Hyperoxaluria and oxalosis
Hyperoxaluria occurs when you have too much oxalate in your urine. Oxalate is a natural chemical in your body, and it's also found in certain types of food. But too much oxalate in your urine can cause serious problems.Hyperoxaluria can be caused by inherited (genetic) disorders, an intestinal disease or eating too many oxalate-rich foods. Quick diagnosis and treatment of hyperoxaluria is important to the long-term health of your kidneys.Oxalosis happens after the kidneys fail in people who have primary and intestinal causes of hyperoxaluria, and excess oxalate builds up in the blood. This can lead to oxalate deposits in blood vessels, bones and body organs.
Treatment will depend on the type, symptoms and severity of hyperoxaluria and how well you respond to treatment.Medications. Prescription doses of vitamin B-6 can be effective in reducing oxalate in the urine in some people with primary hyperoxaluria. Oral preparations of phosphates and citrate help prevent the formation of calcium oxalate crystals. Other medications, such as thiazide diuretics, also may be considered, depending on which other abnormalities are present in your urine.High fluid intake. If your kidneys are still functioning normally, your doctor will likely tell you to drink more water or other fluids. This flushes the kidneys, prevents oxalate crystal buildup and helps keep kidney stones from forming.Dietary changes. The effectiveness of diet will depend on the cause of increased levels of oxalate. Diet may include restricting foods high in oxalates, limiting salt, and decreasing animal protein and sugar (high fructose corn syrup). This may help to lower urinary oxalate in people with enteric hyperoxaluria or excess dietary intake. Dietary restrictions may not be as important for all people with primary hyperoxaluria. Follow the advice of your doctor.
Primary hyperoxaluria type 1 (PH1) is caused by a deficiency of the liver peroxisomal enzyme alanine:glyoxylate-aminotransferase (AGT), which catalyzes the conversion of glyoxylate to glycine. When AGT activity is absent, glyoxylate is converted to oxalate, which forms insoluble calcium salts that accumulate in the kidney and other organs. Individuals with PH1 are at risk for recurrent nephrolithiasis (deposition of calcium oxalate in the renal pelvis/urinary tract), nephrocalcinosis (deposition of calcium oxalate in the renal parenchyma), or end-stage renal disease (ESRD) with a history of renal stones or calcinosis. Age at onset of symptoms typically ranges from one to 25 years. Approximately 19% of affected individuals present before age four to six months with severe disease, often associated with failure to thrive, nephrocalcinosis, anemia, and metabolic acidosis. Approximately 54% of affected individuals present in late childhood or early adolescence, usually with symptomatic nephrolithiasis. The remainder of affected individuals present in adulthood with recurrent renal stones. The natural history of untreated PH1 is one of inexorable decline in renal function as a result of progressive nephrolithiasis/nephrocalcinosis, with eventual progression to oxalosis (widespread tissue deposition of calcium oxalate) and death from ESRD.