Screening for hemochromatosis by measuring ferritin levels: a more effective approach

AbstractBecause the penetrance of HFE hemochromatosis is low, traditional population screening measuring the transferrin saturation is unlikely to be cost-effective because the majority of subjects detected neither have clinical disease nor are likely to develop it. Three independent studies show that only patients with serum ferritin concentrations more than 1000 μg/L are at risk for cirrhosis, one of the main morbidities of hemochromatosis. Among 29 699 white subjects participating in the Scripps/Kaiser hemochromatosis study, only 59 had serum ferritin levels more than 1000 μg/L; 24 had homozygous mutant or compound heterozygous mutant HFE genotypes. In all but 5 of the other subjects, the causes of elevated ferritin were excessive alcohol intake, cancer, or liver disease. Screening for hemochromatosis with serum ferritin levels will detect the majority of patients who will be clinically affected and may detect other clinically significant disease in patients who do not have hemochromatosis genotypes. Because the ferritin level of the majority of adult homozygotes for HFE mutations does not rise over long periods of time, excluding subjects with serum ferritin levels less than or equal to 1000 μg/L should not result in missed opportunities for early treatment of patients who could benefit.

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Screening for Hemochromatosis by Measuring Ferritin Levels: A More Effective Approach.

Blood ◽

10.1182/blood.v110.11.2673.2673 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2673-2673 ◽

Cited By ~ 1

Author(s):

Jill Waalen ◽

Ernest Beutler

Keyword(s):

Serum Ferritin ◽

Screening Program ◽

Ferritin Level ◽

Severe Disease ◽

Hereditary Hemochromatosis ◽

Transferrin Saturation ◽

Cost Effective ◽

Population Screening ◽

Compound Heterozygous ◽

Missed Opportunities

Abstract Population screening for hereditary hemochromatosis has traditionally been performed by determining the serum transferrin saturation. With the recognition that the penetrance of HFE hemochromatosis is extremely low, it has become apparent that population screening with transferrin saturation is unlikely to be cost effective as the vast majority of individuals detected neither have clinical disease nor are likely to develop it. Although the factors that cause a subset of patients to develop the severe disease phenotype have not been identified, it is clear from at least three independent studies that only patients with serum ferritin concentrations of over 1000 ng/ml are at risk. We have utilized data from the Scripps-Kaiser hemochromatosis study to model results of a screening program using this ferritin cut-off value. Among 29,699 white subjects screened, only 59 had serum ferritin levels of greater than 1000 ng/ml. Twenty-four of these had homozygous mutant or compound heterozygous mutant HFE genotypes that could account for the ferritin levels. Among the remaining patients, the main causes of elevated ferritin levels were excessive alcohol intake, cancer, or liver disease. Causes for the hyperferritinemia were found in all but 8% of the 59 patients. We conclude that screening for hemochromatosis with serum ferritin levels will detect the vast majority of patients who will be clinically affected, and may detect other clinically significant disease in patients who do not have hemochromatosis phenotypes. Since it is clear from other longitudinal studies that the ferritin level of the vast majority of adult homozygotes for HFE mutations does not rise over long periods of time, excluding subjects with serum ferritin levels <1000 ng/ml should not result in missed opportunities for early treatment of patients who could benefit.

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The Role of α-Thalassemia and Iron Deficiency in the Difference between Hemoglobin Levels of African-Americans (AA) and Whites.

Blood ◽

10.1182/blood.v104.11.3706.3706 ◽

2004 ◽

Vol 104 (11) ◽

pp. 3706-3706

Author(s):

Ernest Beutler ◽

Carol West

Keyword(s):

Iron Deficiency ◽

Serum Ferritin ◽

Gene Frequency ◽

Ferritin Level ◽

Transferrin Saturation ◽

Hemoglobin Concentration ◽

Iron Deficient ◽

High Prevalence ◽

Hardy Weinberg Equilibrium ◽

The Difference

Abstract The fact that the average hemoglobin concentration (Hb) of AA is lower than that of whites has been documented extensively. Several investigations have shown that this difference of approximately 0.8 g/dL is due neither to iron deficiency nor to socioeconomic status. Its cause remains unknown. We compared the Hb of 1,493 AA and 31,029 white anonymized patients attending a Health Appraisal Clinic and confirmed the known difference in Hb, both for females and males (0.79 and 0.47 g/dL) respectively. The difference persisted when a subset of the subjects were paired by age and narrowed slightly in females when those with serum ferritin levels of <10 ng/ml or transferrin saturations of <16% were excluded (difference in females 0.59 g/dL; males 0.47). We determined the α-thalassemia −3.7 genotype of 298 AA. The gene frequency was found to be 0.17, and the distribution of genotypes fit the Hardy-Weinberg equilibrium. However, in a sample of 155 white subjects only one α-thalassemia allele was found (gene frequency=0.003). Among the AA subjects, the Hb and MCV values were lower in homozygotes (−a/−a) and heterozygotes (aa/−a) for α-thalassemia than in the aa/aa subjects. The table presents data for AA and white subjects after excluding all who did not have a documented serum ferritin level of >9 ng/ml and a transferrin saturation of >16%. Excluding subjects with sickle trait had no effect. Ethnic Group Genotype n Mean Hb SE Hb Mean MCV SE MCV −a/−a 3 11.87 0.418 72.23 2.32 F AA aa/−a 20 12.69 0.202 85.22 0.86 aa/aa 65 13.17 0.127 90.43 0.61 White 2917 13.60 0.016 90.85 0.07 −a/−a 2 13.85 0.550 83.05 1.65 M AA aa/−a 36 14.37 0.161 85.81 0.78 aa/aa 86 14.75 0.123 89.78 0.53 White 5335 15.09 0.013 90.35 0.06 As shown in the table, the average Hb of non-iron deficient AA females and males who had 4 normal α loci (aa/aa) was 0.43 and 0.34 g/dL lower respectively than those of whites, the difference being significant with p<0.01. We conclude that one cause of the lower Hb of AA compared to white subjects is the high prevalence of α-thalassemia in the AA population, but that it accounts for only about one-quarter of the difference after iron deficiency has been excluded. There are other, as yet undefined, causes that play a role. These may include the lower ATP (Biochem. Genet.1:25, 1967) and higher 2,3 BPG (Transfusion18:108, 1978) levels that have been documented in the red cells of AA subjects.

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Molecular Diagnosis of the First Ferroportin Mutation (C326Y) in the Far East Causing a Dominant Form of Inherited Iron Overload.

Blood ◽

10.1182/blood.v104.11.3204.3204 ◽

2004 ◽

Vol 104 (11) ◽

pp. 3204-3204 ◽

Cited By ~ 7

Author(s):

Vip Viprakasit ◽

Alison T. Merryweather-Clarke ◽

Yingyong Chinthammitr ◽

Lisa Schimanski ◽

Hal Drakesmith ◽

...

Keyword(s):

Iron Overload ◽

Serum Ferritin ◽

Transferrin Saturation ◽

Far East ◽

Rflp Analysis ◽

Causative Mutation ◽

The Far East ◽

Hfe Mutations ◽

Genetic Hemochromatosis

Abstract Genetic hemochromatosis (HH) is a common inherited disorder in populations of European origin in which different types of genetic hemochromatosis (type 1–4) have been characterized. Most hemochromatosis-type 1 patients are homozygotes or compound heterozygotes for two HFE mutations C282Y and H63D. Studies of several non-HFE iron overload families led to identification of mutations in hemojuvelin and hepcidin (juvenile form-HFE2A and B), transferrin receptor 2 (HFE3) and ferroportin (HFE4) as a cause of different forms of hemochromatosis. In the Far East, inherited hemochromatosis has rarely been reported and may have been misdiagnosed due to the high prevalence of secondary iron loading from hemoglobin disorders. This report describes, for the first time, non-HFE iron overload in patients from Southeast Asia. The affected Thai family presented with a distinctive clinical phenotype including macrocytosis and elevated transferrin saturation (>95%), increased non-transferrin bound iron (NTBI) as well as raised serum ferritin and marked hepatic hemochromatosis. Our patients tolerated therapeutic phlebotomy well. DNAs from peripheral blood leukocytes were firstly analyzed for three common HFE mutations (C282Y, H63D and IVS5+1 G→A). Subsequently, we screened all coding sequences, promoters and exon/intron boundaries of the HFE, HAMP, TfR2, HJV and SLC40A1 genes using denaturing high performance liquid chromatography (DHPLC). The entire coding region and splice sites of these genes were amplified and directly sequenced. We identified a novel mutation (C326Y) in ferroportin (SLC40A1, IREG-1, MTP-1), a membrane iron transport protein due to a G→A substitution at nucleotide 1281 in exon 7. This mutation was confirmed by restriction fragment length polymorphism (RFLP) analysis using Sfa NI. Six hundred Thai and two hundred Vietnamese chromosomes were analyzed for the C326Y mutation by RFLP analysis and it was not detected in any of the healthy controls studied. This result suggested that the G→A substitution is not a common polymorphism and is likely to be the causative mutation for the phenotype in this family. Previous reported mutations of ferroportin, including A77D and V162del, which lead to type IV hemochromatosis, were characterized by increased serum ferritin despite normal transferrin saturation, in contrast to our patients’ phenotype. These autosomal dominant mutants are postulated to lead to disease due to loss of iron exporting function. Preliminary in vivo assay using transient transfection of wild-type and ferroportin mutants in HeLa or 293T cells revealed, as expected, a loss of function and diminished surface membrane localisation in A77D and V162del mutants. Surprisingly, the C326Y mutant was indistinguishable from wt ferroportin in both iron status of the cell and protein localization suggesting different pathophysiology leading to iron overload in our patients.

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Relationships of Serum Ferritin, Transferrin Saturation, and HFE Mutations and Self-Reported Diabetes in the Hemochromatosis and Iron Overload Screening (HEIRS) Study

Diabetes Care ◽

10.2337/dc05-1592 ◽

2006 ◽

Vol 29 (9) ◽

pp. 2084-2089 ◽

Cited By ~ 61

Author(s):

R. T. Acton ◽

J. C. Barton ◽

L. V. Passmore ◽

P. C. Adams ◽

M. R. Speechley ◽

...

Keyword(s):

Iron Overload ◽

Serum Ferritin ◽

Transferrin Saturation ◽

Hfe Mutations

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PredictingC282YHomozygote Genotype for Hemochromatosis Using Serum Ferritin and Transferrin Saturation Values from 44,809 Participants of the HEIRS Study

Canadian Journal of Gastroenterology and Hepatology ◽

10.1155/2014/698352 ◽

2014 ◽

Vol 28 (9) ◽

pp. 502-504 ◽

Cited By ~ 1

Author(s):

Andrew Lim ◽

Mark Speechley ◽

Paul C Adams

Keyword(s):

Serum Ferritin ◽

Serum Ferritin Level ◽

Ferritin Level ◽

Transferrin Saturation ◽

Area Under The Curve ◽

Easy Access ◽

Regression Equations ◽

Simultaneous Interpretation ◽

Large Primary ◽

Variance Explained

INTRODUCTION: The simultaneous interpretation of serum ferritin level and transferrin saturation has been used as a clinical guide to diagnose genetic hemochromatosis. The Hemochromatosis and Iron Overload Screening (HEIRS) Study screened 101,168 North American participants for serum ferritin level and transferrin saturation, andC282Ygenotyping for theHFEgene.METHODS: Logistic regression involving a subsample of Caucasians (n=44,809) was used to predict individual probabilities ofHFE C282Yhomozygosity using serum ferritin and transferrin saturation values. Men (n=17,323) and women (n=27,486) were analyzed separately. Regression equations were evaluated using area under the curve from ROC analysis and variance explained by Nagelkerke’s pseudo R-squared. An Android smartphone App and website application were developed to provide physicians with easy access to predictingC282Yhomozygosity of theHFEgene.RESULTS: The logistic equation had an area under the ROC curve of 0.91 for men and 0.89 for women. The pseudo R-squared was 0.44 for men and 0.34 for women. An example analysis was a Caucasian man with a transferrin saturation of 50% and a ferritin level of 500 µg/L, who had a 1.3% (95% CI 1.1% to 8.8%) probability of being aC282Yhomozygote.CONCLUSIONS: A large primary care-based sample of 44,809 participants contributed to the development of a new computer/smartphone tool that predicts the probability of being aC282Yhomozygote of theHFEgene from serum ferritin and transferrin saturation values.

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HFE Gene Mutations, Serum Ferritin Level, Transferrin Saturation, and Their Clinical Correlates in a Korean Population

Digestive Diseases and Sciences ◽

10.1007/s10620-008-0432-6 ◽

2008 ◽

Vol 54 (4) ◽

pp. 879-886 ◽

Cited By ~ 15

Author(s):

Sang Hyub Lee ◽

Jin-Wook Kim ◽

So Hyun Shin ◽

Kyoung Phil Kang ◽

Hyun Cheol Choi ◽

...

Keyword(s):

Serum Ferritin ◽

Serum Ferritin Level ◽

Ferritin Level ◽

Transferrin Saturation ◽

Gene Mutations ◽

Korean Population ◽

Hfe Gene ◽

Clinical Correlates ◽

Hfe Gene Mutations

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Unexplained Serum Ferritin Elevations in Primary Care Patients with Elevated Serum Ferritin Concentrations and High Normal Transferrin Saturations.

Blood ◽

10.1182/blood.v106.11.3729.3729 ◽

2005 ◽

Vol 106 (11) ◽

pp. 3729-3729

Author(s):

Onyinye C. Onyekwere ◽

Tiffany N. Johnson ◽

Margaret Fadojutimi-Akinsiku ◽

Fitzroy Dawkins ◽

Victor Gordeuk

Keyword(s):

Primary Care ◽

African Americans ◽

Iron Overload ◽

Serum Ferritin ◽

Transferrin Saturation ◽

Elevated Serum ◽

Ferritin Concentration ◽

Serum Ferritin Concentration ◽

Primary Care Patients ◽

Hfe Mutations

Abstract Non-HFE primary iron overload exists in African Americans and other ethnic groups, but the prevalence and spectrum of clinical manifestations are not known. In the HEIRS (Hereditary Hemochromatosis and Iron Overload Screening) Study, participants were considered for further evaluation if the serum ferritin concentration was elevated and the transferrin saturation was more than 45% for women or 50% for men. We hypothesized that these screening criteria would miss a substantial number of African Americans and members of other ethnic groups with increased iron stores. In the process of screening 21,231 predominantly African-American and Hispanic primary care patients at the Howard University field center of the HEIRS Study, we identified 161 non-HFE-C282Y homozygotes ≥ 25 years of age with serum ferritin concentrations above the 97.5 percentile for the population (>700 ng/ml for men and >500 ng/ml for women) but transferrin saturations in the upper part of the normal range (35–50% for men and 30–45% for women). Of the 123 participants we were able to contact, 68 (55%) participated in a clinical evaluation, including 64 African Americans, three Hispanics and one Asian American with a mean ± SD age of 57 ± 13 years. Thirty-eight (56%) were females, 6 (9%) were HFE H63D heterozygotes and 2 (3%) were C282Y heterozygotes. Seven patients (10%) had normal serum ferritin concentration on repeat testing while 42 (62%) had potential reasons for elevated serum ferritin concentration other than a primary increase in body iron including (sequentially) multiple blood transfusions (>10 lifetime; n = 4), abnormal liver function tests (hepatitis C positive or AST >60 IU/L and AST>ALT; n = 17), hemoglobin < 10 g/dL men or 9 g/dL women (n = 1), elevated C-reactive protein with transferrin saturation not elevated (n = 17), and excessive alcohol use (n = 3). Nineteen patients did not have these explanations for increased serum ferritin concentration and were considered to have a possible primary iron-loading process (see Table). One of the patients with unexplained elevated serum ferritin concentration (an African American) had a diagnostic liver biopsy showing 2-3+ hepatocellular iron and heavy iron deposition in Kupffer cells and is on phlebotomy therapy; the others have been advised to have diagnostic liver biopsy or quantitative phlebotomy. We conclude that there are substantial numbers of African Americans with elevated serum ferritin concentration and normal transferrin saturation who have transfusional iron overload or a probable primary increase in body iron stores. Characteristics of 19 Patients with Unexplained Serum Ferritin Elevations No. (%) of Women 8 (42) Age inyears (mean ± SD) 63 ± 14 Race (African American:Hispanic:Asian) 16:2:1 Hemoglobin in g.dL (mean ± SD) Men 13.8 ±1.5 Hemoglobin in g.dL (mean ± SD) Women 12.9 ± 0.8 HFE mutations in no. (%) C282Y heterozygotes 0 (0) HFE mutations in no. (%) H63D heterozygotes 2 (11) Ferritin category in no. (%) < 500 ng/ml 7 (37) Ferritin category in no. (%) 500–1000 ng/ml 9(57) Ferritin category in no. (%) 1000 ng/ml> 3 (16)

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Subpopulations with Iron Deficiency, Liver Disease, or HFE Mutations Revealed by Statistical Mixture Modeling of Transferrin Saturation and Serum Ferritin Concentration in Asians, African Americans, Hispanics, and Whites.

Blood ◽

10.1182/blood.v110.11.2672.2672 ◽

2007 ◽

Vol 110 (11) ◽

pp. 2672-2672

Author(s):

Christine E. McLaren ◽

Victor R. Gordeuk ◽

Wen-Pin Chen ◽

James C. Barton ◽

Ronald T. Acton ◽

...

Keyword(s):

At Risk ◽

Liver Disease ◽

African Americans ◽

Iron Deficiency ◽

Serum Ferritin ◽

Transferrin Saturation ◽

Mixture Modeling ◽

Ferritin Concentration ◽

Serum Ferritin Concentration ◽

Hfe Mutations

Abstract In previous investigations, we modeled the distribution of transferrin saturation (TS) in Caucasians and demonstrated a strong association between HFE genotype and TS subpopulations. Extending this approach, we now have analyzed joint population distributions of TS and serum ferritin concentration (SF) measured in the multi-ethnic Hemochromatosis and Iron Overload Screening (HEIRS) Study and examined the association of these distributions with the presence of HFE C282Y and H63D mutations, self-reported liver disease, and iron deficiency (defined as SF <15 μg/L). Based on separate models for each race/ethnicity by gender, four components with successively increasing age-adjusted means for TS and SF were identified in data from 26,832 African Americans, 12,620 Asians, 12,264 Hispanics, and 43,254 Whites. Fig. 1 illustrates age-adjusted values from 16,662 White men. Superimposed 95% confidence ellipses reflect component probability densities and show separation of the 1st and 4th components that had the lowest and highest means for TS and SF, respectively. Table 1 presents the range of estimates from individual models and indicates that the 2nd (largest) component had TS means of 22–26% for women (29–30% for men) and SF means of 43–82 μg/L for women (165–242 μg/L for men). The 3rd and 4th components had progressively smaller proportions and higher mean values of TS and SF, while the 1st component in each model had mean TS <16% for women (<20% for men), and mean SF <28 μg/L for women (<47 μg/L for men). Compared to the 2nd component: adjusted odds of iron deficiency were significantly higher in the 1st component (15–48 for women, 61–3530 for men); adjusted odds of self-reported liver disease were significantly higher in the 3rd and 4th components for African-American women and all men; and adjusted odds of any HFE mutation were increased in the 3rd component (1.4–1.8 for women, 1.2–1.9 for men) and in the 4th component for Hispanic and White women (1.5, 5.2, respectively) and men (2.8, 4.7, respectively). Joint mixture modeling identifies one component with lower mean SF and TS at risk for iron deficiency and two components with higher mean SF and TS at risk for liver disorders and HFE mutations. This approach permits characterization of the aggregate effects of hereditary or acquired factors that influence these serum iron measures in populations, and complements and enhances genetic and phenotypic testing for assessment of disease characteristics. Table 1 Range of estimates from models.

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HFEMutations in Caucasian Participants of the Hemochromatosis and Iron Overload Screening Study with Serum Ferritin Level <1000 μg/L

Canadian Journal of Gastroenterology ◽

10.1155/2013/493170 ◽

2013 ◽

Vol 27 (7) ◽

pp. 390-392 ◽

Cited By ~ 12

Author(s):

Paul C Adams ◽

Christine E McLaren ◽

Mark Speechley ◽

Gordon D McLaren ◽

James C Barton ◽

...

Keyword(s):

Iron Overload ◽

Serum Ferritin ◽

Serum Ferritin Level ◽

Ferritin Level ◽

Transferrin Saturation ◽

Elevated Serum ◽

Population Based ◽

Ferritin Concentration ◽

Post Test ◽

Screening Study

BACKGROUND: Many patients referred for an elevated serum ferritin level <1000 μg/L are advised that they likely have iron overload and hemochromatosis.AIMS: To determine the prevalence ofHFEmutations in the hemochromatosis gene for 11 serum ferritin concentration intervals from 200 μg/L to 1000 μg/L in Caucasian participants in a primary care, population-based study.METHODS: The Hemochromatosis and Iron Overload Screening study screened 99,711 participants for serum ferritin levels, transferrin saturation and genetic testing for the C282Y and H63D mutations of theHFEgene. This analysis was confined to 17,160 male and 27,465 female Caucasian participants because theHFEC282Y mutation is rare in other races. Post-test likelihood was calculated for prediction of C282Y homozygosity from a ferritin interval. A subgroup analysis was performed in participants with both an elevated serum ferritin level and transferrin saturation.RESULTS: There were 3359 male and 2416 female participants with an elevated serum ferritin level (200 μg/L to 1000 μg/L for women, 300 μg/L to 1000 μg/L for men). There were 69 male (2.1%) and 87 female (3.6%) C282Y homozygotes, and the probability of being a homozygote increased as the ferritin level increased. Post-test likelihood values were 0.3% to 16% in men and 0.3% to 30.4% in women.CONCLUSIONS: Iron loadingHFEmutations are unlikely to be the most common cause of an elevated serum ferritin level in patients with mild hyperferritinemia. Patients should be advised that there are many causes of an elevated serum ferritin level including iron overload.

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Reference Centiles for Serum Ferritin and Percentage of Transferrin Saturation, with Application to Mutations of the HFE Gene

Clinical Chemistry ◽

10.1093/clinchem/47.10.1804 ◽

2001 ◽

Vol 47 (10) ◽

pp. 1804-1810 ◽

Cited By ~ 36

Author(s):

James A Koziol ◽

Ngoc J Ho ◽

Vincent J Felitti ◽

Ernest Beutler

Keyword(s):

Serum Ferritin ◽

Hereditary Hemochromatosis ◽

Transferrin Saturation ◽

Reference Population ◽

Hfe Gene ◽

Compound Heterozygous ◽

Wild Type ◽

C282y Mutation ◽

Compound Heterozygotes ◽

Healthy Females

Abstract Background: The gene that causes most cases of hereditary hemochromatosis is designated HFE. Individuals with mutations in the HFE gene may have increased serum iron, transferrin saturation, and ferritin concentrations relative to individuals with the wild-type genotype. Methods: We generated reference centiles for percentage of transferrin saturation and serum ferritin concentrations in normal (wild-type), healthy Caucasian adults. We then examined transferrin and ferritin concentrations relative to these centiles in 81 individuals homozygous for the major hemochromatosis mutation C282Y and 438 individuals with the compound heterozygous HFE genotype C282Y/H63D. Results: Serum ferritin concentrations, but not percentage of transferrin saturation, in normal, healthy women tended to increase sharply as they progressed through menopause. Transferrin and serum ferritin centiles for normal, healthy females were lower than the corresponding centiles in normal, healthy males. C282Y homozygotes had abnormally high transferrin saturation and serum ferritin values relative to the wild types. Compound heterozygotes appeared to be a mixture of individuals with unexceptional transferrin and ferritin values and those with abnormally large values similar to the homozygotes, with equal proportions of each. Conclusions: There are age- and sex-related differences in reference centiles for the percentage of transferrin saturation and serum ferritin concentrations in normal, healthy adults. Individuals homozygous for the C282Y mutation in the HFE gene have abnormal transferrin saturation and serum ferritin values relative to the reference population; penetrance with the compound heterozygotes, as reflected by abnormal transferrin and ferritin values, is less than with the homozygotes.

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