Hemochromatosis
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: Haemochromatosis
Diagnosis
Imaging features
Clinically the disease may be silent, but characteristic radiological features may point to the diagnosis. The increased iron stores in the organs involved, especially in the liver and pancreas, result in characteristic findings on unenhanced CT and a decreased signal intensity at MR imaging. Haemochromatosis arthropathy includes degenerative osteoarthritis and chondrocalcinosis. The distribution of the arthropathy is distinctive, but not unique, frequently affecting the second and third metacarpophalangeal joints of the hand. The arthropathy can therefore be an early clue as to the diagnosis of hemochromatosis. MRI algorithms are available at research institutions to quantify the amount of iron present in the liver, therefore reducing the necessity of a liver biopsy (see below) to measure the liver iron content. As of May, 2007, this technology was only available at a few sites in the USA, but documented reports of radiographic measurements of liver iron content were becoming more common. [1]
Chemistry
Serum transferrin saturation- A first step is the measurement of transferrin saturation, the protein which chemically binds to iron and carries it through the blood to the liver, spleen and bone marrow.[2] Measuring transferrin provides a measurement of iron in the blood. Saturation values of 45% are probably a good cutoff to determine whether a patient is a candidate for further testing. [3] The transferrin saturation is usually expressed as a percentage, and is calculated as the total serum iron level divided by the serum iron transferrin level times 100. Serum Ferritin- Ferritin, the protein which chemically binds to iron and stores it in the body. Measuring ferritin provides a measurement of iron in the whole body. Normal values for males are 12-300 ng/ml (nanograms per milliliter) and for female, 12-150 ng/ml. Low values indicate iron deficiency, which may be attributed to a number of causes. Higher than normal also may indicate other causes including haemochromatosis.[4][5] Other blood tests routinely performed: blood count, renal function, liver enzymes, electrolytes, glucose (and/or an oral glucose tolerance test (OGTT)).
Functional testing
Based on the history, the doctor might consider specific tests to monitor organ dysfunction, such as an echocardiogram for heart failure, or blood glucose monitoring for patients with hemochromatosis diabetes.
Treatment
Early diagnosis is important because the late effects of iron accumulation can be wholly prevented by periodic phlebotomies (by venesection) comparable in volume to blood donations.[6] Treatment is initiated when ferritin levels reach 300 micrograms per litre (or 200 in nonpregnant premenopausal women).
Every bag of blood ml) contains 200-250 milligrams of iron. Phlebotomy (or bloodletting) is usually done at a weekly interval until ferritin levels are less than 20 nanograms per millilitre. After that, 1-4 donations per year are usually needed to maintain iron balance.
Other parts of the treatment include:
- Treatment of organ damage (heart failure with diuretics and ACE inhibitor therapy).
- Limiting intake of alcoholic beverages, vitamin C (increases iron absorption in the gut), red meat (high in iron) and potential causes of food poisoning (shellfish, seafood).
- Increasing intake of substances that inhibit iron absorption, such as high-tannin tea, calcium, and foods containing oxalic and phytic acids (these must be consumed at the same time as the iron-containing foods in order to be effective.)
See also
External links
References
- ↑ Tanner MA, He T, Westwood MA, Firmin DN, Pennell DJ (2006). "Multi-center validation of the transferability of the magnetic resonance T2* technique for the quantification of tissue iron". Haematologica. 91 (10): 1388–91. PMID 17018390.
- ↑ Transferrin and Iron Transport Physiology
- ↑ Screening and Diagnosis
- ↑ Screening and Diagnosis
- ↑ Ferritin Test Measuring iron in the body
- ↑ Hemochromatosis - Treatment
de:Hämochromatose it:Emocromatosi he:המוכרומטוזיס nl:Hemochromatose no:Hemokromatose fi:Hemokromatoosi sv:Hemakromotos