Hemochromatosis Thomas W. Faust, M.D., M.B.E. Professor of Clinical Medicine Division of Gastroenterology The University of Pennsylvania Hemochromatosis • Introduction • Classification of iron overload syndromes • Pathogenesis • Clinical manifestations • Diagnosis • Treatment • Screening Hereditary Hemochromatosis Introduction • Inherited disorder of inappropriate dietary iron absorption • Prevalent in 1/250 individuals • Most patients are asymptomatic • Hepatic and extrahepatic manifestations • HFE (autosomal recessive) mutations account for majority of cases • Non-HFE mutations are rare causes of iron overload • Secondary iron overload states Phatak P et al., Ann Intern Med 2008;149:270-272 Hemochromatosis Hereditary Causes • HFE hemochromatosis • C282Y/C282Y (95%) • C282Y/H63D (4%) • H63D/H63D or C282Y/S65C (1%) • Non HFE hemochromatosis (rare) • • • • • Hemojuvelin Hepcidin Ferroportin Transferrin receptor 2 DMT-1 Beutler E. et al, Lancet 2002;359:211-218 Hemochromatosis Non-Hereditary Causes • Secondary iron overload • • • • Thalassemia major Sideroblastic anemias Liver disease (ETOH, HCV, HBV, PCT, NAFLD) Excessive iron ingestion • Parenteral iron overload • RBC transfusions • Iron-dextran infusions • Long-term dialysis Duodenal Iron Absorption • Crypt cells • HFE-transferrin receptor complex senses body iron stores • Upregulation or downregulation of DMT-1 based upon body iron stores • Villous cells • Dietary iron absorption occurs via DMT-1 and ferroportin • Transporter expression based upon body iron stores sensed by crypt cells Bacon B et al, Gastroenterology. 1999;116:193-207. Regulation of Iron Absorption Crypt Cell Model • HFE-transferrin receptor acts as sensor of iron stores in Crypt • DMT-1 synthesized based upon iron stores • Iron absorbed at villus tip Zoller H. et al, Lancet. 1999;353:2120-2123. Regulation of Iron Stores Influence of Hepcidin • Regulation of ferroportin-mediated iron export from enterocyte • Regulation of ferroportin-mediated iron export from macrophages Ganz T. Cell Metab 2008;7:288-290 Regulation of Iron Stores Normal • Hepcidin regulates ferroportin-mediated iron export from duodenum, macrophages, and liver • BMP, HJV, HFE, and TFR2 sense body iron stores and regulates release of hepcidin Nemeth E. et al, Science 2004;306:2090–2093 Hemochromatosis Non-Ferroportin Mutations • Mutations of BMP, HJV, HFE, and TFR2 alter ability of liver to sense body iron stores • Inappropriately low level of hepcidin • Excess ferroportinmediated export of iron from duodenum, macrophages, and liver Nemeth E. et al, Science 2004;306:2090–2093 Hemochromatosis Ferroportin Mutations • Loss of function • Limited ability to export iron • Accumulation of iron in macrophages • Hepcidin increased • Gain of function • Resistant to inhibitory effects of hepcidin • Phenotypically similar to classic hemochromatosis • Hepcidin increased Letocart E. et al, Br J Haematol. 2009;147(3):379 Hemochromatosis Overview of Clinical Manifestations • Asymptomatic state (majority) • Abnormal iron studies and liver function tests • Non-specific systemic symptoms • Weakness, fatigue, lethargy, apathy, weight loss, abdominal pain • Organ-related disease • Hepatic manifestations • Extrahepatic manifestations Hemochromatosis Hepatic Manifestations • Hepatosplenomegaly • Micronodular cirrhosis • Portal hypertensive bleeding • Ascites/SBP/HRS • Encephalopathy • Hepatocellular carcinoma www.gfmer.ch/genetic_diseases_v2/gendis_detail_list.php?cat3=821 Hemochromatosis Physical Examination • Physical findings in patients with progressive liver disease • Findings not specific to hemochromatosis Hemochromatosis Hepatocellular Carcinoma • Patients with cirrhosis at risk for HCC. • All patients with cirrhosis should be screened per AASLD guidelines • OLT considered for cirrhotic patients with HCC Netter’s Gastroenterology, 2nd ed., Elsevier Inc., 2010, all rights reserved Hemochromatosis Extrahepatic Manifestations • Cardiac • Restrictive/dilated cardiomyopathy • Arrhythmias • Rheumatologic • Arthalgias/arthritis • Chondrocalcinosis • Osteoporosis • Dermatologic • Hyperpigmentation • Porphyria cutanea tarda • Endocrinologic • • • • Diabetes Loss of libido/impotence Amenorrhea Hypothyroidism • Infectious • Yersinia, pasteurella, vibrio vulnificus, listeria Hemochromatosis Systemic Disorder • Multiple organs involved with progressive iron overload • Therapeutic phlebotomy may correct some of the clinical manifestations Netter’s Gastroenterology, 2nd ed., Elsevier Inc., 2010, all rights reserved Hemochromatosis Extrahepatic Manifestations Diagnosis of Hemochromatosis Iron Studies Transferrin Saturation Ferritin • Value ≥ 45% most common early phenotypic marker • Sensitivity > 90% • Fasting value preferable • F/U with genetic testing • Rises with progressive iron overload • F/U with genetic testing • Other diseases • ETOH, NAFLD, viral hepatitis, inflammatory disorders, neoplasms • Predicts fibrosis Beutler E. et al, Lancet 2002;359:211-218 Diagnosis of Hemochromatosis Genetic Testing • C282Y/C282Y • C282Y/H63D or other • For all patients with TS ≥ 45% • For all patients with elevated ferritin • Liver biopsy for ferritin ≥ 1000 μg/L or elevated AST/ALT Guyader D. et al, Gastroenterology 1998;115:929-936 • For all patients with TS ≥ 45% • For all patients with elevated ferritin • Exclude other liver or hematologic diseases • Testing for non-HFE mutations not widely available • Consider liver biopsy Liver Biopsy Diagnosis of Hemochromatosis or Fibrosis • Not required • C282Y/C282Y • Ferritin < 1000 μg/L • Normal AST/ALT • Required or suggested • • • • C282Y/C282Y, ferritin ≥ 1000 μg/L, elevated AST/ALT Consider for C282Y/H63D or other Routine histopathology Qualitative and quantitative iron assessment Adams P et al, J Lab Clin Med 1997;130:509-514 Hemochromatosis Liver Histopathology • Hepatocytes • Progressive iron accumulation from periportal (zone 1) to pericentral (zone 3) regions • Routine H&E and Prussian blue stains • Kupffer and biliary epithelial cells • Iron accumulation with progressive iron loading • Fibrosis and cirrhosis • Trichrome stain • Associated with advanced iron overload • Hepatocellular carcinoma Hepatic Iron Overload Other Diseases • ETOH, NAFLD, viral hepatitis, PCT, parenteral • Panlobular and patchy iron distribution • Iron accumulation in hepatocytes and Kupffer cells • Iron accumulation is usually mild • Ferroportin disease associated with iron overload in macrophages and reticuloendothelial cells Hemochromatosis Pathology www.gfmer.ch/genetic_diseases_v2/gendis_detail_list.php?cat3=821 Hemochromatosis Imaging CT Taouli B et al, AJR 2009;193:14-27 Jensen P, Br J Haematol 2004 Mar;124(6):697-711 MR Hemochromatosis Treatment • Weekly or twice weekly phlebotomy • Removal of 2-3 units per week or 0.5 units every other week • Check Hgb/HCT prior to each phlebotomy • Follow TS and ferritin every 3 mo. • Endpoints: TS < 50%, ferritin < 50 μg/L • Maintenance phlebotomy: 1 unit every 3 mo. • Avoid iron deficiency • Imaging and AFP every 6 mo. to screen for HCC in cirrhotic patients • OLT for hepatic decompensation or HCC Bacon B. Gastroenterology 2001;120:718-725 Hemochromatosis Response to Phlebotomy • Improvement • • • • Tissue iron stores Survival in absence of cirrhosis and DM Liver-associated enzymes Cardiac function, DM, skin pigmentation, fibrosis • No improvement • Established cirrhosis • Arthropathy • Testicular atrophy Hemochromatosis Screening Family Screening • HFE (C282Y, H63D) and iron testing for first degree relatives • C282Y/C282Y and C282Y/H63Y relatives with iron overload undergo phlebotomy • C282Y/wt, H63D/H63D, H63D/wt not at risk for iron overload • C282Y/C282Y or C282Y/H63D children undergo yearly ferritin assessment Tavil A. Hepatology 2001;33:1321-1328 Population Screening • Role for population screening with genetic testing unclear • Incomplete penetrance raises questions about clinical utility, cost effectiveness, and genetic discrimination • Non HFE hemochromatosis is rare and genetic testing only available in research labs Hemochromatosis Algorithm Symptomatic Asymptomatic Transferrin saturation/ferritin Transferrin saturation/ferritin Adult 1st degree relative of HH HFE genotype Transferrin saturation/ferritin TS < 45% and normal ferritin TS ≥ 45% and/or elevated ferritin TS < 45% and normal ferritin TS ≥ 45% and/or elevated ferritin TS < 45% and normal ferritin TS ≥ 45% and/or elevated ferritin No further evaluation HFE genotype No further evaluation HFE Genotype No further evaluation HFE genotype Bacon B et al, Hepatology,2011;54:328-343 Hemochromatosis Algorithm HFE genotype C282Y/H63D, C282Y heterozygote , non-C282Y Exclude other liver or hematologic diseases. ± liver biopsy ± Therapeutic phlebotomy C282Y/C282Y Ferritin < 1000 μg/L and normal liver enzymes Ferritin ≥ 1000 μg/L or elevated liver enzymes Therapeutic phlebotomy Liver biopsy for HIC and histopathology + Therapeutic phlebotomy Bacon B et al, Hepatology,2011;54:328-343 Hemochromatosis Take Home Points • HFE (C282Y/C282Y) mutations account for most cases of hereditary hemochromatosis. • Be aware of other non-HFE inherited and secondary causes of iron overload. • Interrelationship between duodenal iron absorption and hepcidin is important. • Patients can present with a variety of hepatic and extrahepatic manifestations. • Diagnosis based upon iron studies, genetic testing, and liver biopsy. • Phlebotomy is mainstay of therapy • Genetic testing recommended for family members of patients with hereditary hemochromatosis. Hemochromatosis Question 1 • A 55 yr old man presents with mildly elevated transaminases. His serum ferritin is 3000 mcg/L, with transferrin saturation exceeding 90%. He is homozygous for C282Y. Liver ultrasound is normal and liver biopsy shows bridging fibrosis and markedly elevated hepatocellular iron. Weekly phlebotomy is started. The patient’s wife is heterozygous for C282Y and one normal allele. The patient has 2 sons ages 26 and 18. The older son’s ferritin is 2500 mcg/L, whereas the younger son’s ferritin is 180 mcg/L. At this time you make all of the following recommendations except: DDSEP 6, AGA Press, 2011. Hemochromatosis Question 1 • A. The older son should be tested for C282Y mutation of HFE gene • B. For the older son, liver biopsy may be justified to R/O cirrhosis • C. The younger son should be tested for C282Y mutation • D. For the younger son, liver biopsy may be justified to R/O cirrhosis • E. The older son should have liver ultrasound DDSEP 6, AGA Press, 2011. Hemochromatosis Question 2 • A baby born to parents of Irish descent (father homozygous for C282Y, mother genetic status unknown) is found to be homozygous for C282Y. What is the lifetime risk of hepatic decompensation and/or hepatocellular carcinoma if the child is carefully followed and undergoes phlebotomy over his/her lifetime? • • • • • A. Zero B. 5% C. 20% D. 50% E. 80% DDSEP 6, AGA Press, 2011. Hemochromatosis Question 3 • An autosomal dominant form of hemochromatosis accompanied by high levels of hepcidin production is associated with mutations of the gene coding for which of the following? • • • • • A. HFE protein B. Transferrin receptor type 2 C. Hemojuvelin D. Hepcidin E. Ferroportin DDSEP 6, AGA Press, 2011. Hemochromatosis Question 4 • Which one of the following statements about liver biopsy in patients with HFE (C282Y homozygous) hemochromatosis is correct? • A. Liver biopsy should be performed in all patients after genetic testing. • B. Kupffer cells take up iron before hepatocytes in patients with HFE (C282Y homozygous) hemochromatosis. • C. Panlobular patchy iron accumulation in hepatocytes and Kupffer cells is classic for C282Y homozygous disease. • D. In patients with C282Y disease, iron is taken up by periportal (zone 1) hepatocytes prior to pericentral (zone 3) hepatocytes. • E. Bridging fibrosis is seen in early disease Hemochromatosis Question 5 • A 65 yr old male is recently diagnosed with C282Y hemochromatosis and cirrhosis. His transferrin saturation is 95% and his ferritin is 5284 mcg/L. Which one of the following statements is incorrect? • A. He will not require surveillance for hepatocellular carcinoma once iron stores have been removed from the liver by phlebotomy. • B. Phlebotomy should be initiated to achieve endpoints of T. Sat of < 50% and ferritin < 50 μg/L. • C. Phlebotomy may improve cardiac function and glucose intolerance. • D. Arthropathy does not usually improve with phlebotomy • E. At the beginning of treatment, weekly or twice weekly phlebotomy is necessary to reach desired endpoints. Hemochromatosis Question 6 • Which one of the following statements about HFE hemochromatosis is correct? • A. C282Y/H63D disease is the most common genetic abnormality. • B. H63D/H63D commonly results in iron overload. • C. Population-based screening for genetic hemochromatosis is recommended. • D. CT and MR of the liver are sensitive tests for diagnosing disease. • E. Hepcidin regulates ferroportin-mediated iron export from duodenal enterocytes. Hemochromatosis Answers to Questions • • • • • • 1. D 2. A 3. E 4. D 5. A 6. E