Frequência dos mutantes C282Y e H63D do gene HFE e sua influência no metabolismo do ferro e na expressão da beta talassemia heterozigota

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metabolismo do ferro e lipoperoxidação eritrocitária em equinos puro sangue árabe sumetidos ao exercício em esteira e suplementados com vitamina E (dl-alfa-tocoferol)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência dos níveis de ferritina sérica, das mutações no gene da beta globina e dos valores das enzimas de detoxificação Catalase e Glutationa S -Transferase na expressão fenotípica de Beta Talassemia Heterozigota

Pós-graduação em Genética - IBILCE

Inflamação, homeostase do ferro e suplementação nutricional na cirurgia de derivação gástrica em Y de Roux em mulheres obesas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anemia, insuficiência cardíaca e manejo clínico baseado em evidências

Anemia is a prevalent comorbidity and marker of a poorer prognosis in patients with heart failure (HF). Its clinical relevance, as well as its pathophysiology and the clinical management of these patients are important subjects in the specialized literature. In the present review, we describe the current concepts on the pathophysiology of anemia in HF, its diagnostic criteria, and the recommendations for iron supplementation. Also, we make a critical analysis of the major studies showing evidences on the benefits of this supplementation. The four main components of anemia are addressed: chronic disease, dilutional, renal and malabsorption. In patients with HF, the diagnostic criteria are the same as those used in the general population: serum ferritin levels lower than 30 mcg/L in patients without kidney diseases and lower than 100 mcg/L or serum ferritin levels between 100-299 mcg/L with transferring saturation lower than 20% in patients with chronic kidney diseases. Finally, the therapeutic possibilities for anemia in this specific patient population are discussed.

Pancreatic iron stores assessed by magnetic resonance imaging (MRI) in beta thalassemic patients

Purpose: To assess the correlation between MRI findings of the pancreas with those of the heart and liver in patients with beta thalassemia; to compare the pancreas T2* MRI results with glucose and ferritin levels and labile plasma iron (LPI). Materials and methods: We retrospectively evaluated chronically transfused patients, testing glucose with enzymatic tests, serum ferritin with chemiluminescence, LPI with cellular fluorescence, and T2* MRI to assess iron content in the heart, liver, and pancreas. MRI results were compared with one another and with serum glucose, ferritin, and LPI. Liver iron concentration (LIC) was determined in 11 patients' liver biopsies by atomic absorption spectrometry. Results: 289 MRI studies were available from 115 patients during the period studied. 9.4% of patients had overt diabetes and an additional 16% of patients had impaired fasting glucose. Both pancreatic and cardiac R2* had predictive power (p < 0.0001) for identifying diabetes. Cardiac and pancreatic R2* were modestly correlated with one another (r(2) = 0.20, p < 0.0001). Both were weakly correlated with LIC (r(2) = 0.09, p < 0.0001 for both) and serum ferritin (r(2) = 0.14, p < 0.0001 and r(2) = 0.03, p < 0.02, respectively). None of the three served as a screening tool for single observations. There is a strong log-log, or power-law, relationship between ratio of signal intensity (SIR) values and pancreas R2* with an r(2) of 0.91. Conclusions: Pancreatic iron overload can be assessed by MRI, but siderosis in other organs did not correlate significantly with pancreatic hemosiderosis. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Analysis of the association of an MMP1 promoter polymorphism and transcript levels with chronic periodontitis and end-stage renal disease in a Brazilian population

Chronic periodontitis (CP) and end-stage renal disease (ESRD) are complex inflammatory conditions. Higher levels of MMP-1 were found in fluids and gingival tissues from CP patients and in the blood and tissues from ESRD patients. MMP1-1607 (1G/2G) is a functional polymorphism, as it alters MMP-1 expression. Objective: The aim of this study was to investigate the association of the MMP1-1607 (1G/2G) polymorphism with CP and ESRD and evaluate differences in transcript levels between the groups. Design: A total of 254 individuals were divided into four groups: Group 1, without CP and without chronic kidney disease (CKD) (n = 67); Group 2, with CP and without CKD (n = 60); Group 3, without CP and with CKD stages (ESRD) (n = 52), and Group 4, with CP and with ESRD (n = 75). The MMP1-1607 polymorphism was analysed by PCR-RFLP. MMP1 gene transcripts from gingival tissues were analysed by real-time PCR. Results: No association was found between the MMP1-1607 polymorphism and CP or ESRD. Increased levels of MMP1 transcripts were observed in CP patients with or without ESRD. No differences were observed in the transcript levels according to the genotypes. Conclusion: It was concluded that the MMP1-1607 polymorphism was not associated with either CP or ESRD. However, higher levels of MMP1 gene transcripts were found at gingival sites of CP in patients both with and without ESRD. (C) 2012 Elsevier Ltd. All rights reserved.

N-Acetylcysteine Protects Rats with Chronic Renal Failure from Gadolinium-Chelate Nephrotoxicity

The aim of this study was to evaluate the effect of Gd-chelate on renal function, iron parameters and oxidative stress in rats with CRF and a possible protective effect of the antioxidant N-Acetylcysteine (NAC). Male Wistar rats were submitted to 5/6 nephrectomy (Nx) to induced CRF. An ionic - cyclic Gd (Gadoterate Meglumine) was administrated (1.5 mM/KgBW, intravenously) 21 days after Nx. Clearance studies were performed in 4 groups of anesthetized animals 48 hours following Gd-chelate administration: 1 - Nx (n = 7); 2 - Nx+NAC (n = 6); 3 - Nx+Gd (n = 7); 4 - Nx+NAC+Gd (4.8 g/L in drinking water), initiated 2 days before Gd-chelate administration and maintained during 4 days (n = 6). This group was compared with a control. We measured glomerular filtration rate, GFR (inulin clearance, ml/min/kg BW), proteinuria (mg/24 hs), serum iron (mu g/dL); serum ferritin (ng/mL); transferrin saturation (%), TIBC (mu g/dL) and TBARS (nmles/ml). Normal rats treated with the same dose of Gd-chelate presented similar GFR and proteinuria when compared with normal controls, indicating that at this dose Gd-chelate is not nephrotoxic to normal rats. Gd-chelate administration to Nx-rats results in a decrease of GFR and increased proteinuria associated with a decrease in TIBC, elevation of ferritin serum levels, transferrin oversaturation and plasmatic TBARS compared with Nx-rats. The prophylactic treatment with NAC reversed the decrease in GFR and the increase in proteinuria and all alterations in iron parameters and TBARS induced by Gd-chelate. NAC administration to Nx rat did not modify the inulin clearance and iron kinetics, indicating that the ameliorating effect of NAC was specific to Gd-chelate. These results suggest that NAC can prevent Gd-chelate nephrotoxicity in patients with chronic renal failure.

Age-adjusted recipient pretransplantation telomere length and treatment-related mortality after hematopoietic stem cell transplantation

Telomere attrition induces cell senescence and apoptosis. We hypothesized that age-adjusted pretransplantation telomere length might predict treatment-related mortality (TRM) after hematopoietic stem cell transplantation (HSCT). Between 2000 and 2005, 178 consecutive patients underwent HSCT from HLA-identical sibling donors after myeloablative conditioning regimens, mainly for hematologic malignancies (n = 153). Blood lymphocytes' telomere length was measured by real-time quantitative PCR before HSCT. Age-adjusted pretransplantation telomere lengths were analyzed for correlation with clinical outcomes. After age adjustment, patients' telomere-length distribution was similar among all 4 quartiles except for disease stage. There was no correlation between telomere length and engraftment, GVHD, or relapse. The overall survival was 62% at 5 years (95% confidence interval [CI], 54-70). After a median follow-up of 51 months (range, 1-121 months), 43 patients died because of TRM. The TRM rate inversely correlated with telomere length. TRM in patients in the first (lowest telomere length) quartile was significantly higher than in patients with longer telomeres (P = .017). In multivariate analysis, recipients' age (hazard ratio, 1.1; 95% CI, .0-1.1; P = .0001) and age-adjusted telomere length (hazard ratio, 0.4; 95% CI; 0.2-0.8; P = .01) were independently associated with TRM. In conclusion, age-adjusted recipients' telomere length is an independent biologic marker of TRM after HSCT. (Blood. 2012;120(16):3353-3359)

A randomized controlled 1-year study of daily deferiprone plus twice weekly desferrioxamine compared with daily deferiprone monotherapy in patients with thalassemia major

BACKGROUND AND OBJECTIVES: The aim of this prospective, randomized, 1-year study was to compare the efficacy and safety of oral deferiprone (DFP) with those of combinations of parenteral desferrioxamine (DFO) with oral DFP. DESIGN AND METHODS: A total of 24 patients with thalassemia major were randomized to receive one of the following two treatments; DFP given at a daily dose of 75 mg/kg in combination with DFO (40-50 mg/kg twice weekly) (n=12) or as single agent (n=12). In addition, 12 patients treated with 40-50 mg/kg DFO 5 days weekly were included as a reference group without randomization. Changes in liver iron concentration (LIC) and serum ferritin (SF) were assessed; total iron excretion (TIE), urinary iron excretion (UIE) and iron balance were calculated. Cardiac function and toxicity were also examined. DESIGN AND METHODS: SF and LIC were significantly reduced after 1 year of combination therapy (p=0.01 and 0.07, respectively). A decrease of LIC was observed in all but one patient (87.5%) following the combination therapy but in only 42% of patients treated with DFP monotherapy. In the DFO reference group, a statistically significant decrease in LIC (p=0.01) associated with a substantial decrease in SF (p=0.08) was observed after 1 year. The combination regimen resulted in greater TIE compared to DFP monotherapy (p=0.08) and was the regimen associated with the highest iron balance compared to DFP monotherapy (p=0.04) or standard DFO treatment (p=0.006). INTERPRETATIONS AND CONCLUSIONS: The addition of subcutaneous DFO twice weekly to oral DFP 75 mg/kg is a highly efficacious and safe chelation therapy providing superior chelation activity to that of DFP and likely has an efficacy profile comparable to that of standard DFO.

Effects of erythropoietin on erythrocyte deformability in non-transfused preterm infants

AIM: Suppression of erythropoiesis due to low plasma erythropoietin levels is an important factor in the development of anaemia of prematurity. Premature infants may therefore be treated with recombinant human erythropoietin (rhEPO). This prospective, randomised and controlled study was designed to find out whether rhEPO treatment improves erythrocyte deformability in preterm infants. METHODS: Sixteen infants were treated with rhEPO (250 IU/kg three times weekly) a total of 15 times beginning on day of life 5 whereas fifteen infants served as controls. Haemoglobin concentration, haematocrit, reticulocyte count, ferritin level and erythrocyte deformability were measured on days 5, 14, 28, 42 and 63. Erythrocyte elongation was determined as an indicator of erythrocyte deformability using a shear stress diffractometer (Rheodyn SSD) at shear forces of 0.3 to 60 Pa. RESULTS: Haemoglobin concentration was significantly higher on days 28 and 42 and reticulocyte percentage on day 28 in the rhEPO group compared to the controls. Serum ferritin was lower in the rhEPO group on day 28. Erythrocyte deformability was significantly increased on days 28 and 42 in the infants receiving rhEPO. We found a strong relationship between erythrocyte elongation and reticulocyte count. CONCLUSION: RhEPO markedly increases the erythropoiesis in preterm infants in the critical first weeks of life and the anaemia of prematurity is obviously reduced. The erythrocyte deformability improved under rhEPO treatment. Erythrocyte deformability was significantly related to the reticulocyte count indicating that the improvement of erythrocyte deformability was due to the formation of well-deformable young erythrocytes.

Copper availability contributes to iron perturbations in human nonalcoholic fatty liver disease

BACKGROUND ; AIMS: Iron perturbations are frequently observed in nonalcoholic fatty liver disease (NAFLD). We aimed to investigate a potential association of copper status with disturbances of iron homeostasis in NAFLD. METHODS: We retrospectively studied 140 NAFLD patients and 25 control subjects. Biochemical and hepatic iron and copper parameters were analyzed. Hepatic expression of iron regulatory molecules was investigated in liver biopsy specimens by reverse-transcription polymerase chain reaction and Western blot analysis. RESULTS: NAFLD patients had lower hepatic copper concentrations than control subjects (21.9 +/- 9.8 vs 29.6 +/- 5.1 microg/g; P = .002). NAFLD patients with low serum and liver copper concentrations presented with higher serum ferritin levels (606.7 +/- 265.8 vs 224.2 +/- 176.0 mg/L; P < .001), increased prevalence of siderosis in liver biopsy specimens (36/46 vs 10/47 patients; P < .001), and with elevated hepatic iron concentrations (1184.4 +/- 842.7 vs 319.9 +/- 451.3 microg/g; P = .020). Lower serum concentrations of the copper-dependent ferroxidase ceruloplasmin (21.7 +/- 4.1 vs 30.4 +/- 6.4 mg/dL; P < .001) and decreased liver ferroportin (FP-1; P = .009) messenger RNA expression were found in these patients compared with NAFLD patients with high liver or serum copper concentrations. Accordingly, in rats, a reduced dietary copper intake was paralleled by a decreased hepatic FP-1 protein expression. CONCLUSIONS: A significant proportion of NAFLD patients should be considered copper deficient. Our results indicate that copper status is linked to iron homeostasis in NAFLD, suggesting that low copper bioavailability causes increased hepatic iron stores via decreased FP-1 expression and ceruloplasmin ferroxidase activity thus blocking liver iron export in copper-deficient subjects.

Treatment of iron deficiency with intravenous ferric carboxymaltose in general practice: a retrospective database study.

BACKGROUND Iron deficiency is a frequent problem in general practice. Oral supplementation may in some cases not be well tolerated or not be efficient. Intravenous ferric carboxymaltose may be an alternative for iron supplementation in general practice. The aim of the present study was to analyze the indications for and the efficacy of intravenous ferric carboxymaltose in a primary care center. METHODS We retropectively analyzed electronic data from 173 patients given intravenous ferric carboxymaltose between 2011 and 2013 in primary care center with 18 GPs in Bern, Switzerland. RESULTS Of all patients, 34% were treated intravenously due to an inappropriate increase in ferritin levels after oral therapy, 24% had side effects from oral treatment, 10% were treated intravenously due to the patients explicit wish, and in 39% of all cases, no obvious reason of intravenous instead of oral treatment could be found. Intravenous ferric carboxymaltose led to a significant increase in hemoglobin and serum ferritin levels. Side effects of intravenous treatment were found in 2% of all cases. CONCLUSION We conclude that treatment with intravenous ferric carboxymaltose is an efficient alternative for patients with iron deficiency in general practice, when oral products are not well tolarated or effective. As treatment with iron carboxymaltose is more expensive and potentially dangerous due to side effects, the indication should be placed with (more) care.

THE APPLICATION OF PATH ANALYSIS TO ASSESSMENT OF IRON NUTRITIONAL STATUS IN MAN

Path analysis has been applied to components of the iron metabolic system with the intent of suggesting an integrated procedure for better evaluating iron nutritional status at the community level. The primary variables of interest in this study were (1) iron stores, (2) total iron-binding capacity, (3) serum ferritin, (4) serum iron, (5) transferrin saturation, and (6) hemoglobin concentration. Correlation coefficients for relationships among these variables were obtained from published literature and postulated in a series of models using measures of those variables that are feasible to include in a community nutritional survey. Models were built upon known information about the metabolism of iron and were limited by what had been reported in the literature in terms of correlation coefficients or quantitative relationships. Data were pooled from various studies and correlations of the same bivariate relationships were averaged after z- transformations. Correlation matrices were then constructed by transforming the average values back into correlation coefficients. The results of path analysis in this study indicate that hemoglobin is not a good indicator of early iron deficiency. It does not account for variance in iron stores. On the other hand, 91% of the variance in iron stores is explained by serum ferritin and total iron-binding capacity. In addition, the magnitude of the path coefficient (.78) of the serum ferritin-iron stores relationship signifies that serum ferritin is the most important predictor of iron stores in the proposed model. Finally, drawing upon known relations among variables and the amount of variance explained in path models, it is suggested that the following blood measures should be made in assessing community iron deficiency: (1) serum ferritin, (2) total iron-binding capacity, (3) serum iron, (4) transferrin saturation, and (5) hemoglobin concentration. These measures (with acceptable ranges and cut-off points) could make possible the complete evaluation of all three stages of iron deficiency in those persons surveyed at the community level. ^

Duodenal expression of iron transport molecules in untreated haemochromatosis subjects

Background and aims: In HFE associated hereditary haemochromatosis, the duodenal enterocyte behaves as if iron deficient and previous reports have shown increased duodenal expression of divalent metal transporter 1 (DMT1) and iron regulated gene 1 (Ireg1) in affected subjects. In those studies, many patients had undergone venesection, which is a potent stimulus of iron absorption. Our study investigated duodenal expression of DMT1 ( IRE and non-IRE), Ireg1, hephaestin, and duodenal cytochrome-b (Dyctb) in untreated C282Y homozygous haemochromatosis patients, iron deficient patients, and iron replete subjects. Methods: Total RNA was extracted from duodenal biopsies and expression of the iron transport genes was assessed by ribonuclease protection assay. Results: Expression of DMT1 ( IRE) and Ireg1 was increased 3 - 5-fold in iron deficient subjects compared with iron replete subjects. Duodenal expression of DMT1 ( IRE) and Ireg1 was similar in haemochromatosis patients and iron replete subjects but in haemochromatosis patients with elevated serum ferritin concentrations, both DMT1 ( IRE) and Ireg1 expression were inappropriately increased relative to serum ferritin concentration. Hephaestin and Dcytb levels were not upregulated in haemochromatosis. DMT1 ( IRE) and Ireg1 levels showed significant inverse correlations with serum ferritin concentration in each group of patients. Conclusions: These findings are consistent with DMT1 ( IRE) and Ireg1 playing primary roles in the adaptive response to iron deficiency. Untreated haemochromatosis patients showed inappropriate increases in DMT1 ( IRE) and Ireg1 expression for a given level of serum ferritin concentration, although the actual level of expression of these iron transport genes was not significantly different from that of normal subjects.