Renal Problems in Wilson Disease

ABSTRACT

PURPOSE: Wilson disease is a hereditary metabolic disorder characterized by an accumulation of copper in tissues which sometimes results in renal problems. This study was performed to evaluate the prevalences of the renal problems in Wilson disease and related risk factors. METHODS: In 31 patients with Wilson disease, we looked for renal problems by history taking, physical examination and laboratory tests such as urinalysis, BUN, serum creatinine, creatinine clearance, 24-hour urine total protein, serum and urine electrolytes, serum and 24-hour urine calcium, phosphorus, uric acid, beta2-microglobulin(beta2-MG) levels and 24-hour urine N-acetyl-beta-glucosaminidase(NAG) excretion. RESULTS: All of the patients were on penicillamine therapy for 4.3+/-3.4 years. None of them had any renal symptoms or signs at the time of this study except one patient who had a history of intermittent puffy face for 6 months. In the laboratory studies, 21 cases(68%) had one or more renal problems. Sixteen cases(52%) had one or more tubular dysfunctions; individually, hypercalciuria, increased excretion of beta2-MG, decreased TRP, increased excretion of NAG were detected in 29%, 19%, 16%, and 10%, respectively. Microscopic hematurias were detected in 8 cases(26%), creatinine clearances(Ccr) were decreased in 4 cases(13%). Two cases(6%) revealed proteinuria. Hematurias were more frequent within 3 years after beginning penicillamine treatment(P<0.05). Though not proven statistically, tubular dysfunctions and proteinurias showed the same trends. Prevalence of the decreased Ccr did not change with the treatment duration. CONCLUSION: In Wilson disease, covert renal problems are relatively common. Tubular dysfunctions are the most frequently observed abnormalities followed by microscopic hematuria, proteinuria, and decreased creatinine clearance in order. Hematuria is more common within 3 years after beginning penicillamine treatment, which is also probable for tubular dysfunctions and proteinuria.