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A Case-Based Review of Iron Overload With an Emphasis on Porphyria Cutanea Tarda, Hepatitis C, C282Y Heterozygosity, and Coronary Artery Disease

Iron overload can impact disease progression and treatment options for patients with comorbid conditions, such as porphyria cutanea tarda, hepatitis C virus, and coronary artery disease.
Federal Practitioner. 2020 February;37(2)a:95-100
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The majority of patients (60-93%) with clinically evident hemochromatosis are homozygous for C282Y mutation. In a heterozygous C282Y mutation with a high transferrin saturation and HH phenotype, additional genetic testing for a heterozygous compound mutation C282Y/H63D is recommended.8 Additional studies could include evaluation for a private HFE mutation in trans or other iron-related genes. Liver biopsy is the gold standard for assessing the degree of hepatic fibrosis. Determining the degree of fibrosis by some means is needed due to the increased risk of hepatocellular carcinoma (HCC) in HH patients with advanced fibrosis and cirrhosis.9

Treatment

Iron depletion with phlebotomy is the cornerstone of treatment in HH. Phlebotomy initially is done weekly with goal of achieving a transferrin saturation < 50%, a serum ferritin level < 50 ng/mL, and a hemoglobin of 12 to 13 ng/mL. When these goals are achieved, patients typically need 4 to 8 phlebotomies per year to maintain a transferrin saturation < 50% (Figure 3).

Hemochromatosis and PCT

Many studies have investigated the relevance of C282Y and/or H63D mutations in patients with PCT.9,10 It appears that ≥ 1 mutation of the HFE gene in PCT may be an important susceptibility factor in the development of clinical PCT. Various studies have shown an incidence of C282Y mutations of 44 to 47% in patients with PCT, compared with 9 to 12% in control populations.9,10 The incidence of the H63D mutation in PCT has been more variable, with some studies showing no difference between patients with PCT and a control group, while other studies showed 31% incidence of H63D mutation in patients with PCT.9,10 A higher incidence of C282Y and H63D mutations in PCT may be a sign that the HFE mutation could be an important factor in developing PCT.

 

Hemochromatosis and Hepatitis C

Transferrin saturation is frequently elevated in patients with HCV. It is yet unclear whether the pathology of liver disease in patients with HCV is influenced by iron overload or limited to the direct cell damage from replication of the virus and subsequent inflammation. It is believed that the pathology of iron overload in the patients with HCV is different from HH. Like other secondary causes of iron overload, the excess iron is stored in the Kupffer cells of patients with HCV. In HH, excess iron is stored in hepatocytes.

The prevalence of the HFE mutation is the same in the patients with chronic HCV and healthy individuals.10,11 However, HFE mutations are more prevalent in 30 to 60% of the patients with chronic HCV who have elevated transferrin saturations. Alone, C282Y heterozygosity, H63D heterozygosity, or C282Y/H63D compound heterozygosity could not lead to clinically significant iron overload in otherwise healthy individuals; however, these could be a significant cause of iron overload in patients with chronic HCV. Theoretically, the combination of iron overload and HFE gene mutations could increase the rate of advanced fibrosis/cirrhosis in chronic HCV. An increase serum ferritin level of 200 ng/dL in women and 250 ng/dL in men has been observed in 32% of patients with chronic HCV. In this subset of patients, phlebotomy reduced the progression of their liver disease and reduction in their liver enzymes.