The impact of initiating posaconazole on tacrolimus pharmacokinetics in allogeneic stem cell transplantation.

BACKGROUND: Posaconazole reduces the risk of invasive Aspergillus in transplant patients, but significantly inhibits tacrolimus metabolism. One study demonstrated that a three-fold dose reduction of tacrolimus was required to obtain therapeutic concentrations when used with posaconazole. However, with empiric dose reduction, there is a risk of subtherapeutic tacrolimus levels and subsequent graft failure or graft-versus-host disease. Overall, the existing data on the impact of posaconazole on tacrolimus pharmacokinetics is limited. OBJECTIVE: The purpose of this study is to determine whether tacrolimus doses should be decreased upon initiation of posaconazole in patients receiving an allogeneic stem cell transplant. METHODS: This is a retrospective chart review at an academic medical center. All allogeneic stem cell transplant adults who received concomitant posaconazole and tacrolimus from February 2016 through December 2017 were included. RESULTS: Seventy-nine patients identified using an internal electronic database were analyzed. The median time to therapeutic tacrolimus concentration was significantly longer in patients who did not receive an empiric dose reduction (0% DR, 10d; 1-30% DR, 4d; 31-65% DR, 5d; >65% DR, 4d; p = 0.0395). The rate of supratherapeutic levels was highest amongst patients who did not receive an empiric DR, and was noted to be significant compared to the group that had 31-65% DR (p < 0.001). CONCLUSION: This study validates our current practice of instituting an empiric 50% dose reduction of oral tacrolimus to 0.03 mg/kg/day when used concomitantly with posaconazole to achieve therapeutic levels in allogeneic stem cell transplant patients.

Moxifloxacin versus levofloxacin for antibacterial prophylaxis in acute leukemia patients.

OBJECTIVE: The primary endpoint of this study was to determine the incidence of febrile neutropenia among patients receiving either moxifloxacin or levofloxacin for antibacterial prophylaxis. Secondary endpoints were number of documented infections and in-hospital mortality in patients who develop febrile neutropenia. METHODS: A single-center retrospective cohort analysis at a large tertiary care academic medical center was conducted. This study included adult acute leukemia patients (age ≥18 years old) who received inpatient antibacterial prophylaxis (moxifloxacin or levofloxacin) from 1 July 2012 to 1 October 2014. Patients were excluded from the study if they were treated with antimicrobial therapy in the preceding five days or admitted to the hospital with neutropenic fever. Fisher's exact test was used for categorical data and Mann-Whitney test for continuous data. Logistic regression analysis was used to determine risk factors for febrile neutropenia. RESULTS: Eighty-five patients were included in the final analysis with 40 patients who received moxifloxacin and 45 patients who received levofloxacin. Baseline characteristics were similar between the two groups. Twenty-two patients experienced febrile neutropenia requiring intravenous antibiotics in the moxifloxacin group and 30 patients in the levofloxacin group (P = 0.190). Age and duration of neutropenia appeared to predict for febrile neutropenia; however, after multivariate analysis, longer duration of neutropenia was shown to be the best predictor for febrile neutropenia with an odds ratio of 4.69 (95% CI, 1.697-12.968). Both groups had similar rates of documented infections and in-hospital morality. CONCLUSION: Moxifloxacin and levofloxacin showed similar rates of febrile neutropenia when used for neutropenic antibacterial prophylaxis in acute leukemia patients.

Intravenous Bevacizumab Therapy in a Patient with Hereditary Hemorrhagic Telangiectasia, ENG E137K, Alcoholic Cirrhosis, and Portal Hypertension.

Intravenous bevacizumab decreased mucosal bleeding in some patients with hereditary hemorrhagic telangiectasia (HHT). We treated a 47-year-old male who had HHT, severe epistaxis, and gastrointestinal bleeding, alcoholic cirrhosis, and portal hypertension with intravenous bevacizumab 2.5 mg/kg every 2 weeks. We tabulated these measures weekly during weeks 1-33 (no bevacizumab); 34-57 (bevacizumab); and 58-97 (no bevacizumab): hemoglobin (Hb) levels; platelet counts; units of transfused packed erythrocytes (PRBC units); and quantities of iron infused as iron dextran to support erythropoiesis. We performed univariate and multivariable analyses. We sequenced his ENG and ACVRL1 genes. Epistaxis and melena decreased markedly during bevacizumab treatment. He reported no adverse effects due to bevacizumab. Mean weekly Hb levels were significantly higher and mean weekly PRBC units and quantities of intravenous iron were significantly lower during bevacizumab treatment. We performed a multiple regression on weekly Hb levels using these independent variables: bevacizumab treatment (dichotomous); weekly platelet counts; weekly PRBC units; and weekly quantities of intravenous iron. There was 1 positive association: (bevacizumab treatment; p = 0.0046) and 1 negative association (PRBC units; p = 0.0004). This patient had the novel ENG mutation E137K (exon 4; c.409G→A). Intravenous bevacizumab treatment 2.5 mg/kg every 2 weeks for 24 weeks was well-tolerated by a patient with HHT due to ENG E137K and was associated with higher weekly Hb levels and fewer weekly PRBC units.

Genetic analysis of 10 pedigrees with inherited retinal degeneration by exome sequencing and phenotype-genotype association.

Our purpose was to identify causative mutations and characterize the phenotype associated with the genotype in 10 unrelated families with autosomal recessive retinal degeneration. Ophthalmic evaluation and DNA isolation were carried out in 10 pedigrees with inherited retinal degenerations (IRD). Exomes of probands from eight pedigrees were captured using Nimblegen V2/V3 or Agilent V5+UTR kits, and sequencing was performed on Illumina HiSeq. The DHDDS gene was screened for mutations in the remaining two pedigrees with Ashkenazi Jewish ancestry. Exome variants were filtered to detect candidate causal variants using exomeSuite software. Segregation and ethnicity-matched control sample analysis were performed by dideoxy sequencing. Retinal histology of a patient with DHDDS mutation was studied by microscopy. Genetic analysis identified six known mutations in ABCA4 (p.Gly1961Glu, p.Ala1773Val, c.5461-10T>C), RPE65 (p.Tyr249Cys, p.Gly484Asp), PDE6B (p.Lys706Ter) and DHDDS (p.Lys42Glu) and ten novel potentially pathogenic variants in CERKL (p.Met323Val fsX20), RPE65 (p.Phe252Ser, Thr454Leu fsX31), ARL6 (p.Arg121His), USH2A (p.Gly3142Ter, p.Cys3294Trp), PDE6B (p.Gln652Ter), and DHDDS (p.Thr206Ala) genes. Among these, variants/mutations in two separate genes were observed to segregate with IRD in two pedigrees. Retinal histopathology of a patient with a DHDDS mutation showed severe degeneration of retinal layers with relative preservation of the retinal pigment epithelium. Analysis of exome variants in ten pedigrees revealed nine novel potential disease-causing variants and nine previously reported homozygous or compound heterozygous mutations in the CERKL, ABCA4, RPE65, ARL6, USH2A, PDE6B, and DHDDS genes. Mutations that could be sufficient to cause pathology were observed in more than one gene in one pedigree.

Adult perceptions of dental fluorosis and select dental conditions-an Asian perspective.

OBJECTIVE: To compare lay people's perceptions with regard to various levels of dental fluorosis and select dental defects versus normal dentition. METHODS: Adults rated digitally created photographs made showing lips (without retraction) and teeth depicting the following conditions: no apparent aesthetic defects (normal, Thylstrup- Fejerskov score 0 - TF0), 6 levels of fluorosis (TF1-6), carious lesions (two cavitated and one noncavitated), malocclusions (Class II, Class III, anterior open bite and greater spacing), extrinsic staining and an incisal chip. The photographs were displayed on colour-calibrated iPads(™) . Participants used a self-administered questionnaire to rate their perceptions on (Item 1) how normal teeth were, (Item 2) how attractive the teeth were, (Item 3) need to seek correction of teeth, (Item 4) how well the person took care of their teeth and (Item 5) whether the person was born like this. Data from Item 5 were excluded due to low reliability. RESULTS: Ratings for Item 1 showed that TF1-4 was similar or significantly better than TF0. For Item 2, TF1 and TF4 were significantly better than TF0, with TF2 and TF3 being similar. For Item 3, there was significantly lower need to seek correction with TF2 and TF4 versus TF0, whereas TF1 and TF3 were similar to TF0. TF5 and TF6 were rated significantly lower than TF0 for Item 1 and Item 2, and significantly higher rating for Item 3 (need to seek correction). Ratings for Item 4 were similar, with TF1, TF2 and TF4 being rated significantly higher than TF0, and TF5 and TF6 being rated lower. Cavitated caries and staining were generally perceived as being significantly less favourable than TF6, with higher need to seek correction as well. Noncavitated carious lesion and incisal chip were rated similar to TF0. Cavitated carious lesions were rated aesthetically similar or significantly worse than TF0 and TF6. CONCLUSIONS: Severe fluorosis (TF5 and 6) was perceived to be less aesthetically pleasing and received higher ratings for need to seek correction than normal teeth. Mild-to-moderate fluorosis (TF1-4) showed similar or better aesthetic perceptions and similar or lower need to seek correction, when compared to normal teeth (TF0). Easily visible cavitated dental caries was rated worse than teeth with severe fluorosis (TF6) and normal teeth (TF0).

Ocular Phenotype of a Family with FAM161A-associated Retinal Degeneration.

BACKGROUND: Characterization of retinal degeneration (RD) using high-resolution retinal imaging and exome sequencing may identify phenotypic features that correspond with specific genetic defects. MATERIALS AND METHODS: Six members from a non-consanguineous Indian family (three affected siblings, their asymptomatic parents and an asymptomatic child) were characterized clinically, using visual acuity, perimetry, full-field electroretinography (ERG), optical coherence tomography and cone structure as outcome measures. Cone photoreceptors were imaged in the proband using adaptive optics scanning laser ophthalmoscopy. The exome was captured using Nimblegen SeqCap EZ V3.0 probes and sequenced using lllumina HiSeq. Reads were mapped to reference hg19. Confirmation of variants and segregation analysis was performed using dideoxy sequencing. RESULTS: Analysis of exome variants using exomeSuite identified five homozygous variants in four genes known to be associated with RD. Further analysis revealed a homozygous nonsense mutation, c.1105 C > T, p.Arg335Ter, in the FAM161A gene segregating with RD. Three additional variants were found to occur at high frequency. Affected members showed a range of disease severity beginning at different ages, but all developed severe visual field and outer retinal loss. CONCLUSIONS: Exome analysis revealed a nonsense homozygous mutation in FAM161A segregating with RD with severe vision loss and a range of disease onset and progression. Loss of outer retinal structures demonstrated with high-resolution retinal imaging suggests FAM161A is important for normal photoreceptor structure and survival. Exome sequencing may identify causative genetic variants in autosomal recessive RD families when other genetic test strategies fail to identify a mutation.

Investigating the Molecular Basis of Retinal Degeneration in a Familial Cohort of Pakistani Decent by Exome Sequencing.

PURPOSE: To define the molecular basis of retinal degeneration in consanguineous Pakistani pedigrees with early onset retinal degeneration. METHODS: A cohort of 277 individuals representing 26 pedigrees from the Punjab province of Pakistan was analyzed. Exomes were captured with commercial kits and sequenced on an Illumina HiSeq 2500. Candidate variants were identified using standard tools and analyzed using exomeSuite to detect all potentially pathogenic changes in genes implicated in retinal degeneration. Segregation analysis was performed by dideoxy sequencing and novel variants were additionally investigated for their presence in ethnicity-matched controls. RESULTS: We identified a total of nine causal mutations, including six novel variants in RPE65, LCA5, USH2A, CNGB1, FAM161A, CERKL and GUCY2D as the underlying cause of inherited retinal degenerations in 13 of 26 pedigrees. In addition to the causal variants, a total of 200 variants each observed in five or more unrelated pedigrees investigated in this study that were absent from the dbSNP, HapMap, 1000 Genomes, NHLBI ESP6500, and ExAC databases were identified, suggesting that they are common in, and unique to the Pakistani population. CONCLUSIONS: We identified causal mutations associated with retinal degeneration in nearly half of the pedigrees investigated in this study through next generation whole exome sequencing. All novel variants detected in this study through exome sequencing have been cataloged providing a reference database of variants common in, and unique to the Pakistani population.

The Tameside and Glossop Early Attachment Service: Meeting the emotional needs of parents and their babies.

Parent-infant emotional health is probably one of the most complex arenas in which mental health, maternity and health visiting services operate. This critical period can be highly emotionally charged, not only for the infant but also be for the parent. While most parents essentially get it right, severe ruptures in the parent-infant relationship can occur, and can have serious consequences. This paper describes a comprehensive and cost-effective parent infant mental health service based on a psychodynamic model. The service aims to meet the needs of all parents from those with a high level of need through to a universal provision. Strategic and theoretical underpinnings of the service model are described.

Molecular diagnostic testing by eyeGENE: analysis of patients with hereditary retinal dystrophy phenotypes involving central vision loss.

PURPOSE: To analyze the genetic test results of probands referred to eyeGENE with a diagnosis of hereditary maculopathy. METHODS: Patients with Best macular dystrophy (BMD), Doyne honeycomb retinal dystrophy (DHRD), Sorsby fundus dystrophy (SFD), or late-onset retinal degeneration (LORD) were screened for mutations in BEST1, EFEMP1, TIMP3, and CTRP5, respectively. Patients with pattern dystrophy (PD) were screened for mutations in PRPH2, BEST1, ELOVL4, CTRP5, and ABCA4; patients with cone-rod dystrophy (CRD) were screened for mutations in CRX, ABCA4, PRPH2, ELOVL4, and the c.2513G>A p.Arg838His variant in GUCY2D. Mutation analysis was performed by dideoxy sequencing. Impact of novel variants was evaluated using the computational tool PolyPhen. RESULTS: Among the 213 unrelated patients, 38 had BMD, 26 DHRD, 74 PD, 8 SFD, 6 LORD, and 54 CRD; six had both PD and BMD, and one had no specific clinical diagnosis. BEST1 variants were identified in 25 BMD patients, five with novel variants of unknown significance (VUS). Among the five patients with VUS, one was diagnosed with both BMD and PD. A novel EFEMP1 variant was identified in one DHRD patient. TIMP3 novel variants were found in two SFD patients, PRPH2 variants in 14 PD patients, ABCA4 variants in four PD patients, and p.Arg838His GUCY2D mutation in six patients diagnosed with dominant CRD; one patient additionally had a CRX VUS. ABCA4 mutations were identified in 15 patients with recessive CRD. CONCLUSIONS: Of the 213 samples, 55 patients (26%) had known causative mutations, and 13 (6%) patients had a VUS that was possibly pathogenic. Overall, selective screening for mutations in BEST1, PRPH2, and ABCA4 would likely yield the highest success rate in identifying the genetic basis for macular dystrophy phenotypes. Because of the overlap in phenotypes between BMD and PD, it would be beneficial to screen genes associated with both diseases.

Iron overload secondary to cirrhosis: a mimic of hereditary haemochromatosis?

AIMS: Hepatic iron deposition unrelated to hereditary haemochromatosis is common in cirrhosis. The aim of this study was to determine whether hepatic haemosiderosis secondary to cirrhosis is associated with iron deposition in extrahepatic organs. METHODS AND RESULTS: Records of consecutive adult patients with cirrhosis who underwent autopsy were reviewed. Storage iron was assessed by histochemical staining of sections of liver, heart, pancreas and spleen. HFE genotyping was performed on subjects with significant liver, cardiac and/or pancreatic iron. The 104 individuals were predominantly male (63%), with a mean age of 55 years. About half (46%) had stainable hepatocyte iron, 2+ or less in most cases. In six subjects, there was heavy iron deposition (4+) in hepatocytes and biliary epithelium. All six of these cases had pancreatic iron and five also had cardiac iron. None of these subjects had an explanatory HFE genotype. CONCLUSIONS: In this series, heavy hepatocyte iron deposition secondary to cirrhosis was commonly associated with pancreatic and cardiac iron. Although this phenomenon appears to be relatively uncommon, the resulting pattern of iron deposition is similar to haemochromatosis. Patients with marked hepatic haemosiderosis secondary to cirrhosis may be at risk of developing extrahepatic complications of iron overload.

Getting it right from the start: evaluation of a DVD and booklet for new parents.

Early universal preventive interventions have the potential to improve the parent-infant relationship. Getting it Right from the Start is a DVD and booklet given free to new parents to promote sensitive and responsive early parenting and infant communication. Parents in the local area were canvassed for their views and opinions as to what their needs and feelings were about infant mental health. The resource is based on evidence from research and clinical studies in infant development and infant mental health. A matched sample design evaluation study was conducted. A 'Baby Quiz' testing parents' knowledge of different areas covered in the DVD and booklet was given to parents in receipt of the materials and also to parents not yet in receipt of the resource. Results indicated that the mean number of correct responses to the quiz items was higher in the group receiving the DVD and booklet. The percentage of poor scorers in the group who received the DVD and booklet was almost half that of the control group, showing the effectiveness of this universal intervention. Getting it Right from the Start represents a simple, low-cost method of reaching parents during the perinatal period.

A late presentation of a fatal disease: juvenile hemochromatosis.

Juvenile hemochromatosis is a rare and severe form of hereditary hemochromatosis. We report the case of a 39-year-old female who presented with heart failure and cirrhosis from previously unrecognized juvenile hemochromatosis. This is the latest presentation described in the literature. An important clue to the diagnosis was a history of amenorrhea since the age of 20 that had never been investigated. The patient died of intractable heart failure two months after the initial presentation. Juvenile hemochromatosis should be suspected in a young patient with endocrine or cardiac manifestations. Early diagnosis is crucial since phlebotomy can improve the prognosis and delay or prevent progression to heart failure and cirrhosis.

Exome analysis identified a novel mutation in the RBP4 gene in a consanguineous pedigree with retinal dystrophy and developmental abnormalities.

Retinitis Pigmentosa (RP) is a common form of retinal degeneration characterized by photoreceptor degeneration and retinal pigment epithelium (RPE) atrophy causing loss of visual field and acuities. Exome sequencing identified a novel homozygous splice site variant (c.111+1G>A) in the gene encoding retinol binding protein 4 (RBP4). This change segregated with early onset, progressive, and severe autosomal recessive retinitis pigmentosa (arRP) in an eight member consanguineous pedigree of European ancestry. Additionally, one patient exhibited developmental abnormalities including patent ductus arteriosus and chorioretinal and iris colobomas. The second patient developed acne from young age and extending into the 5(th) decade. Both patients had undetectable levels of RBP4 in the serum suggesting that this mutation led to either mRNA or protein instability resulting in a null phenotype. In addition, the patients exhibited severe vitamin A deficiency, and diminished serum retinol levels. Circulating transthyretin levels were normal. This study identifies the RBP4 splice site change as the cause of RP in this pedigree. The presence of developmental abnormalities and severe acne in patients with retinal degeneration may indicate the involvement of genes that regulate vitamin A absorption, transport and metabolism.

Identification of a novel mutation in the CDHR1 gene in a family with recessive retinal degeneration.

OBJECTIVES: To describe the clinical phenotype and identify the molecular basis of disease in a consanguineous family of Palestinian origin with autosomal recessive retinal degeneration. METHODS: Eight family members were evaluated with visual acuity and perimetry tests, color fundus photographs, full-field electroretinography, and optical coherence tomography. Cone photoreceptors surrounding the fovea were imaged in 2 members, using adaptive optics scanning laser ophthalmoscopy. Exome was captured using probes and sequenced. Readings were mapped to reference hg19. Variant calls and annotations were performed, using published protocols. Confirmation of variants and segregation analysis was performed using dideoxy sequencing. RESULTS: Analysis detected 24 037 single-nucleotide variants in one affected family member, of which 3622 were rare and potentially damaging to encoded proteins. Further analysis revealed a novel homozygous nonsense change, c.1381 C>T, p.Gln461X in exon 13 of the CDHR1 gene, which segregated with retinal degeneration in this family. Affected members had night blindness beginning during adolescence with progressive visual acuity and field loss and unmeasurable electroretinographic responses, as well as macular outer retinal loss, although residual cones with increased cone spacing were observed in the youngest individual. CONCLUSIONS: Exome analysis revealed a novel CDHR1 nonsense mutation segregating with progressive retinal degeneration causing severe central vision loss by the fourth decade of life. High-resolution retinal imaging revealed outer retinal changes suggesting that CDHR1 is important for normal photoreceptor structure and survival. CLINICAL RELEVANCE: Exome sequencing is a powerful technique that may identify causative genetic variants in families with autosomal recessive retinal degeneration.

Mild iron overload in an African American man with SLC40A1 D270V.

We report on a 46-year-old black man who resided in Alabama with normal transferrin saturation, mild hyperferritinemia, chronic hepatitis C, and 3+ iron in hepatocytes and Kupffer cells. Exome sequencing revealed heterozygosity for SLC40A1 D270V (exon 7, c.809A→T), a mutation previously reported only in 1 black patient with iron overload who resided in the Republic of South Africa. The present patient was also heterozygous for: heme transporter FLVCR1 novel allele P542S (exon 10, 1624C→T); FLVCR1 T544M (rs3207090); hemopexin (HPX) R371W (rs75307540); ferritin scavenger receptor (SCARA5) R471H (rs61737287); and transferrin receptor (TFRC) G420S (rs41295879). He had no HFE, TFR2,HJV, or HAMP mutations. D270V was not detected in 19 other African Americans with iron overload who resided in Alabama. The allele frequency of SLC40A1 D270V in 258 African American adults who participated in a health appraisal clinic was 0.0019 (95% confidence interval 0-0.0057). D270V could explain 'classical' ferroportin hemochromatosis phenotypes in some African Americans.

Common TMPRSS6 mutations and iron, erythrocyte, and pica phenotypes in 48 women with iron deficiency or depletion.

BACKGROUND: TMPRSS6 A736V is associated with lower transferrin saturation (TS), hemoglobin (Hb), and mean corpuscular volume (MCV) levels in general adult populations. We sought to identify relationships of TMPRSS6 K253E, A736V, and Y739Y to iron, erythrocyte, and pica phenotypes in women with iron deficiency or depletion. METHODS: We tabulated observations on 48 outpatient non-pregnant women who had iron deficiency (serum ferritin (SF) <14pmol/L and TS <10%) or iron depletion (SF<112pmol/L). We performed direct sequencing of TMPRSS6 exons 7 and 17 in each patient. We used age, TS, SF, Hb, MCV, pica, and TMPRSS6 allele positivity (dichotomous) or mutation genotypes (trichotomous) as variables for analyses. RESULTS: Forty-six women were white; two were black. 58.3% had iron deficiency. 45.8% had pica (pagophagia, each case). Allele frequencies were 41.7% (K253E), 36.5% (A736V), and 39.6% (Y739Y). K253E frequency was greater in women with TS ≥10% (p=0.0001). Y739Y was more frequent in women with TS <10% (p=0.0135). Mean TS was also lower in women positive for Y739Y (6±4% vs. 13±16%, respectively; p=0.0021). In multiple regressions, neither K253E, A736V, nor Y739Y genotypes were significantly associated with other variables. CONCLUSIONS: TMPRSS6 K253E frequency was greater in women with TS ≥10%. Frequency of Y739 was greater in women with TS <10%. Mean TS was lower in women with Y739Y. We observed no other significant relationship of TMPRSS6 K253E, A736V, or Y739Y with iron, erythrocyte, or pica phenotypes.

Severe microcytic anemia but increased erythropoiesis in mice lacking Hfe or Tfr2 and Tmprss6.

Cell surface proteins Hfe, Tfr2, hemojuvelin and Tmprss6 play key roles in iron homeostasis. Hfe and Tfr2 induce transcription of hepcidin, a small peptide that promotes the degradation of the iron transporter ferroportin. Hemojuvelin, a co-receptor for bone morphogenic proteins, induces hepcidin transcription through a Smad signaling pathway. Tmprss6 (also known as matriptase-2), a membrane serine protease that has been found to bind and degrade hemojuvelin in vitro, is a potent suppressor of hepcidin expression. In order to examine if Hfe and Tfr2 are substrates for Tmprss6, we generated mice lacking functional Hfe or Tfr2 and Tmprss6. We found that double mutant mice lacking functional Hfe or Tfr2 and Tmprss6 exhibited a severe iron deficiency microcytic anemia phenotype mimicking the phenotype of single mutant mice lacking functional Tmprss6 (Tmprss6msk/msk mutant) demonstrating that Hfe and Tfr2 are not substrates for Tmprss6. Nevertheless, the phenotype of the mice lacking Hfe or Tfr2 and Tmprss6 differed from Tmprss6 deficient mice alone, in that the double mutant mice exhibited much greater erythropoiesis. Hfe and Tfr2 have been shown to play important roles in the erythron, independent of their role in regulating liver hepcidin transcription. We demonstrate that lack of functional Tfr2 and Hfe allows for increased erythropoiesis even in the presence of high hepcidin expression, but the high levels of hepcidin levels significantly limit the availability of iron to the erythron, resulting in ineffective erythropoiesis. Furthermore, repression of hepcidin expression by hypoxia was unaffected by the loss of functional Hfe, Tfr2 and Tmprss6.