Screening for hemochromatosis by measuring ferritin levels: a more effective approach. Blood. 2008;111:3373-3376. [PMID: 18025154 DOI: 10.1182/blood-2007-07-102673]

Minimizing Contact Resistance and Flicker Noise in Micro Graphene Hall Sensors Using Persistent Carbene Modified Gold Electrodes

Scalable micro graphene Hall sensors (μGHSs) hold tremendous potential for highly sensitive and label-free biomagnetic sensing in physiological solutions. To enhance the performance of these devices, it is crucial to optimize frequency-dependent flicker noise to reduce the limit of detection (LOD), but it remains a great challenge due to the large contact resistance at the graphene-metal contact. Here we present a surface modification strategy employing persistent carbene on gold electrodes to reduce the contact resistivity by a factor of 25, greatly diminishing μGHS flicker noise by a factor of 1000 to 3.13 × 10-14 V2/Hz while simultaneously lowering the magnetic LOD SB1/2 to 1440 nT/Hz1/2 at 1 kHz under a 100 μA bias current. To the best of our knowledge, this represents the lowest SB1/2 reported for scalable μGHSs fabricated through wafer-scale photolithography. The reduction in contact noise is attributed to the π-π stacking interaction between the graphene and the benzene rings of persistent carbene, as well as the decrease in the work function of gold as confirmed by Kelvin Probe Force Microscopy. By incorporating a microcoil into the μGHS, we have demonstrated the real-time detection of superparamagnetic nanoparticles (SNPs), achieving a remarkable LOD of ∼528 μg/L. This advancement holds great potential for the label-free detection of magnetic biomarkers, e.g., ferritin, for the early diagnosis of diseases associated with iron overload, such as hereditary hemochromatosis (HHC).

Beyond the Usual Suspects: Hereditary Hemochromatosis and Transaminitis in Primary Care

An annual physical examination within a primary care setting, including evaluation of liver enzymes and abnormal serology, is incidental and often asymptomatic. Fatty liver is the most common etiology for transaminitis. Hepatobiliary imaging studies, viral hepatitis serology, evaluation of metabolic liver disease, and alcohol consumption history should be performed for transaminitis evaluation. In patients with prior history of excessive alcohol consumption, transaminitis is often assumed to be alcohol-related. It is prudent to evaluate other infectious and metabolic etiologies, which can change patient management. Iron studies, including ferritin and transferrin saturation, are performed to evaluate hereditary hemochromatosis (HH). We present the case of a 46-year-old patient who visited the clinic for a routine health checkup, during which elevated ferritin levels were detected. Subsequent diagnosis revealed hemochromatosis. The patient underwent phlebotomy, resulting in a reduction of ferritin levels.

Hematoxylin Nuclear Stain Reports Oxidative Stress via Near-Infrared Emission

Hematoxylin & eosin (H&E) is the gold standard histological stain used for medical diagnosis and has been used for over a century. Herein, we examined the near-infrared II (NIR-II) fluorescence of this stain. We observed significant NIR-II emission from the hematoxylin component of the H&E stain. We found that the emission intensity, using the common aluminum(III) hematoxylin mordant, could be modulated by the availability of endogenous iron(III), and this emission intensity increased at higher oxidative stress. Our mechanistic investigations found that hematoxylin emission reported the nuclear translocation of the iron via the protein ferritin. In human tumor tissue samples, oxidative stress biomarkers correlated with hematoxylin NIR-II emission intensity. Emission response of the stain was also observed in human Alzheimer's disease brain tissue regions affected by disease progression, suggesting that ferritin nuclear translocation is preserved in these regions as an oxidative stress response. These findings indicate that NIR-II emission from the H&E stain provides a new source of redox information in tissues with implications for biomedical research and clinical practice.

A Mystery of Joint Pain: Is It Rheumatoid Arthritis (RA) or Hereditary Hemochromatosis (HH)?

A 58-year-old lady with a previous diagnosis of rheumatoid arthritis (RA) was referred to Rheumatology to manage her joint pains. On evaluation, it was noted that the lady did not have any signs of synovial inflammation. The patient had a negative anti-cyclic citrullinated peptide (anti-CCP) (<0.5) and negative rheumatoid factor (RF) (<10) together with high ferritin (1,507 µg/L) which led to consideration of hereditary hemochromatosis (HH) rather than RA. She was then referred to Hematology for regular venesection which settled her symptoms. This case report highlights the importance of considering HH as a differential diagnosis in patients with chronic arthritis particularly if there are no clinical signs and negative tests for RA. More retrospective studies will be needed to quantify how many cases of hemochromatosis arthropathy have been mistakenly diagnosed as RA.

HFE Genotype, Ferritin Levels and Transferrin Saturation in Patients with Suspected Hereditary Hemochromatosis

HFE hemochromatosis is characterized by increased iron absorption and iron overload due to variants of the iron-regulating HFE gene. Overt disease is mainly associated with homozygosity for the C282Y variant, although the H63D variant in compound heterozygosity with C282Y (C282Y/H63D) contributes to disease manifestation. In this observational study, we describe the association between biochemical findings, age, gender and HFE genotype in patients referred from general practice to a tertiary care referral center for diagnostic workup based on suspected hemochromatosis due to persistent hyperferritinemia and HFE variants. C282Y and H63D homozygosity were, respectively, the most and least prevalent genotypes and we found a considerable variation in transferrin saturation and ferritin levels independent of HFE genotype, which may indeed represent a diagnostic challenge in general practice. While our results confirm C282Y homozygosity as the major cause of iron accumulation, non-C282Y homozygotes also displayed mild to moderate hyperferritinemia with median ferritin levels at 500-700 µg/L, well above the reference cut-off. Such findings have traditionally been ignored in the clinic, and initiation of iron depletion has largely been restricted to C282Y homozygotes. Nevertheless, superfluous iron can aggravate pathogenesis in combination with other diseases and risk factors, such as inflammation, cancer and hepatopathy, and this possibility should not be neglected by clinicians.

Tumor interferon signaling and suppressive myeloid cells are associated with CAR T-cell failure in large B-cell lymphoma

Axicabtagene ciloleucel (axi-cel) is a chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory large B-cell lymphoma (LBCL). This study evaluated whether immune dysregulation, present before CAR T-cell therapy, was associated with treatment failure. Tumor expression of interferon (IFN) signaling, high blood levels of monocytic myeloid-derived suppressor cells (M-MDSCs), and high blood interleukin-6 and ferritin levels were each associated with a lack of durable response. Similar to other cancers, we found that in LBCL tumors, IFN signaling is associated with the expression of multiple checkpoint ligands, including programmed cell death-ligand 1, and these were higher in patients who lacked durable responses to CAR-T therapy. Moreover, tumor IFN signaling and blood M-MDSCs associated with decreased axi-cel expansion. Finally, patients with high tumor burden had higher immune dysregulation with increased serum inflammatory markers and tumor IFN signaling. These data support that immune dysregulation in LBCL promotes axi-cel resistance via multiple mechanistic programs: insufficient axi-cel expansion associated with both circulating M-MDSC and tumor IFN signaling, which also gives rise to expression of immune checkpoint ligands.

Hyperferritinemia-A Clinical Overview

Ferritin is one of the most frequently requested laboratory tests in primary and secondary care, and levels often deviate from reference ranges. Serving as an indirect marker for total body iron stores, low ferritin is highly specific for iron deficiency. Hyperferritinemia is, however, a non-specific finding, which is frequently overlooked in general practice. In routine medical practice, only 10% of cases are related to an iron overload, whilst the rest is seen as a result of acute phase reactions and reactive increases in ferritin due to underlying conditions. Differentiation of the presence or absence of an associated iron overload upon hyperferritinemia is essential, although often proves to be complex. In this review, we have performed a review of a selection of the literature based on the authors’ own experiences and assessments in accordance with international recommendations and guidelines. We address the biology, etiology, and epidemiology of hyperferritinemia. Finally, an algorithm for the diagnostic workup and management of hyperferritinemia is proposed, and general principles regarding the treatment of iron overload are discussed.

A Minimal Parameter Set Facilitating Early Decision-making in the Diagnosis of Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune dysregulation syndrome characterized by uncontrolled immune cell activation. Timely diagnosis is important, since early treatment can improve survival rates. However, completing all assessments needed to reach ≥5 positive criteria out of the 8 HLH-2004 criteria can be time consuming and may delay timely initiation of treatment. Hence, we applied a data-driven approach to identify a minimal parameter set for early decision-making towards the initiation of HLH-specific treatment. We retrospectively evaluated 165 patients from five Dutch tertiary hospitals with suspected HLH. Sixteen pHLH (median age 0.5 years) and 70 sHLH patients (median age 8.7 years) were identified using the HLH-2004 criteria. Clustering analysis and multi-receiver operator characteristics were used to identify parameters distinctive of HLH. The presence of either increased ferritin, cytopenia in ≥2 lineages, or splenomegaly distinguished HLH from non-HLH cases with a negative predictive value of 100%. A minimal parameter set consisting of 2 major criteria (phagocytosis and splenomegaly) and 3 minor criteria (cytopenia, increased ferritin, and increased triglycerides/low fibrinogen) predicted HLH with 95% (88-99) sensitivity and 94% (86-98) specificity. This finding was replicated in an independent retrospective validation cohort of 109 US patients (n = 109). By dividing a subset of the HLH-2004 criteria into major and minor criteria, this strategy uses the evaluation of less than 5 criteria to quickly identify patients with HLH. When confirmed in a prospective setting, this approach could be of value for timely diagnosis and treatment of HLH.

Roxadustat for treatment of erythropoietin-hyporesponsive anemia in a hemodialysis patient: A case report

BACKGROUND

Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is a prevalent problem in patients with chronic kidney disease. It is associated with increased morbidity and mortality in patients who undergo dialysis. A significant proportion of patients do not respond to iron supplementation and conventional ESAs. We report a case of severe ESA hyporesponsiveness-related anemia that was successfully treated with oral roxadustat.

CASE SUMMARY

A 59-year-old Chinese woman had high blood glucose for 25 years, maintenance hemodialysis for 7 years, and recurrent dizziness and fatigue for more than 2 years. Laboratory tests showed severe anemia (hemoglobin level of 54 g/L), though bone marrow biopsy, fluorescence in situ hybridization, and hemolysis tests were within normal ranges. We initially administered first-line therapies and other adjuvant treatments, such as blood transfusions, ESAs, and adequate dialysis, but the patient did not respond as anticipated. Her erythropoietin-resistant anemia was probably not only due to chronic renal insufficiency. The patient received the hypoxia-inducible factor prolyl hydroxylase inhibitor roxadustat (100 mg, three times weekly). After 12 wk of treatment, the patient’s hemoglobin increased significantly, and her symptoms were alleviated. During the follow-up period, adverse drug reactions were controllable and tolerable.

CONCLUSION

Oral roxadustat is effective and tolerable for the treatment of ESA hypores-ponsiveness-related anemia in patients undergoing hemodialysis.

Use of C-Reactive Protein and Ferritin Biomarkers in Daily Pediatric Practice

Recent pediatric clinical research has begun to focus on risk stratification tools using multibiomarker models. C-reactive protein (CRP) and ferriti biomarkers are widely available and used to varying degrees in daily practice, but there is no single source examining the evidence behind their use.We set out to summarize the evidence behind the use of CRP and ferritin biomarkers in pediatric practice and to begin development of a consensus for their future use for pediatricians.All the literature involving CRP and ferritin in pediatrics available on PubMed was surveyed. Research applicable to daily pediatric practice was summarized in the body of the article. Pediatric clinicians of various subspecialties contributed to the summary of the use of CRP and ferritin biomarkers in clinical practice in various disease processes. A clinical decision pathway is described, and evidence is summarized.CRP and ferritin biomarkers have diverse uses with various cutoff values in the literature, making their use in daily practice difficult. Elevation of these markers coincides with their significant elevation in uncontrolled inflammation.CRP and ferritin biomarkers are widely used in pediatrics. This review provides a resource summarizing evidence into a single source. There is sufficient evidence to indicate that these biomarkers of inflammation can be useful in guiding clinical decision making in specific clinical scenarios; however, further work is needed to improve their use in clinical practice.

Diagnosis and management of hereditary haemochromatosis

Hereditary haemochromatosis, one of the most common genetic disorders in the United States, can produce systemic iron deposition leading to end-organ failure and death if untreated. The diagnosis of this condition can be challenging as elevated serum ferritin may be seen in a variety of conditions, including acute and chronic liver disease, a range of systemic inflammatory states, and both primary and secondary iron overload syndromes. Appropriate and timely diagnosis of haemochromatosis is paramount as simple interventions, such as phlebotomy, can prevent or reverse organ damage from iron overload. The recognition of other aetiologies of elevated ferritin is also vital to ensure that appropriate intervention is provided and phlebotomy only utilized in patients who require it. In this review, we summarize the existing data on the work up and management of hereditary haemochromatosis and present a practical algorithm for the diagnosis and management of this disease.

Increased Ferritin Concentration and Risk of Atrial Fibrillation and Heart Failure in Men and Women: Three Studies of the Danish General Population Including 35799 Individuals

BACKGROUND

Moderately increased plasma ferritin, as a biomarker of iron overload, has been associated with higher rates of cardiovascular death and heart failure. However, the association of moderately increased plasma ferritin with risk of atrial fibrillation in the general population is unknown.

METHODS

We examined the association of plasma ferritin concentrations with risk of atrial fibrillation and heart failure in metaanalyses of 35799 men and women from 3 studies of the Danish general population: the Copenhagen City Heart Study, the Danish General Suburban Population Study, and the Copenhagen General Population Study.

RESULTS

Multivariable adjusted fixed effects odds ratios for atrial fibrillation were 1.23 (95% CI, 1.05-1.44; P = 0.005) in men for ferritin concentration ≥300 μg/L vs <300 μg/L, 1.13 (95% CI, 0.93-1.38; P = 0.22) in women for ≥200 μg/L vs <200 μg/L, and 1.19 (95% CI, 1.06-1.35; P = 0.005) in both sexes combined (P _{sex interaction} = 0.52). Corresponding fixed effects odds ratios for heart failure were 1.16 (95% CI, 0.98-1.37; P = 0.08) in men, 0.86 (95% CI, 0.67-1.10; P = 0.23) in women, and 1.05 (95% CI, 0.91-1.21; P = 0.45) in both sexes combined (P _{sex interaction} = 0.05). Multivariable adjusted fixed effects odds ratio for atrial fibrillation per step increase in ferritin concentrations was 1.13 (95% CI, 1.06-1.21; P _trend = 0.0005) in both sexes combined (P _{sex interaction} = 0.59); the corresponding value for heart failure was 1.03 (95% CI, 0.95-1.11; P _trend = 0.47) (P _{sex interaction} = 0.08). In sensitivity analyses, there was no evidence of U-shaped relationships between plasma ferritin concentrations and risk of atrial fibrillation or heart failure in men or women.

CONCLUSIONS

Increased ferritin concentration is associated with increased risk of atrial fibrillation in the general population.

Low hepcidin in liver fibrosis and cirrhosis; a tale of progressive disorder and a case for a new biochemical marker

Liver fibrosis is a precursor of liver cirrhosis, which is associated with increased mortality. Though liver biopsy remains the gold standard for the diagnosis of fibrosis, noninvasive biochemical methods are cost-effective, practical and are not linked with major risks of complications. In this respect, serum hepcidin, has emerged as a new marker of fibrosis and cirrhosis. In this review the discussion uncovers molecular links between hepcidin disturbance and liver fibrosis/cirrhosis. The discussion also expands on clinical studies that suggest that hepcidin can potentially be used as a biochemical parameter of fibrosis/cirrhosis and target of therapeutic strategies to treat liver diseases. The debatable issues such as the complicated nature of hepcidin disturbance in non-alcoholic liver disease, serum levels of hepcidin in acute hepatitis C virus infection, cause of hepcidin disturbance in autoimmune hepatitis and hepatic insulin resistance are discussed, with potential solutions unveiled in order to be studied by future research.

Causes of iron overload in blood donors - a clinical study

BACKGROUND AND OBJECTIVES

Despite the obligate iron loss from blood donation, some donors present with hyperferritinaemia that can result from a wide range of acute and chronic conditions including hereditary haemochromatosis (HH). The objective of our study was to investigate the causes of hyperferritinaemia in the blood donor population and explore the value of extensive HH mutational analyses.

MATERIALS AND METHODS

Forty-nine consecutive donors (f = 6, m = 43) were included prospectively from the Capital Regional Blood Center. Inclusion criteria were a single ferritin value >1000 μg/l or repeated hyperferritinaemia with at least one value >500 μg/l. All donors were questioned about their medical history and underwent a physical examination, biochemical investigations and next-generation sequencing of HH-related genes, including the HFE gene, the haemojuvelin gene (HFE2/HJV), the hepcidin gene (HAMP), the ferroportin 1 gene (SLC40A1) and the transferrin receptor 2 gene (TFR2).

RESULTS

Forty of 49 donors were mutation positive with a combined 69 mutations, 54 of which were located in the HFE gene. There were 11 mutations in the TFR2 gene, two mutations in the HFE2 gene and two mutations in the HAMP gene. Only four donors had apparent alternative causes of hyperferritinaemia.

CONCLUSION

HH-related mutations were the most frequent cause of hyperferritinaemia in a Danish blood donor population, and it appears that several different HH-genotypes can contribute to hyperferritinaemia. HH screening in blood donors with high ferritin levels could be warranted. HH-related iron overload should not in itself result in donor ineligibility.

High Neonatal Blood Iron Content Is Associated with the Risk of Childhood Type 1 Diabetes Mellitus

(1) Background: Iron requirement increases during pregnancy and iron supplementation is therefore recommended in many countries. However, excessive iron intake may lead to destruction of pancreatic β-cells. Therefore, we aim to test if higher neonatal iron content in blood is associated with the risk of developing type 1 diabetes mellitus (T1D) in childhood; (2) Methods: A case-control study was conducted, including 199 children diagnosed with T1D before the age of 16 years from 1991 to 2005 and 199 controls matched on date of birth. Information on confounders was available in 181 cases and 154 controls. Iron was measured on a neonatal single dried blood spot sample and was analyzed by laser ablation inductively coupled plasma mass spectrometry. Multivariate logistic regression was used to evaluate if iron content in whole blood was associated with the risk of T1D; (3) Results: A doubling of iron content increased the odds of developing T1D more than two-fold (odds ratio (95% CI), 2.55 (1.04; 6.24)). Iron content increased with maternal age (p = 0.04) and girls had higher content than boys (p = 0.01); (4) Conclusions: Higher neonatal iron content associates to an increased risk of developing T1D before the age of 16 years. Iron supplementation during early childhood needs further investigation, including the causes of high iron in neonates.

Increased Plasma Ferritin Concentration and Low-Grade Inflammation-A Mendelian Randomization Study

BACKGROUND

It is unknown why increased plasma ferritin concentration predicts all-cause mortality. As low-grade inflammation and increased plasma ferritin concentration are associated with all-cause mortality, we hypothesized that increased plasma ferritin concentration is genetically associated with low-grade inflammation.

METHODS

We investigated whether increased plasma ferritin concentration is associated with low-grade inflammation [i.e., increased concentrations of C-reactive protein (CRP) and complement component 3 (C3)] in 62537 individuals from the Danish general population. We also applied a Mendelian randomization approach, using the hemochromatosis genotype C282Y/C282Y as an instrument for increased plasma ferritin concentration, to assess causality.

RESULTS

For a doubling in plasma ferritin concentration, the odds ratio (95% CI) for CRP ≥2 vs <2 mg/L was 1.12 (1.09-1.16), with a corresponding genetic estimate for C282Y/C282Y of 1.03 (1.01-1.06). For a doubling in plasma ferritin concentration, odds ratio (95% CI) for complement C3 >1.04 vs ≤1.04 g/L was 1.28 (1.21-1.35), and the corresponding genetic estimate for C282Y/C282Y was 1.06 (1.03-1.12). Mediation analyses showed that 74% (95% CI, 24-123) of the association of C282Y/C282Y with risk of increased CRP and 56% (17%-96%) of the association of C282Y/C282Y with risk of increased complement C3 were mediated through plasma ferritin concentration.

CONCLUSIONS

Increased plasma ferritin concentration as a marker of increased iron concentration is associated observationally and genetically with low-grade inflammation, possibly indicating a causal relationship from increased ferritin to inflammation. However, as HFE may also play an immunological role indicating pleiotropy and as incomplete penetrance of C282Y/C282Y indicates buffering mechanisms, these weaknesses in the study design could bias the genetic estimates.

Conditions associated with extreme hyperferritinaemia (>3000 μg/L) in adults

BACKGROUND

The clinical significance of extreme hyperferritinaemia has come under scrutiny with the increasing recognition of haemophagocytic lymphohistiocytosis (HLH) in adults. Most studies of hyperferritinaemia have focused on serum ferritin greater than 1000 μg/L, often in ambulatory patients. The conditions associated with more extreme hyperferritinaemia are poorly understood.

AIMS

To examine conditions associated with extreme hyperferritinaemia greater than 3000 μg/L in acutely ill adults at a quaternary care hospital.

METHODS

Patients with serum ferritin greater than 3000 μg/L at Vancouver General Hospital between 1 August 2011 and 1 August 2012 were identified. Those over 18 years of age and with clinical data available were included in the study.

RESULTS

Eighty-three subjects were identified. Twenty-one cases (25%) were due to transfusional iron overload, 16 (19%) due to liver disease and 15 (18%) due to mixed factors. Haemophagocytic lymphohistiocytosis (HLH) was diagnosed in six of 83 patients (7%) with ferritin greater than 3000 μg/L, but six of eight patients (75%) with ferritin greater than 20 000 μg/L.

CONCLUSIONS

Extreme hyperferritinaemia greater than 3000 μg/L is uncommon in adult patients. The highest serum ferritin values are seen in HLH, but the differential diagnosis for serum ferritin greater than 3000 μg/L remains broad with iron overload and liver disease being the most common causes.

Diagnosis of Disorders of Iron Metabolism in Dogs and Cats

Iron is an essential element and is used by every cell in the body. This article summarizes iron metabolism and disorders associated with iron metabolism in dogs and cats. The diagnostic tests currently in use for assessing iron status are discussed.

EMQN best practice guidelines for the molecular genetic diagnosis of hereditary hemochromatosis (HH)

Molecular genetic testing for hereditary hemochromatosis (HH) is recognized as a reference test to confirm the diagnosis of suspected HH or to predict its risk. The vast majority (typically >90%) of patients with clinically characterized HH are homozygous for the p.C282Y variant in the HFE gene, referred to as HFE-related HH. Since 1996, HFE genotyping was implemented in diagnostic algorithms for suspected HH, allowing its early diagnosis and prevention. However, the penetrance of disease in p.C282Y homozygotes is incomplete. Hence, homozygosity for p.C282Y is not sufficient to diagnose HH. Neither is p.C282Y homozygosity required for diagnosis as other rare forms of HH exist, generally referred to as non-HFE-related HH. These pose significant challenges when defining criteria for referral, testing protocols, interpretation of test results and reporting practices. We present best practice guidelines for the molecular genetic diagnosis of HH where recommendations are classified, as far as possible, according to the level and strength of evidence. For clarification, the guidelines' recommendations are preceded by a detailed description of the methodology and results obtained with a series of actions taken in order to achieve a wide expert consensus, namely: (i) a survey on the current practices followed by laboratories offering molecular diagnosis of HH; (ii) a systematic literature search focused on some identified controversial topics; (iii) an expert Best Practice Workshop convened to achieve consensus on the practical recommendations included in the guidelines.

Examining the clinical use of hemochromatosis genetic testing

BACKGROUND

Hereditary hemochromatosis leads to an increased lifetime risk for end-organ damage due to excess iron deposition. Guidelines recommend that genetic testing be performed in patients with clinical suspicion of iron overload accompanied by elevated serum ferritin and transferrin saturation levels.

OBJECTIVE

To evaluate guideline adherence and the clinical and economic impact of HFE genetic testing.

METHODS

The electronic charts of patients submitted for HFE testing in 2012 were reviewed for genetic testing results, biochemical markers of iron overload and clinical history of phlebotomy.

RESULTS

A total of 664 samples were sent for testing, with clinical, biochemical and phlebotomy data available for 160 patients. A positive C282Y homozygote or C282Y⁄H63D compound heterozygote test result was observed in 18% of patients. Patients with an at-risk HFE genotype had significantly higher iron saturation, serum iron and hemoglobin (P<0.001), without higher ferritin or liver enzyme levels. Fifty percent of patients referred for testing did not have biochemical evidence of iron overload (transferrin saturation >45% and ferritin level >300 μg⁄L). Patients were four times more likely to undergo phlebotomy if they were gene test positive (RR 4.29 [95% CI 2.35 to 7.83]; P<0.00001).

DISCUSSION

One-half of patients referred for testing did not exhibit biochemical evidence of iron overload. Many patients with biochemical evidence of iron overload, but with negative genetic test results, did not undergo phlebotomy. A requisition to determine clinical indication for testing may reduce the use of the HFE genetic test. Finally, improvement of current genetic test characteristics would improve rationale for the test.

CONCLUSION

A significant proportion of hemochromatosis genetic testing does not adhere to current guidelines and would not alter patient management.

Improved detection of hereditary haemochromatosis

AIMS

There is high prevalence of hereditary haemochromatosis (HH) in North European populations, yet the diagnosis is often delayed or missed in primary care. Primary care physicians frequently request serum ferritin (SF) estimation but appear uncertain as how to investigate patients with raised SF values. Our aim was to develop a laboratory algorithm with high predictive value for the diagnosis of HH in patients from primary care with raised SF values.

METHODS

Transferrin saturation (Tsat) was measured on SF samples sent from primary care; 1657 male and 2077 female patients age ≥ 30 years with SF ≥ 200 μg/L. HFE genotyping was performed on all 878 male and 867 female patients with Tsat >30%.

RESULTS

This study identified 402 (206 men; 196 women) C282Y carriers and 132 (58 men; 74 women) C282Y homozygotes. Optimal limits for combined SF and Tsat values for HH recognition were established. The detection rate for homozygous C282Y HH for male patients with both SF ≥ 300 μg/L and Tsat >50% was 18.8% (52/272) and 16.3% (68/415) for female patients with both SF ≥ 200 μg/L and Tsat >40%.

CONCLUSIONS

The large number of SF requests received from primary care should be used as a resource to improve the diagnosis of HH in areas of high prevalence.

Diagnostic morphology: biophysical indicators for iron-driven inflammatory diseases

Most non-communicable diseases involve inflammatory changes in one or more vascular systems, and there is considerable evidence that unliganded iron plays major roles in this. Most studies concentrate on biochemical changes, but there are important biophysical correlates. Here we summarize recent microscopy-based observations to the effect that iron can have major effects on erythrocyte morphology, on erythrocyte deformability and on both fibrinogen polymerization and the consequent structure of the fibrin clots formed, each of which contributes significantly and negatively to such diseases. We highlight in particular type 2 diabetes mellitus, ischemic thrombotic stroke, systemic lupus erythematosus, hereditary hemochromatosis and Alzheimer's disease, while recognizing that many other diseases have co-morbidities (and similar causes). Inflammatory biomarkers such as ferritin and fibrinogen are themselves inflammatory, creating a positive feedback that exacerbates disease progression. The biophysical correlates we describe may provide novel, inexpensive and useful biomarkers of the therapeutic benefits of successful treatments.

Total and cause-specific mortality by moderately and markedly increased ferritin concentrations: general population study and metaanalysis

BACKGROUND

Previous population-based studies of plasma ferritin concentration have not revealed a relationship with total mortality. We tested the possible association of increased ferritin concentrations with increased risk of total and cause-specific mortality in the general population.

METHODS

We examined total and cause-specific mortality according to baseline plasma ferritin concentrations in a Danish population-based study (the Copenhagen City Heart Study) of 8988 individuals, 6364 of whom died (median follow-up 23 years). We also included a metaanalysis of total mortality comprising population-based studies according to ferritin quartiles or tertiles.

RESULTS

Multifactorially adjusted hazard ratios (HRs) for total mortality for individuals with ferritin ≥200 vs <200 μg/L were 1.1 (95% CI 1.1-1.2; P = 0.0008) overall, 1.1 (1.0-1.2; P = 0.02) in men, and 1.2 (1.0-1.3; P = 0.03) in women. Stepwise increasing concentrations of ferritin were associated with a stepwise increased risk of premature death overall (log rank, P = 2 × 10(-22)), with median survival of 55 years at ferritin concentrations ≥600 μg/L, 72 years at 400-599 μg/L, 76 years at 200-399 μg/L, and 79 years at ferritin <200 μg/L. The corresponding HR for total overall mortality for ferritin ≥600 vs <200 μg/L was 1.5 (1.2-1.8; P = 0.00008). Corresponding adjusted HRs for ferritin ≥600 vs <200 μg/L were 1.6 (1.1-2.3; P = 0.01) for cancer mortality, 2.9 (1.7-5.0; P = 0.0001) for endocrinological mortality, and 1.5 (1.1-2.0; P = 0.01) for cardiovascular mortality. The metaanalysis random effects odds ratio for total mortality for ferritin upper vs reference quartile or tertile was 1.0 (0.9-1.1; P = 0.3) (P heterogeneity = 0.5).

CONCLUSIONS

Moderately to markedly increased ferritin concentrations represent a biological biomarker predictive of early death in a dose-dependent linear manner in the general population.

Serum ferritin level is higher in poorly controlled patients with type 2 diabetes and people without diabetes, aged over 55 years

AIMS

Diabetes mellitus has been increasing in Mongolia. There is also growing concern about the relationship between iron stores and the severity of type 2 diabetes. In this study, we aimed to evaluate serum ferritin level among Mongolian individuals with and without diabetes.

METHODS

Of 254 participants, a total of 99 previously diagnosed patients with type 2 diabetes and the same numbers of subjects without diabetes were enrolled and invited to a physical examination (BMI, central obesity, blood pressure) and fasting blood tests (fasting blood glucose, HbA1c , serum ferritin, C-reactive protein, aspartate aminotransferase, alanine transferase).

RESULTS

Serum ferritin was higher in the patients with type 2 diabetes compared with the control group without diabetes, with a significant difference in the female groups (341.6 ± 67.2 and 159.1 ± 36.8 ng/ml respectively, P = 0.019). Of the patients with type 2 diabetes, 43.4% had hyperferritinaemia, and 21.2% of the individuals without diabetes had hyperferritinaemia. In the group with type 2 diabetes, serum ferritin level was significantly higher in the group of women whose HbA1c was ≥ 53 mmol/mol (7.0%) compared with the other group of women whose HbA1c was < 53 mmol/mol (7.0%) (562.1 ± 122.1 and 220.5 ± 78.7 ng/ml respectively, P = 0.025). We also found that the subjects without diabetes, aged over 55 years, are at risk of increased serum ferritin.

CONCLUSION

Poorly controlled patients with type 2 diabetes and people without diabetes of over 55 years of age are likely to be at a higher risk of developing hyperferritinaemia. Thus, regular assessments of serum ferritin might be important for those who are at risk of hyperferritnaemia for prevention and an early intervention.

HFE mutations in Caucasian participants of the Hemochromatosis and Iron Overload Screening study with serum ferritin level <1000 µg/L

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 of HFE mutations 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 the HFE gene. This analysis was confined to 17,160 male and 27,465 female Caucasian participants because the HFE C282Y 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 loading HFE mutations 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.

Total and cause-specific mortality by elevated transferrin saturation and hemochromatosis genotype in individuals with diabetes: two general population studies

OBJECTIVE

Mortality is increased in patients with hereditary hemochromatosis, in individuals from the general population with increased transferrin saturation (TS), and also in patients with type 1 diabetes and increased TS from a highly specialized diabetes clinic. Thus, we have recommended targeted screening for TS in specialized diabetes clinics. Whether mortality is also increased in individuals from the general population with diabetes and increased TS is unknown.

RESEARCH DESIGN AND METHODS

In two Danish population studies (N = 84,865), we examined mortality according to baseline levels of TS and hemochromatosis genotype (HFE) G → A substitution at nucleotide 845 in codon 282 (C282Y/C282Y) in individuals with diabetes (type 1, N = 118; type 2, N = 3,228; total, N = 3,346).

RESULTS

The cumulative survival rate was reduced in individuals with diabetes with TS ≥50% vs. <50% (log-rank; P < 0.0001), with median survival ages of 66 and 79 years, respectively. The hazard ratio (HR) for TS ≥50% vs. <50% was 2.0 (95% CI 1.3-2.8; P = 0.0004) for total mortality overall (and similar for men and women separately); 2.6 (1.3-5.4; P = 0.008) for neoplasms; and 3.4 (2.0-6.0; P = 0.00002) for endocrinological causes. A stepwise increased risk of total mortality was observed for stepwise increasing TS (log-rank test, P = 0.0001), with an HR for TS ≥70% vs. TS <20% of 4.8 (2.0-12; P = 0.0006). The HR for total mortality in individuals with diabetes for C282Y/C282Y versus wild type/wild type was 3.3 (1.04-10; P = 0.04), and for C282Y/C282Y and TS ≥50% versus wild type/wild type and TS <50% was 6.0 (1.5-24; P = 0.01). Six percent of these premature deaths can possibly be avoided by early screening for TS or HFE genotype.

CONCLUSIONS

Individuals with diabetes, ascertained in the general population, with increased TS or HFE genotype have a twofold to sixfold increased risk of premature death.

Profound morphological changes in the erythrocytes and fibrin networks of patients with hemochromatosis or with hyperferritinemia, and their normalization by iron chelators and other agents

It is well-known that individuals with increased iron levels are more prone to thrombotic diseases, mainly due to the presence of unliganded iron, and thereby the increased production of hydroxyl radicals. It is also known that erythrocytes (RBCs) may play an important role during thrombotic events. Therefore the purpose of the current study was to assess whether RBCs had an altered morphology in individuals with hereditary hemochromatosis (HH), as well as some who displayed hyperferritinemia (HF). Using scanning electron microscopy, we also assessed means by which the RBC and fibrin morphology might be normalized. An important objective was to test the hypothesis that the altered RBC morphology was due to the presence of excess unliganded iron by removing it through chelation. Very striking differences were observed, in that the erythrocytes from HH and HF individuals were distorted and had a much greater axial ratio compared to that accompanying the discoid appearance seen in the normal samples. The response to thrombin, and the appearance of a platelet-rich plasma smear, were also markedly different. These differences could largely be reversed by the iron chelator desferal and to some degree by the iron chelator clioquinol, or by the free radical trapping agents salicylate or selenite (that may themselves also be iron chelators). These findings are consistent with the view that the aberrant morphology of the HH and HF erythrocytes is caused, at least in part, by unliganded (‘free’) iron, whether derived directly via raised ferritin levels or otherwise, and that lowering it or affecting the consequences of its action may be of therapeutic benefit. The findings also bear on the question of the extent to which accepting blood donations from HH individuals may be desirable or otherwise.

Iron status and survival in diabetic patients with coronary artery disease

OBJECTIVE

To investigate the impact of iron status on survival in patients with type 2 diabetes and coronary artery disease (CAD).

RESEARCH DESIGN AND METHODS

Serum ferritin, transferrin saturation (Tsat), and soluble transferrin receptor (sTfR) were measured in 287 patients with type 2 diabetes and stable CAD (65 ± 9 years of age, 78% men).

RESULTS

During a mean follow-up of 45 ± 19 months, there were 59 (21%) deaths and 60 (21%) cardiovascular hospitalizations. Both serum ferritin and sTfR strongly predicted 5-year all-cause mortality rates, independently of other variables (including hemoglobin, measures of renal function, inflammation, and neurohormonal activation). There was an exponential relationship between sTfR and mortality (adjusted hazard ratio [HR] per 1 log mg/L: 4.24 [95% CI 1.43-12.58], P = 0.01), whereas the relationship between ferritin and mortality was U-shaped (for the lowest and the highest quintiles vs. the middle quintile [reference group], respectively: adjusted HR 7.18 [95% CI 2.03-25.46], P = 0.002, and adjusted HR 5.12 [1.48-17.73], P = 0.01). Similar patterns were observed for the composite outcome of all-cause mortality or cardiovascular hospitalization, and in these multivariable models, low Tsat was related to unfavorable outcome.

CONCLUSIONS

Both low and high serum ferritin (possibly reflecting depleted and excessive iron stores, respectively) along with high serum sTfR (reflecting reduced metabolically available iron) identify patients with type 2 diabetes and CAD who have a poor prognosis.

Diagnosis of disorders of iron metabolism in dogs and cats

Iron is an essential element and is used by every cell in the body. This article summarizes iron metabolism and disorders associated with iron metabolism in dogs and cats. The diagnostic tests currently in use for assessing iron status are discussed.

Increased risk of death from iron overload among 422 treated probands with HFE hemochromatosis and serum levels of ferritin greater than 1000 μg/L at diagnosis

BACKGROUND & AIMS

We investigated the risk of death from iron overload among treated hemochromatosis probands who were homozygous for HFE C282Y and had serum levels of ferritin greater than 1000 μg/L at diagnosis.

METHODS

We compared serum levels of ferritin at diagnosis and other conditions with the rate of iron overload-associated death using data from 2 cohorts of probands with hemochromatosis who were homozygous for HFE C282Y (an Alabama cohort, n = 294, 63.9% men and an Ontario cohort, n = 128, 68.8% men). We defined iron overload-associated causes of death as cirrhosis (including hepatic failure and primary liver cancer) caused by iron deposition and cardiomyopathy caused by myocardial siderosis. All probands received phlebotomy and other appropriate therapy.

RESULTS

The mean survival times after diagnosis were 13.2 ± 7.3 y and 12.5 ± 8.3 y in Alabama and Ontario probands, respectively. Serum levels of ferritin greater than 1000 μg/L at diagnosis were observed in 30.1% and 47.7% of Alabama and Ontario probands, respectively. In logistic regressions of serum ferritin greater than 1000 μg/L, there were significant positive associations with male sex and cirrhosis in Alabama probands and with age, male sex, increased levels of alanine and aspartate aminotransferases, and cirrhosis in Ontario probands. Of probands with serum levels of ferritin greater than 1000 μg/L at diagnosis, 17.9% of those from Alabama and 14.8% of those from Ontario died of iron overload. Among probands with serum levels of ferritin greater than 1000 μg/L, the relative risk of iron overload-associated death was 5.4 for the Alabama group (95% confidence interval [CI], 2.2-13.1; P = .0002) and 4.9 for the Ontario group (95% CI, 1.1-22.0; P = .0359).

CONCLUSIONS

In hemochromatosis probands homozygous for HFE C282Y, serum levels of ferritin greater than 1000 μg/L at diagnosis were positively associated with male sex and cirrhosis. Even with treatment, the relative risk of death from iron overload was 5-fold greater in probands with serum levels of ferritin greater than 1000 μg/L.

IRon Overload screeNing tool (IRON): development of a tool to guide screening in primary care

Iron overload is associated with significant morbidity and mortality yet is easily treated. The objective of this study was to create a tool that could be easily adapted to clinical practice that indicates the likelihood of a patient having undetected iron overload. We used the National Health and Nutrition Examination Survey (NHANES) 1999-2002 for US adults aged 20 years and older to build a model (unweighted n=8,779). We chose potential variables for inclusion that could be gathered by self-report or measured without laboratory data and were suggested by past literature on hemochromatosis and iron overload. We computed logistic regressions to create the scores by initially evaluating the variables' relationship with elevated ferritin and elevated transferrin saturation and then using odds ratios to correspond to scores. The resulting score on the IRon Overload ScreeNing Tool (IRON) was then validated with data on 13,844 adults in the NHANES III, 1988-94. Predictors in the final tool were age, gender, previous diagnoses of liver condition, osteoporosis or thyroid disease. The IRON score yielded an area under the curve (AUC) in the NHANES 1999-02 of 0.720 and an AUC of 0.685 in the NHANES III validation sample. The IRON score is a tool to assist in identification of patients with iron overload that has several qualities that make it attractive for use in clinical practice with an undifferentiated patient population including brevity, easily collected information and predictive ability comparable to other tools that help in directing screening.

Health check-ups and family screening allow detection of hereditary hemochromatosis with less advanced liver fibrosis and survival comparable with the general population

OBJECTIVE

The information concerning the morbidity and mortality of hereditary hemochromatosis is based primarily on clinical cohorts of symptomatic patients. The major aim of this study was to analyze the long-term prognosis for Swedish patients with this condition, with respect to both clinical features and survival, in relation to the route by which the disease was detected.

PATIENTS AND METHODS

373 patients with hemochromatosis detected through routine health check-ups (n = 153), family screening (n = 44), symptoms of arthralgia (n = 23), investigation of other diseases/symptoms (n = 108) or signs of liver disease (n = 45) were monitored for a mean period of 11.9 ± 5.8 years. The degree of liver fibrosis and survival were analyzed.

RESULTS

Overall survival among these patients was not significantly different from that of a matched normal population. The patients diagnosed through health check-ups and family screening were detected at an earlier age and had the highest rate of survival. Liver biopsy at the time of diagnosis revealed cirrhosis in 9% of those detected through the health check-ups and 5% in the case of family screening, compared with 13% for the group with arthralgia, 17% for other diseases/symptoms and 42% for liver disease.

CONCLUSION

Health check-ups and family screening allow detection of hereditary hemochromatosis at an earlier age and with less advanced liver fibrosis, although a few of these patients have already developed cirrhosis. Our study indicates that iron indices should be included in health check-ups, and if abnormal, should lead to further investigation.

Serum ferritin levels, socio-demographic factors and desferrioxamine therapy in multi-transfused thalassemia major patients at a government tertiary care hospital of Karachi, Pakistan

Background

Beta thalassemia is the most frequent genetic disorder of haemoglobin synthesis in Pakistan. Recurrent transfusions lead to iron-overload manifested by increased serum Ferritin levels, for which chelation therapy is required.

Findings

The study was conducted in the Pediatric Emergency unit of Civil Hospital Karachi after ethical approval by the Institutional Review Board of Dow University of Health Sciences. Seventy nine cases of beta thalassemia major were included after a written consent. The care takers were interviewed for the socio-demographic variables and the use of Desferrioxamine therapy, after which a blood sample was drawn to assess the serum Ferritin level. SPSS 15.0 was employed for data entry and analysis.

Of the seventy-nine patients included in the study, 46 (58.2%) were males while 33 (41.8%) were females. The mean age was 10.8 (± 4.5) years with the dominant age group (46.2%) being 10 to 14 years. In 62 (78.8%) cases, the care taker education was below the tenth grade. The mean serum Ferritin level in our study were 4236.5 ng/ml and showed a directly proportional relationship with age. Desferrioxamine was used by patients in 46 (58.2%) cases with monthly house hold income significant factor to the use of therapy.

Conclusions

The mean serum Ferritin levels are approximately ten times higher than the normal recommended levels for normal individuals, with two-fifths of the patients not receiving iron chelation therapy at all. Use of iron chelation therapy and titrating the dose according to the need can significantly lower the iron load reducing the risk of iron-overload related complications leading to a better quality of life and improving survival in Pakistani beta thalassemia major patients.

Conflicts of Interest: None

Should we screen for hereditary hemochromatosis in healthy Lebanese: a pilot study

Hereditary hemochromatosis (HHC) is a genetic disorder of iron metabolism characterized by abnormal accumulation of iron that may lead to organ damage and death. Diagnosis is usually based on various genetic and phenotypic criteria. The study goals were to perform mutation analysis for 18 different mutations associated with HHC in healthy Lebanese, determine their allele frequency, and compare iron-overload status in identified carriers versus those found to be wild-type for mutations analyzed. 116 healthy adults (59 males and 57 females) underwent DNA testing for 18 different HHC mutations, and biochemical testing for percent transferrin saturation (%TS) and ferritin. C282Y mutation was not detected. Only H63D mutation (rs1799945) was found with an overall carrier frequency of 25.8% (24.1% heterozygous and 1.7% homozygous). %TS and ferritin differed significantly between genders. %TS and ferritin were significantly higher in males with H63D mutation when compared to males with wild-type (P=0.001, 0.019; respectively); but not in females. The proportion of subjects with increased %TS and serum ferritin was not statistically different between those with H63D mutation and the wild-type in either gender. In addition, none of the subjects had concurrent increase in %TS and ferritin. In conclusion, the H63D carrier frequency in healthy Lebanese is comparable to other populations in the region, and it does not result in significant biochemical iron overload. Moreover, in the absence of the C282Y mutation, genetic screening for HHC is not recommended according to this preliminary study in healthy Lebanese.

Low prevalence of hereditary hemochromatosis in multiethnic populations in Northern Norway

OBJECTIVE

Hereditary hemochromatosis has an autosomal recessive inheritance. The C282Y homozygosity is the most common genetic mutation in persons of Northern European descent. A screen of two multiethnic populations in Northern Norway was performed to investigate whether the prevalence of hereditary hemochromatosis was consistent with previous results in Northern Europe.

MATERIAL AND METHODS

Participants in two population-based studies in Northern Norway were analyzed for serum ferritin (s-ferritin) and transferrin saturation. Participants with s-ferritin or transferrin saturation above the reference limits in two separate blood samples were tested for three different HFE mutations, namely C282Y, H63D and S65.

RESULTS

The estimated prevalence of the C282Y/C282Y mutation in the two municipalities studied was lower than in comparable studies in Norway. The prevalence was the lowest in the Sør-Varanger population (men 0.19% and women 0.22%), which also had the highest proportion of individuals with Sami and Kven affiliation. In Tromsø, the prevalence was consistent with previous results in Norway.

CONCLUSIONS

The prevalence of hereditary hemochromatosis is lower in multiethnic populations in Northern Norway than in previous studies from other parts of Norway.

Total Mortality by Transferrin Saturation Levels: Two General Population Studies and a Metaanalysis

BACKGROUND

There is evidence for increased mortality in patients with clinically overt hereditary hemochromatosis. Whether increased transferrin saturation (TS), as a proxy for iron overload is associated with increased mortality in the general population is largely unknown.

METHODS

We examined mortality according to baseline TS in 2 Danish population–based follow-up studies (the Copenhagen General Population Study and the Copenhagen City Heart Study) comprising a total of 45 159 individuals, of whom 4568 died during up to 18 years of follow-up, and in a metaanalysis comprising the present studies and an additional general population study.

RESULTS

In combined studies, the cumulative survival was reduced in individuals with TS ≥50% vs &lt;50% (log-rank P &lt; 0.0001). Multifactorially adjusted hazard ratios for total mortality for TS ≥50% vs &lt;50% were 1.4 (95% CI 1.2–1.6; P &lt; 0.001) overall, 1.3 (1.1–1.6; P = 0.003) in men, and 1.5 (1.1–2.0; P = 0.005) in women. Results were similar if the 2 studies were considered separately. A stepwise increased risk of total mortality was observed for stepwise increasing levels of TS (log-rank P &lt; 0.0001), with the highest risk conferred by TS ≥80% vs TS &lt;20% with a hazard ratio of 2.2 (1.4–3.3; P &lt; 0.001). The population-attributable risk for total mortality in the combined studies in individuals with TS ≥50% vs &lt;50% was 0.8%. In metaanalysis, the odds ratio for total mortality for TS ≥50% vs &lt;50% was 1.3 (1.2–1.5; P &lt; 0.001) under the fixed-effects model.

CONCLUSIONS

Individuals in the general population with TS ≥50% vs &lt;50% have an increased risk of premature death.

Identification of a common variant in the TFR2 gene implicated in the physiological regulation of serum iron levels

The genetic determinants of variation in iron status are actively sought, but remain incompletely understood. Meta-analysis of two genome-wide association (GWA) studies and replication in three independent cohorts was performed to identify genetic loci associated in the general population with serum levels of iron and markers of iron status, including transferrin, ferritin, soluble transferrin receptor (sTfR) and sTfR-ferritin index. We identified and replicated a novel association of a common variant in the type-2 transferrin receptor (TFR2) gene with iron levels, with effect sizes highly consistent across samples. In addition, we identified and replicated an association between the HFE locus and ferritin and confirmed previously reported associations with the TF, TMPRSS6 and HFE genes. The five replicated variants were tested for association with expression levels of the corresponding genes in a publicly available data set of human liver samples, and nominally statistically significant expression differences by genotype were observed for all genes, although only rs3811647 in the TF gene survived the Bonferroni correction for multiple testing. In addition, we measured for the first time the effects of the common variant in TMPRSS6, rs4820268, on hepcidin mRNA in peripheral blood (n = 83 individuals) and on hepcidin levels in urine (n = 529) and observed an association in the same direction, though only borderline significant. These functional findings require confirmation in further studies with larger sample sizes, but they suggest that common variants in TMPRSS6 could modify the hepcidin-iron feedback loop in clinically unaffected individuals, thus making them more susceptible to imbalances of iron homeostasis.

Hemochromatosis genotypes and risk of iron overload--a meta-analysis

PURPOSE

The incomplete phenotypic penetrance of high iron Fe genotypes in relation to hemochromatosis poses a practical problem in the interpretation of the genotyping results by clinicians. We carried out meta-analyses of the associations between hemochromatosis genotypes C282Y/C282Y, C282Y/H63D, C282Y/wild-type, H63D/H63D, H63D/wild-type, versus wild-type/wild-type and iron overload, both provisional (elevated serum iron markers) and documented (elevated serum iron markers associated with evidence of iron excess based on liver biopsy and/or quantitative phlebotomy).

METHODS

After reviewing 3572 article titles and evaluating 92 articles in detail, odds ratios were pooled from 43 study populations (9986 cases and 25,492 controls) using a random-effects model.

RESULTS

Homozygosity for either variant or compound heterozygosity was associated with both provisional and documented iron overload. Single heterozygosity conferred no risk for elevated hepatic iron index and/or mobilizable iron by quantitative phlebotomy. In patients with clinical hereditary hemochromatosis, no evidence of provisional and documented iron overload with transferrin saturation (TS) values greater than 55% was evidenced for C282Y and H63D single heterozygotes whereas documented iron overload including TS of 45% to 50% was weakly associated with C282Y/wild-type genotype; H63D/H63D genotype was not associated with documented iron overload in patients with TS values of 45% to 50%.

CONCLUSIONS

The results, mainly from case-control studies, cannot necessarily be extrapolated to the general population.

Musculoskeletal Complications of Hereditary Hemochromatosis: A Case-Control Study

Objective.

Arthropathy that mimics osteoarthritis (OA) and osteoporosis (OP) is considered a classic complication of hereditary hemochromatosis (HH) but has never been investigated in a cross-sectional study. We investigated whether HH is associated with increased prevalence of OA and OP and related factors.

Methods.

A self-administered questionnaire was completed by 306 patients with HH and 304 age and sex-matched unaffected controls.

Results.

The mean age of patients was 60.1 ± 11.3 years, and 47.4% were women. More patients with HH than controls had been given a diagnosis of OA: 50.5% vs 28.9% [adjusted OR (aOR) 2.5, 95% CI 1.8–3.6]. Compared with controls, patients with HH had a higher risk of knee (aOR 5.3, 95% CI 1.1–25.6) and hip replacement prosthesis (aOR 5.2, 95% CI 2.2–11.9). More patients than controls had been diagnosed with OP: 23.3% vs 4.6% (aOR 7.3, 95% CI 3.2–17.0). Patients with HH showed an increased prevalence, although not significant, of wrist (aOR 1.7, 95% CI 0.9–3.0) or vertebral fractures (aOR 1.7, 95% CI 0.8–3.8). The severity of iron overload, as defined by a ferritin level > 1000 μg/l at diagnosis, was associated with OA (p = 0.0005), OP (p = 0.01), presence of hip prosthesis (p = 0.04), wrist fractures (p = 0.002), and vertebral fractures (p = 0.02).

Conclusion.

This case-control study strongly suggests a significant association among HH, OA, and OP. Joint involvement can be severe, especially in patients with substantially elevated ferritin levels.

Serum ferritin: Past, present and future

BACKGROUND

Serum ferritin was discovered in the 1930s, and was developed as a clinical test in the 1970s. Many diseases are associated with iron overload or iron deficiency. Serum ferritin is widely used in diagnosing and monitoring these diseases.

SCOPE OF REVIEW

In this chapter, we discuss the role of serum ferritin in physiological and pathological processes and its use as a clinical tool.

MAJOR CONCLUSIONS

Although many aspects of the fundamental biology of serum ferritin remain surprisingly unclear, a growing number of roles have been attributed to extracellular ferritin, including newly described roles in iron delivery, angiogenesis, inflammation, immunity, signaling and cancer.

GENERAL SIGNIFICANCE

Serum ferritin remains a clinically useful tool. Further studies on the biology of this protein may provide new biological insights.

EASL clinical practice guidelines for HFE hemochromatosis

Iron overload in humans is associated with a variety of genetic and acquired conditions. Of these, HFE hemochromatosis (HFE-HC) is by far the most frequent and most well-defined inherited cause when considering epidemiological aspects and risks for iron-related morbidity and mortality. The majority of patients with HFE-HC are homozygotes for the C282Y polymorphism [1]. Without therapeutic intervention, there is a risk that iron overload will occur, with the potential for tissue damage and disease. While a specific genetic test now allows for the diagnosis of HFE-HC, the uncertainty in defining cases and disease burden, as well as the low phenotypic penetrance of C282Y homozygosity poses a number of clinical problems in the management of patients with HC. This Clinical Practice Guideline will therefore, focus on HFE-HC, while rarer forms of genetic iron overload recently attributed to pathogenic mutations of transferrin receptor 2, (TFR2), hepcidin (HAMP), hemojuvelin (HJV), or to a sub-type of ferroportin (FPN) mutations, on which limited and sparse clinical and epidemiologic data are available, will not be discussed. We have developed recommendations for the screening, diagnosis, and management of HFE-HC.

What is the evidence for gender differences in ferritin and haemoglobin?

Reference ranges for haemoglobin and ferritin in women of reproductive age are widely reported showing values that are lower than equivalent aged males. Similar values would be expected in the absence of different biological requirements. While reference ranges have been derived from data on large populations, it is likely that these populations have included significant numbers of women who are iron deficient in view of menstrual blood loss and poor dietary intake. Populations with a daily iron intake in excess of 100mg have shown that iron deficiency in females is rare. Studies reporting bone marrow with iron stains from 50 years ago pointed out that significant numbers of women were iron deficient and more recently serum ferritin studies have confirmed this. However, a large number of women in the Western world spend a significant part of their lives in a negative iron balance due to a combination of poor diet and menstrual blood loss. The presence of haem iron in the diet of humans enhances non-haem iron absorption but dietary surveys consistently report that women's diet is deficient in iron. Furthermore, the typical Western diet contains many common foods that limit iron absorption. It appears that lower haemoglobin and ferritin values in menstruating women have been accepted as normal rather than possibly representing widespread iron deficiency. Reference ranges should be re-evaluated in populations proven to be iron replete.