Hemocromatosis: actualización clínica y diagnóstica / Hemochromatosis: clinical and diagnostic update

La hemocromatosis es un desorden en el cual la sobrecarga progresiva de hierro puede llevar a complicaciones sistémicas con gran morbimortalidad. Es una entidad clinicopatológica, con múltiples genes comprometidos y una fisiopatología común, con una expresión clínica y fenotípica variable, que depende de múltiples factores, tanto individuales como ambientales. Para su diagnóstico y seguimiento adecuado es necesario tener en cuenta elementos clínicos, bioquímicos y moleculares. En esta revisión, se presentan las generalidades de la hemocromatosis, además de sus mecanismos fisiopatológicos y moleculares, teniendo en cuenta su valor para el diagnóstico de la enfermedad. Adicionalmente, se describe la clasificación y un algoritmo diagnóstico propuestos recientemente por grupos de trabajo de expertos, así como las opciones de manejo y seguimiento de los pacientes con hemocromatosis

Hemochromatosis is a disorder in which progressive iron overload may lead to systemic complications with potential morbidity and mortality. It is a clinicopathologic entity that involves multiple genes and common pathophysiology, and has a variable clinical and phenotypic expression that depends on several individual and environmental factors. To make the diagnosis and perform a proper follow-up, clinical, biochemical, and molecular elements must be considered. This review aims to present the general characteristics of hemochromatosis, its molecular and pathophysiologic mechanisms, and their significance in the diagnosis of this disorder. In addition, a new classification and a proposed diagnostic algorithm by an expert working group are described, as well as management and follow-up options for patients with hemochromatosis

HFE hemochromatosis: an overview about therapeutic recommendations

Abstract Hemochromatosis is currently characterized by the iron overload caused by hepcidin deficiency. Large advances in the knowledge on the hemochromatosis pathophysiology have occurred due to a better understanding of the protein of the iron metabolism, the genetic basis of hemochromatosis and of other iron overload diseases or conditions which can lead to this phenotype. In the present review, the main aims are to show updates on hemochromatosis and to report a practical set of therapeutic recommendations for the human factors engineering protein (HFE) hemochromatosis for the p.Cys282Tyr (C282Y/C282Y) homozygous genotype, elaborated by the Haemochromatosis International Taskforce.

Lesões hepáticas associadas à hemocromatose hereditária / Liver lesions associated with hereditary hemochromatosis

RESUMO A hemocromatose hereditária (HH) é uma doença genética autossômica recessiva, a mais comum encontrada em caucasianos, causada pelo acúmulo de ferro em diferentes órgãos, predominantemente no fígado, causando sua disfunção. As mutações hereditárias relacionadas ao gene HFE representam quase 90% dos casos de hemocromatose entre as populações de descendência europeia. A absorção excessiva do ferro ocasiona acúmulo em órgãos como coração, pâncreas e fígado ocasionando diversas manifestações clínicas. Além dos sintomas gerais, a progressiva sobrecarga de ferro causa uma das principais complicações, a cirrose hepática. A regressão da fibrose pode ser alcançada após o tratamento, promovendo a remoção do estímulo e restaurando a função do fígado. Caso a HH não seja tratada ou o tratamento não tenha sido efetivo, o paciente pode evoluir para um estado fibrótico de cirrose irreversível, que pode culminar com o carcinoma hepatocelular (CHC), complicação responsável por 45% das mortes em pacientes com HH. Nesse sentido, nota-se a importância de compreender os métodos diagnósticos, rastreamento e tratamento, de maneira a possibilitar manejos precoces e evitar complicações potencialmente fatais. Além disso, o fato da população dos estados do sul do Brasil ser composta em sua maioria por descendentes norte-europeus - os mais acometidos pela HH - justifica a importância de literaturas e estudos clínicos mais recentes e realizados nessa região com o objetivo de compreender a evolução clínica da doença e estabelecer medidas preventivas para a manifestação de lesões hepáticas. PALAVRAS-CHAVE: Hemocromatose, HFE, diagnóstico, cirrose hepática, carcinoma hepatocelular

ABSTRACT Hereditary hemochromatosis (HH) is an autosomal recessive genetic disease, the most common found in Caucasians, caused by the accumulation of iron in different organs, predominantly in the liver, causing its dysfunction. Inherited mutations related to the HFE gene represent almost 90% of cases of hemochromatosis among populations of European descent. Excessive iron absorption causes accumulation in organs such as the heart, pancreas and liver, causing several clinical manifestations. In addition to the general symptoms, progressive iron overload causes one of the main complications, liver cirrhosis. Regression of fibrosis can be achieved after treatment, promoting stimulus removal and restoring liver function. If HH is not treated or the treatment has not been effective, the patient may progress to a fibrotic state of irreversible cirrhosis, which can culminate in hepatocellular carcinoma (HCC), a complication responsible for 45% of deaths in patients with HH. In this sense, the importance of understanding diagnostic methods, screening and treatment is noted, in order to enable early management and avoid potentially fatal complications. In addition, the fact that the population of the southern states of Brazil is composed mostly of North European descendants ­ the most affected by HH ­ justifies the importance of more recent literature and clinical studies carried out in this region in order to understand the clinical course of the disease and establish preventive measures for the manifestation of liver damage. KEYWORDS: Hemochromatosis, HFE, diagnosis, liver cirrhosis, hepatocellular carcinoma

Aspectos relevantes en hemocromatosis hereditaria / Relevant features in hereditary hemochromatosis

La hemocromatosis hereditaria es una enfermedad que se caracteriza por la sobrecarga sistémica de hierro y se asocia a múltiples mutaciones genéticas que conducen a una producción inadecuadamente baja de la hormona hepcidina o a una alteración en la unión de la hepcidina a la ferroportina. Esto tiene como resultado un aumento de la absorción intestinal y el depósito de cantidades excesivas de hierro en las células, lo cual, a su vez, si no se corrige, genera daño tisular. La expresión clínica puede variar desde individuos completamente asintomáticos, hasta pacientes con cirrosis hepática a temprana edad, y eventualmente carcinoma hepatocelular. Habitualmente, el diagnóstico no es invasivo e incluye el examen clínico, la evaluación de los parámetros de hierro plasmático, imágenes y pruebas genéticas. El principal tratamiento es la flebotomía, pero terapias alternativas como la suplementación con hepcidina son un tema de investigación actual.

Hereditary hemochromatosis is a disease characterized by systemic iron overload of genetic origin, that leads to an inadequately low production of the hormone hepcidin or a reduction in hepcidinferroportin binding. This results in an increased intestinal absorption and the deposit of excessive amounts of iron in cells, which in turn results in tissue damage if not treated. The clinical expression can vary from completely asymptomatic individuals, to patients with liver cirrhosis at an early age, and eventually hepatocellular carcinoma. Diagnosis is usually noninvasive and includes clinical examination, assessment of plasma iron levels, imaging studies, and genetic testing. The main medical treatment is phlebotomy, but alternative therapies such as hepcidin supplementation are the subject of current research.

Ingesta de hierro y gen HFE en varones adultos de Buenos Aires / Iron intake and HFE gen in male adults from Buenos Aires

El consumo excesivo de hierro (Fe) en portadores de mutaciones en el gen HFE puede resultar en sobrecarga. Para evaluar el riesgo de sobrecarga de Fe fueron investigados 166 varones adultos donantes de sangre de la ciudad de Buenos Aires. Se estimó la ingesta diaria de Fe (IFe), de Fe hemínico y de Fe proveniente de harinas enriquecidas con SO4Fe. Se determinó ferritina sérica y porcentaje de saturación de transferrina (criterio de sobrecarga de Fe: ferritina sérica > 300 ng/ml y saturación de transferrina ≥ 50%). Las mutaciones C282Y, H63D y S65C fueron investigadas en sangre mediante PCR-RFLP. Todos los participantes cubrieron ampliamente el requerimiento estimado promedio de Fe (6 mg Fe/día) y 3.0% superó el máximo tolerable (45 mg Fe/día). El Fe hemínico correspondió al 9.4% de la IFe y el de harinas enriquecidas al 47.7%. Se observó una asociación entre el aumento de IFe y el de ferritina sérica (p = 0.0472), y el 2.3% de los donantes presentaron ferritina sérica > 300 ng/ml y saturación de transferrina ≥ 50%. El 29.3% de los donantes eran portadores de los genotipos H63D, S65C o C282Y, asociados a hemocromatosis hereditaria, y tenían valores de saturación de transferrina significativamente mayores a los de los donantes wild type (p = 0.0167). Si bien la incidencia clínica de hemocromatosis hereditaria fue baja en el grupo estudiado (1.2%), el consumo excesivo de Fe plantea un riesgo potencial para la salud de individuos que ignoran sus antecedentes familiares de sobrecarga de Fe.

Excess iron (Fe) intake in subjects carrying certain mutations in the HFE gene may result in Fe overload. To estimate risk of Fe overload, 166 male blood donors (19-65 years) from Buenos Aires city were investigated. Daily Fe intake (FeI), hem Fe intake, and Fe intake from SO4Fe enriched flours were estimated (SARA Computer Program and Food Composition Table, USDA). Serum ferritin and transferrin saturation were determined; criteria for Fe overload was serum ferritin > 300 ng/ml and transferrin saturation ≥ 50%. HFE genotypes C282Y, H63D and S65C were analyzed by PCR-RFLP in blood samples. No participant presented FeI lower than the estimated average requirement (6 mg Fe/day) and 3.0% was over the upper level (45 mg Fe/day). Hem Fe and Fe from flour enrichment were 9.4% and 47.7% of daily Fe intake, respectively. A significant association was observed between the increase in serum ferritin (ng/ml) and the increase in FeI (p = 0.0472); 2.3% of the donors presented serum ferritin > 300 ng/ml and transferrin saturation ≥ 50%. Genotypes associated with hereditary hemochromatosis (H63D, S65C and C282Y) were found in 29.3% of the donors. The percentage of transferrin saturation was higher in subjects carrying mutation than in wild type subjects (p = 0.0167). Although penetrance of hereditary hemochromatosis in the studied group was only 1.2%, an excessive Fe intake could enhance adverse effects in individuals unaware of any family history of Fe overload.

Hemocromatose hereditária relacionada ao gene HFE / Hereditary hemochromatosis HFE gene related

A Hemocromatose Hereditária (HH) é a desordem hereditária mais comum em caucasianos. Mais de 90% dos casos de HH resultam da simples substituição do aminoácido Cisteína pela Tirosina no gene HFE. Essa mutação causa uma doença recessiva que resulta no acúmulo tissular de ferro. O mecanismo através do qual o HFE influencia a homeostase do ferro nas células e no corpo permanece obscuro. A doença é subdiagnosticada na população em geral devido à inespecificidade de sua apresentação clínica. O prognóstico envolve a detecção precoce da doença e a terapêutica adequada utilizando a flebotomia em fase oportuna. Essa revisão descreve os conceitos atuais a respeito das manifestações clínicas, fisiopatologia, prognóstico e tratamento da Hemocromatose Hereditária relacionada ao gene HFE.

Hereditary hemochromatosis (HH) is the most common inherited disorder in caucasians. Over 90% of the cases of HH result from a single mutation of a Cys to Tyr in the HFE gene. This mutation causes a recessive disease resulting in iron acumulation in selected tissues. The mechanism by which HFE influences iron homeostasis in cells and in the body remains elusive. The disease is underdiagnosed in general population due to inespecific clinical manifestations. Prognosis is related to early diagnostic and correct treatment using pheblotomy. This review describe the current concepts concerning the clinical features, pathophisiology, prognosis and treatment of HFE-related hemochromatosis hereditary.