Copper

Test Description

Copper is an essential trace element needed in the synthesis of hemoglobin and oxidation
reduction. Normally urine contains a very small amount of free copper, since
most copper in the plasma is bound to ceruloplasmin, an alpha2-globulin protein.
Testing for urine copper content is used to aid in the diagnosis of Wilson’s disease,
a hereditary syndrome transmitted as an autosomal recessive trait. In this condition,
decreased levels of ceruloplasmin are manufactured by the liver, serum copper levels
are low, and urine copper levels are high. Without ceruloplasmin to transport the
copper, Wilson’s disease leads to an accumulation of copper in the tissue of the
brain, eye, kidney, and liver. One of the hallmarks of this disease is the presence of
Kayser-Fleischer rings around the iris of the eye, which are caused by copper
deposits. Wilson’s disease can be treated with penicillamine, an anticopper drug,
which promotes the renal excretion of excess copper.

Normal Values

          0–60 mcg/24 hours (0–0.96 μmol/day SI units)
          Elderly: Increased

Possible Meanings of Abnormal Values
Increased
Alzheimer’s disease
Biliary cirrhosis
Chronic, active hepatitis
Hypoceruloplasminemia
Nephrotic syndrome
Pellagra
Proteinuria
Wilson’s disease

Interventions/Implications

Pretest

• Instruct the patient to refrain from taking vitamins, minerals, or herbal supplements for
at least 1 week prior to the urine collection.
• Explain 24-hour urine collection procedure to the patient.
• Stress the importance of saving all urine in the 24-hour period. Instruct the patient to
avoid contaminating the urine with toilet paper or feces.
• Inform the patient of the presence of a preservative in the collection bottle.

Procedure

• Obtain the proper container containing the appropriate preservative from the laboratory.
• Begin the testing period in the morning following the patient’s first voiding, which is
  discarded.
• Timing of the 24-hour period begins at the time the first voiding is discarded.
• All urine for the next 24 hours is collected in the container, which is to be kept refrigerated
  or on ice.
• If any urine is accidentally discarded during the 24-hour period, the test must be discontinued
and a new test begun.
• The ending time of the 24-hour collection period should be posted in the patient’s room.
• Gloves are to be worn whenever dealing with the specimen collection.

Posttest
• Label the container and transport it on ice to the laboratory as soon as possible following
  the end of the 24-hour collection period.
• Report abnormal findings to the primary care provider.