Jeannette L. Dixon

A novel mutation in ferroportin1 is associated with haemochromatosis in a Solomon Islands patient

Background: A severe form of iron overload with the clinicopathological features of haemochromatosis inherited in an autosomal dominant manner has been described in the Solomon Islands. The genetic basis of the disorder has not been identified. The disorder has similarities to type 4 haemochromatosis, which is caused by mutations in ferroportin1. Aims: The aims of this study were to identify the genetic basis of iron overload in a patient from the Solomon Islands. Patient and methods: Genomic DNA was isolated from peripheral blood leucocytes of a Solomon Islands man with severe iron overload. The entire coding region and splice sites of the ferroportin1 gene was sequenced. Results and conclusions: A novel missense mutation (431A>C; N144T) was identified in exon 5 of the ferroportin1 gene. A novel restriction endonuclease based assay which identifies both the N144T and N144H mutations was developed which will simplify the diagnosis and screening of patients for iron overload in the Solomon Islands and other populations. This is the first identified mutation associated with haemochromatosis in the Solomon Islands population.

Clinical cofactors and hepatic fibrosis in hereditary hemochromatosis: The role of diabetes mellitus†‡

The risk of hepatic fibrosis and cirrhosis in hereditary hemochromatosis relates to the degree of iron loading, but iron alone does not explain the variability in disease penetrance. This study sought to identify clinical cofactors that increase the risk of progressive liver disease. We identified 291 patients from our database who were homozygous for the C282Y mutation in HFE and had undergone a liver biopsy with quantification of hepatic iron concentration (HIC) and fibrosis staging. Data were collected from a retrospective chart review, including age, gender, alcohol consumption, medical therapy, smoking history, metabolic risk factors, mobilizable iron, and laboratory results. Male gender, excess alcohol consumption, HIC, and the presence of diabetes were independently associated with increasing fibrosis stage in multivariate analysis. Of these, the presence of diabetes showed the strongest association (odds ratio, 7.32; P = 0.03). The presence of steatosis was associated with higher fibrosis scores, but this was of borderline statistical significance. Risk factors for hepatic steatosis were male gender, impaired glucose tolerance, and increased body mass index. Conclusion: The presence of diabetes was associated with more severe hepatic fibrosis independent of iron loading, male gender, and alcohol consumption. The mechanism for this association is unknown and deserves further evaluation; however, it is possible that diabetes produces an additional hepatic oxidative injury from hyperglycemia. Thus, management of such cofactors in patients with hemochromatosis is important to reduce the risk of liver injury and fibrosis. (Hepatology 2012;56:904–911)

Ferroportin disease due to the A77D mutation in Australia

Ferroportin disease or type 4 haemochromatosis is an autosomal dominant iron overload disorder caused by mutations in the iron exporter ferroportin.1,2 Numerous mutations in ferroportin ( SLC40A1 ) have been identified (see review by Pietrangelo3). The A77D mutation of ferroportin has thus far only been reported in Italy.2 We report the first A77D mutation of ferroportin which resulted in hepatic iron overload in an Australian family. The study was approved by and performed in accordance with the ethical standards of the Queensland Institute of Medical Research Human Research Ethics Committee and the Helsinki Declaration of 1975, as revised in 1983. Informed and written consent was obtained from the patient and family members. The subject, a 45 year old Caucasian male, presented with complaints of lethargy and malaise. He had no risk factors for viral hepatitis, consumed minimal alcohol (20 g/week), and was married with two …

Should HFE p.C282Y homozygotes with moderately elevated serum ferritin be treated? A randomised controlled trial comparing iron reduction with sham treatment (Mi-iron).

Introduction HFE p.C282Y homozygosity is the most common cause of hereditary haemochromatosis. There is currently insufficient evidence to assess whether non-specific symptoms or hepatic injury in homozygotes with moderately elevated iron defined as a serum ferritin (SF) of 300–1000 µg/L are related to iron overload. As such the evidence for intervention in this group is lacking. We present here methods for a study that aims to evaluate whether non-specific symptoms and hepatic fibrosis markers improve with short-term normalisation of SF in p.C282Y homozygotes with moderate elevation of SF. Methods and analysis Mi-iron is a prospective, multicentre, randomised patient-blinded trial conducted in three centres in Victoria and Queensland, Australia. Participants who are HFE p.C282Y homozygotes with SF levels between 300 and 1000 μg/L are recruited and randomised to either the treatment group or to the sham treatment group. Those in the treatment group have normalisation of SF by 3-weekly erythrocytapheresis while those in the sham treatment group have 3-weekly plasmapheresis and thus do not have normalisation of SF. Patients are blinded to all procedures. All outcome measures are administered prior to and following the course of treatment/sham treatment. Patient reported outcome measures are the Modified Fatigue Impact Scale (MFIS-primary outcome), Hospital Anxiety and Depression Scale (HADS), Medical Outcomes Study 36-item short form V.2 (SF36v2) and Arthritis Impact Measurement Scale 2 short form (AIMS2-SF). Liver injury and hepatic fibrosis are assessed with transient elastography (TE), Fibrometer and Hepascore, while oxidative stress is assessed by measurement of urine and serum F2-isoprostanes. Ethics and dissemination This study has been approved by the Human Research Ethics Committees of Austin Health, Royal Melbourne Hospital and Royal Brisbane and Womens Hospital. Study findings will be disseminated through peer-reviewed publications and conference presentations. Trial registration Trial identifier: NCT01631708; Registry: ClinicalTrials.gov

Phenotypic analysis of hemochromatosis subtypes reveals variations in severity of iron overload and clinical disease.

The clinical progression of HFE-related hereditary hemochromatosis (HH) and its phenotypic variability has been well studied. Less is known about the natural history of non-HFE HH caused by mutations in the HJV, HAMP, or TFR2 genes. The purpose of this study was to compare the phenotypic and clinical presentations of hepcidin-deficient forms of HH. A literature review of all published cases of genetically confirmed HJV, HAMP, and TFR2 HH was performed. Phenotypic and clinical data from a total of 156 patients with non-HFE HH was extracted from 53 publications and compared with data from 984 patients with HFE-p.C282Y homozygous HH from the QIMR Berghofer Hemochromatosis Database. Analyses confirmed that non-HFE forms of HH have an earlier age of onset and a more severe clinical course than HFE HH. HJV and HAMP HH are phenotypically and clinically very similar and have the most severe presentation, with cardiomyopathy and hypogonadism being particularly prevalent findings. TFR2 HH is more intermediate in its age of onset and severity. All clinical outcomes analyzed were more prevalent in the juvenile forms of HH, with the exception of arthritis and arthropathy, which were more commonly seen in HFE HH. This is the first comprehensive analysis comparing the different phenotypic and clinical aspects of the genetic forms of HH, and the results will be valuable for the differential diagnosis and management of these conditions. Importantly, our analyses indicate that factors other than iron overload may be contributing to joint pathology in patients with HFE HH.

Transforming growth factor-β and toll-like receptor-4 polymorphisms are not associated with fibrosis in haemochromatosis

AIM To investigate the role of genetic polymorphisms in the progression of hepatic fibrosis in hereditary haemochromatosis. METHODS A cohort of 245 well-characterised C282Y homozygous patients with haemochromatosis was studied, with all subjects having liver biopsy data and DNA available for testing. This study assessed the association of eight single nucleotide polymorphisms (SNPs) in a total of six genes including toll-like receptor 4 (TLR4), transforming growth factor-beta (TGF-β), oxoguanine DNA glycosylase, monocyte chemoattractant protein 1, chemokine C-C motif receptor 2 and interleukin-10 with liver disease severity. Genotyping was performed using high resolution melt analysis and sequencing. The results were analysed in relation to the stage of hepatic fibrosis in multivariate analysis incorporating other cofactors including alcohol consumption and hepatic iron concentration. RESULTS There were significant associations between the cofactors of male gender (P = 0.0001), increasing age (P = 0.006), alcohol consumption (P = 0.0001), steatosis (P = 0.03), hepatic iron concentration (P < 0.0001) and the presence of hepatic fibrosis. Of the candidate gene polymorphisms studied, none showed a significant association with hepatic fibrosis in univariate or multivariate analysis incorporating cofactors. We also specifically studied patients with hepatic iron loading above threshold levels for cirrhosis and compared the genetic polymorphisms between those with no fibrosis vs cirrhosis however there was no significant effect from any of the candidate genes studied. Importantly, in this large, well characterised cohort of patients there was no association between SNPs for TGF-β or TLR4 and the presence of fibrosis, cirrhosis or increasing fibrosis stage in multivariate analysis. CONCLUSION In our large, well characterised group of haemochromatosis subjects we did not demonstrate any relationship between candidate gene polymorphisms and hepatic fibrosis or cirrhosis.

Failure of hepcidin upregulation in HFE-associated haemochromatosis implicates the liver in the regulation of body iron homeostasis

Extrahepatic Portal Vein Thrombosis (EHPVT) is often seen in malignancy. Our aim was to study the clinical profile of non-malignant acute and chronic EHPVT. Method Retrospective study of the clinical presentation, assessment and management of 16 (8M,8F) pts with EHPVT. Clinical presentations were either acute PVT or the chronic sequelae of unrecognised PVT. Results 8 pts presented with acute EHPVT (median age at presentation 47 yr & follow up 4 yr) and 8 with chronic EHPVT (median age 35 yr & follow up 10 yr). In the acute pts, all had abdominal pain. The initial LFT’s were abnormal in 6 of 8 pts but later returned to normal. US was diagnostic in 2 out of 6 pts only. CT was performed in all pts and was diagnostic on initial report in 5, however, PVT was misinterpreted in the remaining 3 who were diagnosed at laparotomy. Aetiology of PVT was from an underlying thrombophilic disorder in 2 of 8 cases, post splenectomy 2 cases and no cause found in 4. Five pts received initial heparin and long term warfarin. Overall 5 of 8 pts developed superior mesenteric vein thrombosis, 1 required bowel resection. Six pts who had follow up CT at mean 17 mo had PV cavernous transformation. Similarly, varices were evident at endoscopy in 5 of 6 pts by 24 mo. For these, 3 pts received prophylactic banding and all pts were trialed on propranolol. No acute presenter has bled during follow up. In the chronic group, 3 presented initially with variceal bleeding, 1 with chronic pain and the other 4 were diagnosed during investigation for thrombocytopenia and/or splenomegaly. Only 2 pts had initial LFT elevation while 4 had thrombocytopenia and 2 leucopenia. US was reported abnormal in only 4 of 7 examinations but CT was diagnostic in all pts with evidence of portal hypertension. 7 of 8 pts had varices at initial endoscopy. During the study period, 5 pts bled requiring sclerotherapy or banding and 2 of these subsequently required emergency shunt surgery, but the shunts thrombosed within 24 mo. The 2 other non-bleeding variceal pts received prophylactic band ligation and 5 of 7 variceal pts received propranolol. An underlying thrombophilic disorder was present in 5 of 8 chronic presenters, subsequently only 1 has received warfarin. No patient has died in either group. Conclusions The clinical presentation and course of pts with EHPVT varies between the acute and chronic groups. Acute pts usually present with pain and elevated LFTs. CT is the most accurate diagnostic modality but may be misinterpreted. Chronic pts present with manifestations of chronic PHT. Bleeding in EHPVT can usually be controlled with endoscopy, but surgery has a role in endoscopic failures. 119

Clinical expression of HFE-associated haemochromatosis in subjects under 40 years of age

Background and Study Aims To reduce costs related to colonoscopies the feasibility of performing unsedated colonoscopies has been explored. The aim with our study was to assess patient satisfaction with on-demand sedation and identify factors related to painful colonoscopies. Patients and Methods The Gastronet registration tools are an endoscopy report (fi lled in on site) and a patient satisfaction questionnaire (fi lled in by the patient on the day after the colonoscopy). Data were collected from January 1, 2004 to December 31, 2006. Colonoscopies reported to be moderately or severely painful were defi ned as ‘painful colonoscopies’. Univariate and multivariate logistic regression analyses were applied. Results Nine endoscopy-centres representing 86 endoscopists reported 14 195 examinations and 12 354 (87%) patient reports were returned. Patient satisfaction with service and information given was >95% for all centres. Mean rate of painful colonoscopies was 34% and mean sedation rate 34%. Adjusted Odds ratio (ORadj) for painful colonoscopies was 2.2 (p < 0.001) when sedation was given. The ORadj for painful colonoscopies were similar for all but on centre (No. 4) with ORadj 1.6 (p = 0.04), while the ORadj for giving sedation was higher for all but one centre (No. 1) compared to the reference centre (ORadj 2.2–7.5, all p-values < 0.001). Conclusion A high rate of painful colonoscopies was found. High sedation rates were not associated with low rates of painful colonoscopies. Recommending increased sedation rates as the only intervention to improve sub-optimal performance may not lead to lower rates of painful colonoscopies.