From the Guidelines
The lab criteria for diagnosing hemochromatosis primarily involve elevated transferrin saturation (>45%) and elevated serum ferritin (>200 ng/mL in premenopausal women or >300 ng/mL in men and postmenopausal women) as indicated by the most recent guidelines 1. The diagnosis of hemochromatosis is based on a combination of clinical presentation, laboratory tests, and genetic analysis.
Key Laboratory Tests
- Transferrin saturation (TSAT) is a critical parameter, with values above 45% being suggestive of hemochromatosis 1.
- Serum ferritin levels are also essential, with elevated levels (>200 ng/mL in premenopausal women or >300 ng/mL in men and postmenopausal women) indicating iron overload 1.
- Genetic testing for HFE gene mutations, particularly C282Y homozygosity or C282Y/H63D compound heterozygosity, can confirm hereditary hemochromatosis 1.
Diagnostic Approach
The diagnostic approach typically follows a stepwise pattern, starting with non-invasive iron studies before proceeding to genetic testing and potentially liver biopsy if the diagnosis remains unclear 1.
Importance of Early Diagnosis
Early diagnosis is crucial as hemochromatosis causes progressive iron accumulation in tissues, leading to organ damage that can be prevented with timely treatment through regular phlebotomy to reduce iron stores 1.
Additional Considerations
Additional testing may include liver function tests to assess organ damage, and in some cases, liver biopsy may be necessary to quantify hepatic iron concentration and evaluate for fibrosis or cirrhosis 1.
From the Research
Lab Criteria for Diagnosing Hemochromatosis
The diagnosis of hemochromatosis involves several lab criteria, including:
- Serum transferrin saturation: elevated levels (>50% in men, >45% in women) are indicative of iron overload 2
- Serum ferritin levels: elevated levels (>300 ng/ml in men, >200 ng/ml in women) are indicative of iron overload 2
- Hepatic iron index: a measure of iron stores in the liver, with levels >1.9 indicating iron overload 3
- Iron removed by venesection: a measure of the amount of iron removed from the body through blood draws, with levels >5 g indicating iron overload 3
- HFE genotyping: a genetic test that identifies mutations in the HFE gene, which is associated with hereditary hemochromatosis 4, 3, 5
Threshold Values for Lab Tests
The following threshold values have been established for lab tests used to diagnose hemochromatosis:
- Transferrin saturation: >43% 6
- Unsaturated iron binding capacity (UIBC): <143 microg/dL (25.6 micromol/L) 6
- Ferritin levels: >300 microg/L in men and >200 microg/L in women 3
Importance of Lab Criteria in Diagnosing Hemochromatosis
The lab criteria listed above are essential in diagnosing hemochromatosis, as they help to identify individuals with iron overload and distinguish them from those without the condition 4, 2, 3, 6, 5. Early diagnosis and treatment of hemochromatosis can help to prevent serious complications and improve patient outcomes 4.