Hereditary hemochromatosis associated with the development of liver cirrhosis / Hemocromatose hereditária associada ao desenvolvimento da cirrose hepática

ABSTRACT Hereditary hemochromatosis (HH) is an autosomal recessive disease, most often associated with mutations in the HFE gene, which result in continuous absorption of iron, causing its overload. Liver tissue is the main site of iron deposition; thus, high levels of iron, when interacting with oxygen, induce the formation of free radicals that will act on proteins, lipids, and deoxyribonucleic acid (DNA), which may trigger deleterious effects at cellular and tissue levels. In order to elucidate the development and progression of liver cirrhosis due to iron overload, the purpose of this study is to describe the pathophysiology of the hepatic system in patients diagnosed with HH. For this purpose, searches for scientific articles were carried out in the main academic databases. We found that patients diagnosed with HH are more likely to develop liver cirrhosis, since chronic iron deposition in liver tissue induces injury and consequent tissue regeneration, progressing to collagen fibers synthesis surrounding the hepatocytes, leading to loss of liver function and development of cirrhosis. Therefore, it is necessary to carry out tests such as iron, ferritin and transferrin measurements, to evaluate body's iron stores, aiming at an early diagnosis of iron overload, thus avoiding deleterious damage at cellular and tissue levels.

RESUMEN La hemocromatosis hereditária (HH) es uma enfermedad autosómica recesiva, asociada, la mayoría de las veces, a mutaciones del gen HFE, que producen absorción continua de hierro, con sobrecarga de esa sustancia. El tejido hepático es el principal sitio de almacenamiento de hierro; así, niveles elevados de hierro, al interactuar con oxígeno, inducen la formación de radicales libres que actuarán sobre proteínas, lípidos y ácido desoxirribonucléico (ADN), pudiendo acarrear efectos dañosos a nível celular y tisular. Para aclarar el mecanismo de desarrollo de la cirrosis hepática debido a sobrecarga de hierro, el objetivo de este estudio es describir la fisiopatologia del sistema hepático en pacientes diagnosticados con HH. Para eso, se efectuaron búsquedas por artículos científicos en los principales bancos de datos acadêmicos. Verificamos que pacientes diagnosticados con HH presentan mayor predisposición a desarrollar cirrosis hepática, porque el depósito crônico de hierro en el tejido hepático causa lesión y consecuente regeneración de tejido, progresando a la formación de fibras de colágeno que rodean los hepatocitos, llevando la pérdida de la función hepática y al desarrollo de la cirrosis. Ante esto, es necesario medir hierro, ferritina y transferrina para evaluación de las provisiones de hierro del cuerpo, buscando un diagnóstico temprano de la sobrecarga de hierro, para evitar efectos deletereos a nível celular y tisular.

RESUMO A hemocromatose hereditária (HH) é uma doença autossômica recessiva, associada, na maioria das vezes, a mutações do gene HFE, que resultam em absorção contínua de ferro, ocasionando a sobrecarga dessa substância. O tecido hepático é o principal sítio de depósito do ferro; dessa forma, níveis elevados de ferro, ao interagir com o oxigênio, induzem a formação de radicais livres que irão agir sobre proteínas, lipídios e ácido desoxirribonucleico (DNA), podendo desencadear efeitos deletérios a níveis celulares e teciduais. Visando elucidar o mecanismo de desenvolvimento da cirrose hepática decorrente da sobrecarga de ferro, o objetivo deste estudo é descrever a fisiopatologia do sistema hepático em pacientes diagnosticados com HH. Para isso, foram realizadas buscas por artigos científicos nos principais bancos de dados acadêmicos. Verificamos que pacientes diagnosticados com HH apresentam maior predisposição de desenvolver cirrose hepática, pois o depósito crônico de ferro no tecido hepático provoca lesão e consequente regeneração tecidual, progredindo para formação de fibras de colágeno que circundam os hepatócitos, levando à perda da função hepática e ao desenvolvimento da cirrose. Diante disso, faz-se necessária a realização de exames como dosagem de ferro, ferritina e transferrina para avaliação dos estoques de ferro do organismo, objetivando um diagnóstico precoce da sobrecarga de ferro, a fim de evitar danos deletérios a níveis celulares e teciduais.

Acquired hemochromatosis: A case report in a Filipino patient and literature review

@#Hemochromatosis is a hereditary or acquired chronic iron overload syndrome that presents with organ damage to the liver, pancreas, heart, joints and skin due to pathologic iron deposition. Hereditary hemochromatosis is a common genetic disorder with human hemochromatosis protein (HFE) mutations found in European ethnic groups but has low-prevalence in the Asian population. Secondary or acquired hemochromatosis may result from ineffective erythropoiesis, liver disease and parenteral iron overload. A 51-year-old Filipino woman presented with generalized hyperpigmentation associated with severe anemia and hepatomegaly. Laboratory investigation revealed a markedly elevated serum ferritin (>2,000 g/L, 10x the normal) and hepatic aminotransferases (6x elevated). Magnetic resonance imaging (MRI) T2-weighted images revealed hypotense signal of the liver with the magnetic susceptibility measurement (MSM) of iron at 12.297 mg/g indicating severe iron overload. Dermatopathology findings revealed hyperpigmented epidermis with hemosiderin found in the basal keratinocytes as well as around cutaneous adnexal structures. Special stain with Perls’ Prussian blue revealed iron granules that are seen as blue pigments in the epidermis and dermis. Treatment with the oral iron chelator deferiprone (DFP) showed improvement. However, the patient developed hospital-acquired sepsis, deteriorated, and eventually died.

Secondary haemochromatosis in a haemodialysis patient

A 39-year-old woman with end-stage renal disease, which was maintained on haemodialysis, developed secondary haemochromatosis after receiving blood transfusions and intravenous iron supplementation without sufficient serum ferritin concentration monitoring. The patient received intravenous deferoxamine three times a week, combined with high-dose recombinant human erythropoietin therapy and haemodialysis. After three months, improvements in biochemical indicators and iron overload were noted.

Evaluación del estado en la reserva neonatal de hierro y las mutaciones del gen HFE / Assessment of neonatal iron store and HFE gene mutations

Introducción: Se presenta la evaluación de la asociación entre la reserva de hierro (Fe) y los polimorfismos del gen de la hemocromatosis (HFE) en neonatos de alto riesgo perinatal. Métodos: Se incluyó una serie de neonatos de alto riesgo perinatal en los que se evaluó la reserva de Fe con la medición de la ferritina sérica (FS). Se dividieron en tres grupos: sobrecarga de Fe (SoFe), con FS >1,000 µg/l; reserva normal de Fe, con FS de 154-1,000 µg/l; y reserva baja de Fe, con FS <154 µg/l. Mediante PCR en tiempo real se buscaron las mutaciones C282Y, H63D y S65C del gen HFE. Resultados: Se estudiaron 97 neonatos. De ellos, 24 casos presentaron SoFe (proporción 0.247) y FS de 1,789 µg/l (IC 95% 1,376-2,201); 36 casos, reserva normal de FS (0.371), FS de 461 µg/l (389-533); y 37 casos, reserva baja de FS (0.381) y FS 82 µg/l (69-96). No hubo casos detectados para las mutaciones C282Y o S65C. Se identificó la variante H63D HFE en 18 neonatos (frecuencia génica de 0.185): la condición de heterocigoto (H63D/WT) en doce casos (frecuencia génica 0.124) y de homocigoto (H63D/H63D) en seis casos (frecuencia génica 0.062). La frecuencia alélica de H63D fue de 0.092. Los variante H63D HFE no mostró asociación con los neonatos de reserva normal de Fe contra reserva baja (OR 1.2; IC 95% 0.3-4.3) ni los de reserva normal contra neonatos con SoFe (OR 2.5; 0.7-9.2). Conclusiones: Cerca del 25% de neonatos de alto riesgo tendrá sobrecarga de Fe. Aún con el posible sesgo de selección, las variantes del gen HFE no influyen sobre el estado de la reserva de Fe.

Background: The association between iron stores (Fe) and HFE gene polymorphisms on high-risk neonates is shown. Methods: We included newborns with high perinatal risk. Newborns were divided into three groups for measurements of serum ferritin (SF): iron overload (IO) with SF 1000 µg/L, normal iron stores (NIS) with SF 154-1000 µg/L and low iron stores (LIS) with SF <154 µg/L. We used real-time PCR for identification of polymorphisms C282Y, H63DE, and S65C of the HFE gene. Results: We studied 97 newborns with IO in 24 cases (ratio 0.247) and SF 1789 µg/L (95% CI 1376-2201), NIS in 36 cases (0.371), and SF of 461 µg/L (389-533) and LIS in 37 cases (0.381) and SF 82 µg/L (69-96). There were no cases detected for C282Y or S65C mutations. We identified 18 neonates with H63D HFE variant (gene frequency 0.185) with heterozygous condition (H63D/ WT) in 12 cases (gene frequency 0.124) and homozygote (H63D/H63D) in six cases (gene frequency 0.062). H63D allele frequency was 0.092. The HFE H63D variant showed no association for comparing infants with NIS vs. LIS (OR 1.2, 95% CI 0.3-4.3) and NIS vs. IO newborn infant (OR 2.5, 0.7-9.2). Conclusions: In high-risk neonates ∼25% show IO even with the possible selection bias. HFE gene variants do not influence on the neonatal iron stores.

Frequency of the HFE C282Y and H63D polymorphisms in Brazilian malaria patients and blood donors from the Amazon region

Malaria is an endemic parasitosis and its causitive agent, Plasmodium, has a metabolism linked to iron supply. HFE is a gene with the polymorphisms C282Y and H63D, which are associated with a progressive iron accumulation in the organism leading to a disease called hereditary hemochromatosis. The aim of the present study was to determine the allelic and genotypic frequencies of the HFE gene polymorphisms in malaria patients and blood donors from the Brazilian Amazon region. We screened 400 blood donors and 400 malaria patients for the HFE C282Y and H63D polymorphisms from four states of the Brazilian Amazon region by polymerase chain reaction and restriction fragment length polymorphism analysis. We did not find any C282Y homozygous individuals, and the only five heterozygous individuals detected were from Pará State. The most frequent genotype in the North region of Brazil was the H63D heterozygote, in both study groups. Our results contribute to the concept that the Brazilian Amazon region should not be regarded as a single entity in South America. These polymorphisms did not influence the symptoms of malaria in the population studied, as neither severe signs nor high parasitemia were observed. Therefore, different hereditary hemochromatosis diagnostic and control measures must be developed and applied within its diverse locations. Investigations are currently being carried out in our laboratory in order to determine the importance of the coexistence of hereditary hemochromatosis in patients affected by parasitic diseases, such as malaria.

The Prevalence of Peripheral Iron Overload and the Presence of HFE gene (H63D) Mutation among the Korean Patients with Nonalcoholic Fatty Liver Disease / 대한간학회지

BACKGROUNDS/AIMS: There are controversies on the role of iron overload in the mechanism of liver injury in nonalcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the prevalence of peripheral iron overload, and to study the presence of HFE mutations (C282Y, H63D, S65C) in a cohort of Korean NAFLD patients. METHODS: 255 patients with NAFLD were included. The patients had been diagnosed as having NAFLD by the criteria of elevated aminotransferase levels, compatible ultrasonographic findings and exclusion of other etiologies. Blood samples were tested for chemistry, iron profile, and mutational analysis for HFE gene (C282Y, H63D, S65C). RESULTS: Of the 255 NAFLD patients, the prevalence of peripheral iron overload was 19.2% according to the cutoff level of transferrin saturation (TS) > 45%, and 3.9% of NAFLD patients were having hyperferritinemia over 400 ng/mL. Hyperferritinemia was significantly associated with elevated serum levels of fasting glucose, AST and TS. We found the presence of H63D mutation, either heterozygote or homozygote, among the NAFLD patients with peripheral iron overload. CONCLUSIONS: The prevalence of peripheral iron overload in the Korean NAFLD patients was not rare, and the presence of H63D mutation among NALFD patients was identified. Further studies on the significance of iron overload or HFE mutation in the pathogenesis of NAFLD are needed.

THE DISTRIBUTION OF HFE GENE MUTATION IN CHINESE ADULT MEN / 营养学报

Objective:To analyze the distribution of HFE gene (hemochromatosis gene) mutation in normal and iron overload men and discuss the influence of HFE gene mutation on iron overload status of Chinese adult men..Method:The data of 226 normal and 331 iron overload men were drawn from National Nutrition and Health Survey in 2002 as control and case group respectively to analyze and compare the distribution of HFE mutation including C282Y mutation, H63D mutation and S65C mutation in normal and iron overload men.Results:In case group, normal gene was 90.03%, homozygosity for H63D mutation 0.6%, heterozygosity for H63D mutation 9.07%, heterozygosity for S65C 0.3%. In control group normal gene was 94.25%, heterozygosity for H63D 5.75%, and no S65C and C282Y mutation was detected. Conclusion: HFE gene mutation was not the major reason resulting in iron overload in Chinese adult men.