Practical recommendations and new therapies for Wilson's disease.

Wilson's disease is an inherited disorder of copper accumulation. The basic defect is a failure of excretion of excess copper in the bile by the liver for loss in the stool. The accumulating copper causes damage primarily to the liver and the brain. Patients typically present in the second to the fourth decades of life with liver disease, a neurological disease of the movement disorder type, or a wide array of behavioural disturbances. Because the manifestations of Wilson's disease are so protean, and the disease masquerades so well as something else, recognition of the possibility of Wilson's disease is a major problem, leading to serious underdiagnosis of the disease. Excellent therapies exist for both the prophylaxis and treatment of Wilson's disease. The longer recognition and diagnosis are delayed, the greater the risk of permanent damage to liver and/or brain. The availability of effective therapy and the risks in delay or therapy make the earliest possible diagnosis critical. Once the disease comes under consideration, a series of diagnostic steps can be undertaken which almost always establish or rule out the diagnosis of Wilson's disease. These include urine copper, blood ceruloplasmin, slit lamp examination for Kayser-Fleischer rings, and liver biopsy with quantitative copper assay. Currently, there are 4 drugs being used as anticopper agents in Wilson's disease. These are zinc, which blocks intestinal absorption of copper, penicillamine and trientine, both of which are chelators that increase urinary excretion of copper, and tetrathiomolybdate which forms a tripartite complex with copper and protein, and can block copper absorption from the intestine, or render blood copper non-toxic. Zinc is clearly the treatment of choice, in our opinion, for maintenance therapy, for the treatment of the presymptomatic patient from the beginning and for the treatment of the pregnant patient, because of its complete efficacy and lack of toxicity. For the initial treatment of the patient presenting with mild liver failure, we empirically use a combination of trientine and zinc. Trientine gives a strong, fast, negative copper balance, and zinc induces hepatic metallothionein, which sequesters hepatic copper. For the initial treatment of patients presenting with neurological disease we use an experimental drug, tetrathiomolybdate, which provides rapid, safe control of copper. These latter patients are at great risk of serious permanent neurological worsening with penicillamine, and zinc is too slow-acting, in our judgment, to be optimal.