Dantas W
Departamento de Clínica Médica da Universidade Federal de Santa Catarina.
Rev Gastroenterol Peru. 2001 Jan-Mar;21(1):42-55.
Hereditary hemochromatosis is an inherited autosomal recessive disease, associated to a mutation in the recently described HFE gene, which is located on the short arm of chromosome 6. The product of this gene combines with the beta-2-microglobulin and the ferritin receptor, and regulates the iron absorption in the small intestine crypt cells. It is possible that the mutation may cause the increased iron uptake by the intestinal cells. The disease is very much common in men after the forties, and its expression is influenced by concomitant alcoholism, iron rich diet, oral and parenteral iron administration, menstrual blood loss or abnormal hemorrhages, blood donations, pregnancy, lactation, and iron malabsorption clinical conditions, like celiac disease. Many patients are asymptomatic, and the diagnosis may be suspected by hepatomegaly of unknown cause, abnormal iron metabolism tests, increased serum aminotransferase levels, diabetes mellitus, and anonymous arthropathy. Less commonly hereditary hemochromatosis presented by symptoms and signs of chronic liver disease, or by the classic triad described by Trousseau skin pigmentation, hepatomegaly and diabetes mellitus. The diagnosis is confirmed by the increased serum ferritin levels and transferrin saturation, and the stainable iron in hepatocytes, measured by scale devised by Scheuer et al, or the measurement of the hepatic iron. The C282Y mutation was found in 64 to 100% of patients; eventually, subjects with hepatic iron overload identical to hereditary hemochromatosis has no mutation, and homozygous for the C282Y mutation do not express iron overload. Iron is best and quickly removed by weekly or twice-weekly phlebotomy of 500 ml, containing approximately 250 mg iron. One to 3 years of weekly phlebotomy may be required to reduce stores to normal. As a guide to long-term maintenance therapy, is recommended phlebotomy every 3 months and the serum ferritin level should be maintained by less than 50 ng/ml.
遗传性血色素沉着症是一种常染色体隐性遗传病,与最近发现的位于6号染色体短臂上的HFE基因突变有关。该基因的产物与β2-微球蛋白和铁蛋白受体结合,调节小肠隐窝细胞的铁吸收。该突变可能导致肠道细胞对铁的摄取增加。这种疾病在40岁以后的男性中非常常见,其表现受并发的酒精中毒、富含铁的饮食、口服和胃肠外补铁、月经失血或异常出血、献血、怀孕、哺乳以及铁吸收不良的临床情况(如乳糜泻)影响。许多患者无症状,可通过不明原因的肝肿大、铁代谢检查异常、血清转氨酶水平升高、糖尿病和隐匿性关节病怀疑诊断。较少见的情况是,遗传性血色素沉着症表现为慢性肝病的症状和体征,或由特鲁索描述的经典三联征(皮肤色素沉着、肝肿大和糖尿病)表现出来。血清铁蛋白水平升高、转铁蛋白饱和度升高以及通过Scheuer等人设计的量表测量的肝细胞内可染色铁或肝铁测量结果可确诊。64%至100%的患者发现有C282Y突变;最终,肝铁过载与遗传性血色素沉着症相同的患者没有突变,而C282Y突变纯合子不表现铁过载。通过每周或每两周一次抽取500毫升血液(约含250毫克铁)能最好且最快地清除铁。可能需要1至3年每周进行放血以将铁储存量降至正常。作为长期维持治疗的指导,建议每3个月进行一次放血,血清铁蛋白水平应维持在50 ng/ml以下。