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Hemochromatosis - Symptoms, Causes & Treatment
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hemocromatosis, hemachromatosis
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| Excess iron is stored in
body tissues, especially the liver, heart, and
pancreas. |
Hemochromatosis, the most common form of iron overload disease, is an
inherited disorder that causes the body to absorb and store too much iron.
The extra iron builds up in organs and damages them. Without treatment,
the disease can cause these organs to fail.
Iron is an essential nutrient found in many foods. The greatest amount
is found in red meat and iron-fortified bread and cereal. In the body,
iron becomes part of hemoglobin, a molecule in the blood that transports
oxygen from the lungs to all body tissues.
Healthy people usually absorb about 10 percent of the iron contained in
the food they eat to meet the body needs. People with hemochromatosis
absorb more than the body needs. Since the body absorbs too much iron from
the diet, hemochromatosis patients end up with an iron overload. The body
has no natural way to rid itself of excess iron, so extra iron is stored
in body tissues, especially the liver, heart, and pancreas.
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Hemochromatosis Causes
Genetic or hereditary hemochromatosis is mainly associated with a
defect in a gene called HFE, which helps regulate the amount of
iron absorbed from food. There are two known important mutations in
HFE, named C282Y and H63D. C282Y is the most important. When C282Y
is inherited from both parents, iron is overabsorbed from the diet and
hemochromatosis can result. H63D usually causes little increase in iron
absorption, but a person with H63D from one parent and C282Y from the
other may rarely develop hemochromatosis.
The genetic defect of hemochromatosis is present at birth, but symptoms
rarely appear before adulthood. A person who inherits the defective gene
from both parents may develop hemochromatosis. A person who inherits the
defective gene from only one parent is a carrier for the disease but
usually does not develop it. However, carriers might have a slight
increase in iron absorption.
Scientists hope that further study of HFE will reveal how the
body normally metabolizes iron. They also want to learn how iron injures
cells and whether it contributes to organ damage in other diseases, such
as alcoholic liver disease, hepatitis C, porphyria cutanea tarda, heart
disease, reproductive disorders, cancer, autoimmune hepatitis, diabetes,
and joint disease.
Juvenile hemochromatosis and neonatal hemochromatosis are two forms of
the disease that are not caused by an HFE defect. Their cause is
unknown. The juvenile form leads to severe iron overload and liver and
heart disease in adolescents and young adults between the ages of 15 and
30, and the neonatal form causes the same problems in newborn infants.
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Risk Factors for Hemochromatosis
Hereditary hemochromatosis is one of the most common genetic disorders
in the United States. It most often affects Caucasians of Northern
European descent, although other ethnic groups are also affected. About 5
people in 1,000 (0.5 percent) of the U.S. Caucasian population carry two
copies of the hemochromatosis gene and are susceptible to developing the
disease. One person in 8 to 12 is a carrier of the abnormal gene.
Hemochromatosis is less common in African Americans, Asian Americans,
Hispanic Americans, and American Indians.
Although both men and women can inherit the gene defect, men are about
five times more likely to be diagnosed with the effects of hereditary
hemochromatosis than women. Men also tend to develop problems from the
excess iron at a younger age.
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Symptoms of Hemochromatosis
Joint pain is the most common complaint of people with hemochromatosis.
Other common symptoms include fatigue, lack of energy, abdominal pain,
loss of sex drive, and heart problems. Symptoms tend to occur in men
between the ages of 30 and 50 and in women over age 50. However, many
people have no symptoms when they are diagnosed.
If the disease is not detected early and treated, iron may accumulate
in body tissues and may eventually lead to serious problems such as
- arthritis
- liver disease, including an enlarged liver, cirrhosis, cancer, and
liver failure
- damage to the pancreas, possibly causing diabetes
- heart abnormalities, such as irregular heart rhythms or congestive
heart failure
- impotence
- early menopause
- abnormal pigmentation of the skin, making it look gray or bronze
- thyroid deficiency
- damage to the adrenal gland
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Diagnosis of Iron Overload
A thorough medical history, physical examination, and routine blood
tests help rule out other conditions that could be causing the symptoms.
This information often provides helpful clues, such as a family history of
arthritis or unexplained liver disease.
Blood tests can determine whether the amount of iron stored in the body
is too high. The transferrin saturation test determines how much iron is
bound to the protein that carries iron in the blood. The serum ferritin
test shows the level of iron in the liver. If either of these tests shows
higher than normal levels of iron in the body, doctors can order a special
blood test to detect the HFE mutation, which will help confirm the
diagnosis. (If the mutation is not present, hereditary hemochromatosis is
not the reason for the iron buildup, and the doctor will look for other
causes.) A liver biopsy, in which a tiny piece of liver tissue is removed
and examined under a microscope, may be needed. It will show how much iron
has accumulated in the liver and whether the liver is damaged.
Hemochromatosis is often undiagnosed and untreated. It is considered
rare and doctors may not think to test for it. The initial symptoms can be
diverse and vague and can mimic the symptoms of many other diseases. Also,
doctors may focus on the conditions caused by hemochromatosis--arthritis,
liver disease, heart disease, or diabetes--rather than on the underlying
iron overload. However, if the iron overload caused by hemochromatosis is
diagnosed and treated before organ damage has occurred, a person can live
a normal, healthy life.
Hemochromatosis is usually treated by a specialist in liver disorders
(hepatologist), digestive disorders (gastroenterologist), or blood
disorders (hematologist). Because of the other problems associated with
hemochromatosis, several other specialists may be on the treatment team,
such as an endocrinologist, cardiologist, or rheumatologist. Internists or
family practitioners can also treat the disease.
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Hemochromatosis Treatment
Treatment is simple, inexpensive, and safe. The first step is to rid
the body of excess iron. The process is called phlebotomy, which means
removing blood. Depending on how severe the iron overload is, a pint of
blood will be taken once or twice a week for several months to a year, and
occasionally longer. Blood ferritin levels will be tested periodically to
monitor iron levels. The goal is to bring blood ferritin levels to the low
end of normal and keep them there. Depending on the lab, that means 25 to
50 micrograms of ferritin per liter of serum. Depending on the amount of
iron overload at diagnosis, reaching normal levels can take many
phlebotomies.
Once iron levels return to normal, maintenance therapy, which involves
giving a pint of blood every 2 to 4 months for life, begins. Some people
may need it more often. An annual blood ferritin test will help determine
how often blood should be removed.
The earlier hemochromatosis is diagnosed and treated in appropriate
cases, the better. If treatment begins before any organs are damaged,
associated conditions--such as liver disease, heart disease, arthritis,
and diabetes--can be prevented. The outlook for people who already have
these conditions at diagnosis depends on the degree of organ damage. For
example, treating hemochromatosis can stop the progression of liver
disease in its early stages, which means a normal life expectancy.
However, if cirrhosis has developed, the person's risk of developing liver
cancer increases, even if iron stores are reduced to normal levels.
Appropriate regular follow-up with a specialist is necessary.
People who have complications of hemochromatosis may want to consider
getting treatment from a specialized hemochromatosis center. These centers
are located throughout the country. Information is available from the
organizations listed under For
More Information.
People with hemochromatosis should not take iron supplements. Those who
have liver damage should not drink alcoholic beverages because they may
further damage the liver.
Although treatment cannot cure the conditions associated with
established hemochromatosis, it will help most of them. The main exception
is arthritis, which does not improve even after excess iron is
removed.
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Tests for Hemochromatosis
Screening for hemochromatosis (testing people who have no symptoms) is
not a routine part of medical care or checkups. However, researchers and
public health officials do have some suggestions:
- Brothers and sisters of people who have hemochromatosis should have
their blood tested to see if they have the disease or are carriers.
- Parents, children, and other close relatives of people who have the
disease should consider testing.
- Doctors should consider testing people who have joint disease,
severe and continuing fatigue, heart disease, elevated liver enzymes,
impotence, and diabetes, because these conditions may result from
hemochromatosis.
Since the genetic defect is common and early detection and treatment
are so effective, some researchers and education and advocacy groups have
suggested that widespread screening for hemochromatosis would be
cost-effective and should be conducted. However, a simple, inexpensive,
and accurate test for routine screening does not yet exist, and the
available options have limitations. For example, the genetic test provides
a definitive diagnosis, but it is expensive. The blood test for
transferrin saturation is widely available and relatively inexpensive, but
it may have to be done twice with careful handling to confirm a diagnosis
and to show that it is the consequence of iron overload.
Keeping on Top of Your Condition
Keeping in tune with your disease or condition not only makes treatment less intimidating but also increases its chance of success, and has been shown to lower a patients risk of complications. As well, as an informed patient, you are better able to discuss your condition and treatment options with your physician.
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Research
Current research in hemochromatosis is concentrated in four areas:
Genetics. Scientists are working to understand more about how
the HFE gene normally regulates iron levels and why not everyone
with an abnormal pair of genes develops the disease.
Pathogenesis. Scientists are studying how iron injures body
cells. Iron is an essential nutrient, but above a certain level it can
damage or even kill the cell.
Epidemiology. Research is under way to explain why the amounts
of iron people normally store in their bodies differ. Research is also
being conducted to determine how many people with the defective HFE
gene go on to develop symptoms, as well as why some people develop
symptoms and others do not.
Screening and testing. Scientists are working to determine at
what age testing is most effective, which groups should be tested, and
what the best tests for widespread screening are.
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More Information on Hemochromatosis
Information about hemochromatosis is available from these
organizations:
American Hemochromatosis Society, Inc.
777 East Atlantic
Avenue
Suite Z-363
Delray Beach, FL 33483-5352
Phone:
1-888-655-IRON (4766) or (561) 266-9037
Fax: (561) 278-0171
Email:
ahs@emi.net
Internet: http://www.americanhs.org/
American Liver Foundation
75 Maiden Lane
Suite 603
New
York, NY 10038-4810
Phone: 1-800-465-4837 or 1-888-443-7222
Fax:
(973) 256-3214
Email: info@liverfoundation.org
Internet:
http://www.liverfoundation.org/
The Hemochromatosis Foundation, Inc.
P.O. Box 8569
Albany,
NY 12208
(Please send a self-addressed, stamped
envelope to receive
materials.)
Phone: (518) 489-0972
Fax: (518) 489-0227
Internet:
http://www.hemochromatosis.org/
National Organization for Rare Disorders, Inc. (NORD)
55
Kenosia Avenue
P.O. Box 1968
Danbury, CT 06813-1968
Phone:
1-800-999-6673 or (203) 744-0100
Fax: (203) 798-2291
Email: orphan@rarediseases.org
Internet:
http://www.rarediseases.org/ |
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