Cystinuria: Causes, Symptoms, Treatment

Cystinuria is a condition that is caused by the accumulation of cysteine, an amino acid that is produced in the kidneys, bladder, and ureters. It is a rare and inherited disease passed to the children when both the parents have the condition.

Kidneys are important for the proper functioning of the body. It does the important function of flushing out toxins and wastes from the body through urine, maintaining your body’s overall fluid balance, and releasing hormones that help in bone health and regulating blood pressure.

In individuals with the condition, cysteine gets accumulated in the kidneys, bladder, and ureters, and eventually create cystine stones. Having one is a painful experience and appropriate treatment is needed. If you have small stones, medications can help them pass through urination. But if you have large stones, a surgical procedure is needed.

Symptoms of Cystinuria

Cystinuria is a condition that can occur in individuals of all age groups.

But the symptoms of the condition are mostly seen in individuals between 10 and 30 years of age. Common symptoms of the condition include:

• Painful urination
• Presence of blood in the urine
• Pain in the abdomen
• Pain in the groin or pelvis area
• Urinary tract infection

Causes

The cause of cystinuria is the defect in SLC3A1 and SLC7A9. These two genes are responsible to provide instructions to your body to produce certain protein complexes present in the kidneys.

These proteins are responsible for regulating the reabsorption of certain amino acids. Defects in even one of the genes can influence the ability of the protein complex to reabsorb amino acids. This further leads to the accumulation of amino acids in the kidneys and the formation of cystine stones.

Risk Factors

You are likely to get the condition only if both your parents have a defect in SLC3A1 or SLC7A9 genes.

Diagnosis of Cystinuria

If you have any symptoms associated with cystinuria, consult your doctor. Your doctor will ask you about your symptoms, frequency of the symptoms, and family history of the condition.

Doctors diagnose cystinuria with the help of the following medical tests:

• Urinalysis – It is a detailed analysis of urine sample that includes physical examination (color and physical appearance), chemical examination (changes in the urine sample with the help of certain chemicals) and microscopic examination (monitoring the urine sample under the microscope).
• 24-hour urine collection – In this test, you need to collect all the urine for a period of 24 hours and submit it to the lab for analysis. They will teach you the proper instructions about collection and storage of the urine sample.
• Imaging tests – Images acquired through tests such as X-rays, CT scan, and ultrasound are helpful to get a clear view of your abdomen from inside and confirm the formation of stones inside the kidneys.
• Intravenous pyelogram (IVP) – In this procedure, a surgeon inserts a dye into the bloodstream and does an X-ray examination.

In most cases, the diagnosis of the condition only happens when an individual already has kidney stones. The kidney stones then undergo testing and analysis to confirm if they are cystine stones.

Treatment of Cystinuria

It is important to treat the condition as soon as it is diagnosed, as it can cause severe complications if left untreated. These complications include infection in the kidneys, damage of kidneys or bladder due to cystine stones, urinary tract infections and, blockage of the ureters.

The main aim of the treatment is to relieve symptoms and prevent the damage as well as the formation of more stones.

Treatment options include:

Increase your fluid intake – The first suggestion your doctor would give you is to increase your fluid intake. Your doctor will help you with the right amount of fluid you need to intake in a day. In some cases, your doctor may even recommend increasing the intake of fluid with the help of IV.

Medications – Your doctor may prescribe you medications that will help the cystine stones to dissolve with the urine. Make sure you take the medications as prescribed by your doctor and only for the recommended period. The medications may cause certain side effects. If you experience any unusual changes after consumption of the medications, make sure you inform your doctor about it.

Your doctor may even prescribe medications to relieve pain.

Surgery – Your doctor may recommend surgical procedures when medications and lifestyle measures are not effective. They will also recommend these procedures when you have severe pain or when the cystine stones are large.

• Ureteroscopy – A procedure that is helpful to remove small cystine stones.
• Percutaneous nephrolithotomy – This procedure involves inserting a small tube directly into your kidneys. This tube then removes the stones or breaks them.
• Extracorporeal shock wave lithotripsy (ESWL) – In this procedure, surgeons pass shockwaves through the body to break the kidney stones. But in some cases, the procedure may not help to break cystine stones as they are hard.

Lifestyle Changes

If both your parents have the condition, you are more likely to get the disease. Even though it is difficult to prevent, you may use the help of certain lifestyle measures and make the condition less painful and prevent further damage.

Some of the lifestyle measures you may consider include:

Home Remedies

• Consume a well-balanced healthy diet that may help prevent the formation of cystine stones in the future.
• Staying hydrated: Increase your fluid intake. Not just water, you may also increase your intake of juices, soups, vegetable stocks, etc.
• Increase your consumption of fruits and vegetables that are rich in citric acid. Citric acid helps prevent the formation of stones in the future as well as prevent the existing stones from enlargement.

Learn more about addressing bladder problems here.