Ingested 10-20 mg/day Ingested 10-20 mg/day Absorbed 1-2 mg/day Absorbed 1-2 mg/day Lost Gut, skin, urine - 1-2 mg/day Menses - 30 mg/month Lost Gut, skin, urine - 1-2 mg/day Menses - 30 mg/month Andrews NC, New Engl J Med 1999; 341:1986
Iron overload states Hereditary hemochromatosis HH: HFE related HH: HFE related C282Y homozygosity C282Y/H63D compound heterozygosity Other mutations of HFE HH: non-HFE related; other gene mutations HH: non-HFE related; other gene mutations Juvenile hemochromatosis Autosomal dominant hemochromatosis (Solomon Islands) Classification
Iron overload states Secondary iron overload Iron-loading anemias ± transfusion Thalassemia major Sideroblastic anemia Chronic hemolytic anemias Dietary iron overload Chronic liver diseases Hepatitis C and B Alcohol-induced liver disease Porphyria cutanea tarda Fatty liver disease Classification
Target populations for screening for HH Target Populations for Hemochromatosis Evaluation Symptomatic patients Unexplained manifestations of liver disease or a presumably known cause of liver disease with abnormality of one or more indirect serum iron markers. Type 2 diabetes mellitus, particularly with hepatomegaly, elevated liver enzymes, atypical cardiac disease or early-onset sexual dysfunction. Early-onset atypical arthropathy, cardiac disease, and male sexual dysfunction.
Target populations for screening for HH Target Populations for Hemochromatosis Evaluation Asymptomatic patients Priority groups First-degree relatives of a confirmed case of hemochromatosis. Individuals with abnormal serum iron markers discovered during routine testing. Individuals with unexplained elevation of liver enzymes or asymptomatic hepatomegaly or radiologic detection of enhanced computed tomography attenuation of the liver, Bronzed skin.
Diagnosis Indirect serologic markers of iron stores: 1.Transferrin saturation (TS): serum iron divided by TIBC, multiplied by 100 > 50 % for women or > 60 % for men has a sensitivity of 0.92, specificity of 0.93, and PPV of 86 % > 50 % for women or > 60 % for men has a sensitivity of 0.92, specificity of 0.93, and PPV of 86 % Saturation cutoff of 45 % used in screening recommendations Saturation cutoff of 45 % used in screening recommendations
Diagnosis Liver Biopsy: Liver Biopsy: –Definitive diagnostic test of iron overload –Allows histochemical assessment of iron stores, measurement of hepatic iron concentration (HIC), detection of cirrhosis, and determination of disease stage –Qualitative hepatic iron determination with Perl’s staining –Quantitative confirmation of iron stores with HIC measurement
Target population Symptomatic Adult 1 st degree Relative of HH Asymptomatic Fasting transferrin saturation & serum ferritin TS < 45 percent & normal ferritin TS ≥ 45 percent & ferritin elevated Step 1 Genotype Step 2 No further iron evaluation
Target population Step 2 TS<45 percent & normal ferritin TS<45 percent & ferritin elevated No further iron evaluation Genotype C282Y/C282Y Age<40 years Ferritin<1000 AND normal ALT/AST Age>40 years and/or Ferritin>1000 Or elevated ALT/AST Compound heterozygote C282Y/H63D Heterozygote C282Y OR non-C282Y
Age<40 years Ferritin<1000 AND normal ALT/AST Age>40 years and/or Ferritin>1000 Or elevated ALT/AST Compound heterozygote C282Y/H63D Heterozygote C282Y OR non-C282Y Target population Exclude other liver or hematologic diseases. ±Liver biopsy Therapeutic phlebotomy Liver biopsy for HIC and histopathology ± + Step 3
Quantitative liver iron=300 mole/g dry weight RJ: Liver Biopsy Iron index = 300 divided by 60 years of age = 5 RJ: Liver Biopsy
Criteria for initiating therapeutic phlebotomy Patient Serum ferritin, ng/mL Persons <18 years of age ≥200 ≥200 Women Reproductive years, not pregnant ≥ 200 ≥ 200 Reproductive years, pregnant ≥ 500 Postreproductive years ≥ 200 Men ≥ 300
Results of therapeutic phlebotomy in patients with hemochromatosis Complications of Iron Overload Expected Treatment Outcome None Prevention of complications of iron overload; normal life expectancy Weakness, fatigue, lethargy Resolution or marked improvement Elevated serum concentrations of hepatic enzymes Resolution or marked improvement Hepatomegaly Resolution often occurs Hepatic cirrosis No change Increased risk for primary liver cancer No change Right upper quadrant pain Resolution or marked improvement Arthropathy Improvement in arthralgias sometimes occurs; change in joint deformity is rare; progression is sometimes seen
Results of therapeutic phlebotomy in patients with hemochromatosis Complications of Iron Overload Expected Treatment Outcome Hypogonadotrophic hypogonadism Resolution is rare Diabetes mellitus Occasional improvement, often temporary Hypothyroidism, hypogonadism Resolution is rare Cardiomyopathy Resolution sometimes occurs Hyperpigmentation Resolution usually occurs HyperferritinemiaResolution Excess absorption and storage of nonferrous metals Infection with Vibrio vulnificus or other bacteria Little or no change
Treatment of iron overload Treatment of Hemochromatosis Hereditary hemochromatosis One phlebotomy (removal of 500 mL of blood) weekly or biweekly Check hematocrit prior to each phlebotomy; allow hematocrit to fall by no more than 20 percent of prior level Check serum ferritin level every 10 to 12 phlebotomies Stop frequent phlebotomy when serum ferritin falls below 50 ng/mL Continue phlebotomy at intervals to keep serum ferritin to between 25 and 50 ng/mL Avoid vitamin C supplements
Treatment of iron overload Treatment of Hemochromatosis Secondary ironoverload dueto dyserythropoiesis Deferoxamine (Desferal) at a dose of 20 to 40 mg/kg body weight per day Consider follow-up liver biopsy to ascertain adequacy of iron removal Avoid vitamin C supplements