Summary :
◉ What is chyluria ?
Chyluria is a rare medical condition characterized by the presence of chyle in the urine, via an abnormal lymphatic connection, which causes the urine to appear milky white.
Chyle is a milky substance composed of lymphatic fluid and chylomicrons formed in the small intestine during the digestion of fatty foods.
Most cases are secondary to infection by Wuchereria parasites. However, in Western countries, non-parasitic causes are most common.
The main symptom is thin, milky, possibly foamy urine, it is usually associated with urinary tract infection, blood in the urine and pain in the kidneys.
Treatment for chyluria will depend on the cause.
Urine from a patient with filarial chyluria (Source).
◉ What is the difference between lymphuria and chyluria?
Chyluria is a condition characterized by the presence of fat and lymph in the urine, while in lymphuria only lymph is present.
◉ What are the causes of chyluria
Chyluria occurs when the lymphatic system is damaged or not functioning as it should and there is abnormal communication between the lymph vessels and the urinary systems.
It is generally classified as parasitic (parasitic infection) or non-parasitic based on its etiopathogenesis
◉ Parasitic causes of chyluria
- Filariasis caused by Wuchereria bancrofti (95% of parasitic causes): the perineal lymphatics dilate and cause lymphatic-urinary fistulas, causing the emission of milky urine.
- Taenia echinococcus
- Ceronomas hominis
- Taenia girl
- Schistosoma haematobium
- Hookworm
- Trichinosis
- Eustrongylus gigas
- Malaria
- Ascaris
◉ Nonparasitic causes of chyluria
- Tumor in the abdomen region.
- Trauma
- Lymphatic malformation and lymphatic obstruction
- Abdominal lymph node enlargement
- Abscess
- Cancellation
- Infections: tuberculosis, fungal infection, leprosy, ETC.
- Surgery
- Thoracic duct stenosis: secondary to aortic aneurysm, cancer, pregnancy, ETC..
- Pregnancy
Note : Whatever the cause, if lymphatic drainage from the bowel is obstructed, the lymphatic vessels dilate and may rupture and flood the urinary tract.
◉ Chyluria symptoms
The main signs and symptoms of chyluria include:
- Milky or cloudy urine excretion: The appearance of urine varies with the amount of lymph present, ranging from clear to opalescent or milky.
- Blood in the urine (hematuria): is seen when there is a rupture of blood vessels in the urinary tract, and may contain blood clots.
- Dysuria
- Flank pain: resembling renal colic due to clots in the urinary tract in severe cases.
- Weight loss and growth problems.
- Hypoproteinemia
- Swelling of the legs (oedema)
- Weakness.
- Hydrocele
Note : The patient may remain completely asymptomatic in some cases.
◉ Diagnosis
To diagnose chyluria, doctors ask about symptoms, do an exam, test urine and blood, and order x-rays
◉ Urine tests: A post-prandial urine sample is recommended. It can be characterized by:
- Disappearance of the milky white urine after a fat-free diet.
- Protein excretion in the urine increases with a fatty meal.
- When allowed to settle, it separates into distinct layers of fat, fibrin and cellular debris, while after centrifugation it remains cloudy
- Urine becomes clear after adding a fatty solvent such as ether.
- A meal containing butter mixed with Sudan III taken 4-6 hours before may produce red-colored urine in the presence of chyle.
- A urinary triglyceride level >15 mg/dL
- Detection of filarial antigen.
◉ Blood tests: blood hypereosinophilia, filarial antigen, emission of nocturnal microfilariae in the circulating blood
◉ Imaging tests: May include CT scan, lymphangiogram, MRI, X-ray, intravenous urography, retrograde pyelography, or ultrasound. These tests can be useful tools to find the cause of the obstruction and localize the chylo-urinary leak
◉ Laparoscopy: A thin rod with a camera attached is passed through a small incision in your abdomen to determine the source of lymphatic leakage.
◉ Treatment
Treatment for chyluria depends on its cause. It may include :
◉ Diet change
- High fluid intake.
- A diet rich in protein, vitamins and green leafy vegetables.
- Limit the amount of fat.
- Replacement of long chain triglycerides with medium chain triglycerides which are absorbed directly into the blood vessels and therefore do not contribute to chyluria.
- To provide absolute enteric rest, there might be a place for total parenteral nutrition
◉ Drugs
- Lipid-lowering drugs: to limit the absorption of cholesterol (e.g. ezetimibe).
- Antiparasitic drugs: in case of chyluria resulting from filariasis (e.g. diethylcarbamazine)
◉ Minimally invasive
- The majority of minimally invasive techniques involve sclerotherapy and this is indicated in patients who have failed conservative or medical treatments.
- The most common sclerosant is silver nitrate.
◉ Invasive treatment
In some situations, the doctor may recommend more invasive procedures, such as surgery:
- If previous procedures failed ( ≥ 2 cycles of sclerotherapy).
- Individuals with significant symptoms: significant weight loss, hypoproteinemia, anasarca, recurrent clot retention, immunodeficiency, anasarca, and psychological disorders.
◉ Frequently Asked Questions
Is chyluria serious ?
Chyluria goes away without treatment (up to 50% of cases). However, It can sometimes cause problems such as vitamin deficiencies, cachexia, hypoproteinaemia and malnutrition.
What the normal color of urine ?
The normal color of the urine is clear to pale yellow. Any changes like white, brown, or red color are considered abnormal. But certain medicines or foods can change the color such as beets, blackberries and fava beans can turn urine pink or red, for example.
Is chyluria life threatening? ?
Although chyluria is not life-threatening, its symptoms may require hospitalization for improvement.
In cas of chyluria, where can happen the obstruction of lymph flow ?
The obstruction of lymph flow and rupture of lymphatic vessels into the renal pelvis, ureters, bladder, or urethra.
What parasite causes chyluria ?
Parasitic chyluria is mainly (95%) caused by Wuchereria bancrofti. It is an unusual manifestation of lymphatic filariasis reported mainly from South Asian countries.
