O ferro é um elemento químico indispensável ao seres humanos e praticamente encontrado em todos os seres vivos. Este íon faz parte de proteínas e enzimas importantes no transporte de oxigênio (hemoglobina e mioglobina), na síntese de DNA (ribonucleotídeo redutase), na produção de energia oxidativa (citocromo, catalase e peroxidase), na respiração mitocondrial (succinato desidrogenase) e na inativação de radicais livres (xantina oxidase). A concentração média de ferro no organismo de um indivíduo adulto é de 4 a 5 g, sendo Alterações moleculares associadas à hemocromatose hereditária Molecular changes associated with hereditary hemochromatosis

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Limited data are available about iron deficiency (ID) in Brazilian blood donors. This study evaluated the frequencies of ID and iron-deficiency anaemia (IDA) separately and according to frequency of blood donations. The protective effect of the heterozygous genotype for HFE C282Y mutation against ID and IDA in female blood donors was also determined. Five hundred and eight blood donors were recruited at the Blood Bank of Santa Casa in Sao Paulo, Brazil. Haemoglobin and serum ferritin concentrations were measured. The genotype for HFE C282Y mutation was determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis. The ID was found in 21.1% of the women and 2.6% of the men whereas the IDA was found in 6.8 and 0.3%, respectively. The ID was found in 11.9% of the women in group 1 (first-time blood donors) and the frequency increased to 38.9% in women of the group 3 (blood donors donating once or more times in the last 12 months). No ID was found in men from group 1; however the ID frequency increased to 0.9% in group 2 (who had donated blood before but not in the last 12 months) and 5.0% in group 3. In summary, the heterozygous genotype was not associated with reduction of ID or IDA frequencies in both genders, but in male blood donors it was associated with a trend to elevated ferritin levels (P = 0.060). ID is most frequent in Brazilian women but was also found in men of group 3.

Hereditary hemochromatosis (HH) is a disorder characterized by increased intestinal iron absorption, which leads to a progressive accumulation of iron in the body. This iron overload has been associated with mutations in HFE gene (C282Y, H63D and S65C) and other genes. The objectives of this study were to assess the frequencies of functional mutations in HFE and TFR2 genes and to investigate their relationship with the iron status in a sample of blood donors. Blood donors (n=542) were recruited at the Hemocenter of the Santa Casa Hospital, Sao Paulo, Brazil. The genotypes for HFE (C282Y, H63D and S65C) TFR2 (Y250X and Q690P) gene mutations were evaluated by PCR-RFLP. The concentrations of serum iron and total iron-binding capacity (TIBC) were measured by automation system Advia®(Bayer Diagnostics) and serum ferritin by Axsym System®(Abbott Laboratories). The frequencies of HFE 282Y, HFE 63D and HFE 65C alleles were 2.1, 13.6 and 0.6%, respectively. The frequency C282Y allele (2.1%) in Brazilian blood donors is lower than that observed in blood donors from Northern Europe (5.1 to 8.2%, P<0.05). The TFR2 250X and TFR2 690P alleles were not found in these subjects. The iron status was similar between HFE genotypes in women. However, men carrying HFE 282CY genotype had higher serum ferritin and lower TIBC concentrations when compared to the HFE 282CC genotype carriers. HFE 282CY genotype was also associated with higher transferrin saturation in men who donated blood at the first time. Moreover, male donors with HFE 63DD plus 63HD genotypes had higher serum iron and transferrin saturation when compared to those with HFE 63HH genotype. A relationship between HFE CY/HH/SS haplotype and lower TIBC concentrations was also found in men. The HFE 282Y and HFE 65C alleles were rare while the HFE 63D was frequent in blood donors. The mutations in TFR2 gene were not found in this study. The HFE 282Y and HFE 63D alleles were associated with alterations on iron status only in male blood donors.