MRI-Based Iron Phenotyping and Patient Selection for Next-Generation Sequencing of Non-Homeostatic Iron Regulator Hemochromatosis Genes.

BACKGROUND AND AIMS: High serum ferritin is frequent among patients with chronic liver disease and commonly associated with hepatic iron overload. Genetic causes of high liver iron include homozygosity for the p.Cys282Tyr variant in homeostatic iron regulator (HFE) and rare variants in non-HFE genes. The aims of the present study were to describe the landscape and frequency of mutations in hemochromatosis genes and determine whether patient selection by noninvasive hepatic iron quantification using MRI improves the diagnostic yield of next-generation sequencing (NGS) in patients with hyperferritinemia. APPROACH AND RESULTS: A cohort of 410 unselected liver clinic patients with high serum ferritin (defined as ≥200 µg/L for women and ≥300 µg/L for men) was investigated by HFE genotyping and abdominal MRI R2*. Forty-one (10%) patients were homozygous for the p.Cys282Tyr variant in HFE. Of the remaining 369 patients, 256 (69%) had high transferrin saturation (TSAT; ≥45%) and 199 (53%) had confirmed hepatic iron overload (liver R2* ≥70 s-1 ). NGS of hemochromatosis genes was carried out in 180 patients with hepatic iron overload, and likely pathogenic variants were identified in 68 of 180 (38%) patients, mainly in HFE (79%), ceruloplasmin (25%), and transferrin receptor 2 (19%). Low spleen iron (R2* <50 s-1 ), but not TSAT, was significantly associated with the presence of mutations. In 167 patients (93%), no monogenic cause of hepatic iron overload could be identified. CONCLUSIONS: In patients without homozygosity for p.Cys282Tyr, coincident pathogenic variants in HFE and non-HFE genes could explain hyperferritinemia with hepatic iron overload in a subset of patients. Unlike HFE hemochromatosis, this type of polygenic hepatic iron overload presents with variable TSAT. High ferritin in blood is an indicator of the iron storage disease, hemochromatosis. A simple genetic test establishes this diagnosis in the majority of patients affected. MRI of the abdomen can guide further genetic testing.

Magnetic resonance imaging of neonatal hemochromatosis.

Neonatal hemochromatosis is a rare condition that causes neonatal liver failure, frequently resulting in fetal loss or neonatal death. It is thought that most cases of neonatal hemochromatosis are caused by gestational alloimmune liver disease (GALD), with neonatal hemochromatosis being a phenotype of GALD rather than a disease process. Extrahepatic siderosis in the pancreas, myocardium, thyroid and minor salivary gland is a characteristic feature of neonatal hemochromatosis. There is also sparing of the reticuloendothelial system with no iron deposition in the spleen. Hepatic and extrahepatic siderosis seen in neonatal hemochromatosis is from iron dysregulation secondary to liver damage rather than iron deposition causing the liver damage. The presence of extrahepatic siderosis in the pancreas and thyroid is diagnostic of neonatal hemochromatosis and can be detected noninvasively by multi-echo gradient recalled echo (GRE) T2*-weighted sequence of MRI within hours of birth. This helps to expedite the treatment in the form of intravenous immunoglobulin and exchange transfusion, which improves the survival in these babies. The finding of hepatic siderosis is nonspecific and does not help in the diagnosis of neonatal hemochromatosis because it is seen with other causes of advanced liver disease.

Balanced by iron. Hereditary hemochromatosis and celiac disease.

We present the case of a healthy 14-year-old adolescent who was referred to our hospital for an incidental alteration of the iron profile (Fe 225 ug/dl, transferrin 186 mg/dl, IST 63.93 %, ferritin 253 ng/ml). The blood count, proteinogram and renal, lipid and liver function tests were in the normal range. Abdominal ultrasound was requested with no findings of interest. The genetic analysis for hereditary hemochromatosis (HH) confirmed that the patient was homozygous for the C282Y mutation.

Clinical evaluation of infiltrative cardiomyopathies resulting in heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction is a very common clinical problem. Its prevalence is increasing with aging of the population. A diverse group of risk factors and etiologies comprise the HFpEF syndrome. No specific therapies have been shown to improve survival for the vast majority of HFpEF cases. Restrictive cardiomyopathies account for a significant portion of HFpEF patients and are characterized by diastolic dysfunction due to infiltration of the myocardium or ventricular hypertrophy. Many of these restrictive diseases occur in the context of myocardial infiltration by other substances such as amyloid, iron or glycogen or endomyocardial fibrosis. These infiltrative diseases usually have important clues in the clinical picture and on cardiac imaging that may allow differentiation from the usual HFpEF phenotype (that is commonly seen in the older, hypertensive patient). Noninvasive diagnosis has replaced endomyocardial biopsy for most instances in the workup of these conditions. Early recognition is important to institute specific therapies and to improve prognosis. In this review, we describe 4 major infiltrative cardiomyopathies (Cardiac Amyloidosis, Sarcoidosis, Hemochromatosis and Fabry disease), and their key imaging features.

Iron-Containing Abdominal Pathologies: Exploiting Magnetic Susceptibility Artifact on Dual-Echo Gradient-Echo Magnetic Resonance Imaging.

A multitude of pathologic entities involve abnormal iron deposition in the abdomen. These lesions demonstrate decreased signal on longer magnetic resonance sequences with longer echo time due to T2* effect. Dual-echo gradient-echo sequences demonstrate increased susceptibility artifact with longer echo sequences. In this article, the spectrum of iron-containing abdominal pathologies is illustrated, with their characteristic distributions. Included is a brief discussion of the physics of magnetic resonance imaging of iron-containing lesions.

Inter-method reproducibility of biexponential R2 MR relaxometry for estimation of liver iron concentration.

PURPOSE: To assess the reproducibility of biexponential R2 -relaxometry MRI for estimation of liver iron concentration (LIC) between proprietary and nonproprietary analysis methods. METHODS: This single-center retrospective study, approved by investigational review board and compliant with the Health Insurance Portability and Accountability Act, included 40 liver MRI exams in 38 subjects with suspected or known iron overload. From spin-echo images of the liver, acquired at 5 different echo times (TE = 6-18 ms), biexponential R2 maps were calculated using 1 proprietary (FerriScan, Resonance Health Ltd., Claremont WA, Australia) and 3 nonproprietary (simulated annealing, nonlinear least squares, dictionary search) analysis methods. Each subject's average liver R2 value was converted to LIC using a previously validated calibration curve. Inter-method reproducibility for liver R2 and LIC were assessed for linearity using linear regression analysis and absolute agreement using intraclass correlation and Bland-Altman analysis. For point estimates, 95% confidence intervals were calculated; P values < 0.05 were considered statistically significant. RESULTS: Linearity between the proprietary and nonproprietary methods was excellent across the observed range for R2 (20-312 s-1 ) and LIC (0.4-52.2 mg/g), with all coefficients of determination (R2 ) ≥ 0.95. No statistically significant bias was found (slope estimates ∼ 1; intercept estimates ∼ 0; P values > 0.05). Agreement between the 4 methods was excellent for both liver R2 and LIC (intraclass correlations ≥ 0.97). Bland-Altman 95% limits of agreement in % difference between the proprietary and nonproprietary methods were ≤ 9% and ≤ 16% for R2 and LIC, respectively. CONCLUSION: Biexponential R2 -relaxometry MRI for LIC estimation is reproducible between proprietary and nonproprietary analysis methods.

Opportunistic Screening for Hereditary Hemochromatosis With Unenhanced CT: Determination of an Optimal Liver Attenuation Threshold.

OBJECTIVE: The purpose of this study was to assess whether a specific liver attenuation threshold for unenhanced CT allows both sensitive opportunistic detection of unsuspected hereditary hemochromatosis and low overall screening test-positive rates. MATERIALS AND METHODS: We used a standard ROI placement method on unenhanced CT studies of 3357 consecutive adults (mean age, 57.0 years) with no symptoms of liver disease who underwent colorectal screening. Hepatic attenuation (in HU) was measured to assess test-positive rates at various liver attenuation thresholds. To assess sensitivity, unenhanced hepatic CT attenuation was also measured in 12 patients with hereditary hemochromatosis (mean age, 48.3 years), who were homozygous for the HFE C282Y mutation. All scans were obtained at 120 kV. Serum ferritin levels were recorded for the hereditary hemochromatosis cohort. RESULTS: Mean liver attenuation ± SD among screened adults was 59.4 ± 12.7 HU, compared with 78.7 ± 13.1 HU (range, 59-105 HU) in the hereditary hemochromatosis cohort (p < 0.001). Screening test-positive rates were 30.6% (n = 1028) at 65 HU, 8.2% (n = 275) at 70 HU, 1.2% (n = 39) at 75 HU, and 0.2% (n = 7) at 80 HU. Corresponding sensitivities for hereditary hemochromatosis at these thresholds were 83.3% (10/12) at 65, 70, and 75 HU; and 50.0% (6/12) at 80 HU. Serum ferritin levels were elevated in all patients with hereditary hemochromatosis (mean, 1678 ng/mL; range, 477-3991 ng/mL). CONCLUSION: An unenhanced CT liver attenuation threshold of 75 HU was sensitive (83.3%) for hereditary hemochromatosis while maintaining an acceptably low screening test-positive rate (1.2%). An unexplained liver attenuation of 75 HU or more on unenhanced CT should trigger appropriate laboratory investigation for iron overload; early intervention with phlebotomy can limit or prevent organ damage in patients with hemochromatosis.

Magnetic Resonance Imaging Findings in Neonatal Hemochromatosis.

BACKGROUND: There are limited data on utility of magnetic resonance imaging (MRI) in the assessment of suspected neonatal hemochromatosis (NH). OBJECTIVES: The aim of the study was to present our experience with utilization of multi-echo sequence MRI technique in the evaluation of NH and to compare MRI findings in infants with and without NH. METHODS: MRI performed for suspected NH were retrospectively reviewed to note the presence and severity of iron deposition (ID) in liver, spleen, pancreas, and kidneys on multi-echo sequences. Findings were compared in infants with and without NH. RESULTS: Of 20 infants (9 boys and 11 girls; median age of 12.5 days) included in the study, 7 of 20 had NH and 13 of 20 were assigned to the non-NH group. Higher degree of pancreatic ID was seen in the NH group (P = 0.001) with 4 of 7 evaluable pancreas showing moderate-to-severe degree and 1 of 7 showing mild degree of ID whereas none of the 13 infants in non-NH group showed moderate or severe degree of pancreatic ID. Even though the severity of hepatic ID was higher in NH group (P = 0.033), variable severity of hepatic ID was seen in both groups with most infants in both groups showing moderate-to-severe degree of ID. The severity of splenic ID was not particularly associated with any group (P = 0.774) but there was no moderate or severe degree of ID in NH. Renal ID was seen in two infants in non-NH group. CONCLUSIONS: A moderate-to-severe degree of pancreatic ID seen on MRI tends to be associated with NH and should be sought to establish a timely diagnosis of NH. Presence and severity of hepatic ID cannot be used for differentiation of NH from other causes of neonatal liver failure.

MRI ankle and subtalar characteristics in haemochromatosis arthropathy: a case-control study.

AIM: To examine the magnetic resonance imaging (MRI) features of the ankle and subtalar joints that might distinguish genetic haemochromatosis (GH). MATERIALS AND METHODS: The present study was a retrospective case-control study comparing 30 MRI studies of GH patients with ankle or subtalar arthropathy with 30 matched controls with ankle pain. Anonymised images were scored using a semi-quantative tool adapted from the MRI osteoarthritis knee score. Scores were generated for bone marrow lesions size, number, and distinguishing the proportion of each lesion consisting of subchondral cyst versus oedema. Articular cartilage loss and osteophytes were documented. The primary comparator was bone marrow lesion size. Paired Student's t-test and the chi-squared test were utilised to compare outcomes. RESULTS: Bone marrow lesion/cyst size and number, presence and extent of full-thickness cartilage loss, and osteophyte scores were significantly higher in ankle joints of GH cases (p<0.01). In the middle subtalar articulation, there were significantly higher scores for full-thickness cartilage loss and extent and osteophytes in GH cases (p<0.05). There were no significant differences in the posterior subtalar articulation. CONCLUSION: The finding of both numerous and large cysts on ankle MRI should raise suspicion of GH. Other MRI features of potential diagnostic value include large osteophytes and the presence of extensive full-thickness cartilage loss in the ankle joint and middle subtalar articulation.

Quantification of liver iron overload disease with laser ablation inductively coupled plasma mass spectrometry.

BACKGROUND: Hereditary hemochromatosis is the most frequent, identified, genetic disorder in Caucasians affecting about 1 in 1000 people of Northern European ancestry, where the associated genetic defect (homozygosity for the p.Cys282Tyr polymorphism in the HFE gene) has a prevalence of approximately 1:200. The disorder is characterized by excess iron stores in the body. Due to the incomplete disease penetrance of disease-associated genotype, genetic testing and accurate quantification of hepatic iron content by histological grading of stainable iron, quantitative chemical determination of iron, or imaging procedures are important in the evaluation and staging of hereditary hemochromatosis. METHODS: We here established novel laser ablation inductively coupled plasma mass spectrometry protocols for hepatic metal bio-imaging for diagnosis of iron overload. RESULTS: We demonstrate that these protocols are a significant asset in the diagnosis of iron overload allowing iron measurements and simultaneous determination of various other metals and metalloids with high sensitivity, spatial resolution, and quantification ability. CONCLUSIONS: The simultaneous measurement of various metals and metalloids offers unique opportunities for deeper understanding of metal imbalances. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a highly powerful and sensitive technique for the analysis of a variety of solid samples with high spatial resolution. We conclude that this method is an important add-on to routine diagnosis of iron overload and associated hepatic metal dysbalances resulting thereof.

Movement Disorders Associated With Hemochromatosis.

BACKGROUND: Hereditary hemochromatosis (HH) is a genetic disorder causing pathological iron deposition and functional impairment of various organs, predominantly the liver. We assessed patients with HH for the presence of movement disorders. METHODS: We reviewed the charts of 616 patients with HH who attended hemochromatosis clinic at London Health Sciences Centre, London, ON, Canada, from 1988 to 2015. RESULTS: We found three HH patients with movement disorders, without any other major systemic manifestation. One had parkinsonism, another had chorea, and the third had tremor. All three patients had evidence of iron deposition in the brain, affecting the basal ganglia in the first two, and the dentate nucleus, red nucleus, and substantia nigra in the third patient. In addition to the C282Y homozygous mutation in the HFE gene, two of our patients had non-HFE gene mutations. CONCLUSION: HH should be considered in the differential diagnosis of movement disorders with pathological brain iron deposition. We report for the first time chorea in a patient with HH. Non-HFE gene mutations may predispose HH patients to iron deposition in the brain.

HFE-related hemochromatosis: an update for the rheumatologist.

Hereditary hemochromatosis is a frequent disease in Caucasian populations. It leads to progressive iron overload in a variety of organs. The most common cause is the C282Y homozygous mutation in the HFE gene. The classical triad of skin hyperpigmentation, diabetes, and liver cirrhosis is nowadays rare but musculoskeletal symptoms are common in HFE-related hemochromatosis. Typically the second and third metacarpophalangeal joints, and the wrist, hip, and ankle joints are affected. Clinical symptoms include osteoarthritis-like symptoms, pseudogout attacks, and synovitis sometimes resembling rheumatoid arthritis. Radiographs show degenerative changes with joint space narrowing, osteophytes, and subchondral cysts. Chondrocalcinosis in the wrist and knee joints is seen in up to 50 % of patients. Although most other organ manifestations regress during phlebotomy, musculoskeletal symptoms often persist or even become worse. Importantly, patients are at an increased risk of severe large-joint arthritis necessitating joint replacement surgery. Therefore, future research should focus on the pathogenesis and treatment options for HH arthropathy.

Clinical and genetic predictors of cardiac dysfunction assessed by echocardiography in patients with hereditary hemochromatosis.

PURPOSE: Hereditary hemochromatosis (HH) may cause iron deposition in cardiac tissue. We aimed to describe the echocardiographic findings in patients with HH and identify risk factors for cardiac dysfunction. METHODS: In this retrospective study, we included patients with HH who underwent transthoracic echocardiography at our tertiary care center between August 2000 and July 2022. We defined three primary outcomes for cardiac dysfunction: 1) left ventricular ejection fraction (LVEF) < 55%, 2) ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') > 15, and 3) global longitudinal strain (GLS) < 18. Multivariable logistic regression was utilized to identify predictors of cardiac dysfunction. RESULTS: 582 patients (median age 57 years, 61.2% male) were included. The frequency of LVEF < 55%, E/e' > 15 and GLS < 18 was 9.0% (52/580), 9.6% (51/534) and 20.2% (25/124), respectively. In multivariable analysis, non-White race, age, and hypertension were associated with E/e' > 15. No specific HFE genetic mutation was associated with LVEF < 55%. A history of myocardial infarction was strongly associated with both LVEF < 55% and E/e' > 15. In patients with LVEF ≥ 55%, the C282Y/H63D genetic mutation was associated with reduced likelihood of E/e' > 15, p = 0.024. Patients with C282Y/H63D had a higher frequency of myocardial infarction. Smoking and alcohol use were significantly associated with GLS < 18 in unadjusted analysis. CONCLUSION: We found the traditional risk factors of male sex, and history of myocardial infarction or heart failure, were associated with a reduced LVEF, irrespective of the underlying HFE genetic mutation. Patients with a C282Y/H63D genetic mutation had a higher frequency of myocardial infarction, yet this mutation was associated with reduced odds of diastolic dysfunction compared to other genetic mutations in patients with a normal LVEF.

Idiopathic hand osteoarthritis vs haemochromatosis arthropathy--a clinical, functional and radiographic study.

OBJECTIVE: Haemochromatosis arthropathy is a secondary OA and the most frequent and earliest clinical presentation of hereditary haemochromatosis (HH). The aim of this study was to perform a direct clinical, functional and radiographic comparison with idiopathic hand OA (HOA) to unravel important differences between these clinical entities. METHODS: In total, 299 patients (141 with HH arthropathy of the hands and 158 patients with idiopathic HOA) were recruited. Structured clinical assessment including hand function tests, as well as hand radiographs with scoring according to Kellgren-Lawrence, were carried out in all patients. RESULTS: HH arthropathy and HOA differed significantly: patients with HH arthropathy were younger and predominantly male as compared with HOA. In males but not females, HH arthropathy led to an earlier start of symptoms than in HOA. Patients with HOA had more tender joints and worse hand function than patients with HH arthropathy, although subjective measures of joint pain and function were similar. MCP and wrist joint involvement was more frequent and severe in HH arthropathy, while HOA patients more frequently had degenerative changes in the first CMC as well as PIP and DIP joints. CONCLUSION: HH arthropathy and idiopathic HOA differ significantly in terms of epidemiology, localization, severity of symptoms and radiographic changes.

Hereditary hemochromatosis is characterized by a clinically definable arthropathy that correlates with iron load.

OBJECTIVE: To determine the frequency and character of arthropathy in hereditary hemochromatosis (HH) and to investigate the relationship between this arthropathy, nodal interphalangeal osteoarthritis, and iron load. METHODS: Participants were recruited from the community by newspaper advertisement and assigned to diagnostic confidence categories for HH (definite/probable or possible/unlikely). Arthropathy was determined by use of a predetermined clinical protocol, radiographs of the hands of all participants, and radiographs of other joints in which clinical criteria were met. RESULTS: An arthropathy considered typical for HH, involving metacarpophalangeal joints 2-5 and bilateral specified large joints, was observed in 10 of 41 patients with definite or probable HH (24%), all of whom were homozygous for the C282Y mutation in the HFE gene, while only 2 of 62 patients with possible/unlikely HH had such an arthropathy (P=0.0024). Arthropathy in definite/probable HH was more common with increasing age and was associated with ferritin concentrations>1,000 µg/liter at the time of diagnosis (odds ratio 14.0 [95% confidence interval 1.30-150.89], P=0.03). A trend toward more episodes requiring phlebotomy was also observed among those with arthropathy, but this was not statistically significant (odds ratio 1.03 [95% confidence interval 0.99-1.06], P=0.097). There was no significant association between arthropathy in definite/probable HH and a history of intensive physical labor (P=0.12). CONCLUSION: An arthropathy consistent with that commonly attributed to HH was found to occur in 24% of patients with definite/probable HH. The association observed between this arthropathy, homozygosity for C282Y, and serum ferritin concentrations at the time of diagnosis suggests that iron load is likely to be a major determinant of arthropathy in HH and to be more important than occupational factors.

Iranian hereditary hemochromatosis patients: baseline characteristics, laboratory data and gene mutations.

BACKGROUND: Hereditary hemochromatosis (HH) is the most common autosomal recessive disorder in white people, characterized by highly abnormal uptake of iron from the gastrointestinal tracts. Recently, mutation studies have focused to detect the genes responsible for HH. MATERIAL/METHODS: In this cross-sectional study, 12 HH patients were recruited, who were referred to Firoozgar Hospital, Tehran, Iran. In addition to the clinical assessments, a complete laboratory evaluation, imaging modalities, histopathologic assessment, atomic absorption spectrophotometry and gene mutation study were performed. The genetic study for HFE gene mutation was examined for all of the patients since 2006, while non-HFE mutation was conducted since December 2010 (only for 1 of them). RESULTS: Twelve patients were evaluated consisting of 11 men and 1 woman, with the mean age of 39.58±12.68 yr. The average of atomic iron loads was 13.25±4.83-fold higher than normal standards. Four patients had heterozygotic mutation of H63D (33.3%). There was no significant difference in either the iron load of liver (P=0.927) and heart (P=0.164) or serum concentration of ferritin (P=0.907) and TIBC (P=0.937) between the HFE-mutant and without HFE mutation HH cases. CONCLUSIONS: In contrast to other studies, C282Y mutation was not detected in any of our Iranian HH patients. Heterozygotic mutations of H63D (HFE) and TFR2 (non-HFE) genes were found to be more common in these patients. Similar to previous reports, these mutations were not found to be significantly associated with severity of presentation in HH patients.

Asymmetrical hemochromatosis arthropathy in a patient with a history of poliomyelitis.

Herein, we report a case of a 67-year-old man with hereditary hemochromatosis and a history of poliomyelitis that had caused a paresis of the right arm. Hemochromatosis-associated arthropathy developed in all but the paretic limb. X-ray and MRI revealed degenerative, massive inflammatory and destructive changes in the joints of the non-paretic hand only. These findings argue for the contribution of physical exposure and non-mechanical factors to the development of the hemochromatosis arthropathy.