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.
Commonly, kidney stones are the first sign of hyperoxaluria. Kidney stones are uncommon in childhood. Kidney stones that form in children and teenagers are likely to be caused by an underlying condition, such as hyperoxaluria. For this reason, all young people with kidney stones should have a thorough evaluation, including measurement of oxalate in the urine. Adults with recurrent kidney stones also should be evaluated for oxalate in the urine.Symptoms of a kidney stone can include the following:Severe or sudden abdominal or flank pain,Blood in the urine,Frequent urge to urinate,Pain when urinating,Fever and chills.Primary hyperoxaluria (PH) that goes untreated can eventually damage your kidneys. Over time your kidneys may stop working. For some people, this is the first sign of the disease.
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.
The primary hyperoxalurias are a group of rare autosomal recessive, inherited diseases with an estimated prevalence of less than 3 in one million and an incidence of 0.15 × 106/year . Three types of PH have been characterized (PH1, PH2, PH3). In all three types, glyoxylate is aberrantly metabolized into oxalate. A remaining subgroup of patients exists that appear to have a genetic cause of hyperoxaluria that cannot be classified into one of the 3 known types.PH1 is the most common form of PH and accounts for 70–80% of all cases 1. It is caused by mutations in the AGXT gene that encodes the liver-specific peroxisomal enzyme alanine/glyoxylate aminotransferase (AGT). The AGT protein is responsible for converting glyoxylate into glycine within liver peroxisomes. Over 100 disease-causing mutations in AGXT have been reported. PH1 is the most severe form of the disease, and typically manifests in childhood with recurrent kidney stones and nephrocalcinosis. ESRD often develops by age 40–50 years but can occur at any age, including infancy.