Cystine Kidney Stones
Mar 08, · Key Points Cystine stones are caused by a rare, inherited disorder called “cystinuria.” Cystinuria is a lifelong condition that will need to be actively managed to keep stones from forming. Treatment starts with doing things to keep stones from forming, . Cystine stones are a type of kidney stone made from a chemical called cystine. This chemical is often a product of a condition called cystinuria. A large part of treatment is to prevent the cystine stones from forming. This is often done through diet changes and increases the amount of water you drink.
Most cystinurics do not have these crystals in their urine but when they are present they confirm the diagnosis. Unlike most stones, they are caused by a genetic mutation and are inherited. There is no sexual predilection and patients may present at any age. The primary symptom of having cystinuria is the formation of urinary calculi.
Stones may be present in single, multiple, or large staghorn configurations. Pure cystine stones are not easily visible on plain x-rays due to their sulfur content. A strong family history of kidney stones, development at a young age, or recurrent stone disease are suggestive of the diagnosis.
Cystine stones are amber in color. Stone analysis will confirm the diagnosis. The limited solubility of cystine is responsible for spontaneous crystallization and subsequent stone formation when it is present in high concentrations.
Urinary pH, or the acidity, does have a profound effect on cystine solubility, however, and manipulating the pH is one of the mainstays of therapy to dissolve and preventive cystine stones. Cystinuria is caused by a genetic mutation that results in abnormal decreased small bowel absorption and kidney reabsorption of cystine and three other amino acids: ornithine, lysine, and arginine.
Three types of genetic mutations can lead to cystinuria. Cystinuric patients can develop stones with amazing rapidity.
Surgical treatment alone is destined to failure. Patients and their families also require genetic counseling, medical management, and regular followup evaluations. Medical therapy is directed at dissolving existing calculi and preventing formation of new calculi. Four methods of achieving these goals have been utilized: 1 increasing fluid intake to decrease the relative concentration of urinary cystine; 2 altering urinary pH to increase cystine solubility; 3 decreasing the amount of urinary cystine by dietary modifications; and 4 binding urinary cystine with medications to form more soluble compounds.
Urinary cystine concentration can most simply and effectively be lowered by increasing urinary volume. Fluid intake adequate to keep the urinary concentration of cystine below its solubility level throughout the day is the goal. This goal is difficult to achieve in homozygous patients and requires almost continual fluid intake throughout the day and repeated intake at night to prevent nighttime increases in cystine urine concentration.
Patients should be encouraged to drink fluid prior to going to bed and at least once during the night total what does mansion mean in the bible 2. Alkalinization takes advantage of the pH dependence of cystine solubility.
An elevated urinary pH can be achieved by divided-dose administration of alkali medications citrate, bicarbonate, or mixed preparations. Potassium containing formulas are preferable to sodium containing preparations because they do not enhance calcium and cystine stone formation.
Citrate may be preferred to bicarbonate because of its relatively prolonged duration of action. Urinary alkalinization above a pH of 7. Patients can be instructed to adjust the dose of medications using home urine pH paper tests similar to home pregnancy tests to maintain their urinary pH between 7.
Methionine is a precursor of cystine and dietary restriction in theory could lead to decreased cystine production and urinary concentrations. Rigid methionine dietary restriction is very difficult however and of limited benefit.
Methods to increase cystine solubility by binding it to various medications have been developed. The chemical structure of cystine, with its disulfide bond joining two cysteine molecules, makes it amenable to this approach. Captopril can form a disulfide bond with cystine and render it more soluble. This thiol-cysteine mixed disulfide is times more soluble than cystine. The effectiveness and mechanism of captopril therapy remains controversial. D-penicillamine and alpha mercaptopropionylglycine a-MPG have documented efficacy in reducing cystine excretion.
They both undergo disulfide exchange with cystine to form more soluble mixed disulfide compounds. The disulfide exchange reaction is facilitated by an alkaline urinary pH. How to ask sponsorship from companies D-penicillamine and a-MPG appear to decrease renal excretion of cystine in addition to increasing cystine solubility. Patients who fail medical therapy or who are symptomatic require surgical treatment.
ESWL has a reduced success rate for the treatment of cystine stones. The organic nature and uniform structure of pure cystine make them the least fragile of all urinary calculi. Cystine stones less than 1. These stones may require substantially more shocks than equivalent sized non-cystine calculi. Small cystine calculi in the distal ureter usually what is a cystine kidney stones be managed easily with ureteroscopic basketing and extraction.
Electrohydraulic and ultrasonic lithotripsy, older technologies, often failed due to the hardness of cystine calculi.
Laser lithotripsy was also initially frequently ineffective but its success has improved with the current generation of holmium lasers, which are able to successfully fragment these stones. Percutaneous surgery should be considered in patients with complex cystine stones, a large stone burden, or stones that have failed medical management, ureteroscopy, or ESWL.
Cystinuria is a lifelong disorder requiring frequent intervention and thus open surgery should be avoided. Cystine calculi can be dissolved by percutaneous and retrograde direct irrigation.
The solutions used are based upon the same principles as for oral dissolution therapy: creating an alkaline environment to increase cystine solubility and causing a disulfide exchange reaction to create a more soluble compound.
Percutaneous irrigants include N-acetylcysteine, N-acetylcysteine with bicarbonate, bicarbonate, and tromethamine-E. The success rate is limited in the presence of mixed cystine stones, since calcium and struvite components will not dissolve and the alkaline environment may actually promote hydroxyapatite and struvite growth. Every attempt should be made to render a patient stone free in order to reduce long-term problems.
Recurrences are frequent even after a stone free status is achieved, highlighting the importance of medical therapy and frequent follow up evaluation to monitor progress. My daughter was diagnosed with cistineuria at 13 years old and is now 20, she takes paracetamol when she is in severe pain but this has no effect, can she take co codamol. I am about to turn 50 and had my 1st stone at 8. Both puberty and pregnancy caused an increase in stone load, so I am worried as I am approaching peri-menopause.
I am a 38 year old woman how do i store tulip bulbs cystinuria and a 10 year old daughter with cystinuria. Does this mean that he actually has the condition or could he still be a carrier???
It would kill me if I have passed it on to my boy as well How do I find out if my children have a chance of having this disease? What does this mean? I have two sisters that have cysteine stone formation out of control. How can we measure the ph in their urine and increase or decrease their potassium and meds mattering on the ph level. Please help! Cystine is is a rare recessive genetic disorder.
For either of your children to have the disorder both you and their father would have to be carriers. If your sisters are your full genetic sisters by the what is a cystine kidney stones parents, you are quite possibly a carrier, but not necessarily unless either of your parents have the disease. If either parent has the disease, you are a carrier. If both parents are carriers, but do not have the disease, you have a 50 percent chance of being a carrier, 25 percent chance of having the disease and 25 percent chance of not being a carrier.
Again, this is a rare issue and if their father is not s carrier, they will be fine. I wish you all the best of luck Urine Ph test strips are available at GNC. I have cystinuria.
Can I marry and have children without cystinuria? And is it a common test. I think my partner may accept this problem Very hardly. Is it a complicated problem for getting married? If your partner has the gene, but not the disease, he would be a carrier and there would be a 50 percent chance of each of your children having the disease and percent that they will carry the gene. If your partner is not a carrier, there is zero percent ability for your how to harvard reference an image to have the disease, they would just be carriers.
I do not know if there is a test for being a carrier. Good luck to you! Anybody have cystine stones while pregnant? Please, any info? I passed 10 cystine stones while pregnant! I was 6 months pregnant when it happened. They were very big stones too. Thankfully I did not need medical intervention and passed them with just taking paracetamol.
How is your pregnancy going? I actually ended up in the emergency room last week and passed 3 stones, after a CT scan they said there are another 5 to go! I had a back operation in October and I think being on bed rest has caused this round of Stones. The last bad episode was when I was pregnant. If possible keep moving as much as you can bad keep drinking that water! My daughter is now 3 and I am keeping a close eye on her in case I pass this affliction on to her!
Hi, I have cystine stone in my both kidneys. In a test of urine 24 hours for cystine found that my cystine in higher than normal range. Please advise how to control it. Jugal Kishore.
What are cystine stones?
May 22, · Cystine stones are amber in color. Stone analysis will confirm the diagnosis. Cystine is an amino acid and normal individuals excrete low amounts in the urine (18 milligrams cystine/gram creatinine). Simple heterozygous adults (those with one inherited gene) usually excrete. Mar 29, · Cystine kidney stones: Cystine kidney stones are due to cystinuria, an inherited (genetic) disorder of the transport of an amino acid (a building block of protein) called cystine that results in an excess of cystine in the urine (cystinuria) and the formation of cystine stones. Cystinuria is the most common defect in the transport of an amino acid. Jun 16, · Cystine kidney stones form because of a rare inherited genetic disorder called “cystinuria” that impacts about % of the population. Cystinuria inhibits the reabsorption of the amino acid cysteine which leads to the formation of kidney stones. Cystinuria is a life-long condition that can be controlled-not cured.
Cystinuria is passed down from parents to children through a defect in a specific gene. In order to actually have cystinuria, a person must inherit the gene from both parents see above photo.
Unfortunately, cystinuria is a life-long condition that can be controlled. But, not cured. Compared to calcium stone formers, people with cystinuria tend to make larger stones, require more urological procedures, and will start making stones at an earlier age.
They also face a greater risk of eventual kidney damage and chronic renal failure compared to calcium stone formers. The primary problem that is caused by cystinuria deals with the reabsorption of the amino acid, cysteine, in the kidneys see above photo.
There are other amino acid reabsorption issues with this disorder as well, including lysine, ornithine, and arginine.
However, cystine is the only amino acid that is clinically significant, as it is the only amino acid in the group that will form kidney stones.
However, some adults have their first cystine kidney stone after age Sadly, children can also get cystine stones. As with many other kidney stone types Calcium Phosphate , Uric Acid , and Struvite , urine pH plays a large role in cystine kidney stone formation. For those with cystinuria, cystine solubility is highly impacted by urine pH levels. In normal urine pH of However, studies have shown that reabsorption and solubility can be improved by alklizing the urine pH of 6.
Please note that achieving urine pH of above 7. Most often, cystinuria is found when you have symptoms of a kidney stone. Once passed, the stone is tested to see if it is made out of cystine. A family history of cystinuria can also be an important clue. Other tests may include:. At the present time, genetic testing for the defective gene is not often used to find cystinuria.
But, it can play a role in diagnosis if needed. Surgical treatment of cystine stones is similar to that of other kidney stones. However, cystine kidney stones are notoriously resistant to extracorporeal shock wave lithotripsy ESWL.
As a general rule of thumb, ureteroscopy with laser lithotripsy is preferred for most cystinuria patients with obstructing cystine stones that require surgery. Total removal of all cystine stones and fragments has demonstrated reduced recurrence rates and better preservation of renal function. Fortunately, surgery has not demonstrated any measurable decrease in overall renal function. This level can often be reached through an increased fluid intake and urinary alkalinization.
A sustained urinary pH of 7. Hydration is usually the first step in medical management. Increasing fluid intake sufficiently to reliably generate 2. For most individuals, this will translate to about L about a gallon worth of water per day just like we mentioned in our previous blog, 4 Keys to Naturally Passing Kidney Stones. Since some cystinuric patients can generate up to mg of cystine per day, hydration alone may not be sufficient, but it is always the first step in management. Up to one-third of cystine stone patients can manage their stone recurrences with fluid management.
Optimal hydration will depend on the patient's cystine excretion. In addition to increased water intake, alkalinization of the urine can help prevent cystine stone formation and also dissolve existing cystine stones. To prevent cystine kidney stones, the urinary pH should be targeted at 7. However, at this high pH level above 7. In such cases, hypercalciuria elevated calcium in urine needs to be controlled tightly with diet. Even reducing salt intake has been shown to help keep cystine stones from forming.
Mineral water, citrus juices, and citrate supplements can help increase pH level, too. The herb Chanca Piedra can also be added to the diet as a booster, as it increases urinary citrate which inhibits the formation of all kidney stone types. Sodium bicarbonate can also be used to help with pH issues, but it tends to have a relatively short-term alkalinizing effect, and the extra sodium intake may increase urinary cystine excretion.
High animal protein diets are also discouraged in cystinuric patients for the same reason. When conservative measures as outlined above are insufficient after a 3-month trial period, a thiol-based drug regimen is usually the next step in active cystine stone formers. Cystine is composed of 2 cysteine molecules bound together by a disulfide bond. Thiol-based drugs have sulfhydryl groups that can reduce this disulfide bond producing a mixed cysteine disulfide compound that is far more soluble than the original cystine molecule.
As a general guide, most patients with a hour urinary cystine excretion of mg or more are likely to need a thiol medication in addition to hydration therapy and alkalization. Thiol-based treatment is also thought to have the extra benefit of possibly making cystine stones more amenable to ESWL treatment.
This may occur because of the mixing of calcium phosphate along with the cystine creating a more fragile stone that is more easily fragmented with ESWL therapy. Urinary alkalinization with mineral water, fruit juices naturally occurring citrates , and potassium citrate synthetic will also greatly increase cystine solubility. Anti-lithic herbs such as Chanca Piedra will also add a boost in prevention due to their ability to naturally boost levels of citrate in urine.
Currently, tiopronin Thiola is the recommended thiol medication of choice based on its efficacy and reduced side effect profile. Long term studies of cystinuria patients followed for 21 years have shown that the best preservation of renal function and the lowest recurrence rates are found in those with early medical management of cystinuria along with complete surgical stone removal.
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