Wilson Disease Health Article

Diagnosis

The diagnosis of Wilson disease can be performed relatively easily through several different tests, however, because Wilson disease is so rare diagnosis is often delayed. The tests used to diagnose Wilson disease can be performed on patients who have or have not already shown symptoms of the disease. It is extremely important to make a diagnosis as soon as possible since liver damage can occur before there are any signs of the disease.

An easy way to diagnose Wilson disease is to measure the amount of a glycoprotein found in the blood called ceruloplasmin. Low levels of ceruloplasmin can diagnose the disease in about 80% of affected patients. This procedure is not as effective for women taking birth control pills, pregnant women, or infants less than six months of age.

A second test involving an eye examination to detect a characteristic ring of copper deposited in a membrane of the cornea (referred to as Kayser-Fleischer rings) is very easy to perform and is very useful in diagnosing patients who have already exhibited symptoms. This test

is not as effective in persons without symptoms. This diagnostic test cannot be used by itself to make a diagnosis because some patients with liver disease but not Wilson disease will test positive.

A third test for diagnosing Wilson disease involves measuring the amount of copper in the liver. This can be accomplished by sampling a portion of the liver in a procedure called a biopsy. This is one of the most effective ways to diagnose Wilson disease, however, the procedure itself is more difficult to perform than the others.

Other tests are also useful, for example, measuring the amount of copper passed into the urine daily (high in Wilson disease). Another lab test measures the ability of a patient's ceruloplasmin to bind with a form of copper (decreased in Wilson disease). And finally, as discussed under genetic profile, some patients can be diagnosed through a DNA test to determine whether or not they carry two genes for Wilson disease. This test does not always prove to be useful in certain patients and is used mostly to test the brothers and sisters of affected patients.

Treatment and management

Treatment involves life-long administration of either D-penicillamine or trientine hydrochloride. Both of these drugs remove copper deposits throughout the body by binding to the copper which is removed from the body in urine. Zinc acetate and a low copper diet are other ways to treat Wilson disease.

Penicillamine has a number of serious side effects:

• joint pain
• neurological problems
• systemic lupus erythematosus
• decreased production of all blood elements
• interference with clotting
• allergic reactions

Careful monitoring is necessary. When patients have side effects from penicillamine, the dose can sometimes be lowered to an effective level that causes fewer difficulties. Alternatively, steroid medications may be required to reduce certain sensitivity reactions. Trientine has fewer potential side effects, but must still be carefully monitored.

Treatment with zinc is also an effective way to remove excess copper from the body. Zinc is a metal that works to block copper absorption and bind copper in the intestinal cells until it is all released into the stool approximately one week later. The benefit of treatment with zinc is that there are no toxic side effects, however, zinc is a slower acting agent than the other drugs. It takes four to eight months for the zinc to be effective in reducing the overall amount of copper in the body.

Finally, patients with Wilson disease are encouraged to follow a diet low in copper, with an average copper intake of 1.0 mg/day. Foods to avoid for their high levels of copper include liver and shellfish. Patients are also instructed to monitor their drinking water for excess levels of copper and drink distilled water instead.

Prognosis

Without treatment, Wilson disease is always fatal. With treatment, symptoms may continue to worsen for the first six to eight weeks. After this time, definite improvement should start to be seen. However, it may take several years (two to five) of treatment to reach maximal benefit to the brain and liver. Even then, many patients are not returned to their original level of functioning. Patients with Wilson disease need to maintain some sort of anti-copper treatment for the rest of their lives in order to prevent copper levels from rising in the body. Interruptions in treatment can result in a relapse of the disease which is not reversible, and can ultimately lead to death.

BOOKS

Scheinberg, I. Herbert. "Wilson's Disease." Harrison's Principles of Internal Medicine. Ed. by Anthony S. Fauci, et al. 14th ed. New York: McGraw-Hill, 1998.