Cystinuria

Cystinuria – General Information

Cystinuria is an inherited autosomal recessive medical disorder in which affects the stones (also known as cystine) formed in the kidney, bladder and ureter. This medical condition is characterized by the incomplete reabsorption of the cystine during the period of filtering of the kidneys. This inadequate reabsorption leads to an excessive concentration of amino acid. If the Ph of the urine is neutral or acid, then the cystine will precipitate from the urine and will form crystals (or stones) in the bladder, kidneys and ureters.
The possible complications which can result from Cystinuria are:

• Bladder injury from the stones
• Ureteral obstruction
• Kidney injury from stones
• Kidney infection

Cystinuria is known to be a life-long chronic condition, as after the treatment the stones usually reappear. The good part is that this medical condition does not affect the other internal organs and it does not result in kidney failure. The researchers have found out that what produce this disease are the mutations in the SLC3A1 and SLC7A9 genes. These two genes are the ones which give the instructions for producing the tow components of a transporter protein which is produced in the kidneys. This transporter protein allows some types of amino acids (also including cystine) to be reabsorbed in the blood from the fluid which will transform into urine. Any kind of mutation in the two genes weakens the ability of the protein to reabsorb the amino acids, which makes the urine to be concentrated in amino acids. Once the levels of cystine in the urine increase, the crystals can form, leading to the appearance of the stones in the kidneys. Studies have revealed the fact that this medical disorder affects approximately 1 in 7000 people, making it one of the most common inherited disorders.

Cystinuria – Symptoms

It is well known the fact that any medical disorder (including Cystinuria) can trigger a variety of symptoms. Therefore, some of this medical condition's most uncommon symptoms have not been listed (mentioned) here. This is why we strongly recommend you to contact your personal health care provider whenever you develop any unusual, bothersome or unpleasant symptoms. Your personal physician will be able to tell you if you are suffering from Cystinuria or from any other medical disorder. Here is a list of the most common symptoms that a person who suffers from Cystinuria, may experience:

• Blood in the urine ( also known as hematuria)
• Pus in the urine
• Flank pain or pain in the side or back:
• Which is severe
• Which is on localized in one side
• Which may worsen in a few days
• Which can be felt in the groin, genitals, pelvis
• Which can be felt between the upper abdomen and the back
• Renal colic which can be intense and cramping as a result of the stones which formed in the urinary tract
• Urinary tract infections
• Obstructive uropathy – this is a urinary tract disease which appears as a consequence of the obstruction
• High blood pressure
• Kidney insufficiency
• Recurrent Urinary tract infections
• Kidney damage
• The stones are present in both kidneys
• Difficulty urinating
• Intense back pain
• Nausea
• Vomiting
• Pain during urination
• Urinary urgency
• Urinary frequency
• Urinary hesitancy
• Excessive urinations at night
• Cloudy urine
• Foul – smelling urine
• Fever
• Chills
• Bloating
• Except the high levels of the cystine in the urine, there are other amino acids which are very concentrated in the urine, such as arginine, lysine, and ornithine.

Cystinuria – Treatment

You doctor or personal health care provider will perform a series of tests before he establishes the diagnostic of Cystinuria. These tests include a blood test, a urine test and a 24-hour urine collection test. The last test is done in order to monitor the volume of the urine, if the stones pass into the sample and also to monitor the acidity levels. Other tests may include:

• A kidney ureter bladder x-ray (also abbreviated KUB) – this test is done in order to produce an image of the zone of the kidney-ureter-bladder and to see if there are any stones in these areas.
• A kidney ultrasound – during this test, high frequency sound waves are introduced into the kidneys in order to see if there are any obstructions.
• Intravenous pyelogram (also abbreviated IVP) - during this test, a substance is injected in the patient’s vein. This substance will reach the kidneys and then it will be excreted and concentrated. This colorless substance will whiten the are around the kidneys and in the kidneys, this will reveal if there are any obstructions or dilatations in the kidneys, as the affected parts will whiten slower than the healthy ones.
• CT scan – is an x-ray of the kidneys which helps the doctor to see if there are any stones in the kidneys.

Like in any other treatment, the goal of the Cystinuria treatment is to ameliorate the symptoms and to prevent or stop the appearance and development of further stones. The persons who suffer from Cystinuria and experience severe symptoms require hospitalization. The doctors usually recommend the patients who are suffering from Cystinuria to drink plenty of fluids (at least 6 to 8 glasses of water a day), especially water, in order to produce large amounts of urine and to avoid the consumption of salt, as the salt retains the water. Doctors can also prescribe medications which help to dissolve the cystine crystals or pain relievers which are given in order to ameliorate the pain in the kidney or bladder area (this pain usually appears with the passage of the stones).

Surgery is another alternative treatment of Cystinuria, in the cases in which the medicines are not enough, here are some surgical treatment which can be recommended if the stones are too large to pass, if the stones cause constant pain and are blocking the urine flow, if the stones cause urinary tract infections and damage the kidney tissues:

• Extracorporeal shockwave lithotripsy (also known as ESWL) – the therapy uses non-electrical shock waves, which travel through the body until they reach the stones, making the sand-like and easier to pass.
• Percutaneous nephrolithotomy (also known as PNL) – this treatment method is used only when the stones are very large or if they are localized in an area in which the shockwaves are not effective. The doctor makes a little incision in the back, creating a direct tunnel in the kidney. Then using an instrument called nephroscope he localizes and removes the stones.
• Ureteroscopic stone removal – in this procedure, the doctor introduces a small fiber optic instrument in the ureter and after that he localizes and removes the stones.
• Incisional surgery - in this procedure the doctor opens the affected zone and removes the stones.