Hyperoxaluria

Introduction Primary hyperoxaluria is an autosomal recessive disorder caused by a lack of alanine-glyoxylate aminotransferase in the liver, resulting in excessive production of oxalic acid, clinical manifestations of high oxalic aciduria and recurrent urine. Road stones. Because of the oxalic acid metabolism disorder in patients after renal transplantation, the recurrence rate is extremely high. Therefore, patients with primary hyperoxaluria have been considered unsuitable for kidney transplantation. Recently, it has been found that liver and kidney transplantation can achieve better results.

Cause

The disease is caused by the lack of alanine-glyoxylate aminotransferase in the liver, resulting in excessive production of oxalic acid. The maximum output of urinary oxalate in normal people is about 40-50 mg per day, the main source of which is endogenous, and about 40% is evolved from the metabolism of glycine. Glycine is converted to glyoxylic acid by transamination. There are several pathways for further metabolism of glyoxylic acid, one of which is oxidation to oxalic acid, the oxalate being its final metabolite, and the latter being excreted by urine.

Type 1I high oxalic aciduria, also known as hydroxyacetic aciduria, is caused by a defect in glyoxylate metabolism. The patient lacks -ketoglutaric acid: glyoxylic aldehyde-enzyme, which hinders the catabolism of glyoxylic acid and accumulates in the body. The formation of oxalic acid and trans-acetic acid increases, and the excretion of oxalic acid, transacetic acid and glyoxylic acid in urine increases. The daily urinary oxalate discharge is generally above 60mg, and some patients can reach 150-650mg.

2 type II hyperoxaluria, also known as L-glyceric aciduria, due to the lack of D-glycerate dehydrogenase, inhibits the conversion of D-glycerate to beta hydroxypyruvate, which is reduced by lactate dehydrogenase (LDH) It is discharged from the urine for L-glyceric acid. In addition, D-glycerate dehydrogenase may be the same enzyme as glyoxylate reductase, and thus the reduction of glyoxylic acid to glycolic acid is blocked, which promotes the formation and excretion of oxalic acid.

an examination

Related inspection

Urinary system CT examination

Therefore, patients with high oxalic acid should be clinically examined:

First, physical examination

Taking a medical history gives us a first impression and revelation, and also guides us to a concept of the nature of the disease.

Second, laboratory inspection

Laboratory examinations must be summarized and analyzed based on objective materials and medical examinations, and several possible diagnostics are proposed, and then further examinations are performed to confirm the diagnosis. Such as: urine routine, renal function tests, etc.

Differential diagnosis

Identification:

Intestinal high oxalic aciduria: Limiting oxalic acid and fat intake, supplementing potassium citrate can significantly increase urine pH and niacin. On the one hand, as an inhibitory substance formed by crystallization, on the other hand, it combines with the oxalic acid in the intestinal tract to prevent absorption of the latter, thereby reducing urinary acid excretion. Magnesium hydroxide or magnesium oxide can be used. Cholestyramine can correct intestinal malabsorption, but does not continue to inhibit absorption of oxalic acid.

There was no significant difference in clinical manifestations between the two types. The ratio of male to female incidence was about 1.3:1, and about 12% of patients developed symptoms before the age of one. 65% were ill before the age of 5. The main manifestations of this disease are kidney stones, renal calcium deposition and extrarenal calcium deposition. The patient has recurrent renal colic and hematuria, often with pyelonephritis and hydronephrosis. Extrarenal tissue calcium deposits occur mostly in the heart, male reproductive organs and bones. Calcium oxalate crystals can settle on the vessel wall. The disease progresses rapidly, and uremia gradually develops. At this time, secondary hyperparathyroidism can be combined. Infants who died in infants died before the age of 20, and the prognosis of adult patients was relatively good.

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