Urate

Keywords: Uric acid, UA

Specimen:

5 mL blood in lithium heparin or plain tube.

Method:

Spectrophotometry.

Reference Interval:

Female: 0.15-0.40 mmol/L

Male: 0.20-0.45 mmol/L.

Application:

Diagnosis and monitoring of gout and pregnancy-induced hypertension.

Monitoring of therapy in malignancies where there is a high rate of cell destruction and uric acid production.

Assists in the diagnosis of SIADH.

Interpretation:

The likelihood of gout is low if the serum urate concentration is repeatedly below 0.42 mmol/L. The risk of developing gout is three times greater if the serum urate concentration is consistently above 0.42 mmol/L. However, a raised serum urate level alone is insufficient to diagnose gout.

Impaired renal function, pregnancy-induced hypertension, diuretics, fasting, hyperlactataemia, hyperketonaemia and low dose salicylates can all produce increased urate levels.

Hypouricaemia is seen in patients with a low purine intake, in SIADH, with hypouricaemic drugs (eg, allopurinol) and in the rare condition of xanthinuria.

Reference:

Liote F. Curr Rheumatol Rep 2003; 5(3): 227-234.