Cystine kidney stones
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. Although cystine is not the only overly excreted amino acid in cystinuria, it is the least soluble of all naturally occurring amino acids. Cystine tends to precipitate out of urine and form stones (calculi) in the urinary tract.
Small stones are passed in the urine. However, big stones remain in the kidney (nephrolithiasis) impairing the outflow of urine while medium-size stones make their way from the kidney into the ureter and lodge there further blocking the flow of urine (urinary obstruction).
Obstruction of the urinary tract puts pressure back up on the ureter and kidney. causing the ureter to widen (dilate) and the kidney to be compressed. Obstruction also causes the urine to be stagnant (not moving), an open invitation to repeated urinary tract infection. The pressure on the kidneys and the urinary infections results in damage to the kidneys. The damage can progress to renal insufficiency and end-stage kidney disease, requiring renal dialysis or a transplant.
The stone are responsible for all the signs and symptoms of cystinuria, including:
Hematuria — blood in the urine;
Flank pain — pain in the side, due to kidney pain;
Renal colic – intense, cramping pain due to stones in the urinary tract;
Obstructive uropathy — urinary tract disease due to obstruction; and
Urinary tract infections.
For a fuller understanding of cystinuria, including the diagnosis, the different modes of treatment, the genetics of cystinuria and the prognosis for persons with this disease, please see the Cystinuria article.
Read Also:
- Cystine transport disease
Cystine transport disease: Commonly known as cystinuria, this is an inherited (genetic) disorder of the transport of an amino acid (a building block of protein) called cystine resulting 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 […]
- Cystinosis
Cystinosis: A genetic disease characterized by the widespread deposition of the amino acid cystine in cells due to a defect in cystine transport. (Cystine normally forms after protein degradation and is transported from structures called lysosomes into the cytoplasm. In cystinosis, cystine accumulates in the lysoosmes and eventually forms crystals throughout the body. Cystinosis is […]
- Cystinuria
An inherited (genetic) disorder of the transport of an amino acid (a building block of protein) called cystine resulting 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. Although cystine is not the only overly excreted […]
- Cystitis
Cystitis: Inflammation of the bladder. Cystitis can be due for example to infection from bacteria that ascend the urethra (the canal from the outside) to the bladder. Symptoms include a frequent need to urinate, often accompanied by a burning sensation. As cystitis progresses, blood may be observed in the urine and the patient may suffer […]
- Cystitis, interstitial (IC)
Cystitis, interstitial (IC): Disease that involves inflammation or irritation of the bladder wall. This inflammation can lead to scarring and stiffening of the bladder, and even ulcerations and bleeding. Diagnosis is based on symptoms, findings on cystoscopy and biopsy, and eliminating other treatable causes such as infection. Because doctors do not know what causes IC, […]