Iron Overload Hemochromatosis
Iron Overload Hemochromatosis
In a healthy individual, the intestines reduce iron absorption from food and drink when iron stores are adequate, preventing excessive iron levels. However, people with iron overload absorb more iron than usual from their diet or supplements. The body cannot eliminate this excess iron quickly enough, causing it to accumulate, primarily in the liver, heart, and pancreas.
Types and Causes of Hemochromatosis
Iron overload disorders come in various forms, each with different origins.
Primary Hemochromatosis
Hereditary hemochromatosis, or primary hemochromatosis, is a prevalent genetic disorder, especially among white individuals. A 2018 study found that about 1 in 200 white people in the United States and Australia have hereditary hemochromatosis, with 10-14% of these populations carrying the genetic mutations.
This condition results from a mutation in the HFE gene, which controls iron absorption. Over 100 mutations have been identified in this gene, with C282Y and H63D being the most common. Most individuals with hereditary hemochromatosis inherit two copies of the C282Y mutation. Those who inherit one C282Y and one H63D mutation may develop symptoms, though inheriting two copies of H63D is rare.
Secondary Hemochromatosis
Secondary hemochromatosis is caused by external factors such as excessive iron supplements, frequent blood transfusions, or conditions affecting red blood cell production. Conditions leading to secondary iron overload include sickle cell disease, thalassemia, sideroblastic anemia, hemolytic anemia, and myelodysplasia.
Juvenile Hemochromatosis
Juvenile hemochromatosis is an inherited condition resulting from defects in the HJV gene. Symptoms usually appear before age 30 and include diabetes, issues with sexual development, and heart abnormalities. Without treatment, juvenile hemochromatosis can cause serious complications.
Diagnosing Hemochromatosis
Diagnosing hemochromatosis can be challenging due to symptom overlap with other conditions. Specialists like hepatologists or cardiologists may be involved. Diagnostic tests include blood tests, liver tests, MRI scans, and genetic testing. Two key blood tests are:
- Serum transferrin saturation test: Measures iron bound to transferrin, with saturation values over 45% being too high.
- Serum ferritin test: Measures stored iron levels, aiding diagnosis and treatment monitoring.
These tests are not routine but may be recommended for those with a family history of hemochromatosis or related symptoms like diabetes, elevated liver enzymes, erectile dysfunction, extreme tiredness, heart disease, or joint disease.
Hemochromatosis Treatment
Phlebotomy
Phlebotomy, or venesection, is the primary treatment, involving regular removal of iron-rich blood. The frequency depends on age, sex, overall health, and iron overload severity. Typically, 1 pint of blood is removed weekly until levels normalize, then every 2-4 months as needed.
Chelation
Iron chelation therapy involves taking medication to bind and excrete excess iron. This is usually a secondary treatment option.
Hemochromatosis Diet
Dietary changes can help manage symptoms and reduce iron levels. Recommendations include avoiding iron and vitamin C supplements, reducing iron-rich foods, avoiding uncooked fish and shellfish, and limiting alcohol intake.
Complications of Hemochromatosis
Without treatment, iron accumulation can lead to complications such as cirrhosis, liver cancer, diabetes, heart failure, arrhythmias, endocrine problems, arthritis, and skin discoloration. Other possible complications include depression, gallbladder disease, and certain cancers. Some studies suggest a link between neurodegenerative diseases and abnormal brain iron levels.
FAQ?
Symptoms include fatigue, joint pain, abdominal pain, liver enlargement (hepatomegaly), skin discoloration (bronze or grayish), and in advanced cases, organ damage.
Diagnosis involves blood tests to measure serum ferritin and transferrin saturation levels, genetic testing to identify HFE mutations, and imaging studies (like MRI) to assess organ damage.
Treatment includes regular blood removal (phlebotomy) to reduce iron levels, dietary changes to limit iron intake, and in some cases, medications to help reduce iron absorption. Early diagnosis and treatment can prevent complications.