RESUMO
OBJECTIVE: Iron deficiency is likely the most common nutritional deficiency worldwide; low iron concentrations have been related to alterations in immune system functions; therefore, the aim of this study was to determine the effect of low serum iron (LSI) concentrations on the production of proinflammatory cytokines by peripheral blood leukocytes in 8- to 12-y-old children from a local community. METHODS: We obtained 120 blood samples and determined full blood counts and serum iron concentrations. An LSI and a control group, paired by age and sex were established using serum iron <60 µg/dL as the cutoff point. Ferritin and C-reactive protein concentrations were quantified. Serum interferon (IFN)-γ and tumor necrosis factor (TNF)-α concentrations were measured in these groups by enzyme-linked immunosorbent assay. A second blood sample was taken from children in both groups to isolate peripheral blood mononuclear cells (PBMCs) and measure IFN-γ and TNF-α production by unstimulated and lipopolysaccharide/phorbol myristate acetate/ionomycin-stimulated leukocytes in vitro. RESULTS: Of the participants in the present study, 17.5% (21 children) presented LSI, as well as decreased ferritin concentrations. Differential counts from total blood samples showed a significant increase in leukocyte numbers in the LSI group, along with increased neutrophil frequencies and numbers but decreased lymphocyte frequencies. Decreased serum IFN-γ concentrations and decreased in vitro production of IFN-γ by PBMCs were found in the LSI group. CONCLUSIONS: The results of the present study suggest that low iron levels alter leukocyte subpopulations in circulation and have a detrimental effect on leukocyte production of proinflammatory cytokines after an antigenic challenge.
Assuntos
Anemia Ferropriva/fisiopatologia , Doenças Assintomáticas , Fenômenos Fisiológicos da Nutrição Infantil , Interferon gama/metabolismo , Leucócitos Mononucleares/imunologia , Leucocitose/etiologia , Fator de Necrose Tumoral alfa/metabolismo , Anemia Ferropriva/sangue , Anemia Ferropriva/imunologia , Anemia Ferropriva/metabolismo , Contagem de Células Sanguíneas , Proteína C-Reativa/análise , Ionóforos de Cálcio/farmacologia , Criança , Feminino , Ferritinas/sangue , Humanos , Interferon gama/biossíntese , Interferon gama/sangue , Ionomicina/farmacologia , Ferro/sangue , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , México , Mitógenos/farmacologia , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacologia , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/sangueRESUMO
Prebiotics may increase intestinal Fe absorption in anaemic growing rats. The present study evaluated the effects of high-performance (HP) inulin and oligofructose on factors that regulate Fe absorption in anaemic rats during the growth phase. Male Wistar rats aged 21 d of age were fed AIN-93G ration without Fe for 2 weeks to induce Fe-deficiency anaemia. The rats were fed on day 35 a control diet, or a diet with 10 % HP inulin, or a diet with 10 % oligofructose, without Fe supplementation. The animals were euthanised after 2 weeks, and segments of the duodenum, caecum, colon and liver were removed. The expression levels of proteins in the intestinal segments were assessed using Western blotting. The levels of serum, urine and liver hepcidin and the concentrations of IL-10, IL-6 and TNF-α in the caecum, colon and liver were measured using the ELISA test. HP inulin increased the expression of the divalent metal transporter 1 protein in the caecum by 162 % (P= 0·04), and the expression of duodenal cytochrome b reductase in the colon by 136 % (P= 0·02). Oligofructose decreased the expression of the protein ferroportin in the duodenum (P= 0·02), the concentrations of IL-10 (P= 0·044), IL-6 (P= 0·036) and TNF-α (P= 0·004) in the caecum, as well as the level of urinary hepcidin (P< 0·001). These results indicate that prebiotics may interfere with the expression of various intestinal proteins and systemic factors involved in the regulation of intestinal Fe absorption in anaemic rats during the growth phase.
Assuntos
Anemia Ferropriva/dietoterapia , Proteínas de Transporte de Cátions/metabolismo , Grupo dos Citocromos b/metabolismo , Mucosa Intestinal/metabolismo , Prebióticos , Regulação para Cima , Anemia Ferropriva/imunologia , Anemia Ferropriva/metabolismo , Anemia Ferropriva/patologia , Animais , Proteínas de Transporte de Cátions/agonistas , Ceco/imunologia , Ceco/metabolismo , Ceco/patologia , Colo/enzimologia , Colo/imunologia , Colo/metabolismo , Grupo dos Citocromos b/química , Grupo dos Citocromos b/genética , Duodeno/imunologia , Duodeno/metabolismo , Duodeno/patologia , Hepcidinas/sangue , Hepcidinas/metabolismo , Hepcidinas/urina , Mediadores da Inflamação/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Inulina/efeitos adversos , Inulina/uso terapêutico , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Masculino , Oligossacarídeos/efeitos adversos , Oligossacarídeos/uso terapêutico , Tamanho do Órgão , Prebióticos/efeitos adversos , Ratos Wistar , Aumento de PesoRESUMO
Although oral iron preparations are widely prescribed to prevent and to treat iron deficiency anemia in pregnancy, comparative data on their effects to the mother, fetus and placenta are limited. In this study, the effects of oral iron polymaltose complex (IPC), ferrous fumarate (FF) and ferrous sulfate (FS) were compared in anemic pregnant rats, their fetuses and placentas. Hematological variables and oxidative stress markers in the liver, heart and kidneys of the dams and fetuses as well as the markers for oxidative stress, inflammation and hypoxia in placentas were assessed. Pregnancy outcome was measured by number of fetuses, and by neonate and placental weight. All therapies were comparably effective in correcting anemia. FS and FF, but not IPC, resulted in liver damage in dams and oxidative stress in dams, fetuses and placentas. FS group presented the highest catalase and GPx levels in dams, fetuses and placentas. IPC, but not FF or FS, restored normal TNF-α and IL6 expression levels in placentas whereas FS-treated animals presented the highest cytokine levels, suggesting a local inflammatory reaction. Anemia-induced high levels of HIF-1α were partially lowered by IPC and FF but further elevated by FS. Most of the negative effects associated with IDA were resolved by IPC treatment. Especially FS treatment was found to elicit hepatic damage in the dams, oxidative stress in the dams, fetuses and placenta as well as inflammation and high levels of HIF-1α in the placenta. Pregnancy outcome of FFand FS-treated animals was worse than that of IPC-treated animals.
Assuntos
Anemia Ferropriva/tratamento farmacológico , Compostos Férricos/administração & dosagem , Placenta/efeitos dos fármacos , Administração Oral , Anemia Ferropriva/imunologia , Anemia Ferropriva/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Compostos Férricos/efeitos adversos , Compostos Ferrosos/administração & dosagem , Compostos Ferrosos/efeitos adversos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Placenta/metabolismo , Gravidez , Resultado da Gravidez , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The aim of this study was to evaluate biochemical parameters of iron metabolism in rats experimentally infected with Trypanosoma evansi. To this end, 20 rats (Wistar) were intraperitoneally inoculated with blood containing trypomastigotes 10(6) (Group T) and 12 animals were used as negative control (Group C) and received saline (0.2 mL) through same route. Blood samples were collected by cardiac puncture on day 5 (C5, T5) and 30 (C30, T30) post-inoculation (pi) to perform complete blood count and determination of serum iron, transferrin, ferritin, total and latent iron fixation capacity, transferrin saturation and prohepcidin concentration. Also, bone marrow samples were collected, to perform Pearls staining reaction. Levels of iron, total and latent iron binding capacity and prohepcidin concentration were lower (P<0.05) in infected rats (T5 and T30 groups) compared to controls. On the other hand, levels of transferrin and ferritin were higher when compared to controls (P<0.05). The transferrin saturation increased on day 5 pi, but decreased on day 30 pi. The Pearls reaction showed a higher accumulation of iron in the bone marrow of infected animals in day 5 pi (P<0.01). Infection with T. evansi in rats caused anemia and changes in iron metabolism associated to the peaks of parasitemia. These results suggest that changes in iron metabolism may be related to the host immune response to infection and anemic status of infected animals.
Assuntos
Ferro/metabolismo , Tripanossomíase/metabolismo , Anemia Ferropriva/imunologia , Anemia Ferropriva/parasitologia , Animais , Peptídeos Catiônicos Antimicrobianos/sangue , Medula Óssea/metabolismo , Cães , Contagem de Eritrócitos , Índices de Eritrócitos , Ferritinas/metabolismo , Hematócrito , Hemoglobinas/análise , Hemossiderina/metabolismo , Hepcidinas , Sistema Imunitário/metabolismo , Ferro/sangue , Masculino , Parasitemia/imunologia , Parasitemia/parasitologia , Precursores de Proteínas/sangue , Ratos , Ratos Wistar , Transferrina/metabolismo , Trypanosoma/crescimento & desenvolvimento , Tripanossomíase/sangue , Tripanossomíase/complicações , Tripanossomíase/imunologiaRESUMO
BACKGROUND & AIMS: To investigate the effect of vitamin A supplementation on parameters of the immune system of vitamin A-deficient children. METHODS: The study was carried out in four phases: 1) determination of serum retinol in 631 children from 36 to 83 months of age; 2) assessment of immunological markers [immunoglobulins and complement fractions, immunophenotyping of T and B lymphocytes, and natural killer (NK) cells], blood count, and serum ferritin of 52 vitamin A-deficient children (serum retinol < 0.70 micromol/L); 3) supplementation of the 52 deficient children with 200,000 IU of vitamin A; 4) determination of serum retinol and the immunological parameters 2 months after vitamin A supplementation. RESULTS: before vitamin A supplementation, 24.0 % of the children were anemic and 4.3 %had reduced ferritin concentrations. There was no significant difference between mean values of retinol according to the presence/absence of anemia. The mean values of the humoral and cellular immunological parameters did not show a statistically significant difference before and after supplementation with vitamin A. Children with concomitant hypovitaminosis A and anemia presented a significant increase in absolute CD4 and CD8 T-cell counts after vitamin A supplementation (p < 0.05). CONCLUSION: vitamin A had an effect on the recruitment of T and B lymphocytes to the circulation of children with hypovitaminosis A and anemia.
Assuntos
Suplementos Nutricionais , Sistema Imunitário/efeitos dos fármacos , Deficiência de Vitamina A/tratamento farmacológico , Deficiência de Vitamina A/imunologia , Vitamina A/uso terapêutico , Anemia/epidemiologia , Anemia/imunologia , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/imunologia , Biomarcadores/sangue , Contagem de Células Sanguíneas , Brasil/epidemiologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/efeitos dos fármacos , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Feminino , Ferritinas/sangue , Humanos , Masculino , Pacientes Desistentes do Tratamento , Prevalência , Vitamina A/administração & dosagem , Vitamina A/sangue , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/epidemiologiaRESUMO
Iron deficiency is a common nutritional disorder, affecting about 30% of the world population. Deficits in iron functional compartments have suppressive effects on the immune system. Environmental problems, age, and other nutrient deficiencies are some of the situations which make human studies difficult and warrant the use of animal models. This study aimed to investigate alterations in the immune system by inducing iron deficiency and promoting recuperation in a mouse model. Hemoglobin concentration, hematocrit, liver iron store, and flow cytometry analyses of cell-surface transferrin receptor (CD71) on peripheral blood and spleen CD4+ and CD8+ T lymphocyte were performed in the control (C) and the iron-deficient (ID) groups of animals at the beginning and end of the experiment. Hematological indices of C and ID mice were not different but the iron stores of ID mice were significantly reduced. Although T cell subsets were not altered, the percentage of T cells expressing CD71 was significantly increased by ID. The results suggest that iron deficiency induced by our experimental model would mimic the early events in the onset of anemia, where thymus atrophy is not enough to influence subset composition of T cells, which can still respond to iron deficiency by upregulating the expression of transferrin receptor.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Deficiências de Ferro , Receptores da Transferrina/metabolismo , Anemia Ferropriva/imunologia , Animais , Feminino , Citometria de Fluxo , Hematócrito , Hemoglobinas/análise , Ferro/metabolismo , Ferro da Dieta/administração & dosagem , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Baço/imunologia , Baço/metabolismoRESUMO
Iron deficiency anemia (IDA) is considered to be the most prevalent micronutrient deficiency in the world. Estimates indicate that 1.2 billion people suffer mild to severe forms of anemia and that up to 46% of schoolchildren in developing countries are affected. In 2003, ENDSA, the national demographic and health survey of Bolivia showed that 60% of children under five and 72% of children under 2 years old were anemic. Micronutrient deficiency has been suggested to impair cell-mediated immunity. In particular, iron, zinc and vitamin A deficiencies have an impact on the immune system. In vitro and in vivo laboratory studies indicate a link between iron deficiency and impaired T-lymphocyte proliferation. The exact effects or mechanisms of iron deficiency on maturation and proliferation of T-lymphocytes in vivo are, however, not yet known. This study investigated the effects of iron on the maturation of T-lymphocytes in anemic but otherwise healthy schoolchildren (no apparent protein-energy deficiency or other morbidity). Anemic children of a poor peri-urban school of Cochabamba city, Bolivia, were given iron treatment for three consecutive months. We chose to look at CD1a+ lymphocytes, which are immature thymocytes. The proportions of CD1a+ lymphocytes in the peripheral circulation measured at baseline and after treatment were compared with a reference group of age-matched non-anemic children controls from the same school. The immunologic parameters, although improved, did not reach the proportions of the control group. Overall, the proportion of circulating immature T-lymphocytes decreased from 18.3% to 9.2% in the treated following iron supplementation in anemic children, compared with 3.4% in non-anemic children.
Assuntos
Anemia Ferropriva/tratamento farmacológico , Ferro/uso terapêutico , Linfócitos T/efeitos dos fármacos , Oligoelementos/uso terapêutico , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/imunologia , Antígenos CD1/sangue , Bolívia/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Prevalência , Linfócitos T/imunologia , Oligoelementos/deficiênciaRESUMO
La anemia ferropénica es un problema de salud pública a nivel mundial. Los niños pequeños son más vulnerables a esta deficiencia. Determinar los factores de riesgo y protección para la anemia ferropénica en niños menores de 6 años. Estudio descriptivo, transversal. Se evaluaron 100 niños. Edad, género, estratificación social, tipo de lactancia, edad de ablactación, diagnóstico nutricional, características de la dieta (calorías, proteínas y hierro). Hemoglobina (Hb), Hematocrito (HTO), Volumen Corpuscular Medio (VCM), Hemoglobulina Corpuscular Media (HCM), hierro sérico. A las variables se les aplicó un análisis de regresión logística simple. 46 por ciento de los pacientes tenían anemia. Siendo la media para la edad de 19,2 meses, tiempo de lactancia materna exclusiva 5,2 meses, inicio de ablactación de 5,7 meses, hemoglobina de 9,9 g/dl. Se observa que en los niños de menor edad existe un mayor riesgo de presentar anemia. No se demostró una diferencia estadísticamente significativa entre los pacientes anémicos y no anémicos en relación al Gaffar Méndez Castellano y diagnóstico nutricional. Los factores de riesgo para la anemia con valores de Odds Ratio (OR) >1 fueron la edad menor de 24 meses, ausencia de lactancia materna exclusiva en menores de 6 meses, ablactación antes de los 5 meses, dietas hipocalóricas y el hierro sérico < 41 ug/dL. La dieta normoproteica resultó ser factor de protección (OR<1). Se evidenció la importancia de la lactancia materna y de una adecuada alimentación complementaria a partir del 5° mes de la vida como factores de protección para la anemia ferropénica en niños menores de 6 años.
Iron deficiency anemia is considered as a worlwide public health problem. Small children are more vulnerable to this deficiency. To determine the risk and protection factors for iron deficiency anemia in children under 6 years of age. This is a descriptive and cross-sectional study. 100 children were evaluated. Age, gender, social stratification, nursing type, complementary feedings, nutritional diagnosis, characteristic of the diet (calories, proteins and iron). Hemoglobin (Hb), hematocrit (HTO), mean corpuscular volume (VCM), mean corpuscular hemoglobin (HCM), total and fractional proteins, serum iron. 46% of patients wer anemic. Average values were: age 19,2 months, duration of exclusive breastfeeding 5.2 months, beginning of complementary feeding 5,7 months, hemoglobin 9.9 g/dl. Younger children had an increased risk of developin ganemia. There was not a statistically significant difference between anemic and non anemic patients in regard to Graffar and nutritional diagnosis. Risk factors for anemia (Odds Ratio-OR-values >1) were age under 24 months, lack of exclusive breastfeeding in children under 6 months, complementary feedings before 5 months of age, hypocaloric diet and serum iron <41 ug/dL. Normoproteic diets proved to be a protection factor (OR<1). Breastfeeding and appropriate complementary feedings after 5 months of age are protection factors for iron deficiency anemia in children under 6 years of age.
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Anemia Ferropriva/imunologia , Anemia Ferropriva/patologia , Anemias Nutricionais/diagnóstico , Deficiências de Ferro/diagnóstico , Heme/análise , Índices de Eritrócitos/fisiologia , Cuidado da Criança , Ingestão de Energia , Composição de AlimentosRESUMO
Hepcidin has been proposed as an important factor in the pathogenesis of the anaemia of chronic disease (ACD). The aim of this study was to assess the relationship between anaemia and inflammatory activity in patients with solid tumours. Patients were classified as having iron deficiency anaemia (IDA) (hypoferremia and hypoferretinemia), ACD (hypoferremia, normal or increased serum ferritin) and anaemia related to cancer (ARC) (no abnormalities in iron status). Serum pro-hepcidin, IL-6, C-reactive protein (CRP) and iron status parameters were measured using commercial kits. CRP and IL-6 levels were significantly higher in patients with ACD when compared to IDA, ARC and non anaemic patients (P < 0.005). Serum pro-hepcidin levels were not different among all studied groups (P = 0.138). A negative correlation was observed between haemoglobin and serum ferritin, CRP and IL-6 levels only in group of ACD. Serum pro-hepcidin concentrations were not correlated with degree of anaemia or iron metabolism parameters. According to our results the inflammatory activity represented by high levels of IL-6 and CRP are involved in the pathogenesis of ACD, probably due to the action of inflammation on iron metabolism, but not in ARC. It was not possible to demonstrate a significant effect of pro-hepcidin on the anaemia in cancer patients.
Assuntos
Anemia/imunologia , Proteína C-Reativa/metabolismo , Interleucina-6/sangue , Ferro/sangue , Neoplasias/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/classificação , Anemia/complicações , Anemia/metabolismo , Anemia Ferropriva/complicações , Anemia Ferropriva/imunologia , Anemia Ferropriva/metabolismo , Peptídeos Catiônicos Antimicrobianos/metabolismo , Estudos de Casos e Controles , Feminino , Hepcidinas , Humanos , Inflamação/complicações , Inflamação/imunologia , Inflamação/metabolismo , Deficiências de Ferro , Masculino , Pessoa de Meia-Idade , Neoplasias/imunologia , Neoplasias/metabolismo , Índice de Gravidade de DoençaRESUMO
The data on the relationship between iron deficiency and infection are conflicting. Some researchers conclude that mild iron deficiency is beneficial for immunity, whereas others contend that any deficit is not good for immunity. Additionally, infection or inflammation generate anemia and profound changes in iron metabolism mediated by cytokines. These changes are important confounders to consider in assessments of iron status.