Martella Vilma, Sozzo Efisio, Montagna Elio, Stefanizzi Salvatore, Cito Annarita, Marinello Enrico, Terzuoli Lucia, Micheli Vanna, Napoli Marcello
U.O.C. Nefrologia e Dialisi, P.O. S. Caterina Novella, Galatina (Lecce), Italy.
G Ital Nefrol. 2011 Nov-Dec;28(6):648-53.
Xanthinuria is a rare autosomal recessive disorder associated with a deficiency of xanthine oxidoreductase (XOR), which normally catalyzes the conversion of hypoxanthine to uric acid. The effects of this deficit are an elevated concentration of hypoxanthine and xanthine in the blood and urine, hypouricemia, and hypouricuria. The deficit in XOR can be isolated (type I xanthinuria) or associated with a deficit in aldehyde oxidase (type II xanthinuria) and sulfite oxidase (type III xanthinuria). While the first two variants have a benign course, are often asymptomatic (20%), and clinically indistinguishable, type III xanthinuria is a harmful form that leads to infant death due to neurological damage. The clinical symptoms (kidney stones, CKD, muscle and joint pain, peptic ulcer) are the result of the accumulation of xanthine, which is highly insoluble, in the body fluids. We describe a case of type I xanthinuria in a 52-year-old woman who presented with hypouricemia, hypouricuria and kidney stones. The diagnosis was based on purine catabolite levels in urine and serum measured by 3 nonroutine methods: high-pressure liquid chromatography, mass spectrometry, and magnetic resonance imaging. To identify the type of xanthinuria the allopurinol test was used. We believe that these tests will facilitate the diagnosis of xantinuria especially in asymptomatic patients without the need for a biopsy of the liver or intestines, which is useful only for scientific purposes.
黄嘌呤尿症是一种罕见的常染色体隐性疾病，与黄嘌呤氧化还原酶（XOR）缺乏有关，该酶通常催化次黄嘌呤转化为尿酸。这种缺陷的影响是血液和尿液中次黄嘌呤和黄嘌呤浓度升高、低尿酸血症和低尿酸尿症。XOR缺乏可以是孤立的（I型黄嘌呤尿症），也可以与醛氧化酶缺乏（II型黄嘌呤尿症）和亚硫酸盐氧化酶缺乏（III型黄嘌呤尿症）相关。虽然前两种变异型病程良性，通常无症状（20%）且临床上难以区分，但III型黄嘌呤尿症是一种有害形式，会因神经损伤导致婴儿死亡。临床症状（肾结石、慢性肾脏病、肌肉和关节疼痛、消化性溃疡）是高度不溶性的黄嘌呤在体液中蓄积的结果。我们描述了一例52岁女性的I型黄嘌呤尿症病例，该患者表现为低尿酸血症、低尿酸尿症和肾结石。诊断基于通过三种非常规方法测量的尿液和血清中的嘌呤分解代谢物水平：高压液相色谱法、质谱法和磁共振成像。为了确定黄嘌呤尿症的类型，使用了别嘌呤醇试验。我们认为这些检测将有助于黄嘌呤尿症的诊断，特别是对于无症状患者，无需进行肝脏或肠道活检，活检仅用于科研目的。
