Hepatic Iron Concentration Research Articles

Maximal standard dose of parenteral iron for hemodialysis patients: an MRI-based decision tree learning analysis.

Background and ObjectivesIron overload used to be considered rare among hemodialysis patients after the advent of erythropoesis-stimulating agents, but recent MRI studies have challenged this view. The aim of this study, based on decision-tree learning and on MRI determination of hepatic iron content, was to identify a noxious pattern of parenteral iron administration in hemodialysis patients.Design, Setting, Participants and MeasurementsWe performed a prospective cross-sectional study from 31 January 2005 to 31 August 2013 in the dialysis centre of a French community-based private hospital. A cohort of 199 fit hemodialysis patients free of overt inflammation and malnutrition were treated for anemia with parenteral iron-sucrose and an erythropoesis-stimulating agent (darbepoetin), in keeping with current clinical guidelines. Patients had blinded measurements of hepatic iron stores by means of T1 and T2* contrast MRI, without gadolinium, together with CHi-squared Automatic Interaction Detection (CHAID) analysis.ResultsThe CHAID algorithm first split the patients according to their monthly infused iron dose, with a single cutoff of 250 mg/month. In the node comprising the 88 hemodialysis patients who received more than 250 mg/month of IV iron, 78 patients had iron overload on MRI (88.6%, 95% CI: 80% to 93%). The odds ratio for hepatic iron overload on MRI was 3.9 (95% CI: 1.81 to 8.4) with >250 mg/month of IV iron as compared to <250 mg/month. Age, gender (female sex) and the hepcidin level also influenced liver iron content on MRI.ConclusionsThe standard maximal amount of iron infused per month should be lowered to 250 mg in order to lessen the risk of dialysis iron overload and to allow safer use of parenteral iron products.

Utility of Transient Elastography (Fibroscan) in Estimating Hepatic Iron Concentration in Comparison to MRI in Patients with Transfusion Dependent Hemoglobinopathies

BackgroundPatients with severe hereditary anemias (e.g. β-Thalassemia Major) are transfusion-dependent for survival. Current guidelines suggest monitoring serum ferritin every three months and annual MRI to assess hepatic and cardiac iron load1. However, MRI, particularly the R2 sequence (FerriScan) which has high specificity and sensitivity in estimating the liver iron concentration, is expensive and not always readily available. Transient elastography (FibroScan) measures liver’s stiffness and predicts fibrosis. Previous studies have suggested its utility in other conditions that increase liver stiffness, such as amyloidosis2and perhaps iron overload.AimTo determine if FibroScan value correlates with hepatic iron concentration estimated using R2 MRI (FerriScan), and/or serum ferritin level.MethodsA prospective cross-sectional study was conducted at a university-affiliated tertiary care center (St. Paul’s Hospital, Vancouver, BC) in 2013 and 2014. Inclusion criteria: Age ≥ 19 years with transfusion-dependent hereditary anemias. Exclusion criteria: liver cirrhosis, primary liver disease (e.g. Wilson’s disease, hereditary hemochromatosis), and chronic viral hepatitis (e.g. Hepatitis B, C and HIV). In addition to having annual MRI and ferritin levels monitored every three months, subjects underwent FibroScan within six months of MRI in 2013. In 2014, participants were invited to undergo repeat FibroScan within three months of the annual MRI. Linear regression analysis was used to determine if there is any correlation/linear fit between FibroScan result, MRI result, and ferritin levels. This study was approved by the University of British Columbia Research Ethics Board.Results20 subjects have been recruited as of August 1, 2014, with 35 and 33 complete FibroScan and MRI results, respectively. 14 (70%) were female. Mean age was 30.7±9.8 years. Most common primary diagnosis was transfusion-dependent beta-thalassemia (Major and intermedia) (n=17).Linear regression analysis showed a weakly positive correlation between hepatic iron concentrations estimated with R2 MRI (FerriScan) and ferritin levels (R2=0.29; p=0.004), when they are performed within four weeks apart. The correlation remained statistically significant when all subjects were included regardless of time lapse between the two investigations (R2=0.30; p=0.001). However, FibroScan values did not appear to correlate with MRI, regardless of whether the scans are performed within six months (R2=0.011; p=0.58) or three months apart (R2=0.035; p=0.44). Similarly, there was no correlation between FibroScan and Ferritin (R2=0.022; p=0.49) when the investigations were performed within 4 weeks part.ConclusionInterim analysis did not demonstrate any correlation between FibroScan result and MRI-estimated hepatic iron concentration. A final analysis will be performed upon complete formal evaluation of the remaining MRI and FibroScan data.

Exome Sequencing Identifies a GNPAT Variant Associated with Severe Iron Overload in HFE C282Y Homozygous Men with Extreme Phenotypes; Possible Role in Regulation of Hepcidin Expression

▪Variability in the severity of iron overload among homozygotes for the HFE C282Y polymorphism is one of the major unsolved problems in our understanding of hereditary hemochromatosis (HH). We previously conducted exome sequencing of DNA from 35 HFE C282Y male homozygotes with either markedly increased iron stores (n=22; cases) or normal to mildly increased iron stores (n=13; controls) to identify rare and common causal variants associated with variability of disease expression in HH. The 35 participants, residents of the U.S., Canada, and Australia, reported little or no alcohol consumption. Criteria for HFE C282Y homozygotes with increased iron stores included serum ferritin >1000 µg/L at diagnosis and either (a) hepatic iron concentration >236 µmol/g dry weight (reference range 0-36 µmol/g) or (b) mobilized body iron >10 g by quantitative phlebotomy. Criteria for HFE C282Y homozygotes with normal or mildly elevated iron stores included (a) serum ferritin <300 µg/L or either (a) age ≥40 y with ≤2.5 g iron removed by phlebotomy to achieve serum ferritin <50 µg/L, or (b) age ≥50 y with ≤3.0 g iron removed by phlebotomy. After quality control filtering, sequencing data included 82,068 single nucleotide variants and 1,403 insertions/deletions (indels); 10,337 genes were tested for a difference between cases and controls. We identified the polymorphism GNPAT p.D519G (1556A>G; exon 11; chromosome 1q42; rs11558492) as the most significantly different variant between cases and controls (p=0.033 by the likelihood ratio test after correction for multiple comparisons). In a principal components analysis of ancestry, all 35 study participants were clustered closely together within a larger group of Europeans. Mean (SD) ages at presentation were 53 (11.5) y and 57 (10.0) y for cases and controls, respectively. Median serum ferritin was 2391 µg/L in cases and 302 μg/L in controls. The median transferrin saturation (96%) was greater in cases than controls (70%).Sixteen of 22 case participants had polymorphism GNPAT p.D519G (rs11558492) (15 heterozygotes, 1 homozygote); no control participant had this polymorphism. The homozygous case presented at age 26 y with severe iron overload but no cirrhosis. One GNPAT p.D519G heterozygote presented at age 36 y with severe iron overload and cirrhosis. GNPAT p.D519G is common among people of European descent (allele frequency 20.6%) and might interact with aberrant HFE to increase the risk of hepatic iron overload. More recently, we compared the allele frequencies of GNPAT p.D519G in the present 22 cases and 13 controls with that of 4300 European Americans in the NHLBI Exome Sequencing Project Exome Variant Server. The allele frequency in cases was greater than that of European Americans (38.6% vs. 20.6%, respectively; p = 0.0076). The allele frequency in controls was significantly lower (0% vs. 20.6%, p = 0.0054). Next, to determine whether other known mutations influenced iron phenotypes, the exome data were used to screen for mutations in HAMP, HJV, TFR2, FPN1, and TMPRSS6. One case participant was heterozygous for HJV p.G320V; he was among the six case participants who did not have GNPAT p.D519G. No other known or probable mutation that would possibly explain differences in expression between cases and controls was found.To examine functional consequences of GNPAT deficiency, we now have performed siRNA-based knockdown of GNPAT in the human liver cell line HepG2/C3A. GNPAT was efficiently knocked down by its siRNA by ~85% compared to control siRNA as assayed by qPCR. This knockdown resulted in a >17-fold decrease in HAMP mRNA expression. mRNA expression of two genes coordinately regulated with HAMP, ID1 (inhibitor of DNA binding protein 1) and SMAD7 (SMAD family member 7), was similarly decreased, as was expression of phospho-SMAD 1/5/8, suggesting that GNPAT knockdown affects the baseline activity of the bone morphogenetic protein 6 (BMP6)-SMAD pathway.Our data indicate that GNPAT p.D519G is associated with a high-iron phenotype in male HFE C282Y homozygotes and may participate in hepcidin regulation, thereby modifying severity of iron overload. The results identify GNPAT as a candidate gene for expanded studies to examine its function in regulating iron absorption and metabolism and to identify newly-diagnosed C282Y homozygotes whose risk for development of severe iron overload is great. DisclosuresNo relevant conflicts of interest to declare.

Reproducibility of liver iron concentration measured on a biopsy sample: a validation study in vivo.

Determination of liver iron concentration is essential to predict iron related tissue damage and to guide chelation therapy. To assess the reliability of a single biopsy iron concentration determination in representing the whole liver iron concentration, we conducted a prospective study performing two immediately successive liver biopsies from 61 noncirrhotic, iron overloaded thalassemia patients, directing the needle to different direction from the same skin cut. The correlation among sample biopsies was determined by both regression analysis and the Bland-Altman method. The results showed that overall correlation between the two samples was high (Pearson's coefficient of correlation r = 0.970, P < 0.0001; 95% CI 0.951-0.981; R(2) = 0.941). To evaluate if sample dimension had an impact on the analysis we analyzed separately biopsy couples were both sample gross weight were ≥1 mg dry weight (n = 16) from the others [one or both had a specimen gross weight <1 mg dry weight (n = 45)]. In the first case, correlation coefficient r was equal to 0.998 (P < 0.0001; 95% CI: 0.995-0.999; R(2) = 0.996) while in the latter was 0.960 (P < 0.0001; 95% CI: 0.928-0.977; R(2) = 0.921). In no instance second specimen prediction interval was outside the interval implying different prognostic and therapeutic decision if both liver samples gross weight were ≥1 mg dry weight. The Bland-Altman plot analysis showed the same trend observed using Pearson's correlation coefficient in the analyzed sample categories. Hepatic iron concentration determined in "good quality" biopsy specimen (i.e. sample gross weight ≥1 mg dry weight) is a reliable indicator of whole liver iron concentration.

Hyperinsulinemia induces hepatic iron overload by increasing liver TFR1 via the PI3K/IRP2 pathway.

Dysmetabolic iron overload syndrome (DIOS) is frequently observed, but the underlying mechanism remains unclear. We propose the hypothesis that hyperinsulinemia, a common characteristic of DIOS, may stimulate liver transferrin receptor 1 (TFR1) expression via the PI3K/iron regulatory protein 2 (IRP2) pathway, leading to the occurrence of DIOS. The hepatic iron content, serum iron parameters, and expressions of TFRs and IRPs in the liver were determined in rats with temporary or long-lasting hyperinsulinemia induced by acute or chronic administration of insulin. The effect of insulin on TFR1 expression and its molecular mechanism were determined in HL-7702 cells in vitro. It was found that long-lasting hyperinsulinemia significantly increased TFR1 expression in the liver and induced mild-to-moderate hepatic iron overload, which was accompanied by a normal level of serum iron. Insulin markedly upregulated both protein and mRNA levels of TFR1 in HL-7702 cells. The stability of TFR1 mRNA stability, together with expression of IRPs expression, were both significantly increased by insulin treatment. Insulin-induced TFR1 expression was blocked by IRP2, but not by IRP1 interference, and disappeared when HL-7702 cells were pretreated with LY294002, triciribine hydrate, or rapamycin. In conclusion, the findings of this study indicate that hyperinsulnemia could induce hepatic iron overload by upregulating liver TFR1 via the PI3K/AKT/mTOR/IRP2 pathway, which may be one of the main reasons for the occurrence of DIOS.

Brain iron overload, insulin resistance, and cognitive performance in obese subjects: a preliminary MRI case-control study.

The linkage among the tissue iron stores, insulin resistance (IR), and cognition remains unclear in the obese population. We aimed to identify the factors that contribute to increased hepatic iron concentration (HIC) and brain iron overload (BIO), as evaluated by MRI, and to evaluate their impact on cognitive performance in obese and nonobese subjects. We prospectively recruited 23 middle-aged obese subjects without diabetes (13 women; age 50.4 ± 7.7 years; BMI 43.7 ± 4.48 kg/m2) and 20 healthy nonobese volunteers (10 women; age 48.8 ± 9.5 years; BMI 24.3 ± 3.54 kg/m2) in whom iron load was assessed in white and gray matter and the liver by MRI. IR was measured from HOMA-IR and an oral glucose tolerance test. A battery of neuropsychological tests was used to evaluate the cognitive performance. Multivariate regression analysis was used to identify the independent associations of BIO and cognitive performance. A significant increase in iron load was detected at the caudate nucleus (P < 0.001), lenticular nucleus (P = 0.004), hypothalamus (P = 0.002), hippocampus (P < 0.001), and liver (P < 0.001) in obese subjects. There was a positive correlation between HIC and BIO at caudate (r = 0.517, P < 0.001), hypothalamus (r = 0.396, P = 0.009), and hippocampus (r = 0.347, P < 0.023). The area under the curve of insulin was independently associated with BIO at the caudate (P = 0.001), hippocampus (P = 0.028), and HIC (P = 0.025). BIOs at the caudate (P = 0.028), hypothalamus (P = 0.006), and lenticular nucleus (P = 0.012) were independently associated with worse cognitive performance. Obesity and IR may contribute to increased HIC and BIO being associated with worse cognitive performance. BIO could be a potentially useful MRI biomarker for IR and obesity-associated cognitive dysfunction.

Armodafinil, Not So Silent as It Appears!

Introduction: Armodafinil is the pharmacologically active R-enantiomer of modafinil, a widely prescribed wake-promoting agent used to treat several sleep-related disorders including narcolepsy, shift work sleep disorder, and obstructive sleep apnea. The most common side effects of armodafinil are headache, nausea, and insomnia. The most serious adverse effects are angioedema, severe psychosis, and palpitations. There was no previously reported adverse event of acute hepatitis for this drug. Here, we report first such case. An 18-year-old male with a recent diagnosis of narcolepsy was started on armodafinil therapy. Within a week of starting the drug, the patient developed progressive headache, decreased appetite, nausea, and later jaundice, which required him to visit the emergency department (ED). His CBC with differential count was normal, but the total bilirubin was 2.3 mg/dL (direct 0.9 mg/dL), AST 24 U/L, and ALT 101 U/L. All the above parameters were normal a week before the therapy was begun. The patient did not take acetaminophen, NSAIDs, or alcohol prior to his presentation to the ED. He was also not on any other medications at this time, hence an idiosyncratic reaction to armodafinil was suspected and the medication was discontinued. On his follow-up appointment 10 days later, the patient’s total bilirubin was 0.6 mg/dL (normal) with no clinical evidence of jaundice. The patient was commenced on an alternative therapy for narcolepsy. Further investigations were negative for viral hepatitis A, B, and C; however, he was found to have elevated iron saturation of 94%, serum iron 218 mcg/dl, and TIBC 232 mcg/dL. Hereditary hemochromatosis was suspected. Further testing for HFE gene mutation was positive for C282Y homozygous mutation, and negative for H63D. MRI showed a pattern of iron deposition consistent with primary hemochromatosis with hepatic iron concentration of 3.3 mg/g, consistent with mild iron overload. The patient is currently being treated with phlebotomy for hereditary hemochromatosis. We report for the first time, a new drug reaction for armodafinil. The exact etiology is not clear as yet, but it appears that this could be an idiosyncratic type reaction. Since our patient was on monotherapy with a clear temporal relationship, it was easy to diagnose. This can be a very challenging drug reaction to diagnose in patients on polypharmacy, especially when there were no reported cases before. For this reason, this case report serves as an index case and carries paramount significance in alerting physicians. Physicians treating patients with armodafinil should consider checking liver function tests soon after starting this drug, especially in patients with hemochromatosis.

Branched-chain amino acids reduce hepatic iron accumulation and oxidative stress in hepatitis C virus polyprotein-expressing mice.

Background & AimsBranched-chain amino acids (BCAA) reduce the incidence of hepatocellular carcinoma (HCC) in patients with cirrhosis. However, the mechanisms that underlie these effects remain unknown. Previously, we reported that oxidative stress in male transgenic mice that expressed hepatitis C virus polyprotein (HCVTgM) caused hepatic iron accumulation by reducing hepcidin transcription, thereby leading to HCC development. This study investigated whether long-term treatment with BCAA reduced hepatic iron accumulation and oxidative stress in iron-overloaded HCVTgM and in patients with HCV-related advanced fibrosis.MethodsMale HCVTgM were fed an excess-iron diet that comprised either casein or 3.0% BCAA, or a control diet, for 6 months.ResultsFor HCVTgM, BCAA supplementation increased the serum hepcidin-25 levels and antioxidant status [ratio of biological antioxidant potential (BAP) relative to derivatives of reactive oxygen metabolites (dROM)], decreased the hepatic iron contents, attenuated reactive oxygen species generation, and restored mitochondrial superoxide dismutase expression and mitochondrial complex I activity in the liver compared with mice fed the control diet. After 48 weeks of BCAA supplementation in patients with HCV-related advanced fibrosis, BAP/dROM and serum hepcidin-25 increased and serum ferritin decreased compared with the pretreatment levels.ConclusionsBCAA supplementation reduced oxidative stress by restoring mitochondrial function and improved iron metabolism by increasing hepcidin-25 in both iron-overloaded HCVTgM and patients with HCV-related advanced fibrosis. These activities of BCAA may partially account for their inhibitory effects on HCC development in cirrhosis patients.

Liver toxicity of thioacetamide is increased by hepatocellular iron overload.

An increase in hepatic iron concentration might exacerbate liver injury. However, it is unknown whether hepatic iron overload may exacerbate acute liver injury from various toxins. Therefore, we evaluated how manipulations to increase hepatic iron concentration affected the extent of acute liver injury from thioacetamide. In this study, we used rats with either "normal" or increased hepatic iron concentration. Iron overload was induced by either providing excess iron in the diet or by injecting iron subcutaneously. Both routes of providing excess iron induced an increase in hepatic iron overload. Meanwhile, the subcutaneous route induced both hepatocellular and sinusoidal cell iron deposition; the oral route induced lesser degree of hepatic iron concentration and only hepatocellular iron overload. Thioacetamide administration to the rats with "normal" hepatic iron concentration induced hepatic cell necrosis and apoptosis associated with a remarkable increase in serum aminotransaminases and depletion of hepatic glutathione and other antioxidative indices. Thioacetamide administration to the iron-overloaded rats exacerbated the extent of liver injury only in the rats orally induced with iron overload. In the rats subcutaneously induced with iron overload, the extent of liver injury from thioacetamide was not different from that observed in the rats with "normal" iron overload. It was concluded that the outcome of thioacetamide-induced acute liver injury may depend on both the level of hepatic iron concentration and on the cellular distribution of iron. While isolated hepatocellular iron overload may exacerbate thioacetamide-induced acute liver injury, a combined hepatocellular and sinusoidal cell iron deposition, even at high hepatic iron concentration, had no such an effect.

The therapeutic effects of MSc1 nanocomplex, synthesized by nanochelating technology, on experimental autoimmune encephalomyelitic C57/BL6 mice.

PurposeCurrently approved therapies for multiple sclerosis (MS) at best only slow down its progression. Therefore, it is necessary to utilize novel technologies in order to synthesize smart multifunctional structures. In the present study, for the first time we evaluated the therapeutic potential of MSc1 nanocomplex, which was designed based on novel nanochelating technology.Materials and methodsMSc1 cell-protection capacity, with and without iron bond, was evaluated against hydrogen peroxide (H2O2)-induced oxidative stress in cultured rat pheochromocytoma-12 cells. The ability of MSc1 to maintain iron bond at pH ranges of 1–7 was evaluated. Nanocomplex toxicity was examined by estimating the intraperitoneal median lethal dose (LD50). Experimental autoimmune encephalomyelitic mice were injected with MSc1 14 days after disease induction, when the clinical symptoms appeared. The clinical score, body weight, and disease-induced mortality were monitored until day 54. In the end, after collecting blood samples for assessing hemoglobin and red blood cell count, the brains and livers of the mice were isolated for hematoxylin and eosin staining and analysis of iron content, respectively.ResultsThe results showed that MSc1 prevented H2O2-induced cell death even after binding with iron, and it preserved its bond with iron constant at pH ranges 1–7. The nanocomplex intraperitoneal LD50 was 1,776.59 mg/kg. MSc1 prompted therapeutic behavior and improved the disabling features of experimental autoimmune encephalomyelitis, which was confirmed by decreased clinical scores versus increased body mass and 100% survival probability. It did not cause any adverse effects on hemoglobin or red blood cell count. Histopathological studies showed no neural loss or lymphocyte infiltration in MSc1-treated mice, while the hepatic iron content was also normal.ConclusionThese results demonstrate that MSc1 could be a promising beneficial novel agent and has the capacity to be evaluated in further studies.

Hemochromatosis Mistakenly Treated as Rheumatoid Arthritis

A 44-year-old female patient was admitted to our clinic with complaints of episodic pain, swelling attacks, and progressive deformity in both wrists and metacarpophalangeal joints lasting for five years. Based on her complaints, she had been diagnosed with rheumatoid arthritis and taken methotrexate, sulphasalazine, and prednisolone for two years, however, the patient had discontinued her treatment a year earlier due to ongoing symptoms. Physical examination revealed limited range of motion of both wrists and flexion deformity of the fingers without active inflammation signs. Hand X-ray showed typical signs of osteoarthritis characterized by narrowed joint spaces, subchondral sclerosis, and cyst formation. The distal and proximal interphalangeal joints were markedly preserved, and there were large, hook-like osteophytes in the heads of the metacarpal bones, indicating a typical presentation of hemochromatosis. Laboratory tests revealed that the erythrocyte sedimentation rate and C-reactive protein and uric acid levels were within the normal range, and the antibody tests were negative for rheumatoid factor, anti-nuclear antibodies, and anti-cyclic citrullinated peptides. Although the serum iron and ferritin levels were normal, there was a high transferrin saturation rate. Magnetic resonance imaging demonstrated a hepatic iron concentration of 44 µmol/g (reference: <36 µmol/g). Genetic studies showed homozygous for the H63D mutation. Based on these findings, the patient was diagnosed with hereditary hemochromatosis and scheduled for follow-up visits. In conclusion, hemochromatosis should be considered in the differential diagnosis in patients suffering from slow-progressing arthritis with chronic deformity.

Hepcidin Is Directly Regulated by Insulin and Plays an Important Role in Iron Overload in Streptozotocin-Induced Diabetic Rats

Iron overload is frequently observed in type 2 diabetes mellitus (DM2), but the underlying mechanisms remain unclear. We hypothesize that hepcidin may be directly regulated by insulin and play an important role in iron overload in DM2. We therefore examined the hepatic iron content, serum iron parameters, intestinal iron absorption, and liver hepcidin expression in rats treated with streptozotocin (STZ), which was given alone or after insulin resistance induced by a high-fat diet. The direct effect of insulin on hepcidin and its molecular mechanisms were furthermore determined in vitro in HepG2 cells. STZ administration caused a significant reduction in liver hepcidin level and a marked increase in intestinal iron absorption and serum and hepatic iron content. Insulin obviously upregulated hepcidin expression in HepG2 cells and enhanced signal transducer and activator of transcription 3 protein synthesis and DNA binding activity. The effect of insulin on hepcidin disappeared when the signal transducer and activator of transcription 3 pathway was blocked and could be partially inhibited by U0126. In conclusion, the current study suggests that hepcidin can be directly regulated by insulin, and the suppressed liver hepcidin synthesis may be an important reason for the iron overload in DM2.

HFE gene mutations in hyperferritinemia associated with one or more components of metabolic syndrome

Hyperferritinemia is a common abnormality. This study determined the prevalence of hepatic iron overload in subjects of northern European origin with hyperferritinemia.Fifty-two consecutive subjects referred for evaluation of suspected iron overload (serum ferritin level >350 μg/L) were divided into 3 groups: group 1, increased transferrin saturation and no significant hemochromatosis gene product (HFE) mutations (N = 17); group 2, increased transferrin saturation and C282Y homozygosity or C282Y/H63D compound heterozygosity (N = 22); and group 3, normal transferrin saturation and no significant HFE mutations (N = 13). All subjects underwent magnetic resonance R2 relaxometry for quantitation of hepatic iron concentration (HIC).The HIC was significantly higher in group 2 subjects (123 ± 22 μmol/g) compared with groups 1 and 3 subjects (39 ± 4 and 36 ± 5 μmol/g, respectively) (P < .01). Nine of 22 subjects in group 2 had an increase of their HIC to greater than 3 times the upper limit of normal compared with none in the other 2 groups (P < .01).An increase of HIC to greater than 3 times the upper limit of normal is highly unlikely in hyperferritinemic subjects who do not have HFE-related hereditary hemochromatosis or causes of secondary iron overload.

Estimating Iron Overload in Patients with Suspected Liver Disease and Elevated Serum Ferritin

BackgroundIron status evaluation in patients with suspected liver disease and elevated serum ferritin is often challenging because hyperferritinemia does not always indicate iron overload. A reliable approach to estimate iron overload without exposing the patient to unnecessary investigations would help the clinician to identify patients who may take advantage of iron-removal therapy. MethodsWe analyzed all liver biopsies, including measurement of hepatic iron concentration, performed at the University Hospital Zurich from 1997 to 2010 to identify clinical and laboratory predictors of iron overload in patients with elevated serum ferritin (n = 147). ResultsHyperferritinemia was predictive of iron overload only in patients with a high level of serum ferritin (>2000 μg/L). In patients with moderate hyperferritinemia, liver transaminases inversely correlated with hepatic iron concentration. A combination of both parameters expressed as ferritin/aspartate transaminase ratio was highly predictive of tissue iron overload (sensitivity 83.3%, specificity 78.6%). Receiver operating characteristic analysis resulted in an area under the curve of 0.83. ConclusionsWe established a simple and reliable method to correctly estimate iron overload in patients with suspected liver disease and elevated serum ferritin.

Optimal region-of-interest MRI R2* measurements for the assessment of hepatic iron content in thalassaemia major

ObjectivesTo evaluate the performance of region-of-interest (ROI)-based MRI R2* measurements by using the first-moment noise-corrected model (M1NCM) to correct the non-central Chi noise in magnitude images from phased arrays for hepatic iron content (HIC) assessment. MethodsR2* values were quantified using the M1NCM model. Three approaches were employed to determine the representative R2*: fitting of the ROI-averaged signal (average-then-fit, ATF); outputting the median and mean of R2*s from the pixel-wise fitting of decay signals within the ROI (denoted as PWFmed and PWFmea, respectively). The accuracy and precision of the three approaches were evaluated on synthesized data. The agreement among these approaches and their intra- and inter-observer reproducibility were assessed on 105 thalassaemia major patients. ResultsSimulations showed that ATF consistently yielded the highest accuracy and precision at varying noise levels. By contrast, PWFmed and PWFmea slightly and significantly overestimated high R2* at poor signal-to-noise ratios, respectively. Patient study showed that ATF agreed well with PWFmed, whereas PWFmea produced high R2* measurements for patients with severe HIC. No significant difference was observed in the reproducibility of the three approaches. ConclusionsPWFmea tends to overestimate high R2*, whereas ATF and PWFmed can produce more accurate R2* measurements for HIC assessment.

Iron deficiency alters megakaryopoiesis and platelet phenotype independent of thrombopoietin

Iron deficiency is a common cause of reactive thrombocytosis, however, the exact pathways have not been revealed. Here we aimed to study the mechanisms behind iron deficiency-induced thrombocytosis. Within few weeks, iron-depleted diet caused iron deficiency in young Sprague-Dawley rats, as reflected by a drop in hemoglobin, mean corpuscular volume, hepatic iron content and hepcidin mRNA in the liver. Thrombocytosis established in parallel. Moreover, platelets produced in iron deficient animals displayed a higher mean platelet volume and increased aggregation. Bone marrow studies revealed subtle alterations that are suggestive of expansion of megakaryocyte progenitors, an increase in megakaryocyte ploidy and accelerated megakaryocyte differentiation. Iron deficiency did not alter the production of hematopoietic growth factors such as thrombopoietin, interleukin 6 or interleukin 11. Megakaryocytic cell lines grown in iron-depleted conditions exhibited reduced proliferation but increased ploidy and cell size. Our data suggest that iron deficiency increases megakaryopoietic differentiation and alters platelet phenotype without changes in megakaryocyte growth factors, specifically TPO. Iron deficiency-induced thrombocytosis may have evolved to maintain or increase the coagulation capacity in conditions with chronic bleeding.

Iron deficiency anemia in a ring-tailed lemur (Lemur catta) with concurrent chronic renal failure

A 16-year-old vasectomized male ring-tailed lemur (Lemur catta) with a history of suspected chronic renal failure was evaluated because of extreme lethargy, hyperpnea, and abscess of the right pectoral scent gland. Examination of the anesthetized patient revealed an impacted right pectoral scent gland with serosanguineous exudate. A CBC and serum biochemical analysis revealed severe anemia, marked azotemia, hyperphosphatemia, and hypocalcemia. Supportive care (including fluid therapy and phosphorus binder administration) was initiated for renal failure; the affected gland was cleaned, and antimicrobials were administered. The patient received 1 blood transfusion, and darbepoetin alfa was administered weekly to stimulate RBC production. Anemia and azotemia persisted. Three months after treatment started, serum iron analysis revealed that iron deficiency was the probable cause for the lack of a consistent regenerative response to darbepoetin injections. Iron dextran injections resulted in a marked regenerative response; however, serum biochemical analysis results after the second injection were consistent with hepatic injury. Hepatic enzyme activities normalized following discontinuation of iron dextran treatment, but the lemur's Hct declined rapidly despite supplementary iron administration PO. The patient developed severe mandibular osteomyelitis and was euthanized because of poor prognosis. Postmortem evaluation of hepatic iron concentration confirmed iron deficiency. The family Lemuridae is considered prone to hemosiderosis and hemochromatosis, which delayed rapid diagnosis and treatment of the lemur's disease. Apparent hepatic injury following iron dextran injections further complicated treatment. Findings for this lemur support the use of species-specific total iron binding capacity and total serum iron and ferritin concentrations in evaluation of an animal with suspected iron deficiency.

Ductular reaction in hereditary hemochromatosis: The link between hepatocyte senescence and fibrosis progression

The development of portal fibrosis following the iron loading of hepatocytes is the first stage of fibrogenesis in hereditary hemochromatosis. In other chronic liver diseases it has been shown that a ductular reaction (DR) appears early, correlates with fibrosis progression, and is a consequence of activation of an alternative pathway of hepatocyte replication. This study was designed to investigate the presence of the DR in hemochromatosis and describe its associations. Liver biopsies from 63 C282Y homozygous patients were assessed for hepatic iron concentration (HIC) and graded for iron loading, fibrosis stage, steatosis, and inflammation. Immunostaining allowed quantification of the DR, hepatocyte senescence and proliferation, and analysis incorporated clinical data. Hepatocyte senescence was positively correlated with HIC, serum ferritin, and oxidative stress. A DR was demonstrated and occurred prior to histological fibrosis. HIC, age, hepatocyte senescence and proliferation, portal inflammation, and excessive alcohol consumption all had significant associations with the extent of the DR. In multivariate analysis, iron loading, hepatocyte replicative arrest, and portal inflammation remained independently and significantly associated with the DR. Of factors associated with fibrosis progression, the DR (odds ratio [OR] 10.86 P<0.0001) and the presence of portal inflammation (OR 4.31, P=0.028) remained significant after adjustment for cofactors. The extent of the DR regressed following therapeutic venesection. Iron loading of hepatocytes leads to impaired replication, stimulating the development of the DR in hemochromatosis and this correlates strongly with hepatic fibrosis. Portal inflammation occurs in hemochromatosis and is independently associated with the DR and fibrosis, and thus its role in this disease should be evaluated further.

Liver transplantation normalizes serum hepcidin level and cures iron metabolism alterations inHFEhemochromatosis

Defects in human hemochromatosis protein (HFE) cause iron overload due to reduced hepatic hepcidin secretion. Liver transplantation (LT) is a key treatment for potential complications from HFE-related hereditary hemochromatosis (HH). This study evaluated hepcidin secretion and iron burden after LT to elucidate HH pathophysiology. Patients (n=18) homozygous for the p.Cys282Tyr mutation in the HFE gene underwent LT between 1999 and 2008. Serum iron, serum hepcidin, and hepatic iron concentrations were determined before LT and at the end of follow-up (median 57 months). Mortality and causes of death were determined. Survival was compared to that of the overall patient population that received LT. Before LT, serum hepcidin levels were low (0.54 ± 2.5 nmol/L; normal range: 4-30 nmol/L). After LT, 11 patients had iron evaluations; none received iron depletion therapy; all had normal transferrin saturation. The mean serum ferritin was 185 (± 99) μg/L. Magnetic resonance imaging showed that iron overload was absent in nine patients, mild in one patient with metabolic syndrome, and high (180 μmol/g) in one patient with hereditary spherocytosis discovered after LT. At the end of follow-up, serum hepcidin was normal in 10 patients (11.12 ± 7.6 nmol/L; P<0.05) and low in one patient with iron deficiency anemia. Survival was 83% and 67% at 1 and 5 years, respectively. Survival was similar for patients with HH and patients that received LT for other causes. In HH, LT normalized hepcidin secretion and prevented recurrence of hepatic iron overload. Survival was similar to that of patients who received LTs for other liver diseases.

Efficacy and safety of combined oral iron chelation therapy with deferasirox and deferiprone in a patient with beta-thalassemia major and persistent iron overload.

Efficacy and safety of combined oral iron chelation therapy with deferasirox and deferiprone in a patient with beta-thalassemia major and persistent iron overload.