What does the presence of urobilinogen in urine indicate?

From the Guidelines

The presence of urobilinogen in urine indicates liver function or hemolysis issues, with normal levels ranging from 0.1-1.0 Ehrlich units or 0.5-4.0 mg/24 hours, and elevated levels suggesting conditions such as hemolytic anemia, liver disease, or biliary obstruction. When interpreting urobilinogen levels, it's essential to consider the clinical context, as this test is often part of a routine urinalysis, and results should be evaluated alongside other laboratory tests and findings. According to recent studies, such as the one published in the Journal of Extracellular Vesicles in 2021 1, commercially available dipsticks can measure urine pH and various contents, including urobilinogen, to identify patient status and exclude deviating samples. Some key points to consider when evaluating urobilinogen in urine include:

• Normal urine contains small amounts of urobilinogen
• Elevated levels may indicate increased red blood cell destruction, liver disease, or biliary obstruction
• Urobilinogen forms when bilirubin is reduced by intestinal bacteria and partially reabsorbed into the bloodstream
• Liver disease can lead to increased urinary excretion of urobilinogen due to the damaged liver's inability to remove it from the blood
• Hemolytic conditions can produce more bilirubin, resulting in higher urobilinogen levels
• Absent urobilinogen may indicate complete bile duct obstruction or antibiotic use that has killed intestinal bacteria. It's crucial to interpret urobilinogen test results in conjunction with other clinical findings and laboratory tests to determine the underlying cause of abnormal levels, as stated in the study published in the Journal of Extracellular Vesicles 1.

From the Research

Urobilinogen in Urine

The presence of urobilinogen in urine can indicate several conditions, including:

• Hemolytic anemia, where red blood cells are broken down faster than they can be made 2
• Liver disease or dysfunction, as urobilinogen is a byproduct of bilirubin breakdown and can accumulate in the urine if the liver is not functioning properly 3, 4
• Increased red cell destruction, which can lead to an increase in urobilinogen production and excretion in the urine 5
• Certain infections, such as chickenpox, which can cause hemolytic anemia and increased urobilinogen levels 2
• Acute hepatic porphyria, a rare genetic disorder that can cause abdominal pain and increased urobilinogen levels in the urine 6

Clinical Significance

The presence of urobilinogen in urine can be an important diagnostic indicator, but it should be interpreted in the context of other clinical findings and laboratory results. For example:

• A high urinary urobilinogen/serum total bilirubin ratio can be a sensitive and specific marker for acute hepatic porphyria 6
• Urobilinogen levels can be elevated in patients with hemolytic anemia, but this can also be a transient and self-limiting condition 2
• The presence of urobilinogen in urine can be a nonspecific finding and may not always indicate a specific underlying condition 3, 4

Laboratory Testing

Urobilinogen levels can be measured in urine using various laboratory tests, including:

• Urine dipstick tests, which can detect the presence of urobilinogen but may not provide quantitative results 6
• Laboratory-based assays, which can provide more accurate and quantitative results but may not be routinely available 3, 4