Wednesday, September 17, 2008

Hemochromatosis

Synonym: Iron Storage Disease. Hemochromatosis and siderosis have been used to describe the presence of stainable iron in the cells. This disorder manifests when the iron body supply exceed the normal stores of 0.2 to 2.0 grams. When the body storage level increases to 4.0 grams or more, then the conditions of hemochromatosis exists. Values of 15 to 40 grams have been reported. The reticuloendothelial cells seem to tolerate the elevated intracellular levels whereas such levels are toxic to parenchymal cells. The presence of excess iron can initiate fibrotic formation, cause functional insufficiency of organs, and otherwise damage cells. This is a progressive disorder that can lead to organ failure.


When excess iron forms deposits in hemochromatosis, it forms insoluble granular aggregates with a golden brown color. These aggregates are known as hemosiderin. The most common symptom is hepatomegaly.


The following lab criteria generally is determinate in diagnosing this disorder:

  • [1] serum ferritin is increased [N = 20 to 200 μg/dL]
  • [2] serum iron is increased [N = 60 to 160 μg/dL]
  • [3] TIBC will be normal or low [N = 250 to 350 µg/dL]
  • [4] Liver biopsy is an option. It is considered to be a procedure to be avoided.
  • [5] Bone marrow is characterized by large deposits of hemosiderin.
  • [6] Percent transferrin saturation is elevated. [N = 22 to 46%]
  • [7] Urinary iron is increased [N = 0 to 2 µg/24 hours]

This is not an anemic condition unless there is some complicating condition, in which case will constitute acquired hemochromatosis. There are two forms of hemochromatosis: acquired and hereditary. If hereditary, there is aberrant iron metabolism with abnormal iron deposits which can occasionally cause a bronze skin appearance. If a patient presents with an unexplained [a] hepatomegaly, [b] skin pigmentation, [c] diabetes mellitus, [d] arthritis, [e] testicular atrophy, and/or [f] liver and cardiac impairment; then hemochromatosis should be ruled out.

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