Dietary iron requirements in patients with sickle cell disease (SCD) remain unclear. SCD is a neglected hemoglobinopathy characterized by intense erythropoietic activity and anemia. Hepcidin is the hormone mainly responsible for iron homeostasis and intestinal absorption. Intense erythropoietic activity and anemia may reduce hepcidin transcription. By contrast, iron overload and inflammation may induce it. Studies on SCD have not evaluated the role of hepcidin in the presence and absence of iron overload. We aimed to compare serum hepcidin concentrations among individuals with sickle cell anemia, with or without iron overload, and those without the disease. Markers of iron metabolism and erythropoietic activity such as hepcidin, ferritin, and growth differentiation factor 15 were evaluated. Three groups participated in the study: the control group, comprised of individuals without SCD (C); those with the disease but without iron overload (SCDw); and those with the disease and iron overload (SCDio). Results showed that hepcidin concentration was higher in the SCDio > C > SCDw group. These data suggest that the dietary iron intake of the SCDio group should not be reduced as higher hepcidin concentrations may reduce the intestinal absorption of iron.

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Sickle cell disease (SCD) is a genetic hemoglobinopathy characterized by chronic hemolysis. Chronic hemolysis is promoted by increased oxidative stress. Our hypothesis was that some antioxidant micronutrients (retinol, tocopherol, selenium, and zinc) would be determinant factors of the degree of hemolysis in SCD patients. We aimed to investigate the nutritional adequacy of these antioxidants and their relationships to hemolysis. The study included 51 adult SCD patients regularly assisted in two reference centers for hematology in the State of Rio de Janeiro, Brazil. Serum concentrations of retinol, alpha-tocopherol, selenium, and zinc were determined by high-performance liquid chromatography or atomic absorption spectrometry. Hematological parameters (complete blood count, reticulocyte count, hemoglobin, direct and indirect bilirubin, total bilirubin, lactate dehydrogenase) and inflammation markers (leukocytes and ultra-sensitive C-reactive protein) were analyzed. A linear regression model was used to test the associations between the variables. Most patients presented selenium deficiency and low selenium consumption. Linear regression analysis showed that selenium is the main determinant of hemolysis among the antioxidant nutrients analyzed. Thus, data from this study suggest that the nutritional care protocols for patients with SCD should include dietary sources of selenium in order to reduce the risk of hemolysis.

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Artigo de revisão Resumo Doença falciforme (DF) é o termo utilizado para designar alterações genéticas caracterizadas pela presença da hemoglobina S (HbS). Diferentes genótipos são encontrados nos indivíduos com DF, incluindo a anemia falciforme (HbSS), as associações com variantes de hemoglobinas (HbD, HbC) e as interações com talassemias. Uma importante complicação associada à DF é a nefropatia falciforme. O objetivo deste estudo é revisar a fisiopatologia da doença renal crônica (DRC) em adultos com DF. Revisão simples, estruturada em artigos publicados entre 2005 e 2015, utilizando os descritores "doença falciforme", "doença renal crônica" e "nefropatia" nas bases de dados Pubmed/MEDLINE, apenas de estudos realizados em adultos humanos. A vaso-oclusão e a hemólise acentuada causam danos aos tecidos levando à lesão de órgãos, dentre eles os rins. As anormalidades renais observadas, tais como hipostenúria, acidificação deficiente da urina, hematúria e proteinúria, são frequentes, pois a porção medular do rim é uma área particularmente caracterizada por anóxia, hipertonicidade e baixo pH, condições favoráveis à falcização. Embora a fisiopatologia da nefropatia falciforme ocorra mais acentuadamente em indivíduos homozigotos para a HbS, manifestações clínicas da doença renal também são observadas em heterozigotos. Chama a atenção o fato do crescimento da prevalência da DRC estar diretamente relacionada ao aumento da idade e sua repercussão no prognóstico da DF. Os cuidados dos pacientes com DF devem ser adotados desde a infância, uma vez que a DRC e a DF agravam-se com o aumento da idade e o prognóstico da DF é pior na presença da DRC.

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