From the Guidelines
The diagnostic blood tests for hereditary hemochromatosis (HH) include transferrin saturation and serum ferritin tests as initial screening, followed by genetic testing for HFE gene mutations if these are elevated. The initial screening tests are crucial in identifying individuals with iron overload, which is a hallmark of hereditary hemochromatosis 1.
Key Diagnostic Tests
- Transferrin saturation: This test measures the percentage of transferrin that is saturated with iron. A level above 45% is considered elevated and may indicate iron overload 1.
- Serum ferritin: This test measures the level of ferritin in the blood, which is a protein that stores iron. Elevated levels of ferritin can indicate iron overload 1.
Additional Tests
Additional tests may include:
- Complete blood count (CBC) to assess for anemia or other blood disorders
- Liver function tests (LFTs) to assess for liver damage
- Blood glucose to assess for diabetes
- Genetic testing for HFE gene mutations, particularly C282Y and H63D, to confirm hereditary hemochromatosis 1
Importance of Early Detection
Early detection and treatment of hereditary hemochromatosis are crucial in preventing serious complications such as liver cirrhosis, diabetes, and heart problems 1. Regular monitoring of ferritin levels every 3-6 months during treatment and annually thereafter is recommended to ensure that iron levels remain within a safe range 1.
Treatment
Treatment typically involves therapeutic phlebotomy (removal of 500mL of blood) weekly until ferritin levels normalize (below 50-100 ng/mL), followed by maintenance phlebotomies 2-4 times yearly 1.
From the Research
Diagnostic Blood Tests for Hereditary Hemochromatosis (HH)
The diagnostic blood tests for hereditary hemochromatosis (HH) include:
- Serum ferritin level: Elevated ferritin levels can indicate iron overload, which is a hallmark of HH 2, 3, 4, 5, 6
- Transferrin saturation (TSAT): TSAT is calculated as serum iron/total iron binding capacity × 100, and elevated TSAT levels can suggest HH 3, 4, 5, 6
- Genetic testing for HFE gene mutations: Specifically, testing for the C282Y and H63D mutations, which are commonly associated with HH 2, 3, 4, 5
Interpretation of Blood Test Results
The interpretation of blood test results for HH diagnosis is as follows:
- Elevated ferritin levels and TSAT >45% in females and TSAT >50% in males and postmenopausal women can suggest provisional iron overload and diagnose HH in patients homozygous for p.Cys282Tyr in HFE 5
- In patients with high TSAT and elevated ferritin but other HFE genotypes, diagnosis requires the presence of hepatic iron overload on MRI or liver biopsy 5
- Low or normal TSAT with high serum ferritin levels should alert the physician to other causes of iron overload besides HH 6
Additional Diagnostic Tests
Additional diagnostic tests that may be used to confirm HH diagnosis or assess disease severity include: