health issues, is hard to measure accurately. Around 3.9% to 6.9% of Americans have some form of chronic liver disease, which may cause bilirubinuria. However, bilirubinuria can also occur in patients with sudden liver and biliary disease or in those with unrelated systemic illnesses.
Signs and Symptoms of Bilirubinuria
When assessing a patient’s medical history, it’s critical to evaluate any conditions linked to liver and gallbladder diseases such as fatty liver disease, pregnancy, viral hepatitis, alcohol-related liver disease, celiac disease, thyroid disease, and heart failure affecting the right side of the heart. Track all medications, including prescription drugs, over-the-counter treatments, and dietary supplements since these can impact liver function.
Also, certain drugs like phenazopyridine and the anti-inflammatory medication etodolac can lead to the presence of bilirubin in urine. A detailed surgical history, particularly concerning abdominal surgeries, and family history of inherited disorders like Dubin-Johnson and Rotor syndrome are essential. Knowing the patient’s travel history could indicate if they’ve visited regions where hepatitis is prevalent.
Social habits such as alcohol intake can affect liver function, and this information is essential. Risk factors for viral hepatitis like intravenous drug use, risky sexual behavior, and exposure to needles or blood transfusions should also be inquired about. Mental stress can potentially cause bilirubin in urine and might be easily overlooked.
Identifying the type of liver injury, whether it’s caused by damage to liver cells or blockage of bile flow, is useful. Symptoms like weight loss or immune deficiency can point towards obstructions due to cancer or infections. Patients with blocked bile ducts might report dark urine, light-colored stools, or itching skin.
Physical examination, focusing especially on the skin and eyes, can provide clues such as the presence of yellowish skin and eyes. Other indications to look out for are signs of chronic liver disease like liver-related skin changes (large, swollen blood vessels on the skin, red palms, spider-like blood vessels, and breast enlargement in men), as well as signs of liver congestion like enlarged liver felt on touch, higher pressure in the jugular veins, and fluid accumulation in the abdomen.
Testing for Bilirubinuria
Bilirubinuria, or the presence of a substance called bilirubin in the urine, is typically measured using a standard urine test. In this test, a special strip containing a chemical called a diazonium salt reacts with the bilirubin, creating a red dye. The color intensity of this dye corresponds with the amount of bilirubin in your urine.
However, it’s important to note that there can be cases where the test results do not accurately reflect your body’s bilirubin levels. Certain conditions or substances can interfere with the bilirubin’s reaction with the diazonium salts, leading to a false negative. These include the presence of urinary nitrates, urine with a pH below 5.5, the use of antibiotics (which reduce your gut’s natural flora), or the presence of vitamin C, which can react with the salts instead.
Conversely, a false positive can occur if certain substances that cause color changes in your urine are present. These can make the urine appear redder than it would be from bilirubin alone and include drugs like phenazopyridine and chlorpromazine or the breakdown products (metabolites) of a drug called etodolac.
As of now, there’s no definitive process to follow in the case of bilirubinuria, though it’s proposed that a certain sequence of steps should be followed if bilirubin is detected in your urine.
Treatment Options for Bilirubinuria
The treatment for bilirubin in urine depends on the underlying health conditions that are causing this issue. Sometimes, a liver biopsy may be needed to find the cause of an excess of a specific type of bilirubin in the blood (known as “conjugated hyperbilirubinemia”) if blood tests and a review of your health history don’t provide enough information.
There’s a procedure called ERCP (endoscopic retrograde cholangiopancreatography), which can be very helpful both for diagnosing and treating patients who have bilirubin in their urine and a high level of conjugated bilirubin in their blood due to a blockage in the common bile duct (the tube that carries bile from the liver to the small intestine), often caused by a stone. This procedure allows doctors to examine the pancreatic and bile ducts and remove any obstructions if necessary.
What else can Bilirubinuria be?
In simpler terms, a false positive – which means the test shows you have a condition when you actually don’t – can happen when certain substances, which can alter the color of the result, are present. These substances might include phenazopyridine, indicans, chlorpromazine, or etodolac metabolites, all of which can cause your urine to turn reddish.
On the other hand, a false negative – meaning the test doesn’t detect a condition you actually have – might happen in a condition called prolonged cholestasis. This is when, despite having an abnormal level of a substance called conjugated bilirubin in your blood, the majority of this bilirubin is attached to another substance, albumin. This combination, known as delta bilirubin, cannot be filtered by an organ in your body called the glomerulus, and so the test may miss it.
What to expect with Bilirubinuria
The outlook for people with bilirubin in their urine, a condition known as bilirubinuria, largely depends on what is causing it. Generally speaking, if the bilirubinuria is caused by more benign conditions, such as gallstones or a narrowing of the bile duct known as biliary stricture, the outlook can be quite good. However, if the condition is caused by something more severe, like a blockage in the bile duct due to cancer or a disease that can lead to liver cirrhosis (which is severe scarring of the liver), the outlook might not be as good.
Possible Complications When Diagnosed with Bilirubinuria
Unconjugated bilirubin, a certain type of bilirubin, has the ability to pass through the barrier that protects the brain from harmful substances. The reason behind this is its fat-soluble nature that allows it to get into nerves and support cells in the brain. This activity can lead to a range of diseases which fall under the term ‘biliary encephalopathy’. Diseases and death linked to having too much conjugated bilirubin, another type of bilirubin, and bilirubin in urine are typically due to the underlying disease causing these conditions.
Key Points:
- Unconjugated bilirubin, due to being fat-soluble, can get through the brain’s protective barrier.
- This can lead to a range of diseases known as ‘biliary encephalopathy’.
- Having too much conjugated bilirubin, and bilirubin in urine can be linked to diseases and death.
- The primary cause for these bilirubin-related conditions is typically the underlying disease itself.
Preventing Bilirubinuria
Having bilirubin in your urine may be an early warning sign of a problem in your liver. If you think this might be the case, it’s important to speak with your doctor.
Before taking any herbal supplements, it’s important that you first ask your doctor. Some of these supplements can be harmful to your liver.
Try to avoid drinking too much alcohol and using injected drugs. Practicing safe sex is strongly recommended as well. These simple steps can help keep your liver healthy.
If you’re planning to travel to an area where hepatitis, a liver disease, is common, remember to consult your doctor. They will give you the necessary vaccines and precautions you should take to stay safe and healthy.
