Uric acid (24 hour urine)

Hereditary deficiency of the enzyme hypoxanthine-guanine-phosphoribosyltransferase (HPRT) in young patients with gouty arthritis and nephrolithiasis or those who excrete 1000 mg of uric acid / 24 hours a day. The uric acid / creatinine ratio in morning urine samples is used to diagnose Les-Nihan syndrome, which is associated with a complete lack of enzyme activity. To detect partial deficiency of the same enzyme in adult patients with gout, this test can also be used on 24-hour urine samples.

The uric acid / creatinine ratio in spontaneous urine may also be helpful in secondary differentiation of acute renal failure due to gouty nephropathy.

How to prepare for the test?

Patient training is not required.

Study material / urine collection rule

24-hour urine. At 7 o'clock in the morning the patient urinates and does not store this urine, and during the next urination he collects the whole volume of urine in a plastic container (2-3 liter urine container) until 7 o'clock in the morning of the next day (24 hours); The patient should transfer 100 ml of urine from this container (e.g. with a syringe) to a disposable plastic cup for urine and should be stored at 2-8 ° C before the test (1-1,5 h).