What causes brushite in urine?
Unfortunately, there is limited research on the etiology and pathophysiology of brushite stone formation. A low urine volume, a urinary pH in the range of 6.5 to 6.8 and an increased renal excretion of calcium and phosphate are considered to be urinary risk factors for brushite stone formation [12].
What causes brushite kidney stones?
Some have theorized that many brushite stone formers started as routine calcium oxalate (CaOx) stone formers who sustained an injury to the nephron (such as SWL). The injury to the nephron leads to failure of urine acidification and eventual brushite stone formation.
Why is brushite important?
Brushite is the original precipitating material in calcium phosphate kidney stones. It is also one of the minerals present in dental calculi.
What is Brushite relative supersaturation?
The relative supersaturation for brushite is calculated as the ratio of the free-ion activity product of calcium and phosphate in the individual urine to the solubility of calcium phosphate. Ratios of 1 connote a sample at equilibrium, above 1 supersaturation, and below 1 undersaturation.
How do you prevent calcium phosphate stones?
Talk with a health care professional about how much calcium you should eat to help prevent getting more calcium phosphate stones and to support strong bones. It may be best to get calcium from plant-based foods such as calcium-fortified juices, cereals, breads, some kinds of vegetables, and some types of beans.
What are hydroxyapatite stones?
Most calcium phosphate stones are reported by labs as hydroxyapatite, the same crystal phase seen in bone. Many of these stones probably start as brushite, a relatively unstable phase of calcium phosphate that may convert in vivo to hydroxyapatite.
What causes urate crystals in urine?
The formation of amorphous urate crystals can be caused by a combination of factors, including a diet rich in meat, decreased urine volume or a condition that acidifies urine such as chronic diarrhea. They are also present in individuals who have gout or during chemotherapy.
Why do we get Hypocitraturia?
Hypocitraturia is a common metabolic abnormality found in 20% to 60% of stone formers. It is most commonly idiopathic in origin but may be caused by distal renal tubular acidosis, hypokalemia, bowel dysfunction, and a high-protein, low-alkali diet.
How do you prevent hydroxyapatite stones?
A. Drink more fluids, consume less sodium and eat a diet that includes calcium-rich foods. The rest depends on the chemical composition of your stones. More than 90 percent of stones contain calcium, usually in the form of calcium oxalate, calcium phosphate or hydroxyapatite.
Do all brushite stone formers need 24-hour urine studies?
Based on these data we recommend all brushite stone formers undergo 24-hour urine studies and have close long-term followup. Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc.
Why are some kidney stones classified as brushite stones?
The reason is that these stone types have special causes and treatments. Brushite is very uncommon in human kidney stones, and associates with large tubule plugs and more severe tissue damage. So when any stone contains brushite we classify the patient as a brushite stone former even though brushite is a minority of stone mineral.
How many brushite crystals are there in a urine sample?
Of 28 urine samples 25 contained only brushite crystals. It was this observation that led him to work out the mathematics for calculating supersaturation with respect to brushite, and show that it was higher in stone formers than in normal subjects.
What is the difference between hydroxyapatite and brushite crystals?
A majority have hydroxyapatite as their stone CaP mineral admixed with variable amounts of calcium oxalate (CaOx), and these 2 crystal types make up their stones. We call these hydroxyapatite calcium phosphate stone formers (HASF). The other IPSF have brushite their stones and we call them BRSF.