2,8-Dihydroxyadeninuria-induced progressive renal failure

Adenine phosphoribosyl-transferase (APRT) is the key enzyme that transforms adenine into adenylate monophosphate (AMP). In case of APRT deficiency, xanthine oxidase rapidly oxidizes adenine into 2,8-dihydroxyadenine (2,8-DHA), which is then eliminated by the kidneys through tubular secretion. 2,8-DHA is insoluble at a physiologic range of pH; therefore, it can easily precipitate in the urine. Although subjects with APRT deficiency may have repeated kidney stones, some of these patients may remain asymptomatic throughout life [1,2]. Nevertheless, a handful of reports propose that APRT deficiency can also lead to 2,8-DHA crystal-induced acute or chronic renal failure [3,4]. In this paper, we report a case of a middle-aged man with APRT deficiency that led to 2,8-DHA crystal-induced chronic active tubulointerstitial nephritis.