How is hemochromatosis diagnosed?
In the fasting state, transferrin saturation (iron/total iron-binding capacity × 100) greater than 60% in men or 50% in women along with elevated ferritin greater than twice the normal level is 95% sensitive and 85% specific for diagnosis of hemochromatosis. Genetic screening is recommended for all patients with transferrin saturation >45% and ferritin >200 μg/L. Serum ferritin levels are an accurate measure of peripheral iron stores but may also be increased in the settings of acute liver injury (e.g., alcohol), fatty liver, systemic inflammation, and neoplasia (i.e., lymphoma). A definitive diagnosis is made by direct measurement of iron in a liver biopsy. In addition, synovial biopsies will reveal iron deposition in type B synovial lining cells in patients with arthritis. This pattern of iron deposition is different to that seen in other diseases causing iron deposition in synovial tissue (rheumatoid arthritis, osteoarthritis, pigmented villonodular synovitis, hemophilia, and hemarthrosis). However, biopsies are usually not necessary in the setting of abnormal iron studies in a patient homozygous for the C282Y HFE mutation.
