Comparison of the effect of allopurinol and febuxostat on urinary 2,8-dihydroxyadenine excretion in patients with Adenine phosphoribosyltransferase deficiency (APRTd): A clinical trial.

To access publisher's full text version of this article click on the hyperlink belowAdenine phosphoribosyltransferase (APRT) deficiency is a rare, but significant, cause of kidney stones and progressive chronic kidney disease. The optimal treatment has not been established. The purpose of this pilot study was to compare the effect of the xanthine oxidoreductase inhibitors allopurinol and febuxostat on urinary 2,8-dihydroxyadenine (DHA) excretion in APRT deficiency patients. Patients listed in the APRT Deficiency Registry of the Rare Kidney Stone Consortium, currently receiving allopurinol therapy, were invited to participate. The trial endpoint was the 24-h urinary DHA excretion following treatment with allopurinol (400mg/day) and febuxostat (80mg/day). Urinary DHA was measured using a novel ultra-performance liquid chromatography - electrospray tandem mass spectrometry assay. Eight of the 10 patients invited completed the study. The median (range) 24-h urinary DHA excretion was 116 (75-289) mg at baseline, and 45 (13-112) mg after 14days of allopurinol therapy (P=0.036). At the end of the febuxostat treatment period, 4 patients had urinary DHA below detectable limits (