Hemochromatosis is a genetic condition in which iron is abnor-mally (excessively) absorbed from the gastrointestinal tract. The excessive iron is deposited in various organs, particularly the liver,myocardium, testes, thyroid, and pancreas. Eventually, the affected organs become dysfunctional. The actual incidence of hemochro-matosis is unknown; however, hereditary hemochromatosis is diagnosed in 0.5% of the population in the United States (ie, 1 million people). Recent data suggest that this defect may be a common cause of diabetes (Schechter, et al., 2000). Because of to their natural loss of iron through menses, women are less affected than men.
Because the accumulation of iron in body organs occurs gradu-ally, there often is no evidence of tissue injury until middle age. Symptoms of weakness, lethargy, arthralgia, weight loss, and loss of libido are common. The skin may be hyperpigmented with melanin deposits (occasionally hemosiderin, an iron-containing pigment) and appears bronze in color. Cardiac dysrhythmias and cardiomyopathy can occur, with resulting dyspnea and edema. En-docrine dysfunction is manifested as hypothyroidism, diabetes mel-litus, and hypogonadism (testicular atrophy, diminished libido, and impotence).
A significant effect of hemochromatosis is the development of hepatocellular carcinoma in one third of those af-fected. CBC values are typically normal. The most useful labora-tory findings are an elevated serum iron level and high transferrin saturation (more than 60% in men, more than 50% in women). The definitive diagnostic test is a liver biopsy. Recently, a mutation in the HFE gene has been shown to occur in most patients with hereditary hemochromatosis (Gochee & Powell, 2001). Patients who are homozygous for the gene are at high risk for development of the disorder.
Therapy involves the removal of excess iron via therapeutic phle-botomy (removal of whole blood from a vein). Each unit of blood removed results in a decrease of 200–250 mg of iron. The objec-tive typically is to reduce the serum ferritin to less than 50 μ g/L and the transferrin saturation to 35% or less. To achieve this, a frequent phlebotomy schedule is required (1 to 2 units weekly), with a grad-ual reduction in frequency of phlebotomies over a 1- to 3-year period. After 1 to 3 years, the frequency of phlebotomy can be reduced to 1 unit of blood every several months to prevent reaccu-mulation of iron deposits. Removal of excess iron appears to di-minish the severity of diabetes and skin hyperpigmentation; cardiac function also tends to improve.
Patients with hemochromatosis often believe that it is important to limit their dietary intake of iron, although this management method has been shown to be very ineffective and need not be en-couraged. However, it is important for these patients to avoid any additional insults to the liver, such as alcohol abuse. Serial screen-ing tests for hepatoma are important; alpha-fetoprotein is used for this purpose. Other body systems should be monitored for signs of organ dysfunction, particularly the endocrine and cardiac systems. These systems should also be screened routinely for dysfunction so that appropriate management can be implemented quickly. Be-cause patients with hemochromatosis require frequent phlebot-omies, problems with venous access are common. Patients who are heterozygous for the HFE do not develop the disease but need to be counseled that they can transmit the gene to their children.
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