Classification of hyperuricemia is important for the selection of appropriate treatment, however, the classification by using 60-minute (60-min)or 24-hour (24-h) urine collection in outpatients is not conventional. The aim of the present study was to compare the classification by using 60-min and 24-h urine collection and the urinary uric acid/urinary creatinine (UUA/UCr) ratio determined by spot urine. Subjects were 9 hypertensive inpatients with hyperuricemia (3 females and 6 males, mean age : 62±15 (SD) years), who did not take diuretics or UA-lowering drugs. Patients underwent 60-min and 24-h urine collection to determine UA metabolism advocated by the guidelines for the treatment of hyperuricemia and gout. We compared the classification of hyperuricemia by 60-min urine collection to that obtained by 24-h urine collection or by the UUA/UCr ratio in spot urine. Based on 60-min urine collection, the decreased UA excretion type was found in 77.8% and 22.2% showed the overproduction type. On the other hand, the decreased UA excretion type and mixed type were found in 88.9 and 22.2%, respectively, by 24-h urine collection. When the cutoff values of 0.5, 0.6, and 0.7 for the UUA/UCr ratio of spot urine were adopted, the decreased UA excretion type was found in 66.7, 88.9 and 100%, respectively. The consistent classification by both 60-min and 24-h methods was obtained in 66.7% of the patients. On the contrary, the consistent classification by both 60-min and spot urine UUA/UCr ratio methods with cutoff values of 0.5, 0.6, and 0.7 were obtained in 66.7, 66.7 and 77.8%, respectively. In conclusion, the UUA/UCr ratio determined by spot urine seems to be useful and conventional in clinical practice to classify hyperuricemia.

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We have reported that monosodium urate (MSU) crystals show the distinct advantages of a protein carrier binding with positively charged proteins and delivering antigenic protein into dendritic cells (DC), as well as an adjuvant promoting DC maturation and inducing cytotoxic T lymphocytes in vitro. However, the biological reaction due to subcutaneous injection of the MSU crystals remains unclear.
Therefore, here, we investigated the morphological changes after the administration of MSU crystals or uric acid powders in mice. In addition, the skin reaction at the injection site was observed. The slide sections indicated that treatment with the MSU crystals caused acute inflammatory responses with the migration of activated monocytes which engulfed the fragmentary MSU crystals. On the other hand, the implantation of uric acid powders barely induced any inflammatory cells except for small number of mononuclear cells. In comparison with the morphological differences, neither MSU crystals nor uric acid powders resulted in local skin abnormalities, including rash, swelling, and fever.
These findings suggest that the subcutaneous injection of MSU crystals was relatively safe, and that the crystals are available as a promising protein carrier of cancer vaccine peptides in vivo.

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A prospective survey of benzbromarone (Urinorm®) use was conducted to examine the benzbromarone dose and renal function and their relationships with serum uric acid levels with routine drug usage, particularly the rate of achieving of a serum uric acid level ≤ 6.0mg/dL. Of 3,150 patients whose serum uric acid level had been measured before benzbromarone administration and at least once during the six months of administration, 74.1% achieved a serum uric acid level ≤ 6.0mg/dL six months after the administration of benzbromarone.
In the same way, the rate of achieving a serum uric acid level ≤ 6.0mg/dL was examined in 2,938 of 3,150 patients whose serum uric acid level had been over 7.0 mg/dL before drug administration, and the rate was 73.1% at six months.
For 916 patients whose serum uric acid levels had been measured at all stages (before benzbromarone administration, at one to two months, at three to four months, and at five to six months), the proportion who achieved a serum uric acid level ≤ 6.0mg/dL was 65.1% at one to two months, 77.0% at three to four months, and 81.9% at five to six months after the administration of benzbromarone. Of the 916 patients, 845 had a serum uric acid level > 7.0mg/dL before benzbromarone administration, and their rates of achieving a serum uric acid level ≤ 6.0mg/dL were 63.8, 76.0, and 80.8%, respectively.
The rate of achieving a serum uric acid level ≤ 6.0mg/dL increased with elevations in the benzbromarone dose in all baseline eGFR groups. In addition, in patients with a baseline eGFR ≥ 30mL/min/1.73m², the rate of achieving a serum uric acid level ≤ 6.0mg/dL was almost the same regardless of the eGFR level.

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