What is chyluria?

Chyluria is a rare condition in which lymphatic fluid leaks into the kidneys and turns the urine milky white. In parts of the world with fewer healthcare resources, chyluria is often associated with a parasitic infection called Wuchereria Bancrofti. However, chyluria can also be caused by lymphatic conduction disorders.  

The lymphatic system plays a crucial role in immune function and in the delivery of vital nutrients to the body. Functioning almost like a sponge, the lymphatic system absorbs excess lymph fluid — watery fluid containing protein, electrolytes, cells and other substances — from the body’s organs and returns it to the blood stream.

In a healthy body, the lymphatic channels from the kidney drain towards the thoracic duct, which is the main lymphatic vessel responsible for lymph drainage. In children and adults with chyluria, channels beginning in the kidneys flow in the opposite direction, creating leaks into the urinary collecting system. This causes the urine to appear white. As lymphatic fluid spills into the kidneys, there is no way for the body to absorb it. This fluid loss results in abnormally low levels of albumin, electrolytes, coagulants and even T-cells.

Causes of chyluria

Experts in the Jill and Mark Fishman Center for Lymphatic Disorders at Children’s Hospital of Philadelphia (CHOP) are leaders in lymphatic research, diagnostics and treatment. This research is changing the way the scientific and medical communities think about chyluria. 

Chyluria can be caused by primary and secondary disorders. Primary causes of chyluria include conduction disorders, such as:

• RASopathoies
• Central conducting lymphatic anomaly (CCLA)
• Lymphangiomatosis/Generalized lymphatic anomaly (GLA)
• Kaposiform lymphatic anomaly (KLA)
• Gorham-Stout disease (GSD)

Filariasis (a group of infectious tropical diseases caused by parasitic round worms) is a secondary cause of chyluria. Regardless of the cause, imaging has shown that lymphatic leaks are localized. In chyluria, lymphatic leaks are most often found in the kidney. 

Signs and symptoms of chyluria

Some of the symptoms associated with chyluria include: 

• Milky white urine 
• Pain during urination 
• Blood in urine 
• Frequent urination 

Diagnosing chyluria

The world-renowned experts in the Jill and Mark Fishman Center for Lymphatic Disorders developed a specialized imaging technique — dynamic contrast magnetic resonance lymphangiography (DCMRL) — that is used to pinpoint the exact source of lymphatic leaks. During this procedure, an MRI contrast agent (a safe, injectable dye) is injected directly into the lymphatic system and tracked by MRI. 

There are three points of access through which the contrast agent is injected:

• Intranodal (inguinal lymph nodes) 
• Intrahepatic (liver) 
• Intramesenteric (mesentery)  

Each point of access for DCMRL provides a different view of the lymphatic system for the most comprehensive lymphatic imaging. Individuals with chyluria receive all three points of access, allowing our physicians to clearly see the anatomy of the lymphatic system, the direction and speed of lymphatic flow and the exact source of any leaks. It is especially important in chyluria diagnosis and treatment to identify the exact source of the leak and to target an intervention.  

Testing a urine sample for the presence of lymphatic fluid such as lymphocytes and triglycerides can also help in identifying chyluria.

Treatment of chyluria

The treatment for chyluria depends on what is causing the condition. Medications such as diuretics, in addition to a low-fat diet, can sometimes decrease the among of lymphatic fluid leaking into the kidneys. If symptoms persist, physicians may recommend comprehensive lymphatic imaging and intervention — a selective or targeted embolization which seals off leaking lymphatic channels.

During a lymphatic embolization, several different types of embolization agents may be used. These embolizing agents are injected through a catheter to stop the leaks and seal abnormal lymphatic vessels.

Long-term outlook for chyluria

In the Jill and Mark Fishman Center for Lymphatic Disorders, children and adults with chyluria are treated by the world’s most experienced specialists in lymphatic imaging and intervention.

The highly advanced treatment options for chyluria are cutting-edge, and there is also more to learn about them. Our experts are invested in further research to determine the long-term outlook for chyluria patients and the role of lymphatic imaging and intervention in the treatment of this condition.