Serum folate and cytokines in heterozygous ß-thalassemia.

INTRODUCTION: Folate deficiency is commonly reported in ß-thalassemia. Individuals heterozygous for ß-thalassemia may have higher folate requirements than normal individuals. OBJECTIVES: To document the concentration of serum total folate and its forms in ß-thalassemia heterozygote users (ß-TmU) and nonusers (ß-TmN) of 5 mg folic acid/d; to determine whether folic acid (FA) consumption from fortified foods allows beta-Tm patients, who do not take FA supplements, to meet their dietary folate requirements; and to investigate the association between higher serum unmetabolized folic acid (UMFA) and inflammatory cytokine concentrations. METHODS: Serum total folate and forms were measured in 42 ß-Tm (13 ß-TmU and 29 ß-TmN) and 84 healthy controls. The mononuclear leucocyte mRNA expression of relevant genes and their products and hematological profiles were determined. RESULTS: ß-TmU had higher serum total folate, 5-methyltetrahydrofolate, UMFA, and tetrahydrofolate (THF) compared with ß-TmN. The ß-TmN had lower serum total folate and THF than controls. Plasma total homocysteine (tHcy) was lower in ß-TmU compared with both ß-TmN and controls, while ß-TmN had higher tHcy than controls. ß-TmU had higher IL-8 than their controls while ß-TmN had higher IL-6 and IL-8 than their controls. ß-TmU have higher levels of serum total folate, 5- methyltetrahydrofolate, UMFA, and THF than controls. There was no association between UMFA concentrations and cytokine levels. CONCLUSIONS: Mandatory flour fortification with FA in Brazil may be insufficient for ß-TmN, since they have higher tHcy and lower serum total folate than controls. Furthermore, ß-TmN have higher IL-6 levels than ß-TmU. UMFA was not associated with inflammatory cytokine levels.

Daily supplementation with 5 mg of folic acid in Brazilian patients with hereditary spherocytosis.

Patients with hereditary spherocytosis (HS) have increased rates of erythropoiesis and higher folate requirements. In a case-control study of patients with HS, we evaluated the associations between the use of 5 mg folic acid (FA) daily and serum concentrations of folate, unmetabolized folic acid (UMFA), interleukin (IL)-6, IL-8, IL-10, interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α); and mRNA expression of dihydrofolate reductase (DHFR), methylene tetrahydrofolate reductase (MTHFR), IL8, IFNG and TNFA genes. Total serum folate and folate forms were measured in 27 patients with HS (21 users [HS-U] and 6 non-users [HS-NU] of supplemental FA) and 54 healthy controls not consuming 5 mg/day supplemental FA. Each patient was matched to two controls based on age, sex and body mass index. The mononuclear leucocyte mRNA expression of relevant genes and their products were determined. Serum folate, UMFA, 5-methyl-tetrahydrofolate (5-methyl-THF) and tetrahydrofolate (THF) concentrations were significantly higher in HS-U compared with matched healthy controls (p<0.001, n=42). HS-NU had lower serum folate concentrations than matched healthy controls (p=0.044, n=12). HS-U and HS-NU presented similar hematological and biochemical markers profiles. No differences were found between HS-U and HS-NU for cytokine serum concentrations and mRNA expression genes. DHFR mRNA expression was higher in HS-U than in HS-NU. The use of high daily doses of FA for treatment of patients with HS may be excessive and is associated with elevated serum UMFA and elevated DHFR mRNA expression. It is not known whether long-term high-dose FA use by patients with HS might have adverse health effects.

Association between Serum Unmetabolized Folic Acid Concentrations and Folic Acid from Fortified Foods.

OBJECTIVE: To investigate the association between serum unmetabolized folic acid (UMFA) concentrations and folic acid from fortified foods and nutrients known as dietary methyl-group donors (folate, methionine, choline, betaine and vitamins B2, B6 and B12) in participants exposed to mandatory fortification of wheat and maize flours with folic acid. METHODS: Cross-sectional study carried out with 144 healthy Brazilian participants, both sexes, supplement nonusers. Serum folate, UMFA, vitamin B12 and total plasma homocysteine (tHcy) were biochemically measured. Dietary intake was assessed by 2 non-consecutive 24-hour dietary recalls (24-HRs) and deattenuated energy-adjusted nutrient data were used for statistical analysis. RESULTS: Ninety eight (68.1%) participants were women. Median (interquartile range) age was 35.5 (28.0-52.0) years. Elevated serum folate concentrations (>45 nmol/L) were found in 17 (11.8%), while folate deficiency (<7 nmol/L) in 10 (6.9%) participants. No one had vitamin B12 deficiency (<148 pmol/L). An elevated serum UMFA concentration was defined as > 1 nmol/L (90th percentile). UMFA concentrations were positively correlated with folic acid intake and negatively correlated to choline, methionine and vitamin B6 intakes. Participants in the lowest quartile of UMFA concentrations had lower dietary intake of total folate (DFEs) and folic acid, and higher dietary intake of methionine, choline and vitamin B6 than participants in the highest quartile of UMFA. Folic acid intake (OR [95% CI] = 1.02 [1.01-1.04)] and being a male (OR [95% CI] = 0.40 [0.19-0.87) were associated with increased and reduced odds for UMFA concentrations > 0.55 nmol/L (median values), respectively. CONCLUSION: UMFA concentrations were directly influenced by folic acid intake from fortified foods in a healthy convenience sample of adult Brazilians exposed to mandatory flour fortification with folic acid.

A Daily Dose of 5 mg Folic Acid for 90 Days Is Associated with Increased Serum Unmetabolized Folic Acid and Reduced Natural Killer Cell Cytotoxicity in Healthy Brazilian Adults.

Background: The effects of high-dose folic acid (FA) supplementation in healthy individuals on blood folate concentrations and immune response are unknown.Objective: The aim of the study was to evaluate the effects of daily consumption of a tablet containing 5 mg FA on serum folate; number and cytotoxicity of natural killer (NK) cells; mRNA expression of dihydrofolate reductase (DHFR), methylenetetrahydrofolate reductase (MTHFR), interferon γ (IFNG), tumor necrosis factor α (TNFA), and interleukin 8 (IL8) genes; and concentrations of serum inflammatory markers.Methods: This prospective clinical trial was conducted in 30 healthy Brazilian adults (15 women), aged 27.7 y (95% CI: 26.4, 29.1 y), with a body mass index (in kg/m2) of 23.1 (95% CI: 22.0, 24.3). Blood was collected at baseline and after 45 and 90 d of the intervention. Serum folate concentrations were measured by microbiological assay and HPLC-tandem mass spectrometry [folate forms, including unmetabolized folic acid (UMFA)]. We used real-time polymerase chain reaction to assess mononuclear leukocyte mRNA expression and flow cytometry to measure the number and cytotoxicity of NK cells.Results: Serum folate concentrations increased by ∼5-fold after the intervention (P < 0.001), and UMFA concentrations increased by 11.9- and 5.9-fold at 45 and 90 d, respectively, when compared with baseline (P < 0.001). UMFA concentrations increased (>1.12 nmol/L) in 29 (96.6%) participants at day 45 and in 26 (86.7%) participants at day 90. We observed significant reductions in the number (P < 0.001) and cytotoxicity (P = 0.003) of NK cells after 45 and 90 d. Compared with baseline, DHFR mRNA expression was higher at 90 d (P = 0.006) and IL8 and TNFA mRNA expressions were higher at 45 and 90 d (P = 0.001 for both).Conclusion: This noncontrolled intervention showed that healthy adults responded to a high-dose FA supplement with increased UMFA concentrations, changes in cytokine mRNA expression, and reduced number and cytotoxicity of NK cells. This trial was registered at www.ensaiosclinicos.gov.br as RBR-2pr7zp.

Efeitos do ácido fólico não metabolizado na metilação global do DNA, na expressão de RNAm dos genes de DHFR, MTHFR, interferon-γ, TNF-α e interleucina-8, e na citotoxicidade das células NK / Effects of unmetabolized folic acid on global DNA methylation, on mRNA expression of DHFR, MTHFR, interferon-α, TNF-α and interleukin-8 genes, and on NK cells cytotoxicity

Com o início da fortificação de farinhas com ácido fólico (AF) no Brasil, a partir 2004, a população passou a estar exposta de modo compulsório a maiores quantidades desta vitamina. Sabe-se que o AF na sua forma sintética pode não ser completamente convertido para formas metabolicamente ativas, levando ao aparecimento de uma fração não metabolizada no organismo. Este fato é mais preocupante nos indivíduos que além da fortificação, fazem uso terapêutico dessa vitamina, como em pacientes com anemias hemolíticas (esferocitose hereditária (EH), ß-talassemia heterozigótica (ß-TH), entre outras). O objetivo desse estudo foi avaliar se as concentrações séricas de AF não metabolizado (UMFA) afetam a metilação global do DNA; a expressão de RNAm de genes da DHFR, MTHFR, interferon-γ, TNF-α e interleucina (IL)-8; e a citotoxicidade de células NK. Foram incluídos 27 pacientes com EH, 50 indivíduos com ß-talassemia heterozigótica (ß-TH) e 136 indivíduos saudáveis. Outros 30 indivíduos saudáveis foram incluídos num estudo de intervenção com 5mg/dia de AF durante 90 dias. Foram realizadas as análises de: ácido fólico sérico, eritrocitário e UMFA, vitamina B12, homocisteína total; expressões de RNAm dos genes de MTHFR, DHFR, IFN-γ, TNF-α e IL-8; citotoxicidade das células NK; metilação global do DNA e citocinas séricas IL6, IL-8, IL10, IFN-γ e TNF-α. Resultados: Os pacientes EH apresentaram maiores concentrações de AF (sérico, eritrocitário e UMFA) que seus controles, sendo que 55,5% (método microbiológico) e 74,1% (método LC-MS/MS) apresentaram concentrações suprafisiológicas da vitamina, e 74,1% apresentaram concentrações aumentadas de UMFA. No grupo ß-TH foi observado maiores concentrações de folato eritrocitário comparado ao controle e 22% dos indivíduos tinham concentrações suprafisiológicas de AF. No estudo de intervenção, após 45 e 90 dias de uso de AF as concentrações suprafisiológicas estavam presentes em 93,3% dos indivíduos e 100% deles apresentavam concentrações aumentadas de UMFA. Não foram observadas diferenças nas taxas de metilação global do DNA entre os grupos EH e ß-TH quando comparados aos seus controles e não foi verificada correlação entre metilação global e concentrações de UMFA. Tanto EH quanto ß-TH apresentaram maior expressão de RNAm de IL-8, quando comparados aos seus controles. No grupo de intervenção houve maior expressão de IL-8 após 45 dias de uso de AF quando comparado ao período pré-intervenção. Foi mostrada uma correlação inversa entre as concentrações de folato eritrocitário com o número de células NK no grupo EH e com a capacidade citotóxica das células NK no grupo total (EH + controle). No grupo intervenção foi observado menor número e menor capacidade citotóxica das células NK após 90 dias de uso de AF. Conclusões: O uso de AF 5mg/dia foi associado com aumento expressivo das concentrações de folato sérico, eritrocitário, UMFA, na expressão de RNAm de genes da citocina inflamatória IL-8 e redução do número e da citotoxicidade das células NK. Dessa forma, altas doses de AF podem resultar em alterações de componentes do sistema imune podendo prejudicar os mecanismos de vigilância celular das células NK. Os nossos achados sugerem que é importante o acompanhamento terapêutico dos pacientes que fazem uso de AF, especialmente aqueles indivíduos que fazem uso crônico desta vitamina por longo tempo, como os pacientes com anemias hemolíticas, mulheres que desejam engravidar e gestantes

With the beginning of the fortification of flour with folic acid (FA) in Brazil, since 2004, the population has been exposed compulsorily to larger amounts of this vitamin. It is known that FA in its synthetic form can not be completely converted to metabolically active forms, leading to the appearance of an unmetabolized fraction in the body. This fact is more worrying in subjects beyond fortification, make therapeutic use of this vitamin, such as patients with hemolytic anemia (hereditary spherocytosis (HS), ß-thalassemia heterozygotic (ß-TH), among others). The aim of this study was to evaluate if serum concentrations of unmetabolized FA (UMFA) affect the global DNA methylation; mRNA expression of DHFR, MTHFR, interferon-γ, TNF-α and interleukin (IL)-8 genes; and on cytotoxicity of NK cells. It was included 27 patients EH, 50 subjects ß-TH and 136 healthy subjects. Another 30 healthy subjects were included in an intervention study with 5 mg/FA daily during 90 days. Analyzes performed were: serum and erythrocyte folate, and UMFA, vitamin B12, tHcy; mRNA expression of MTHFR, DHFR, IFN-γ, TNF-α and IL-8 genes; cytotoxicity of NK cells; global DNA methylation and serum cytokines IL6, IL-8, IL10, IFN-γ and TNF-α. Results: EH patients presented higher FA concentrations (serum, erythrocytes and UMFA) than controls ones, and 55.5% (microbiologic method) and 74.1% (LC-MS/MS method) showed supraphysiologic concentrations of vitamin, and 74.1% presented increased concentrations of UMFA. In ß-TH group, it was observed higher erythrocyte folate concentrations compared with the control and 22% of subjects had supraphysiological concentrations of FA. In the intervention study, after 45 and 90 days of FA use, supraphysiological concentrations were present in 93.3% of subjects and 100% of them showed increased concentrations of UMFA. It was not observed differences in global methylation of DNA between EH and ß-TH groups when compared to their controls and it was not observed significant correlation between global DNA methylation and UMFA levels. Both EH and ß-TH showed higher mRNA expression of IL-8 gene, when compared to controls. In the intervention group, there was higher mRNA expression of IL-8 gene after 45 days of FA use when compared to pre-intervention period. It was demonstrated an inverse correlation between erythrocyte folate levels and the number of NK cells in EH group; and cytotoxic capacity of NK cells on total group (EH + control). In intervention group, it was observed fewer number and lower cytotoxic capacity of NK cells after 90 days of AF use. Conclusions: The use of AF 5mg daily was associated with a significant increase in serum and erythrocytes folate levels, accompanied by increase in UMFA levels, an increase in mRNA expression of IL-8 gene, and reduction of the number and the cytotoxicity capacity of NK cells. Thus, high doses of AF can result in modifications of the immune system components, which may damage the cell surveillance mechanisms of NK cells. Our findings suggest that is important the therapeutic follow up of patients that are using AF, especially those subjects with chronic use of this vitamin, such as patients with hemolytic anemia, women who wish to become pregnant and pregnant women

Evaluation of toxic metals and essential elements in children with learning disabilities from a rural area of southern Brazil.

Children's exposure to metals can result in adverse effects such as cognitive function impairments. This study aimed to evaluate some toxic metals and levels of essential trace elements in blood, hair, and drinking water in children from a rural area of Southern Brazil. Cognitive ability and δ-aminolevulinate dehydratase (ALA-D) activity were evaluated. Oxidative stress was evaluated as a main mechanism of metal toxicity, through the quantification of malondialdehyde (MDA) levels. This study included 20 children from a rural area and 20 children from an urban area. Our findings demonstrated increase in blood lead (Pb) levels (BLLs). Also, increased levels of nickel (Ni) in blood and increase of aluminum (Al) levels in hair and drinking water in rural children were found. Deficiency in selenium (Se) levels was observed in rural children as well. Rural children with visual-motor immaturity presented Pb levels in hair significantly increased in relation to rural children without visual-motor immaturity (p < 0.05). Negative correlations between BLLs and ALA-D activity and positive correlations between BLLs and ALA-RE activity were observed. MDA was significantly higher in rural compared to urban children (p < 0.05). Our findings suggest that rural children were co-exposed to toxic metals, especially Al, Pb and Ni. Moreover, a slight deficiency of Se was observed. Low performance on cognitive ability tests and ALA-D inhibition can be related to metal exposure in rural children. Oxidative stress was suggested as a main toxicological mechanism involved in metal exposure.