Practice guideline development task force of the College of American Pathologists. Hereditary hemochromatosis.

Hereditary hemochromatosis is an autosomal recessive disorder, the gene for which occurs in approximately 10% of Americans, most of whom are unaffected heterozygotes. Approximately 5/1000 white Americans are homozygous and at risk of developing severe and potentially lethal hemochromatosis. The disorder affects numerous organ systems, but the most common symptoms are fatigue, palpitations, joint pains, and impotence; the most common signs are those that relate to hypothalamic, cardiac, hepatic or pancreatic dysfunction, including poor cold tolerance, impotence in males, amenorrhea in females, cardiac arrhythmias, dyspnea, edema, hepatosplenomegaly, spider telangiectases, ascites, deformity, swelling or limitation of motion of joints, weight loss, hyperpigmentation. Characteristic abnormalities of laboratory tests include elevated serum iron concentration, high transferrin saturation, elevated serum ferritin concentration, elevated serum transaminases, hyperglycemia and low values for thyroid-stimulating hormone (TSH) and gonadotropins. Death may be the result of cardiac arrhythmia, congestive heart failure, liver failure or liver cancer. Since many of these complications cannot be reversed once they have developed, early diagnosis and treatment are essential. In view of the high prevalence in the American population (prevalence varies with ethnic background), the low cost of diagnosis and treatment, the efficacy of treatment if begun early, and, on the other hand, high costs and low success rate of late diagnosis and treatment, systematic screening for hemochromatosis is warranted for all persons over the age of 20 years. The initial screening should be by measurement of serum iron concentration and transferrin saturation. The practice guideline provides a diagnostic algorithm for cases in which the serum transferrin saturation is 60% or greater. It also provides guidelines for clinical management.

A history of phlebotomy therapy for hemochromatosis.

Hemochromatosis was recognized as an iron-storage disease for 50 years before it was proposed to treat it by removing hemoglobin. Davis and Arrowsmith are credited with the first report that demonstrated its value. Larger series have provided statistically valid evidence of improved quality of life and increased longevity. The earlier the disease is discovered, the less risk of morbidity and mortality. Screening tests (serum iron, total iron-binding capacity, serum ferritin) are recommended for all blood relatives of index cases of this hereditary disease and for all clinics where complications of hemochromatosis may be treated: liver disorder however mild, diabetes mellitus, heart disease, arthropathies, sterility, impotence, premature menopause, and abnormal pigmentation of the skin.

Blocking of iron absorption by a preliminary oral dose of iron.

Using a small-dose iron tolerance test (ITT) in mildly iron-deficient healthy adults, we have examined the phenomenon of mucosal block. First proposed and demonstrated by Hahn et al with radioiron, "mucosal block" describes diminished avidity for iron of the intestinal mucosa following an orally administered blocking dose. In the ITT, the index of absorption is an increase in plasma iron concentration, rather than retained radioactivity. The absorption of a blocked 10-mg test dose of iron was compared with that of a 10-mg control dose given to the same subject. Both 60- and 30-mg blocking doses of iron resulted in diminished absorption of the test dose. The refractory state of the intestine lasted as long as 24 hours.