Unusual cause of crystalline nephropathy

Abstract

Adenine phosphoribosyltransferase deficiency is a rare, inherited autosomal recessive disease presenting with 2,8-dihydroxyadenine (DHA) urolithiasis, DHA nephropathy, and chronic kidney disease. The presence of DHA crystals in urine and renal biopsy is pathognomonic of the disease. We report a 23-year-old female with acute renal failure and nephrotic proteinuria. Urinalysis showed reddish brown, round crystals with dark outline, and central spicules consistent with 2,8-DHA crystals. Renal biopsy showed membranous nephropathy and 2,8-DHA nephropathy. Our patient improved with liberal fluid intake, restriction of high adenine content foods, and oral xanthine dehydrogenase inhibitor febuxostat. Early diagnosis and initiation of treatment prevent renal complications.